Oil in coolant

I was driving in warm weather last week when my '99 C2 cab got hot, so I pulled over before I pegged the temp guage and had it towed to my mechanic. He didn't pull it apart, but upon his visual inpsection, he found oil in the coolant tank. The coolant is a bit brown and thicker than normal. Unfortunately, according to him, I probably blew an internal oil seal which is allowing oil to get into the cooling system. However, in order to fix the seal, the motor has to be torn apart and he says he doesn't have all the tools to do so--only the dealer does and of course a new crate motor from the dealer is around $20k. This is a real bummer has the car is extremely clean and I love the car. The IMS has been changed, new clutch, etc. and the car still runs, it just overheats. Having never torn one of these things apart, I have no idea how much work is involved, but he is saying at least 50 hours or more in labor. Any suggestions or thoughts? Thanks--I think!

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Could be other causes. But, my very first thought is.... find a better mechanic. Only the dealer has the tools to pull to motor apart? What sort of mechanic do you have? Any reasonable shop should be able to pull the motor apart. Anyway, read this thread: https://rennlist.com/forums/996-foru...-the-yard.html

Here's another one worth reading: https://rennlist.com/forums/996-foru...n-coolant.html

Sounds like your AOS went bad. It will most likely need a rebuild. There are very few places that can really work on this engine. I recommend you talk to Flat Six Innovations out of Cleveland, GA and Innovative Auto Sports out of Carrolton, TX. And yes you are going to have a lot more in this car than buying another one would cost. But if you get it done right, it will last a whole lot longer and be worth every penny.

Where are you located? A good indie with the proper tools can do a rebuild. Yes, you need to find a better mechanic. I can recommend one if you are in my area.

There is no seal that can just blow in the engine!! That's guy has no idea!! Do you have intermix in the sump, or is the oil clear on the dipstick?? It may just be your AOS , there is a coolant feed to it in a sepperate compartment to the oil vent side but if it fails they can mix and put oil in the coolant so don't start tearing your engine down until you check the simple stuff first. Tool wise you only need the cam hold down tool when removing the cam covers to stop cam damage but otherwise it's normal tools so don't know what that guy is on about. Good luck, hope it's something easy and not too expensive !!

Or perhaps a cracked head.Hope not.

Thanks for the replies and also the various links. Yeah, I think I need to look for a new "Wrench" ASAP. He's getting pretty close to retirement and I just don't think he wants to do the work. FYI, I looked closer at my coolant tank, oil filler tube and dip stick. The coolant tank definitely has that beige sludge like liquid wax. The filler tube has a similar film in it, but the dip stick doens't have anything on it but Redline. Does this tell anyone anything? Also, since I'm new to this forum, I don't know how to post any pics. If you can share that, I'd love to post some of these. So, in reading the various comments, I have a few questions: -You mention that if it's the AOS, that could be "simple" vs. having to tear down the motor, yet I thought I saw someone mention that if it is the AOS, that would require a tear down. -I also saw on another site that replacing a AOS is about $1500. That seems awfully cheap. Wouldn't it be considerably more than that? -Worst case scenario, it's something pretty catastrophic, do you have opinions for either: 1. a wrecking yard motor (and of course replacing the IMS straight away)--I've heard this is around $5k not counting labor to put it in, so I'm ballparking another $2-3k for that 2. a complete tear down and rebuild - which I understand could be $12-13k 3. or a rebuilt motor in the crate. If so, any recommendations? Also, if I go with this option, can I opt in for the 3.6 as an upgrade to my 3.4? -Also, I'm in Northern CA in the East Bay (Benicia/Walnut Creek/Concord), so if you have any recommendations for a good mechanic, I'd love to know. Mahalo, Joe

AOS failure is one of the most prevalent causes of intermix. It's a $150 part that takes about 6 hours to replace. But once the intermix happens, the water mixing into the oil is usually catastrophic to the engine. At the very least it needs to be torn down and cleaned by somebody that specializes in M96 engines. I would highly recommend against used motors. That has been a very short term solution for most that have tried it. For a rebuild, you can get a short block from the factory for about $6k. Depending on what else needs to be replaced, you are looking at 10-15k. If you want to upgrade to a 3.8, research LN Nickies.

Great. That's what I thought. So one more dumb question. We all love these things--otherwise, we wouldn't be on a forum talking about them, but at what point do you decide to jump ship. By that I mean sell it and take what I can get for it as is (I'm assuming $3-5k) then go buy a 997-2 or something like that. Granted, I'd be dropping a lot more money, but I'm theoretically buying piece of mind. Or an I thinking about this in the wrong way. A 996 rebuild IS buying piece of mind?

You can get 5-8k as a roller. The '99 is the best model year for a 911. Seriously, out of any year made. Any older and it lacks power. The newer you get the more the car does for you and the less you get to drive it. It is truly the best year. So in my opinion, it is totally worth fixing right and enjoying it for a long time to come.

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That point is easy.... if you don't love the car and have the cash, go with a 997.2. That's my opinion.

Update on my 996 mess with the coolant and oil milkshake. I found a reputable PCA recommended mechanic and he has looked into everything and concluded that unfortunately, it is something much more catastrophic. He has determined that all the typical things like the AOS, the oil cooler, etc. are not the cause, so we are now looking at a total rebuild. I'm attached to the car and will probably end up having it rebuilt. I'd love to hear from someone who has gone through this process. -Do crate motors have warrantees? -Is it worth going the shortblock route or just get a whole new motor? -What's the typical "all in" cost? -Are there any reasonable upgrades I should be looking while it's apart? -Also, I hope to not be branded a heretic, but I have looked into Renegade Hybrids and although this is not my first choice, the LS option does have some merit. Does anyone have any experience with this? I'm trying to get as much dat as I can in order to make a final decision on this. Any opinions would be helpful. Thanks, Joe

I don't think you can buy a new crate motor anymore. But if you can, it will be more expensive than just buying a new car. There are some aftermarket rebuilts available from a couple sources. If a rebuild can be done on your motor, I would suggest going that route. The LS conversions are great, from what I hear. It will be expensive too. I believe in the $15K range (parts and labor). In California, it would be very difficult to register an LS conversion. No idea where you are located.

From what i gather, we are looking at either a junkyard motor that we would rebuild, a rebuilt motor from the factory or one from Flat 6 Innovations. The last one is the most interesting option as they have a variety of stages to choose from, but even in stock form, the motors are supposedly bulletproof. As for the LS option, it seems you are correct. I live in CA and trying to get a referee to approve the installation can be difficult. Thanks for your reply.

I think this was caused by a cracked cylinder head, usually on an exhaust valve seat on the first cylinder, which is a common issue on the 3.4 engines. This most likely can be fixed by a reputable machine shop. There are multiple topics on this experience/issue and people have used the costa mesa machine shop based in california to rebuild the cylinder heads. Some guy fixed this issue on his cab for around $1000... I would flush the entire cooling system right away multiple times, before working on the car. Before asking anyone to drop the engine and remove the cylinder head, please do some research since most likely you would need to follow some critical steps to prevent damage to the motor.

This is the topic I was talking about https://rennlist.com/forums/996-foru...ad-repair.html

Rebuilt motors from the factory are not a "thing" as far as I know. There was some rumor that M96 short blocks were going to be coming from Porsche again, but to the best of my knowledge, this never materialized.

I know the 3.4l short blocks list for around $6,300. Not sure on the 3.6l. It's actually the X51 version. And randomly, here is the appendix to the PCA Racing rules that allows the substitution. 996 short blocks The 3.4 liter 996 may use the X51 short block, part number 996.100.951.TX. The 3.6 liter 996 may use the X51 short block, part number 996 .100.996.XX.

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I'm not exactly sure what an "x51" shortblock is as all the x51 modifications were on the top end. Maybe a marketing scam to charge us even more money than what a full long block was selling for 10 years ago? For those that don't know, just lookup full factory engine replacement prices, including labor from 10+ years ago. It's funny to see how many people huffed and puffed and thought it was a ripoff back then. Compared to now, that's peanuts. lol

I would suggest digging into it deeper. If you can DIY checkout my thread "my milkshake brings all the boys to the yard" My coolant in the oil and oil in the coolant issue which all the shops said was going to require a total rebuild is being solved by a cracked head repair. Total for that repair (including gaskets, seals, etc is a DIY under $2k including the head repair. I am replacing everything else perishable while I'm in there so my total will be closer to $5k when I'm done. I'm doing everything but cracking the block open. Good luck.

Thanks for your replies. I just got estimates back and my mechanic is quoting $18k for a rebuilt RND FSI motor plus labor, assorted new parts (clutch, Nickies cylinder sleeves, oil coolers, radiator, hoses, etc. etc. plus a $8k core charge for a grand total of around $34k Worst case scenario, if the core is bad I lose the $8k. If not, I'm in for around $26k. He is not recommending the short block option. Is this reasonable? I was thinking I would get hit for around $15k. Also, if this is just a cracked head, how do I confirm that? Of course, if he finds a junkyard motor in good shape and replaces the IMS, etc., we are probably looking at $12-15k all in. Of course, with that option, you're never completely sure how good the motor is and what other problems may exist with it as where with the rebuilt motor, there is a 1 year 12k warrantee. I'm leaning toward getting it fixed, but want to make the right decision. The other option is to sell the tub for $5-7k and go out and buy a 997. The problem is, since I would buy a 997.2, that's $60k or more which is a lot more than $30k. Knock on wood, I have the resources to fix it, but I don't want to throw good money after bad, but I'm not sure I want to spend $60k+on a 997. As always thanks in advance for your input. Thanks, Joe

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That's me. Car just turned 85,000 miles, intermix happened at 48,000 in 2008. It can be done, have worked with several other owners who had the same problem and fixed the engines without a rebuild. Is a rebuild better, sure. But a couple of thousand dollars vs $24,000 on a car that is worth $15,000-$25,000 running, no brainier.

Wait, help me understand..."Rebuilt RND engine" and your mechanic is charging you extra for Nickies cylinder sleeves? From what I've read all the RND engines comes with Nickies??

I recently experienced the same decision on our 996. Our 996 suffered from a common IMS situation that put us in the same decision you seem to be considering. We did something unique with the purchase of another Porsche (997) and Repair/rebuild the existing (996). From a logical point of view the 996 with its current and potential financial value, I honestly would never recommend it. The cost of rebuilds has exceeded the value price point when you consider the the value of your car as a roller and cost of repair. There seems to be the 12-15K rebuild shops and then there is the 20-23K rebuild shops. Either way you look at it, if you were to have it rebuilt and turn and sell it immediately (at best you break even and at worse you have lost an additional 10K). To me that is a lose - lose situation from a financial sense. Now you have to consider that the guy who would be coming to look at the car would almost be saying to himself, should I put little more money with it and get a 997 that has currently more upside than the 996. So at this point you are dealing with a shrinking buyer pool. Of course, there are those who will tell you "if you love it, pay the money", but realistically you more than likely will fall in love with the newer car after the first drive and be happier of your choose with the better financial upside choice you made. Would you build a 1 million dollar house in a 300K neighborhood? (These folks always go to0 far and then say they are going to live in it forever to justify it too themselves - I have never seen any of them live in it for more than 14 years - let alone forever.

Thank you for thoughts Jason, but thing to think about... Unless your buying the 997.2 or newer, you're still in the same IMS boat. Therefore, if I buy a 996 for $15-$20k and it dies then it's ouch, but if I buy a 997 for $35k+, then it's an enormous " please take me out back and shoot me" OUCH. Dig?

The fastest SP996 at MSR in TX '00 C2. It has a rebuild with a factory short block that cost him $10k parts and labor. I would go that route if you don't plan on keep it or get in line with FSI if you do plan on keeping it.

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The OP expressed the decision of Rebuilding/Replacing his existing 996 engine or purchasing a 997 in post #22. In either circumstance Rebuild/Replace or purchase of a 997, a IMS device would be likely purchased. I apologize in advance if I missed a post that expressed interest in purchasing another 996 as an 3rd option. I was under the understanding it was a decision between Rebuild/Replace existing 996 engine in existing 996 car or purchasing a 997 (997.2 to be specific that he wrote in post #22). I will re-read thread to verify specifics of intended question.

B3FREAK - I re-read the entire thread and could not find any post that he was considering selling his current 996 in roller condition and purchasing another 996. In fact in post #10 he first expresses his options and re-iterates it in post #22. Unless he was to recoup value for his current 996 in roller condition 4-7K and then purchased a 996 for 15-20K stated in your post, this would be the option that would roughly 20K (new 996) - 7K (existing 996 roller) = 13k. His expressed option in post was to sell existing roller to purchase a 997. As for the cost for IMS upgrade/replacement, this does not factor in due to any of the 3 options would more than likely for piece of mind require a IMS upgrade/replacement cost factor unless you got lucky with a purchase that recently had it done.

The short block is available from Porsche (at least it was last year when my engine imploded). I was quoted a price of about $11.5K for the short block, plus lots of labour cost. I think it would have been almost $30K in the end. That was at the local Porsche dealer. All prices $CDN. Instead, my indie installed an awesome 997 engine for under $20K. The engine was slightly used (about 10K km). Came with a 2 year warranty. I am into my second year with it and am more than happy with my decision. Check out all your options before deciding. There is another engine builder on this forum that you might consider. I think it is called MB Motorsports. Vertex is another company that can supply a long block. They always advertise in Panorama.

Jason, I remember your story and it confused me then, as it does now. You had a 996 failure and decided to fix that - and buy a 997 as well? Indeed, that was a unique solution!

If you have to experience a failure, this is THE one to have. Generally there's no collateral damages that effect the 6 major core components that we retain. The items that are damaged are among the 100 pounds of junk that we throw away, whether its good, or bad.... So there's no addition costs with this over an elective build... Now, that said. DRAIN THE COOLING SYSTEM NOW! Why? The petroleum thats now in the system is attackinbg every hose, and reservoir within the cooling system. This includes the 29 coolant hoses throughout the car, as well as the radiators, heater core, and even the coolant tank, and valve. If this is not done ASAP, once the engine is repaired, you'll find hoses that are so soft from damage that you can tear them in half with your bare hands. They'll blow and leave you stranded. Learned this the hard way, many moons ago. Once the system is drained, it must be flushed of all the mess, and we do that as soon as a car arrives using a system that we had to make from scratch just for the job. No one else will shed light on this, but trust me, it happens.

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Yes, It was confirmed during the rebuild to be a IMS failure. The only confusing part for me was not experiencing (or on my part possibly recognizing at time of dropping off) any issues prior to arriving to get the IMS upgrade installed. We purchased a 997.2 mainly to continue our weekend enjoyment while the rebuild took place and to participate in Track days together with my wife at the same time rather than sharing one car. This for the majority of people is not a financially smart decision due to (1) Their financial income situation (2) Spouse not having same interest in participation as my wife does. As for the hypocrisy in fixing the 996 that I recognize and point out freely on myself, and I agree. Purchasing the 997.2 was a good financial decision that I am proud with. This is why when I read the OP post, I was compelled to offer my opinion, since I had gone through a similar decision making process. I tackle everything from a financial stand-point and it has served me well in life (except when the decision involves making my wife happy - which this did). In his situation it appeared the budget was of concern as well as a desire to have a 997. I was simply just pointing out the options in a financial basis. (1) 7K (selling existing 996) - 20K (new 996) = 13k (cost) 20K (Value) (2) 7K (selling existing 996) - 30K (new 997.1) = 23K (cost) 30K (Value) (3) 7K (selling existing 996) - 60K (new 997.2) = 53K (cost) 60K (Value) NOTE: this option has the greatest upside potential with much documented projection) (4) Paying for rebuild from a 12-15K shop = 15K (cost) + 7K (value in existing 996) = 22K 22K (Value) (5) Paying for rebuild from a 20-23K shop = 23K (cost + 7K (value in existing 996) = 30K 25K (Value) NOTE: Option 4 & 5 currently have little to no upside potential (at least not at this point documented projection) So if you were to give advice to your child or friend - it doesn't take much to see which options are the best! You MUST always keep "Value" in the decision process in a financial decision. Side Note: Just like when people finance a house rather than paying cash, They get a loan for say 5% on a 30 year mortgage. then 15 years later they sell their house for roughly the same amount as purchased or with a marginal increase and think they did ok, WRONG the cost of the interest made them lose that profit. Do the math 5% a year for 15 years (which usually is front loaded on interest and not principal). Especially on a 850K house here in Florida where that is common for people our age and time as a business owner. ALWAYS PAY CASH! I would rather see a young adult live at home longer and save the money needed than get a mortgage.

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Makes more sense now, thanks for the clarification!

But it is always more complicated than this. For the 996 or the 997.1 there is a change (I know, a small one, from 1-8%) that it could happen again. So for option #5 you have a car you know with the major issues of m96/97 failure fixed. So if everything else on your car is perfect and you have a bullet proof motor you have a better long term value than all of the options above - except maybe the 997.2 And an your side note - agreed, if you are buying a house as an investment with a 5% 30 year loan you are an idiot. But if you are buying the house to raise a family and you may have a 30 year mortgage at 5% but you are living on your own raising a family. Maybe cheaper expense than rent in the long term - still money going out with little return - but you are not living in my basement. Again - everything is always way more complicated than "cash value" today

To clarify a few things: -Post #23 references fixing the intermix problem without total rebuild. Can you please elaborate more on that? -the RND motor does have Nicklies already as well as several other new components. Supposedly, the FSI motors are supposed to be incredibly strong and dependable, but is it worth $18K? -Based on all the research I have done, yes, I would be looking at a 997.2 to avoid the potential IMS issues--although the '05-'06 models look really enticing. -I'm surprised at the number of newer and even low mileage 996s available, but I'm assuming that if I bought a used one, it's at least another $1500-$2k for a new IMS install and perhaps other misc stuff. -Per post#30, I'm curious how difficult it was to put in the 997 motor. And how was iit possible to get a 2 yr. warranty? RND s FSI warranty is 1 yr or 12k. -Can anyone confirm how much additional work would it take in order to install a 3.6?

BTW, Jake, no disrespect intended as I understand you guys make a great product.--I'm merely looking at economics. As far as I know, all the hoses will be changed as well as the cooling system to be refreshed.

To answer your question, my indie had the 997 3.6L Porsche crate engine sitting on the shelf in his shop. That is the engine now in my car. Apparently, the swap was without issue. The 2 year warranty is with my indie. He is a dedicated Porsche mechanic and an engine builder so I guess if anything goes wrong with the engine he can do the repair himself, which would obviously lower his risk. I was actually surprised that he offered 2 years rather than just 1. For your car, if you do go the engine replacement route, I am pretty sure you will need to replace it with another 3.4L. The good thing about that is that the 3.4 is significantly less to buy than the 3.6.

With oil in coolant and no other damage so far it may be worth pulling the motor and removing the heads. If just the head is cracked it can be repaired/replaced and all of the coolant lines flushes/replaced for a few thousand dollars. But you need a diagnosis of just a cracked head. Need more information - why did the mechanic say total rebuild. Lots of others have repaired intermix by just fixing the head.

After researching just about everything, I have come to a couple of conclusions: 1. Without pulling the heads, we cannot ascertain if there is a cracked head. Even using a borscope was inconclusive. The other thing is, if it is a head and it gets fixed, going forward, there is still a possibility of the motor going south at some point. Most mechanics I've spoke to say that once over 100k, the M96 motors can begin to exhibit a variety of issues. So even having it fixed, I'd always be looking for the next issue to happen. So.... 2. With the new RND motor, for $30k, I get some serious piece of mind, and I get my guards red cabrio back. However, I ran across another option. Rather than going with the new RND motor or buying a 997, I understand that a 996 TT is a much better option. It's a completely different block (derived from the GT 1) and there are plenty of them with well over 100k on the clock. In addition, the cost is in the same range ($30-40k with 50-75k mi) for the 996TT vs the RND motor. Am I missing something here or is the 996 TT really as good as it seems? So, if you can call it a dilemma, I'm willing to let go of my '99 C2 and buy a 996 TT vs. putting a new RND motor. I'd be interested in your comments of buying the turbo (inherent problems, etc.) vs. paying the money to replace the motor on my C2. Thanks

I think you got it about right.

Right, the turbo has the Mezger engine which doesn't have the same IMSB flaw as the M96. I considered going for a turbo when my engine went as well. However, after doing some research and talking about it with my indie mechanic I decided to make the investment in my 996 instead. The turbo has its own issues which can also be very expensive to fix. Plus, I had a great low mileage 996 that I knew very well, and now with an even better engine. My advice is spend the time to do your research on the turbo.

The biggest issue with the 996TT engine is the coolant pipes which you've probably read about by now. It isn't a show stopper like some of the M96 problems. Not cheap to resolve but not horribly expensive either (like an engine rebuild).

I just finished the below 996TT engine... It failed, which is why it ended up here. When a TT breaks, you know it... I won't touch one for less than 35K, and most end up at 45K or more. Everything on the Turbo is more of a bitch to deal with, and all the parts are more expensive. Very little interchanges with the Carrera engines. The coolant pipe job is around 5K to do, I just finished an extensive service for a 60K mile car a couple months ago, and a failed coolant sleeve is what initiated that service, which cost 15K total. That said, the RND engine should not cost you 30K, your core engine should not have any collateral damages that would make it unacceptable as a core, and it looks like the engines are on special through www.rndeuroparts.com at the present. You'd not have anywhere near 30K in that engine Flat 6 Innovations R36T Track Performer with Tial 3071s, external waste gates, AWE exhaust and all LN/ Flat 6 Innovations internal components.

Is there any extra complications when fitting a tt engine in a carrera?

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Dozens... but I know where a 17k mile 996TT engine is for sale... Complete for 12k

I'm certainly no expert, but from the reading I've been doing, the TT is a completely different chasis. Everything is stiffer, beefier, etc. I suppose it would fit, but past that, not sure what other complications might arise.

So Jake, are you suggesting that with the RND motor in, a lot of these gremlins that appear after 100k should mostly disappear? I get the part about the TT having it's own issues, but if I'm a betting person, I'm thinking that down the road, even 996 TTs are going up in value as where the Carreras aren't going to. Also, the fun factor is a no-brainer. Still, I want to make the right decision. I'm going to check on the price of the RND motor, but based on what I heard from a pretty well known mechanic here in Nor Cal, he felt that putting more money into a 996 TT is better spent vs. a high mileage C2. After driving one, I would tend to agree but, I'm still searching for answers. Thanks.

I have decided to sell my C2, but when my tech diagnosed the cat, he had to remove several things like the AC, the oil cooler, etc. to diagnose the issue. When I brought the car in, it was running, but due to the "mikeshake" issue, I can't run it for too long. Since I'll be selling it as a roller, does it make sense to pay my tech the extra $600 bucks to put on the things he took off? Will it potentially net me more money since I will be able to show buyers that the car starts and runs? Bottom line, is it worth the money? Thanks.

Nope. A roller is a roller. I wouldn't put another dime into it.

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Every minute the car sits with oil in the coolant, all 29 of the coolant hoses are being further destroyed. A few weeks of this will find the petroleum in the oil injuring the hoses even more... The system needs to be flushed clean ASAP, else the next guy will get a 4,000 dollar surprise. That's what I'd be most concerned about. following oil in coolant I've been able to rip main coolant hoses in half with my bare hands with little effort.

Yeah, I forgot about the hose thing as I was planning on replacing them anyway if I was going to keep the car, so as a roller, it may not even work now that the hoses have been sitting and probably deteriorating just as the car has been sitting for the last coupole of months. So I won't have the car put back together again, but how do I find out what to ask for the car? It's a really clean cabrio. Great paint, 19" lobster claws with pretty new rubber and a near perect interior and top. I've had some people say $5k and others say $15k (which I think is nowhere near realistic in my mind). I can't even find any online rollers to ball park it. Aside from the milkshake issue, the clutch and IMS have also been changed in the last 10k. Any ideas on pricing? Thanks!

The 5K figure is about all it'll really sell for... Coupes bring a little more. I hav a customer looking for a broken cab, send us some pics.

I'd give you 8k if it was a coupe.

As an FYI, I sold my broken 99 for $6,400 on EBAY....

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Broken cabs are hard to sell... The Coupes get gobbled up pretty quickly by my customers.

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Jake, you rock my friend. Thank you.