996 engine rebuild just say no

Hi all first time here, wish it was just to deliver flowers or serve drinks....just purchased 2004 40 anniversary 911 with 66k. Drove it from Florida to Canada. One of the cats failed coming up, dealer here fixed under warranty. Cylinder four is misfiring, flashing at idle and rough idle, goes steady at 2000 rpm and runs good. Coils good, injector good, plugs good, vacuum good, compression is down a bit in 4 170 vs 245-250 in the other 5 cylinders. Leak down done. Engine has been dropped and head removed and all checks out. Mechanic who is not a Porsche pro but knowledgeable, thinks it's rings in that cylinder, thinks car over heated and dropped a ring, claims he see's some whitening around exterior of cylinder. He is suggesting a full engine job with new rings, pistons, cylinders the works $$$$. YIKES . Could we not just do a cylinder clean up and do the rings alone,. the IMS at same time, maybe the head because now's the time.... Any insight/help would be hugely appreciated. This is my first Porsche the child hood dream is a bit of a nightmare. :$ Thank you and cheers rob ( umm no car wasn't PP-Inspec...I know)

The big challenge with this is getting new rings to seal. The cylinders tend to go oval and then new rings won't seal.

Wow.... that's a tough spot to be in. What codes were you getting.

Tough luck. The seller or PO needs a swift kick in the pants. Maybe you as well for not having it fully checked over before buying. Hope its all covered by warranty for you.

Your first mistake is mechanic is not a Porsche pro!

yeah I am afraid that now the engine is open you kind of have to go with whatever your tech is telling you to do. Or at least make him change his mind, because I would not feel good going against the advise of the guy who will put my engine back together. I have read a lot of problem on this forum but never heard of this kind of problem. Opening the engine to check for rough idle is something I have never seen. Engine rebuild is even harder to justify if this guy is not a Porsche pro. Your best bet is to search and find someone who had similar problem as yours to see what solved it for them.

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I have to disagree, I would get that car in whatever shape it's now in to a Porsche indy that knows the M96 engine well. Otherwise you may be in for a long painfull and expensive future. Best of luck!

Sounds like your #4 has ovaled bad enough to cause misfires. I am practically in the same boat but not bad enough for misfires to happen. Just extreme oil usage. I think if it's only #4 and the others look good then you don't have to do all of them but depending on what the tech says is what I would go with. Kinda sad to hear the X51 engine with its extra rad and more oiling still has the same issues as the first gen 3.6l that I have.

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Happens to more engines then the IMS problem. Thing is that depending on how bad the ovaling is that you could not even know about it. I have 2 local friends with a 3.4 and 3.6 that had it happen, plus my self. Talked to a indy and he has rebuild many 996 engine for that reason. Thing is with IMS, the engine is toast so you'll her more people complain about it.

Sorry to hear of your trouble with your new car. If you cylinder is ovaled then it would be a complete waste of time trying to add new rings. Also for the price of new rings you can practiaclly have new forged pistons AND rings. If your tech is not an expert on 996 engines I would seriously consider taking the car to a shop who has rebuilt these motors with good success. Speaking from experience here... My motor failed last year and I opted to upgrade to a 3.8L package from LN Engineering. Yes, the project was time consuming and rather expensive but I either had to buy a reman or rebore. I decided to rebore and take advantage of an unfortunate situation. With a 3.8 you will pick up almost 50 HP/TQ. Good luck with whatever you decide. Do not rush into anything. Read posts here and contact the experts before deciding on a plan.

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Now this advice makes good sense to me!!

Jumper, there is no third radiator in the 40th despite what has been published in some very expensive books. Nore is the exhaust sound package standard. Hardback, 50HP from 200cc? I just purchsed a 40th last month and all I can say is if the engine goes, I will not be able to afford the repairs. My fingers are crossed. Cheers, Paul

Good advice from alot of guys here. talk to the folks at LN engineering if you don't have any good P-car contacts near you. Hopefully you have some local Pcar owners in your area to give you some input. Do your homework before you spend any $$ that may end up wasted. And you get a new engine to boot!

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+1 I have no doubt about this. I can't speak from experience with my car but I have seen many others. All the more reason to stay on top of your cooling system. I think (just my opinion) waiting for the water pump to actually make noise or fail falls into the category of excessive stupidity & neglect. And this has been debated amongst many a thread but the lower temp stat (160) just works. And keep those rads clean! This doesn't seem to be as important but the temp management of these cars can be difficult sometimes.

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Yup all great advice. After my rebuild I will be doing the 3rd rad and LN Low temp sensor to prevent it from happening again.

I have 69 k on my 99 911 and don't have any problems ...should I be worried .

between IMS, Ovaling, coolant tanks.waterpumps,and AOS there is a lot to be worried about

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Yes sir, dyno runs before motor was broken in showed rear wheel HP at 327 and TQ at 298. Not too shabby... and yes we decoupled the front drive. Also, you must factor in parasitic loss of about 10%.

Hi all, thanks a bunch for the time you all took to respond to the first time post/first porsche newbie. Well let me tell you, for all of you who haven't your Porsche catastrophically fail you yet, once the dust settles and the reality hits it will be okay. I think for a lot of us/most of us, buying a Porsche is either a childhood dream and/or a desire to not drive the honda, the pontiac, or the hyundai thats parked in your neighbors drive or the spot next to yours at work in the parking lot. Not that all those cars miss a function, had smart people behind there design, and have smart folks driving them. We want something a little different, something maybe a little special ...wanting a little romance for your drive to work and/or the weekend drive is a wonderful thing. My dad had five kids, was the old doctor that would do house calls at all hours, made no more money in the end then the plumber fixing our pipes, devoted his life to his kids and his wife our mom, always had a little thing for cars, never bought a Porsche, would have loved one in another life without five kids, so my little Porsche was about him for me a bit too. The "fear" that some of us Porsche owners have I think is about the, " what the hell was I thinking buying a used slightly older/older Porsche. If it dies, the engine blows, etc., etc., it will not only be the dream crashing to the ground but will be about a stupid, reckless, perhaps selfish decision to buy/own and this is all a, serves you right-reality check. Well I think for most of us this is not the case. Buying a Porsche at least for me was about doing something I thought I deserved, a way to pay me back for hard work, about a lust for life, an appreciation for excellence...even if Porsche perhaps fell short with build quality at times/here and there, and let economics dictate direction. They wouldn't be the first nor the last. So for all of you Porsche drivers that start and drive their cars everyday and/or just the weekends, who are waiting for the curtains to fall, i wouldn't . Do the maintenance to the best of your ability/pocket book, don't worry bout the what if's, enjoy the design, enjoy the the best part's of the engineering and whatever happens happens. A nice metaphor for life! Don't doubt the fact that you deserve it, life should be about celebrating achievement and hard work and or easy work. ( My father happened to be Protestant) L&N looks good, (or perhaps somewhere closer to home although shipping the block in two pieces even from Canada both ways is pretty cheap) go to 3.8 , new pistons, re-sleaved and coated for under 5k, I can live with that, do the bearings, the IMS, do the heads too. Sorry for the ramble, off to bed, thanks again!

robss996, my thinking exactly

Great perspective and attitude, thank you for sharing!

I thought the same way when I made the purchase.

Excellent perspective all the way around! At the end of the day it is a car, a machine. I bought my first 04 after saying for nearly 30 years that "someday" I'd own another Porsche. It was my wife who supported the decision with an "if you can pay for it, buy it, because sometimes someday never comes". And now we deal with her "somedays" that she may never see as she has Ovarian Cancer. A little off topic - I just got back from three weeks in Tucson for work. My wife actually sent me photos of the cars via text messaging with a note saying " I know you miss your cars so here they are". How sweet. My wife has always loved to plant flowers around the homes, when I got home our property looked stunning - she had planted more flowers, and potted almost as many, than I had ever seen her do in over 25 years. I get it though - this is her someday - she is doing what she loves while she can. I drive Porsches because I appreciate and respect the engineering, but most importantly because I truly enjoy the heck out of them. I don't care what the neighbors think, I don't care about what they drive or how they live. In the big picture a Porsche is just a car, and if it breaks I'll get over it, it can be fixed, money can be earned. Other things..... not so simple. Make today your "someday". Drive and enjoy.

With just 69K miles on your 99 I'd say you have something to be worried about. I have 256K miles on my 02 Boxster and its original engine, complete with unoval cylinders, original IMS bearing, original clutch, etc. Sure I've replaced the AOS two times (the 1st one at 80K miles but I can't recall the miles the 2nd one failed), the water pump (172K miles), fuel pump (200K miles) and the coolant tank (220K miles) and the 'biggie' the passenger side VarioCam solenoid/actuator (230K miles) but the engine is still a good 'un. What this means to you is you are way behind in your driving. Get off line and go drive your car more. Sincerely, Macster.

Wow Macster, those are amazing stats! Congrats on having a great car!

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heavy tracking requires oil cooler as well if you really want to add longevity to that motor.... I've installed 3rd rad and high-speed fan switch these two mods really bleed off the heat... but I don't dare run it for more than a 30 min session on high speed track... on tracks where you are mostly 2nd and 3rd gear I limit it to 20 minutes .. MAX.... cooling is mandatory... and despite what is said abut 5W40 I have seen better oil pressure with a 50 weight oil in the hot summer months on the track... I don't think you run any risk of using a 5w50 or 15w50 in the hot summer months from june-august... (i'm in toronto)... because these engines don't do a good job of cooling the heavier weight oil will still flow quite nicely at track temps.... IMHO.

and for the OP... send off what you have to flat 6 to have it re-done and make damn sure you get your engine put back together by somebody who knows 996 motors. I would thank your current indy for his effort, pay him for his work and find somebody with lots of experience assembling 996 motors. If you want a recommendation PM me as we know a few experts here in the Toronto area; you only want to go through this once... so do it right the first time.

Call Jake at Flat6.

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Hey Rob, Welcome to Rennlist! wish the circumstancee were better!

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Is that oil cooler the one fron LN? It switches out the OEM one that actually is a oil warmer for heating up the oil quickly for those winter days. The fan switch operates which fan? I don't know for sure but I think I may have over heated the engine not on the track but coming back from the track. It was a very humid day and hazy. Sitting in dead still traffic on the 401. I saw the temp gauge raise above past the 80's zero "0". but it stayed there for 60 seconds or so and then dropped down again when the car started moving again. It also did this again not long ago when I was stuck in traffic again. The first time though I think a saw a flashing light but it went away when the temperature dropped, no flashing light the second time but it was scary looking at the gauge going up and not being able to drive anywhere to get air flowing.

Had very similar symptoms on mine, turned out it was a stuck lifter. Good luck

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Greg, it's the high speed fans you want to hook up via switch to operate on demand.... EU can do it for you... this will eliminate what you saw in traffic... guaranteed. I've had it on my car for 3 years and it keeps the needle nice and strait on the hottest day.... tracking is different it helps bleed of heat faster but I also have a 3rd rad and that helps a bit ... oil cooler would be the final step... as for the oil cooler I don't have one but am tempted to get one for next season as displayed on the LN engineering site... I'd go with a dual fan unit since your already starting a small project there...

Silotwo...John thank you for your response and thank you for sharing what your wife and you are dealing with. I hope she's feeling okay and enjoying her gardens! I wonder how many of us here have a loved one who is battling cancer? Thank you to the rest of you for your suggestions and welcomes. This community has so much inherent value.... it's not just about the immediate and generous sharing of valuable/knowledgeable information which is outstanding in it's own right, it's about connection and community, we know a little about John's life now we can all send along our thoughts. Cheers - R ( PS hey Macster, hope your balancing that laptop carefully on your lap while you cruise up the miles in your Boxster and only sending us insights and suggestions at the stop lights! )

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John, incredibly poignant story that really puts things in perspective... Hit my wife and i like a ton of bricks. Thanks for sharing. We both wish you health and happiness. David

Thanks for the comments. I do appreciate them. We know that we are not alone.

John, thanks for sharing your very personal story. Best wishes to you and your wife. David, I hope you and Mary are doing well. I always enjoy seeing both of you. Rob, welcome to Rennlist....sorry it is under negative circumstances. If you add a few horsepower when you fix your engine, you won't feel nearly as bad about the money spent on the repair. Good luck.

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107k on mine & still going strong......

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Hey John thanks, sweet looking ride you have...exactly, I am now really looking very forward to making a stronger better engine out of all this. Only real sad part is it will all come together in time for storage with our not so cold but slightly messy east coast winter, big bummer. What we have yet to discover here is if this puppy did over heat, why? Have added maybe a liter of antifreeze to car only, during trip north from Orlando, was super hot there in April and slow at times on the I95 with easter wkd fender benders. Cat also went ( was gone prior to trip) could have created back pressure and heat?

Sorry that should have been Hey Mark !

Just buy a rebuilt engine from a reputable source and have it installed.

Hi Hardback, My m96 engine failed at VIR in May. Looking into many options. One of them is sending the block to LN to get them to sleeve it to a 3.8. Then i would buy a head from vertex and have it all assembled by my mechanic. How was your 3.8 LN build experience? Flat 6 sounds like the most bullet proof option but so expensive. mike [phone removed] cell [email removed]

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I have over 20,000 miles on the 3.8 now. Runs like a champ. Confuses many guys at the track also. My decision to upgrade worked out really well and didn't cost as much as you would expect. My advice would be to spend the next 3-4 weeks researching builders and optional parts to strengthen the engine. The process took me 4 months so you'll need patience. Ill send email to elaborate if your interested.

If you want to save money get a boxster 3.2 block and swap it out. I have 10000 mi on my swap and don't really notice the loss of 20hp. it was about 3000 as a DIY.

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Care sharing the cost and parts that went into this build? Looking into similar option myself..