Heart stopper

On Monday morning I got up and washed my car prior to taking it on a 40 odd mile run out to Montauk (would be returning the following day). Before I left I decided to check the oil and the coolant. The coolant was fine (right on the min mark when cool) but the oil was low - just the tip of the dip stick/bottom line on the meter. Hmmm... I put a whole quart in. It seemed really strange, because I hadn't noticed any smoke at start up, and hadn't noticed any puddles in my driveway either. In fact, the car has been running great - no strange noises (which I've really been listening for due to all the recent work I've done - especially the under-drive pulley just the day before). Needless to say, I watched the temp gauge and oil pressure gauge like a hawk on my trip out. The car ran great and quiet all the way out to Montauk (the east end of Long Island for those who don't know it). The car sat for about 10 or 15 minutes before I jumped back in and headed out for lunch. I was a little bit concerned when I looked at the oil level gauge and noticed it was down about 2 bars, but shrugged it off as the car was on a incline - once again it was running smoothly and quietly. We got to the restaurant which was about 5-6 miles away with no issues. Had a great lunch outside, the weather was perfect... I couldn't get this nagging feeling out of my head, because from where I was sitting, I could see the back of my car and the right rear corner looked different than the rest of the rear bumper (I was thinking soot/oil>...). After finishing lunch and saying our goodbyes, upon getting back out to the car I realized that the rear corner was covered with a fine oil spray. The first thing I looked at was the tailpipe...clean! No soot, no oil on the inside... Ok, that's kind of a good thing... I stuck my head under near the back of the back wheel - I couldn't see much, but I could see oil dripping down the sway bar by the drop link and I could tell it was coming from further up on the engine. The bottom cam plug was present, and though it was covered in oil, I could tell that it wasn't the source of the leak. I thought it might be the upper cam plug, but didn't want to go reaching around blindly and get covered with oil? I drove the car back to the house some 5 miles away - no lights, no strange noises - I parked the car, and my mind raced. I've driven close to 1000 miles since doing the work on the car...why now? Needless to say I didn't sleep very well last night, as I knew I had a hectic day ahead. Fortunately I was able to get a truck and trailer, and trailer the car back to my shop. In the mean time, I did have to start it a couple times to move it to a spot where I could get it on the trailer, and then I had to drive it onto the trailer. Before doing so, I added another quart of oil. The car ran fine - no noises, no lights - really bizarre! When I got the car back to my shop and was about to take it off the trailer and drive it up into the shop, what did I find on the deck of the trailer? The green Cam plug - it's in perfect condition and looks brand new! It didn't have so much as a scratch on it (and from what I remember, it went in pretty tight. Now I'm wondering if the cam cover bolts loosened up and allowed it to blow out? Why else would it come out? I know about possibly blocking the oil passage by the plug with cover sealant, but it seems that would have happened much sooner if that was the case. I'm hoping to get up to the shop tonight and figure out what's going on. I'll update when I figure it out - in the meantime, let's open it up for speculation. Just do me a favor and keep the CEF talk to a minimum for now ok?

You are one lucky bastard! Interested to hear what happened when you figure it out

Mice....

That's some good luck

[Image-only post; no author-written text. Original image references:] https://cimg0.ibsrv.net/gimg/rennlist.com-vbulletin/239x210/hkpozeh_f429c50a3cebc3d6f59a921cba928059fc0169ed.jpg

Not sure what other work you have been doing but check the end of the camshaft and make sure the expansion plug is there. The cams are filled with pressurized oil. When I was repairing my engine years ago I used a home made tool to hold the cams down when I took off the cam cover and it deformed the expansion plug that then blew out of the cam. Jake Raby told me that this is one of the modes of failure he has diagnosed. My cams now have threaded plugs in both ends of all 4 cams.

At the shop tonight I was able to get the cam plug reinstalled and all the cam cover bolts checked for proper torque. All the bolts were tight and the plug went in tight as well. So now the question is why the plug popped out in the first place? I'm going to drop the sum plate Thursday night and check the aos/swirl pots and see if they're clogged up with chain pad material...

Wierd situation so an odball question _ Is it possible that the AOS system has failed and somehow the crankcase is pressurizing ?

I'm glad that I took a look at this thread. My 2000 Carrera 4 has the same issue... the back bumper of the car is covered in a thin film of oil and the car will smoke upon accelerating. I bought the car in June and it has 145,000 miles on the original engine as far as I know. I first suspected the AOS because what seems to be increased vacuum pressure in the engine when removing the oil cap... the AOS may need replacing but it isn't the smoke issue. The smoke does not come from the exhaust but seems to be burning oil on the drivers side header. I had the car on a lift yesterday and it looks like it is coming from the cam cover. I'm going to have the engine taken down and reseal the cam covers/plugs, change out the clutch, AOS, IMS bearing, RMS, water pump, oil cooler, spark plugs and tubes and anything else that looks suspect. The engine still runs smooth and pulls well so I don't think there is anything mechanically wrong with the motor. When I had the car on lift I also found out the front diff seals are shot and it ate a bearing up too... lot of work ahead!

Quotes source post: 14457734

I "think"did feel the plug in the end of the cam before I re-installed the plastic "cap" at the end of the cam cover. Unfortunately, with the engine in the car you can't really see that top cam as it's buried up behind the rear suspension components. I suppose I could thread a bore-scope up there to have a look. "Wierd situation so an odball question _ Is it possible that the AOS system has failed and somehow the crankcase is pressurizing ?" This is exactly what I'm thinking - per a post a few days ago referencing a clogged oil sump aos. I'm going to pull the sump plate and check it tomorrow. If it turns out to be clean, I'll probably go back and check the plug in the end of the cam-shaft mentioned above by Dharn55 ** I also think that if the cam end plug blew out, I'll probably find it in the sump...

When my cam expansion plug blew out it blew the green plug right out and there was a huge amount of oil coming out, it would have emptied the engine quickly so this is probably not the problem, but it is certainly worth looking at. Something is crating enough pressure to push out the green plug.

Quotes source post: 14459048

I'll let you know what I find when I open up the sump and check out the swirl pot/aos. My fingers are crossed, as I'm not looking forward to dropping the engine again

To 'observe' the green plugs are in place or to verify cam timing I use a smart phone camera.There is just enough space to slide it in there. Shoot video if that is easier. Good illumination helps.

Quotes source post: 14459183

Good to know^^ I've got a bore-scope that I bought while doing all the work on my engine earlier this year - I'm pretty sure I can snake that up there to get a look - I'm thinking my I-phone 6 may be a little large

I used an iphone 6.Yes, It does require some dexterity to operate there !

If someone has removed the cam cover and got some sealant in the oil return hole(s) the plug can be pushed out by the pressure build up. See post 7 http://forums.pelicanparts.com/boxst...owing-out.html Or this See Ts post august 5 2009 https://www.renntech.org/forums/topi...nyellow-fluid/

Or the upside down Scavenge Pump

While those are both possibilities and I won't totally rule them out I think the probability is pretty low. I was extremely careful with the sealant - but who knows, I'm certainly not infallible. The scavenge pump I marked before I took it out, and i did only one side at a time so i'm fairly certain it's oriented properly... I'll post back whern I find out what's going on.

The scavenge pump orientation marks are difficult to see with the engine in place - Use the Smart Phone camera to be sure - takes a few minutes and eliminates doubt. I used a paint pen on my pumps to ensure the orientation was easy to see.Ugly but effective.

Ok, I got up to the shop last night and pulled the sump plate (after draining the oil of course!!! ). I really was hoping to find the swirl pot(s) clogged up with pad material, but was disappointed - both of them were clean. The oil and magnet were also clean (only 1000 mi. on fresh DT40) but I did find 2 little chunks of aluminum (non-ferrous/non-magnetic) in the pan. My blood pressure rose slightly for a few seconds until I did the magnet test... I'm thinking maybe I loosened up a piece that had been inside the block while I was turning the engine over on the stand while working on it (I don't know how many times I turned it over but it was quite a few). I can't think of where else this chunk may have come from...I also wonder if it could have had anything to do with my green cam cover plug popping out? Are the cam end plugs aluminum (the ones that seal the cam shaft)? It doesn't seem nearly large enough to constitute the entire plug...Would the rest of it still be up under the cam cover? I won't be able to get back to the car until next week, but in the meantime, I re-sealed the sump plate and ordered a few more of the green cam cover caps. I think before I re-fill it with oil, I'll pop off the green end cap and check for the cam end plug. If that thing is floating around in there, I don't want to start the engine 'til I get it out! If the cam end plug turns out to be where it should be, I'm thinking it could just be a case of excess cam cover sealant clogging the oil return...I suppose I'll cross that bridge when I get to it...

The excessive+sealant-plugging the oil return hole problem is a theoretical possibility with a noob who hasn't read this Forum. I can't imagine you made that mistake. You'd have to plug all/most of the holes. If you badly fumbled reinstalling the cam cover and smeared excessive sealant maybe? The DHarn camshaft 'freeze plug' issue is one only you could evaluate - did you use a diy tool to lock the cam ? So is the cause 1. a localize high pressure jet of oil behind the cam plug or 2. a general pressurization of the cranckcase? The answer to that leads in 2 different directions for the hunt.

I was incredibly careful with the sealant - that being said, I did find a very small amount in the oil pick-up in the sump (1 little blob that was wrapped around 1 of the wires of the screen - I can't imagine it would clog anything, but who knows what else is up under the cam cover). As for the freeze plug - No, I used a factory tool to lock the cams and I was very careful not to put any inward pressure on the cam plus - finger tight only enough to seat against the plugs and hold the cams down [i] These were the chunks of aluminum that were in the sump near the pickup tube

These plugs typically eject when someone re-seals the cam covers and uses so much sealat that the "drains" at the back of the aft camshaft journals become blocked with sealant. Unable to relieve waste oil, the pressure within the camshafts increases, and the expansion plug becomes ejected. There are also times when the primary oilmpressure relief valve becomes stuck, elevating oil pressure, resulting in the same net effect. Loctite 620 (wicking) is used on all expansion plugs that we do not thread here. Just as a precaution.

Quotes source post: 14466448

thanks for checking in Jake. As I said earlier, I was extremely careful with the amount of sealant I used so I'm pretty doubtful, but I guess anything is possible. I'm going to pull the cam cover end cap back out on Tuesday and check the expansion plug. If it turns out to be the expansion plug I'll figure out how to deal with it.

I made it back up to the shop tonight after work. I pulled the green Cam cover cap back out so I could take a look at the end of the cam to see if the expansion plug was still present (Even though I thought I felt it in the end of the cam shaft before I replaced the green cap - I wasn't consciously checking for it so I couldn't be totally sure). Sure enough, the plug was there...Hmmm, I suppose that's good news but I'm still not sure why the green cap popped out. I put everything back together and refilled with oil. I didn't have time to start it tonight...will have to wait 'til tomorrow...

The only remaining ,likely cause for ejecting a correctly fitted cam plug (that I can think of) is pressurization of the crankcase . What I can't imagine is how any part of the work you just did could result in that problem. Presumably the problem did not show before you did this work? The usual cause is badly worn rings/cylinders or valves but that happens gradually ,not suddenly

^^Yeah^^ nothing like this happened prior to any of the work I did. Also, the fact that I drove close to 1000 miles before it took place makes it strange as well. The oil pressure never looked unusual. Jake mentioned that perhaps the oil pressure relief valve got stuck and caused pressurization of the crankcase. I suppose it's easy enough to check that. I did change the spring and piston when I did all my work, but there was nothing unusual about it at that time - very simple job, the piston and bore were both smooth.

The upgraded piston that you used has a small bevel on the leading edge of it's circumference. So that makes it much less likely to stick than the original style that you replaced. At least this is my understanding. Easy enough to remove,inspect ,measure,lube and replace.

Quotes source post: 14472867

Yup^^ This is the plan (pull it out and check it), but I don't foresee any problems there. We'll see... Once I get everything back together and running (I'm basically there - just have to get it back off the jack stands), I'll just have to monitor for oil leaks. I'm really hoping that whatever caused this has cleared itself in much the same way as it "appeared". If not, I'll have to drop the engine again and check the cam cover sealant.

I got back up to the car this afternoon. First order of business was to pull the oil pressure relief valve. When I first loosened and unscrewed the cap/spring holder, very little oil came out at first (maybe a couple ounces). It wasn't until I pushed the spring back up into the piston that it really started to flow (at which time I promptly screwed the cap back in). This leads me to believe that maybe the piston did get stuck in the bore - I don't know why that would happen though (it's the upgraded piston and spring). Now that the oil is totally surrounding it, maybe that wont happen again!

Oh well... Bummer! Green cam cover cap popped out again. It looks like at the very least, I'll have to remove bank 2 cam cover - perhaps even drop the engine again ...

I'm going to try to just go in through the side, via removal of wheel, muffler, muffler bracket etc. I'll probably have to remove the suspension crossbrace so I can lower the engine a bit so I have access to the upper cam cover bolts. I started yesterday evening but probably won't get back to it until Sunday afternoon at the earliest... In the photo you can see the top cam cover cap partially blown out.

Dporto, you may want to drop the valve cover and inspect the oil return drain veins to insure they are not clogged (areas identified by red arrows). If those are clogged I can see the pressure build up that could perhaps be causing the plugs to pop out and the oil build up. I know others have said it but no one had an image to portray the area and better give you and idea as to why it could be happening.

Looking at how much sealant is squeezed out you might have too much when sealing that cam cover. " there is no gasket other than the sealant you squeeze out -- 1.5mm-- wide & hope it doesn't clog a oil passage but prevent oil leaks. The only thing easy to do is have it leak more after the "fix"." From Pelican http://986forum.com/forums/performan...placement.html

"Dporto, you may want to drop the valve cover and inspect the oil return drain veins to insure they are not clogged (areas identified by red arrows). If those are clogged I can see the pressure build up that could perhaps be causing the plugs to pop out " ^Yes^ This is the plan! I'm actually wondering if there is a way to get a flexible piece of wire (guitar string) into that passage to possibly clear it without removing the cam cover at all... Hmmm... "Looking at how much sealant is squeezed out you might have too much when sealing that cam cover." Yeah, I hear ya! I was so careful putting the sealant on 1 - 1.5mm bead - especially at the ends where the relief passages are (you can see how even the squeeze out is). Regardless, I clearly have a clog, so something went wrong... I don't get why it took so long though...I drove close to 1000 mi. before the cap popped off the first time

So after moving a bunch of stuff out of the way and pulling out the closest spark plug tube (cyl#6) I'm able to look at the clogged passage. The dark area is the clogged oil passage next to the cam Now all I have to do is fashion a tool that allows me to clear that tiny passage of the cam cover sealant that's clogging it. If I can figure out how to get a fair amount of the sealant out of there, I'll have to pull the cam cover back off and start over! What little I've tried gives me a new appreciation for endoscopic surgeons!

Worth a 1000 words!

Quotes source post: 14483725

^^Yes absolutely! Even better if you can relate it to this... What your actually looking at is number 12 (with red arrow) in the photo above, except in my borsecope photo it's rotated 90 degrees counter clockwise... (I hope that makes sense...)

So , just a quick update to this saga. I spent a couple hours trying to clear the oil passage with a couple different homemade tools that I whipped up quickly with what was on hand - One from a piece of flat stainless steel wire from a windshield wiper blade and one from a guitar string (.026 wound "d" string). While I'm able to get the tools into the cavity and move the sealant around, I haven't been able to extract any of it to any degree. The other problem is that if I am able to dislodge any of it, it's just going to fall into the cam area of the head, and I don't want it to be floating around in there. There's no doubt in my mind that if I had a proper/well developed tool (with say, a tiny flexible cutting head and suction around it) I'd be able to pull this off! I know, just bite the bullet, remove the cam cover, clean out the passage and then re-seal it - more carefully next time!!! I was really hoping I wouldn't have to do that ... Below are few links to the "endoscopic surgery" video's I made of my somewhat feeble skilz... https://www.youtube.com/watch?v=tleS...ature=youtu.be https://www.youtube.com/watch?v=ofaD...ature=youtu.be https://www.youtube.com/watch?v=7DWl...ature=youtu.be

One thing I do to keep from blocking the oil drain is to use a piece of small rope/cord to lay in the passage before installing the cover. The rope/cord keeps the sealer from filling the drain passage and is removed as soon as the cover is torqued while the sealant is still fresh. It literally wipes the drain passage as it's removed.( Note Caution : do not use too big of a rope/cord as it will get pinched and cannot be pulled out.) PS: CEL? lol

Quotes source post: 14490195

Wow! Thanks for the tip 👍 That was my plan - glad to know it works. I'll leave the end of the string hanging out the spark plug hole... I'll measure the passage with a micrometer before settling on what sort of string/chord to use. Any suggestions are welcome!

Quotes source post: 14490444

There is room to leave the cord hanging out of the hole for the cap. There is a fair amount of distance between the start of the drain and the Cam.

Quotes source post: 14490461

Really? That's weird - my first idea was to try to clear the sealant fro the outside - because I thought there was a gap there. I couldn't get even a .010 guitar string past the end of the cam???...

Quotes source post: 14490663

Yea you can't poke anything into it from the outside ,it is at a 90 degree angle under the cam, anything flexible enough to make the turn isn't stiff enough to push. That's why a cord works best, because any stiffer will be to hard to pull out. I have used the plastic straw from a silicon spray can, but it's almost too big and stiff, I have had them to break off and had to remove the cover and clean it all up again,(PITB). lol Just use a cord and don't try to get one too big, a small one with a knot in it works best.

^^ ^^ A couple quick questions: I've removed the center cross-member under the engine, and am going to remove the transmission support as well. 1) How far can I drop the engine without disconnecting anything major in the engine compartment? 2) I'm pretty sure I'll have to unhook the clips that hold the power steering lines, maybe the fuel line, and I think two air lines to the throttle body...??? 3) Exhaust O2 sensors? Also, locking down the cams/chain tensioners. Crankshaft is locked at TDC (bank 2) 1) Remove chain tensioner for bank 2? (the one under the AC compressor right?) Anything else I'm missing?

Leave the cross member and trans mount, just remove the rear motor mount bolts and let the engine down onto the cross member. There is enough slack in the hoses and wiring for this to happen except for the 02 sensors need to be loosened from the holders and power steering hoses from the holders. No need to lock the cams or crank as you will not be removing the chains, just support the cams on the opposite end from the chain with the cam support tool. It can be done fairly easy with the engine still in, the only aggravation will be the exhaust muffler support bracket top bolts, and the top front cover bolts are close quarters as is the scavenge pump on bank 1. No need to remove chain tensioners, as you are not removing the timing chains.edit" you are working on bank 2 tha'ts even better, scavenge pump is easy to get to, close quarters on the front for the cam support tool. Again no need to remove the tensioner as you will not be removing the chain. FYI if you try to drop the engine any further than to rest on the cross member you will have to remove coolant hoses, wiring harness ect. PS. drain all the oil and still be prepared for it to drip constantly from the removed cover for HOURS. This is the most time consuming part of the operation and can be messy if rushed.

Yes - Bank 2...The cross-member is already out...Crank is locked as well. Drain oil...Hmmm, I wasn't going to do this - I'm glad you weighed in, as this would have been a nightmare now that I think about it!!! As you say, scavenge pump wont be a problem but I can only get one of the bolts in for the cam support tool - the sub-frame is in the way of the other. This is why I think it's necessary to drop the motor a little further than the cross-member would have allowed. Tensioner - good to know, as I was dreading the AC compressor job !

I got up to the shop yesterday and got the cam cover off. Wow, what a mess! While I thought I was being frugal with the sealant, I clearly have no idea what a 1mm bead looks like! As this was the second cover I did, I have a feeling I got a little complacent/careless. As you can see from the photo both upper and lower passages were clogged - I guess the upper one was just worse... I cleaned it up and re-sealed it, being super careful (I heard that before) and putting strings in the passages this time. When I was done torquing the cam-cover bolts, I pulled the strings out. Going to go put everything back together now...

Very helpful Posts . How many cam cover R&Rs have resulted in partial blockage ? Not enough to cause the green cam plugs to blow out but enough to cause oil starvation ?

So you are using red (hi-temp) RTV on this joint? Seems like something a lot thinner to start with would give better or safer results. Like Drei Bond or the Loctite equivalent (5xx - can't remember the number) anaerobic sealant.

3 Bond works O.K. with the engine in the car. A thinner sealant may sag because the surfaces are vertical.and that may easily cause blockage of the oil return holes. With the engine out and rotated so the treated surfaces are horizontal (not vertical as in this case), thinner sealant may work but why not use the recommended 3 Bond ?

Quotes source post: 14494849

Loctite 517

The red stuff was Permatex high temp rtv. It was the best I could get at the time, as the driebond I had ordered was out of stock. I used the driebond this time and it seems to have worked well. Of course I won't know for sure until I get oil in it later on tonight (I'm giving it a full 24 hrs to cure &#128521 . It's a little blurry but you can see the oil passage is clear this time. The red you see is assembly lube on the cam

Quotes source post: 14495205

That would work, but I was thinking of Loctite 574 which works great on metal to metal joints.

So, just to wrap up this thread. Everything is back together and the car is running well, no leaks and everything looks good so far...

Alright! Job well done Dporto. Now it's time to roll more miles of smiles on that odometer.

Congrats! That was quick! Glad you didn't have to drop the engine again.

*thumbs up*