High Mileage Engine Out Questions

[nuvolari]

Ok, long story short is I have my 2000 986S 3.2 liter engine out and partially disassembled to correct an oil leak from the head gasket and I was planning on not splitting the crankcase but now I want to see what you guys with M96 engine experience think. The car has 160k miles on it and was running great. I have 6 speed tranny problems and after pulling the transmission and experiencing a bad oil leak while driving cross country, I pulled the engine to fix the oil leak. I guess the heads were pulled recently before I bought the car and then then reassembled with a bit of funk that compromised the sealant lip on the head gasket resulting in an oil leak.
Anyway, my questions are what to do about the crankcase and rod bearings as well as the inner timing chain tensioner pads, not to mention piston rings.
Am I able to inspect the inner pad surfaces before splitting the case to see what condition they are in? (Forgive my obvious questions here as I am 2000 miles away from the car and can't just look at it to answer these questions.)
Also, the outer bores look good with no scoring but I will use a boroscope to check the lower/inner bores when I get back to the car next month.
However, if the bores are good and the pads are good, would you guys still split the case or just put it back together with reconditioned heads?
I think the case has been apart as the sealant between the case halves is black and a bit on the heavy side? Did Porsche slather on the sealant here or is it usually not noticeable? I assume the heads have been off due to the oil leak but who knows, maybe that's OE. I would doubt any manufacturer would do this but in the M96 world, all bets are off!









Can you guys tell if this case has been apart before? You can see how much sealant was used, especially where it comes out the end of the threaded hole where the bolts were installed.

Oh, and how much extra will splitting the case run me? I'm assuming once I split the case, I'll probably want new rings, rod bearings, tensioner pads + aluminum pad arm, tensioner chains, etc. What I'm not sure about is if I'll want ARP rod bolts or OEM.
I'm guessing all of these parts will add about $1200 to my M96 debt. What else am I forgetting?

Anyway, I would love to hear opinions on any of this. Is all this overkill or added necessity?

I guess I'll wait to hear if we can determine whether the case has been apart before....

[pilot4fn]

I would be surprised if there would be any sealant placed on the head gasket. To my understanding this should be a metal gasket installed dry.
Then the cam covers should have sealant and seems oftem to be used way too much - even to the point of blocking the small oil channels next to the end of the cams (causes blowing the cam plugs out).

[Homeoboxter]

If the engine was running fine and wasn`t burning too much oil I wouldn`t split the crankcase. If you split it probably you`ll find a couple of things out of spec and you`ll want to replace everything just because you got this far. That will be a huge undertaking and a lot of money if you want to do it properly. Why not do this when the engine is really worn out?

[986tate]

No, I wouldn’t split it either. Unless you have crazy leak down numbers and a lot more than $1200

[Coaster]

I've not split a case so take this with a grain of salt.

I'm considering tearing mine down and rebuilding but as I understand it - re-ringing isn't really an option as these cylinders tend to become oval over time. If you have the ~$6k you can replace the cylinders and pistons with LN Nickies and JE pistons. But then what else needs to be done....

[nuvolari]

Originally Posted by Homeoboxter

If the engine was running fine and wasn`t burning too much oil I wouldn`t split the crankcase. If you split it probably you`ll find a couple of things out of spec and you`ll want to replace everything just because you got this far. That will be a huge undertaking and a lot of money if you want to do it properly. Why not do this when the engine is really worn out?

Originally Posted by 986tate

No, I wouldn’t split it either. Unless you have crazy leak down numbers and a lot more than $1200

Originally Posted by Coaster

I've not split a case so take this with a grain of salt.

I'm considering tearing mine down and rebuilding but as I understand it - re-ringing isn't really an option as these cylinders tend to become oval over time. If you have the ~$6k you can replace the cylinders and pistons with LN Nickies and JE pistons. But then what else needs to be done....

Thanks for the info and advice. I definitely would rather not split it and it was running fantastically with no obvious problems other than the oil leak but my main concerns at this point are the timing chains and pads, rod bearings and rod bolts. It would be nice to refresh all those parts or possibly upgrade them but there goes $1k just in parts for all that! And even after that, I'd still have all the bore issues and piston skirt wear plus rings and other things I'm forgetting right now.

Anyway, thanks for the advice....

[seningen]

Originally Posted by nuvolari

Ok, long story short is I have my 2000 986S 3.2 liter engine out and partially disassembled to correct an oil leak from the head gasket and I was planning on not splitting the crankcase but now I want to see what you guys with M96 engine experience think. The car has 160k miles on it and was running great. I have 6 speed tranny problems and after pulling the transmission and experiencing a bad oil leak while driving cross country, I pulled the engine to fix the oil leak. I guess the heads were pulled recently before I bought the car and then then reassembled with a bit of funk that compromised the sealant lip on the head gasket resulting in an oil leak.
Anyway, my questions are what to do about the crankcase and rod bearings as well as the inner timing chain tensioner pads, not to mention piston rings.
Am I able to inspect the inner pad surfaces before splitting the case to see what condition they are in? (Forgive my obvious questions here as I am 2000 miles away from the car and can't just look at it to answer these questions.)
Also, the outer bores look good with no scoring but I will use a boroscope to check the lower/inner bores when I get back to the car next month.
However, if the bores are good and the pads are good, would you guys still split the case or just put it back together with reconditioned heads?
I think the case has been apart as the sealant between the case halves is black and a bit on the heavy side? Did Porsche slather on the sealant here or is it usually not noticeable? I assume the heads have been off due to the oil leak but who knows, maybe that's OE. I would doubt any manufacturer would do this but in the M96 world, all bets are off!









Can you guys tell if this case has been apart before? You can see how much sealant was used, especially where it comes out the end of the threaded hole where the bolts were installed.

Oh, and how much extra will splitting the case run me? I'm assuming once I split the case, I'll probably want new rings, rod bearings, tensioner pads + aluminum pad arm, tensioner chains, etc. What I'm not sure about is if I'll want ARP rod bolts or OEM.
I'm guessing all of these parts will add about $1200 to my M96 debt. What else am I forgetting?

Anyway, I would love to hear opinions on any of this. Is all this overkill or added necessity?

I guess I'll wait to hear if we can determine whether the case has been apart before....

That doesn't look oem -- or a particularly clean reseal -- It's been about 10 years since I've been inside one of these engines -- I'm remembering the case sealant being orange-ish?

https://www.********************************************** **************/pn/00004301000?utm_source=google&utm_medium=cpc&utm_campaign=frooglePN&utm_term=230649&gclid=CjwKCAiA7vWcBhBUEiwAXieItuHVDs7ZohF4_d4nBQBD SJte9gr6AIxzvJXnKpdKpaBAB5DeKE8xPRoCoK4QAvD_BwE

loctite 574

The reassembly of these cases is not for the faint of heart as you need a special tool to put the wrist pin locks in place and its a blind assembly.
My mechanic buddy made his own -- otherwise its a pricey tool from Porsche if memory serves right.

If you don't mind the reassembly, the bearings could be refreshed while you are in there. You could check ovality and either reassemble as is, or choose your re-ring / cylinder options.

The head gaskets are indeed a dry assembly. And as was mentioned the valve covers are a light sealant -- where less is more.

Mike

[nuvolari]

Originally Posted by seningen

That doesn't look oem -- or a particularly clean reseal -- It's been about 10 years since I've been inside one of these engines -- I'm remembering the case sealant being orange-ish?

https://www.********************************************** **************/pn/00004301000?utm_source=google&utm_medium=cpc&utm_campaign=frooglePN&utm_term=230649&gclid=CjwKCAiA7vWcBhBUEiwAXieItuHVDs7ZohF4_d4nBQBD SJte9gr6AIxzvJXnKpdKpaBAB5DeKE8xPRoCoK4QAvD_BwE

loctite 574

The reassembly of these cases is not for the faint of heart as you need a special tool to put the wrist pin locks in place and its a blind assembly.
My mechanic buddy made his own -- otherwise its a pricey tool from Porsche if memory serves right.

If you don't mind the reassembly, the bearings could be refreshed while you are in there. You could check ovality and either reassemble as is, or choose your re-ring / cylinder options.

The head gaskets are indeed a dry assembly. And as was mentioned the valve covers are a light sealant -- where less is more.

Mike

I have the proper tools; they came in a set with valve timing tools I bought. And I've seen many online info/videos about the whole wrist pin installation which looks like lots of fun!

I've asked on other forums if the sealant is factory and some have said yes, that's the sloppy factory sealant which I do find hard to believe but we all know how many dumb things Porsche did with our beloved M96 engines!

I'd still like to know if it's actually OEM or not though as no one has really said either way with a sense of sureness.

And, yes, head gaskets were dry in my engine. Well, except for the large gash of oil that was leaking out past one of them and the reason for this entire engine out fiasco. I'm not sure why people seem to think I said the head gaskets had sealant on them because they did not.

Oh, and I was told by Len Hoffman to coat the section of the head gasket that is held by the small Allen bolts (around the timing chain section) with spray-on copper sealant. I had forgotten this until I was watching yogi's garage and he sprays his gaskets in the video and then I remembered this. His heads were rebuilt by Hoffman so that makes sense. I guess it's been a problem for the gaskets to leak oil in these sections so the copper helps seal it in the initial heat cycles of a newly built engine.

Video here:

https://youtu.be/z_K3fG5BwS8



His later videos are very helpful. He even gets in trouble for spilling too many LN "secrets," ha ha. I have to say the video where he tells many details is the best one and that's when I began to really find the videos helpful. Then the next video begins with how LN didn't like that and now he would tone it down a bit. But he still provides much needed info especially for the amateur Porsche mechanic that is so tough to find anywhere else. Not sure why these cars are so secretive, mysterious and temperamental but if I ever learned why, I would tell people. Of course, Porsche should have told us from the start but that's another story....

Anyway, yogi's garage and man in a garage videos are very helpful.

[986tate]

The way he installed the crank seal was pretty goofy.
Thanks for sharing the link

[nuvolari]

Originally Posted by 986tate

The way he installed the crank seal was pretty goofy.
Thanks for sharing the link

Yes, he does do some questionable things....but don't we all?!?

However, he does provide some great knowledge that I haven't found in other videos, not to say the other videos aren't helpful as well but the more you watch, the more you know....Especially with an engine as problematic/difficult/tempermental/lovable as our's.

[986tate]

Totally. Plus he’s got a wife that is into it

[elgyqc]

I just reread this thread and will offer the results of some of my thoughts on this question. You may have seen my thread on tearing down the broken engine from my 2000 S.
What can I do with this 3.2l engine?

I have gone over several scenarios for this engine and did a list of necessary parts if I decided to rebuild it. Then decided to shelve it till I get my replacement engine installed in the car in the spring.

When you remove the heads you will see the condition of the bores, which, in my opinion, after much research, is a central question.

My price for parts once you split the case is a minimum of $1500 US. That includes a new but stock IMSB, reusing the pistons and rings, but new bearings and changing only the IMS chain guide. The new bearing carrier and head bolts alone are $700 US. Add a net $150 to this for ARP big end bolts.

One advantage of splitting the cases is that you get to inspect/change the IMS chain guide which you cannot see otherwise. But I have not seen reports of a lot of failures of that part.

Once I had disassembled the broken engine I started looking at the replacement engine and wondered if I should pull the heads and... but decided not to go there. I changed the tensioner chain pads, which were in very sad shape and am now putting it back together.

I tend towards thinking that the tensioner pads are more of a problem than the IMS bearing. I have seen 4 IMSBs (all double row) on engines with from 90K miles and up and all of them were still in good shape. I have inspected the tensioner pads on 3 of those engines and they were all well worn and on my replacement 3.2 engine (133K miles) they were getting close to failure.

So much for my very amateur 2 cents worth.

[Homeoboxter]

Originally Posted by elgyqc

I tend towards thinking that the tensioner pads are more of a problem than the IMS bearing. I have seen 4 IMSBs (all double row) on engines with from 90K miles and up and all of them were still in good shape. I have inspected the tensioner pads on 3 of those engines and they were all well worn and on my replacement 3.2 engine (133K miles) they were getting close to failure.

So much for my very amateur 2 cents worth.

Agreed....

[nuvolari]

Thanks , guys. I really want to do the whole thing but money will probably be the deciding factor at this point. The bores look good but the engine has 160k on it. I already have most of the parts needed except for the IMSB as I have been doing research and having trouble deciding which to go with. I feel the IMS Solution is the best choice but the price is just ridiculous. All of the other choices are risky but right now I'm deciding between the OEM bearing that Grant used or the Precision Automotive bearing which although not a common choice, seems to have unique and reasonable qualities as well as a decent price.
At this point the heads are off the engine and the heads are disassembled. The cam tensioner pads are worn but are still within the useable realm. Of course, I have the new pads ready and waiting. I originally took the engine out and apart because I had a bad oil leak from Bank 2 at the lower cam chain area, near the lowest M6 Allen bolt that secures the head gasket in that area. It ended up being a speck of crud that was right next to the sealing ridge/lip of the head gasket causing the gasket to never seal. I don't know why the heads were off or how long it was like that as I had just bought the car two weeks earlier. Long story which is documented in one of my other threads.

Anyway, here are some pics of the bores. I've been told they look good, at least the ones shown. I'll do more checking and scoping once I'm back in Nashville where the car is located. And I'll check the other tensioner pads as best I can to see their condition.




And the offending gasket leak: