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YOUR RESEARCHCoolant in exhaust
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Install backward
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It was a reman Factory engine and the shim was installed backward.
Leading evidence: 'Install backward' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check plugs' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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It's the one that was installed backward, as there's no signs of wear on the inboard side, but a ton on the outboard.
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Actually the thrust shim pictures was installed correctly, but the second one on the opposite side of the carrier was at fault first.
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Suggestion · Original poster
6 looked cleaner than 5 but did not quite have that typical "steam clean" look you would usually see when the combustion chamber is filled with steam.
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99 c2 106k miles. I believe I found the cause (or result) of my recent coolant system issues. Coolant is getting into the exhaust from one of the 3 cylinders on the passenger side of the engine. This causes white smoke to come out of the driver side exhaust pipe. This is not overflow dripping down, because I found coolant leaking out of the exhaust at the gasket on the opposite side of the car from the coolant tank. I have included a picture. I tasted the fluid coming out and it is definitely coolant.
Obviously I am thinking cracked head or head gasket but I just wanted to see if there is any other possible cause. This does make sense since, as Ahsai pointed out in an earlier thread, my coolant system pressure has apparently been getting too high. I have read things about the AOS but I do not see how that would allow this much coolant into only the passenger side of the engine. I thought the usual cracked head was on cylinder 1 which I thought was on the driver side, so I am leaning towards a blown head gasket on the passenger side. Any other ideas?
Thanks for that info. In that case it sounds like a cracked head I guess. I just want to make sure there is nothing else that could cause coolant to enter the exhaust on only one side.
For a cracked head, there's only one guy to go to - Len Hoffman at Hoffman Automotive Machine Group. He'll fix it and have it better than new. 1-3 bank cracks are common on the 996.1 heads, I'm told (no direct experience).
Looks like that is what I will have to end up doing. The coolant is getting into the passenger side of the engine which I thought was the 4-5-6 side. That is the only weird thing.
I am having problems with what I believe is cylinder 2. I do not see an easy way to get in there. I have the boots off the other plugs, but it might be a moot point.
If this is a cracked head or cracked cylinder (damaged intake or other major engine damage) I will not have the time to deal with it now anyway so I will be throwing in the towel on this.
I just want to be sure there is nothing else that can allow coolant into the passenger side of the engine before I give up on it. The other strange thing is the fact that the coolant system held pressure of over 20psi for over 20min when I tested it recently. If coolant is getting into the engine from a cracked head or cylinder how is the coolant system passing a pressure test?
What I was trying to say is that if it is something that will require me to pull out the engine I will probably not be the one doing it. I would have to bring it to the indy either way at that point.
The thing that confuses me is that the coolant system passed a pressure test. So how is the coolant getting into the engine? Maybe something to do with vacuum, or maybe the compression stroke temporarily opening a crack up, I have no idea. It seems to stop consuming coolant when it heats up so maybe it is a small crack somewhere just barely opening up when it is running cold.
Either way, if there is no way for coolant to get in absent physical engine damage, then I think it is time for me to bring it in.
Typically this is a cracked cylinder. I have seen some increasing numbers of a different type of cracked head that can lead to this as well.
The heads can crack very deeply within the casting, and coolant can enter the secondary air capillaries, then exit at the exhaust flange.
Pull the exhaust head pipes and see where the source of the coolant is.. Take pics and post. I'll assist.
Pedal: If you have time do as Jake(Flat6) suggests. Don't know if you know, he is the M96(and many other engines) Engine Whisper! I.E.: He knows his stuff!
Do you have a universal joint set for your sockets? Those and set of hex metric sockets work great with a 1/4" driver and extensions. I've had really good luck with buying Tekton tools off of Amazon.
Thanks guys. I unbolted the exhaust and one of the bolts between cylinder 5 and 6 was wet. I could not tell if it was coolant or condensation, but it looked suspicious. I can not pull the exhaust very far down to see in or get a good pic, but both 5 and 6 look about the same to me, I can not see inside 4 at all.
I pulled the plugs from 5 and 6. Both boots were covered in oil, so there is another obvious problem, haha. 6 looked cleaner than 5 but did not quite have that typical "steam clean" look you would usually see when the combustion chamber is filled with steam.
I have pics of anything anyone wants to see
I wont try this unless someone who knows tells me it is safe, but I was thinking about just running open for about 1min. The steam/coolant usually starts right away, that would narrow it down to the correct cylinder, but I guess that still wont tell me exactly what the damage is.
I would recommend doing as Jake asks if he is going to take the time to help you troubleshoot.
FYI, if you are using your phone you will need to upload pics via your phone browser as the app tends to bomb out.
I may have misunderstood his instructions. I thought he wanted pics after I unbolted the exhaust, but I cant see in well. Here is an example of the best pic I could get of 6.
Below are pics of the wet exhaust bolt and its hole between 5 and 6.
I got the exhaust out and it looks like the moisture is only coming from cylinder 5. Here is a pic showing the wetness. It is totally wet like that all the way to where both exhaust valves seat.
Also, the valve stems look whiteish like they have been steamed on cylinder 5 (pictured below). The color is a little hard to see in the pics
4 and 6 are pictured below respectively for comparison.
Thats not as wet as I'd expect. Typically the pencil sized holes will drip coolant if a 3 chain head is cracked internally.
I see moisture in the #5 exhaust, and at this point that's pointing toward a cracked cylinder. The good news is, thats its not horrible yet. Definitely do not run it anymore, and get it to an M96 Specialist. If the cylinder cracks too far the chunk will break away, and thats a massive failure.
I'd pressurize the cooling system without the engine running, and see what happens. Roll the engine over so the exhaust valves on cylinder 5 are open, pressurize the system, and wait for the show.
This gold nugget advice from Raby is worth a lot of money - just think how much a shop would have charged for it, even if you had taken off the exhaust manifold yourself.....
Thanks Jake. I pressurized the system to 20psi, but the cap vented it down to just under 15psi. After a few minutes water started to come out from one of the open exhaust valves in cylinder 5. It is dripping at a rate of one drip every 4 seconds. I can not even really see a change in PSI after over 30min (still almost 15PSI), maybe 1/4 PSI loss. This must be why I thought it was passing a pressure test earlier.
So does this confirm a cracked cylinder wall and not a cracked head? Thanks again Jake
Thanks for everyone's help on this. I really appreciate the professional diagnosis Jake. This engine is totally original at 106k miles, so it wont hurt to have an expert go through it anyway.
If you re going to have a failure, cylinder failure via a crack is the one to have.. Not catastrophic and collateral damages are limited to maybe an O2 sensor.
So much better than this!
Actually, the thrust shim was the primary failure.
It was a reman Factory engine and the shim was installed backward. When this occurs the oiling grooves face the carrier and not the crankshaft, so the surfaces do not get enough oil. The lack of lubrication makes for more friction. As the thrust shim wears it becomes thinner and eventually will fall out like this one has.
Actually the thrust shim pictures was installed correctly, but the second one on the opposite side of the carrier was at fault first. It's the one that was installed backward, as there's no signs of wear on the inboard side, but a ton on the outboard.
This is the 5th time I have documented this mode of failure.
