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Supercharged 996 c2 3.6 with a blown head gasket, need aftermarket options please
Ive got a 996 c2 3.6 and it looks like I popped the head gasket. Symptoms were random misfires on the same cylinder, coolant burning off on start up and coolant coming out of the exhaust. Im going to have to deck the head and block which means I can't run a factory head gasket. There seem to be options for turbo and gt3 head gaskets but nothing for the 3.6 out of the c2. Can anyone direct me in the right direction for an aftermarket head gasket? I'll need something thicker so that I don't increase the compression.
99 out of 100 times it's not the head gasket with these engines. It's a metal gasket and there are much weaker parts of the engine that will give out before it does.
I'm curious if you bought the car super charged or if you added it post purchase. The M96/97 and added boost don't work very well together.
A dollar says (unfortunately) you have a cracked head, not a blown head gasket. Even under boost, blowing out a 996 head gasket just doesn't happen. Compare a 996 head gasket to most others and you'll see why - the amount of gasket material between each cell is massive compared to gaskets for other engines.
Here's what a 996 head gasket looks like - the amount of material is huge compared to some other common head gaskets...
Compared to a Supra head gasket, you get an idea which of the two is more likely to have an issue...
Hopefully, you DO have a blown head gasket, but you might want to go into this repair with the possibility that you're looking at a head repair. It would suck to pay for a gasket install, fire up the car, and realize you're still losing coolant...
Having coolant coming out the tail pipes and misfiring sounds like something different than a cracked head, as everyone is suggesting, is going on. Now blowing a head gasket is rare but, not unheard of. Being that it is boosted this could be the issue. I'm more curious to know what would give waybthat would allow coolant to flow into the exhaust ports.
Trendy996
coolant is all around the cylinder and head so basically either cracked cylinder or head or head gasket but unlikely , the cylinder sucks the water into the cylinder from one of these locations as it draws in a new air and fuel charge then after combustion it will go out of the exhaust system a lot with the spent gasses hence the water coming out of the tail pipes, misfires will be due to the excess water content in the cylinder effecting the mixture so it won't be getting a proper clean burn on the power stroke I would say!
Looking at a head I would highly doubt a cracked. Bc of where they typically crack at. I'd prob be leaning towards a cracked or chuncked cylinder wall.
Its a 3.6 with boost. The cylinder will fail before the head gasket will. The cracked cylinder has the exact same symptom as a cracked head.
A failing cylinder can also have secondary collateral damage in the form of a failed head gasket.
These cylinders fail routinely with without boost, force feeding the failure is all the boost does.
Coolant out the tail pipe is a classic cracked cylinder symptom. I've personally seen that one 16 times this year so far. Of those, all but one of them was misdiagnosed by the shops that first saw the engine.
Last edited by Flat6 Innovations; 12-05-2016 at 02:40 PM.
These cylinders fail routinely with boost, force feeding the failure is all the boost does.
Lol. Well put. I know companies will do anything to make a buck but it still surprises me they make turbos and SC's for the 996. Especially TPC which seems to be a very reputable company.
Lol. Well put. I know companies will do anything to make a buck but it still surprises me they make turbos and SC's for the 996. Especially TPC which seems to be a very reputable company.
Lots of fishing lures don't work either.... But they catch Fisherman.
The turbo/ Supercharger isn't the issue.. Its the inherent weaknesses of an engine with an open deck design. The EJ series Suby engines were open deck as well, and they routinely had/ have head gasket issues from a lack of cylinder support that causes them to fail under boost, too.
I won't even perform an IMS job on an M96/ M97 that has been boosted. No way am I going to be caught in the middle of that chain of events. Saying NO! in an acquired skill.
Sorry to go a bit off track but the more I looked into turbocharging the red flags popped up. These motors have very high compression ratio to be boosting which can be an issue. But again hope your issue as you said is a head gasket.
Ive pulled the engine apart, Im very luck that the cylinder walls are ok. The car has seen some decent amount of track time and drive at WOT under boost. Once the car is fixed and back together I will just enjoy it, Im debating on whether or not I should remove the supercharger kit as well. Here is where the HG leak was/is.
You must inspect the cylinder deck with a flat edge to ensure the cylinders have not started to sag. This will cause the head gasket to fail, as it reduces clamping load between the head and the gasket, in a localized area.
The center cylinders are the most common to fail in this manner.
The place where you see the discoloration is highly suspect for sag. Start measuring there. a 24" machinist flat edge is your friend.
You must inspect the cylinder deck with a flat edge to ensure the cylinders have not started to sag. This will cause the head gasket to fail, as it reduces clamping load between the head and the gasket, in a localized area.
The center cylinders are the most common to fail in this manner.
Good call, I will more than likely have to deck the head and the block, part of the reason I need a custom HG. I'll need a thicker HG than stock as to not raise the compression.
12-01-2016, 06:27 PM
Supercharged 996 c2 3.6 with a blown head gasket, need aftermarket options please
