Possible Head Gasket Failure

[WestBankM4]

Engine has 80k miles on it, I've replaced all the spark plugs, coil packs, and valve cover gaskets, screws, etc. with OEM parts. Engine is dead stock, no upgrades.

I've had the Vanos upgraded with all Besian parts and saw that it passed the test with flying colors.

I'm chasing a misfire, essentially rough starting when cold but gets better when it warms up. The problem is a pinging (marbles) noise once the car heats up, happens around 2500-3500 and with load on the motor, worse when going uphill. I think the car may have some sort of pre-detonation and it's throwing codes for cylinder 2 and 3 misfire.

Tomorrow I plan on yanking the plugs and doing a compression test. I'm praying it's not the head gasket.

If it's not, I'm installing the OEM fuel filter and fuel pressure regulator, if that doesn't solve it, then I'll send out the injectors to RC. Not sure what is causing this, thoughts?

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[maupineda]

it does sound like HG as you mention pinging, but for sure the compression test will help with confirming further as you will likely see less compression on those cylinders

[sapote]

It’s easier to hear the gasket leak by doing leak down test if you have air compressor

[Halftim3]

Same symptoms as I had, it was the headgasket blown between each cylinder because it's so thin in those areas. I also heard the same pinging at the same RPM (2500-3500) under load.

Leak down tested it and heard air blowing through. I was getting the same misfire codes with good plugs and coils recently replaced, but mine was at 210k. Also stock tune. I had the head resurfaced with a valve adjustment, new OE head bolts, beisan parts, etc and it runs great again. PM me if you want I can text you photos or the shop I went to.

-Mike

[jet_dogg]

I doubt it's the head gasket with 80k.

[eacmen]

I doubt it's the head gasket with 80k.

Overheating can also cause HG failure. Not just mileage.

Leak down is ultimate test.

Block tester chemicals can also be useful if you suspect exhaust gas in the coolant.

[sapote]

Tomorrow I plan on yanking the plugs and doing a compression test. I'm praying it's not the head gasket.

If gasket leaked between chambers, this could eat through the thin combustion divider on the head. So don't drive anymore until it's sorted out.

[WestBankM4]

Halftim3 Thank you, I'm doing a compression test tomorrow when I return home to start there. Thanks for the offer but if it ends up being the headgasket, I think I have enough know how to do the work myself. It'll be my first time with an S54 but there's enough info and I have the right tools to get it done. I do plan on sending out the head to clean and resurface.

sapote Good call, I drove it today and it has great low end torque so I don't see the typical headgasket issues with power. Car doesn't burn an ounce of oil and there is zero smoke. I was leaning more towards a fuel issue since I doubt the fuel filter/FPR has been replaced, injectors may have inadequate pressure and the fuel pump is in question too. Let me get the compression numbers and report back, we'll go from there. I appreciate your advice.

jet_dogg I hope you're right, I'm praying. Usually cylinder 5-6 go first because of their position in the rear and the heat, but it's cylinder 2-3 chiming off as a misfire. I'm thinking fuel but let me get those numbers and report back tomorrow.

[WestBankM4]

I went ahead and pulled the coil packs, sparkplugs and ran a compression test after the car was up to temperature.

I think I'm in trouble. Pulling the spark plugs, there was oil in the spark plug wells on #2 and #3, the rest were clean.

Numbers are,

Cylinder #1 - 175
Cylinder #2 - 90
Cylinder #3 - 95
Cylinder #4 - 175
Cylinder #5 - 180
Cylinder #6 - 180

Thoughts?

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[Slideways]

Those results seem to indicate a break in the headgasket between cylinder 2 and 3, ugh. How much oil was in the spark plug bore?

[Syfon]

Sorry to hear it's the HG. Not too difficult a job to diy! Maybe time for some head upgrades too

[sapote]

I think I'm in trouble. Pulling the spark plugs, there was oil in the spark plug wells on #2 and #3, the rest were clean.

Oil in #2 and 3 wells is a coincident, as the broken gasket has nothing to do with the oil, unless the detonation cracked the head???

[maupineda]

maybe the ring seals of those plugs have failed, how old were they, but based on your symptoms and the compression test is pretty obvious you have HG failure

[WestBankM4]

Here are photos of the spark plug wells I took,

There was slight oil in 2, 3, and 4 actually. The rest are clean and dry. Thoughts boys?

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[eacmen]

Here are photos of the spark plug wells I took,

There was slight oil in 2, 3, and 4 actually. The rest are clean and dry. Thoughts boys?

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Don’t worry about the oil. Change your valve covergasket and spark plug seals and you should be fine.

The compression test however does say you need a head gasket. Sucks man, sorry.