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Blown head gasket?

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Old Jan 30, 2012 | 09:45 PM
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Rod Knockin''s Avatar
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Default Blown head gasket?

Got a decent amount of coolant in my oil. Looks like a dark milkshake on the dipstick.

Car is a D1 blown car with about 16psi throught the stock heads on a forged LS2/ARP2000 studs and GM MLS gaskets. Tune was spot-on on 180mph plus tuning pulls with 0 KR on 93 octane and lots of meth with 20 deg timing adv and 10.1:1 CR. Bearings sounded fine. Did blow the starter out trying to start it earlier that day, replaced the starter and started right up but idle was very rough and saw lots of blowby from the oil breather/hot to the touch also. Idle smoothed out once the car was warm and the blowby went away. So drove the car around the parking lot and car felt like it was loosing compression.

Pulled the dipstick and bingo! Did a leakdown and first pass failed bad on a few cylinders but second pass for the rings was good.

I think I got detonation from bad gas and blew out the head gasket?

Heads are off and they look good, the gasket has a few spots that look like a little something got threw and one spot that looks burnt around the edge of the cylinder(on the gasket) but no catastrophic failures to the gaskets. Heads look good(no visible cracks) and the head shop said the valve seals look good but he will do a full diagnostic/pressure test on them. Car has NEVER overheated.

Last edited by Rod Knockin'; Jan 30, 2012 at 09:53 PM.
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Old Jan 30, 2012 | 09:51 PM
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Originally Posted by Rod Knockin'
Got a decent amount of coolant in my oil. Looks like a dark milkshake on the dipstick.

Car is a D1 blown car with about 16psi throught the stock heads on a forged LS2/ARP2000 studs and GM MLS gaskets. Tune was spot-on on 180mph plus tuning pulls with 0 KR on 93 octane and lots of meth with 20 deg timing adv and 10.1:1 CR. Bearings sounded fine. Did blow the starter out trying to start it earlier that day, replaced the starter and started right up but idle was very rough and saw lots of blowby from the oil breather/hot to the touch also. Idle smoothed out once the car was warm and the blowby went away. So drove the car around the parking lot and car felt like it was loosing compression.

Pulled the dipstick and bingo!

I think I got detonation from bad gas and blew out the head gasket?
I would also be concerned about a bent rod due to hydrolock when you tried to start the engine.
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Old Jan 30, 2012 | 10:03 PM
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Originally Posted by gotjuice?
I would also be concerned about a bent rod due to hydrolock when you tried to start the engine.
Didn't see any sign of coolant in the cylinder when I pulled the heads. Car sounded fine but felt like it was losing compression going around the parking lot.

Last edited by Rod Knockin'; Jan 30, 2012 at 10:28 PM.
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Old Jan 31, 2012 | 12:14 AM
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If you toasted the starter trying to start it, I would be concerned that there would be other damage. What did the pistons, bores & spark plugs look like ?

Something must have stopped the starter from rotating, broke and then allowed it to start on 7 cylinders when you replaced the starter. I doubt that the head gasket & starter just happened to go bad at the same time.

good luck
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Old Jan 31, 2012 | 09:19 AM
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Originally Posted by Tommy D
If you toasted the starter trying to start it, I would be concerned that there would be other damage. What did the pistons, bores & spark plugs look like ?

Something must have stopped the starter from rotating, broke and then allowed it to start on 7 cylinders when you replaced the starter. I doubt that the head gasket & starter just happened to go bad at the same time.

good luck
The battery died the night before, so maybe trying to start with low voltage may have done the starter in.

I've heard many bent rod, bad bearing, and cracked piston cars before. This car idled rough for a minute and a half maybe then sounded normal. Bores are as smooth as a newborn babies a$$. Pistons are fine, rotated the crank with the heads off and pistons all traveled uniformally to the top of the bores. Zero oil below the car and no codes on the obd2.
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Old Jan 31, 2012 | 09:59 AM
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If your oil is milky you need to check all the connecting rod and crank bearings.
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