Just curious for those out there that have owned, know of, or work on the 6.2L MPI's if they have a history of eating head gaskets. Got a buddy with one of the earlier ones (July '01) that has a bad head gasket at 500 hours. Thought it had a u-joint knock (engine quiet at idle and at elevated RPM in neutral but had mechanical knock sound under load from right off idle in gear). His mechanic told him bad head gasket and needs valve job. I asked if it was burnt between two cylinders but he doesn't know as mechanic didn't tell him. Oil was clear. I've been around small block Chevy marine engines (5.0's/5.7's) for a long time but not around many of the 6.2's. Just seems unusual to me it ate a head gasket in that few hours.

I've had head gaskets torch between two cylinders on a 389 Tri Power Pontiac but it never produced a knock noise. I guess if it was causing a cylinder to lean out it'd be possible though.

Yeah the reason I asked him where the gasket was bad was that his oil was clean and I'm not sure how if it was leaking around a water passage that it would make it knock. So I was thinking if it was between two cylinders maybe it was cross firing. The knock was not like a spark knock noise. Very mechanical in nature and sounding like it was coming from rear of engine near the transom. That is why our initial thought was u-joints since he pulls his kids tubing all the time. Just wondering if there is something at play here that caused the gasket to go bad if my assumption is correct that it burned between two cylinders. Hopefully he finds out from his mechanic where it was bad.

I have had a headgasket fail from the cylinder to the outboard edge of the block......sounded just like a cracked exhaust manifold.

But this was on a 4.6 ford V8 in a F150.

something sounds fishy here, never heard a head gasket knock...maybe they can..but if it is killing gaskets, need to ck block and heads for straitness, use a high quality gaskets, clean out threads in block, and maybe even new head bolts, all a 6.2 is a 350 block 400 crank...nothing special and not much compression

Typical headgaset issue for the sbc's is because of being overheated. And usually between the two middle cylinders. This is because of the exhaust ports are next to each other here. No water flow causes this area to heat up greater first and will 'eat thru' the 'firing ring'of the headgasket in this area, sometimes will groove this area of the cylinder head too...sometimes the block.... never had one create a knock,but it is possible I guess since the 2 cylinders will be open to 'cross talk'with each other.

^^^^ that is correct and most of the time the sound is like an air --- ( pssssst ) especially when cranking the engine over.


disable fuel and spark --- crank the engine over. Alot of times you can hear a bad head gasket and even a low compression engine.

Finally got more info out of my buddy. It was burnt between two cylinders as well as was ingesting some water. Yeah, the knocking sound is what really threw me off. I'd never heard of that either personally or thru someone else before. I mean it was a very distinct mechanical-sounding knock and only did it once he put it in gear. This thread is for not anyways as I found out from my buddy on Sunday that last year he lost an impeller and got the thing hot as he was blasting music for his teenage kids and didn't hear the alarm. Uh, that would have been nice to know!!!! So now we know the cause. I was mainly concerned something else might have been the culprit. I always want to know root cause, not just fix the symptoms.