I pose the following question to fellow forum members for no other reason other than my own interest in the opinions of others in my field of work.
I'm currently smack in the middle of a head gasket job on a 1992 C4 Corvette. 157k miles, auto, L98 TPI engine. It originally came in running poorly, missing on cylinders 6 and 8, and while running it would literally chill the intake runners for said cylinders to the point that after 10 minutes of idling they felt like the low-side A/C line during operation.
Long story short, the fuel pressure regulator diaphragm had given up after 30 years, causing fuel to be sucked into the vacuum port for said regulator that just happened to be directly across from the intake runners for cylinders 6 and 8. Gotta love high school physics!
The lower intake gasket was also leaking coolant, so the customer decided to move ahead with my recommended repair: a set of plugs, complete intake reseal, fuel pressure regulator repair, and a coolant flush with oil change. The car ran flawlessly after repairs.
Unfortunately, all was not well. The engine overheated during my test drive, ejecting coolant out the rear of the left head faster than you can say "head gasket". Limped her back to the shop, and confirmed the issue. Coolant leak dead center of the LH cylinder head to block mating point. A quick Google showed that the L98 does indeed tend to eat it's LH head gasket, especially if a lower intake gasket is left unattended to.
The customer elected to have the heads pulled and re-done, against my personal opinion. He got the car cheap, it's nothing special, and he'll be upside down on it no matter which way you look at it. I got the heads off today, and my suspicions were confirmed. There isn't a lick of crosshatch left on the cylinder walls. None. I could shave in them (ok, not that bad) but it looks exactly like a ridden-hard-and-put-away-wet Corvette would. I immediately informed my writer that doing a head job on this engine was pointless, however he and the customer decided to press on. I've been told to "scuff up" the cylinder walls before I put the heads on.... yes, you read that right. "Scuff up". I was adamant that any "scuffing" I could do to a cylinder wall would last about as long as it took the engine to build oil pressure on first start, but that's what I've been told to do.
I have half a mind to just slap the heads on when they come back and call it a day. Why would I waste an hour or more on a meaningless procedure? All this thing has to do is run smooth and cool at this point, beyond that it's on it's own. I said my piece, I was overruled.
What would you do?
I'm currently smack in the middle of a head gasket job on a 1992 C4 Corvette. 157k miles, auto, L98 TPI engine. It originally came in running poorly, missing on cylinders 6 and 8, and while running it would literally chill the intake runners for said cylinders to the point that after 10 minutes of idling they felt like the low-side A/C line during operation.
Long story short, the fuel pressure regulator diaphragm had given up after 30 years, causing fuel to be sucked into the vacuum port for said regulator that just happened to be directly across from the intake runners for cylinders 6 and 8. Gotta love high school physics!
The lower intake gasket was also leaking coolant, so the customer decided to move ahead with my recommended repair: a set of plugs, complete intake reseal, fuel pressure regulator repair, and a coolant flush with oil change. The car ran flawlessly after repairs.
Unfortunately, all was not well. The engine overheated during my test drive, ejecting coolant out the rear of the left head faster than you can say "head gasket". Limped her back to the shop, and confirmed the issue. Coolant leak dead center of the LH cylinder head to block mating point. A quick Google showed that the L98 does indeed tend to eat it's LH head gasket, especially if a lower intake gasket is left unattended to.
The customer elected to have the heads pulled and re-done, against my personal opinion. He got the car cheap, it's nothing special, and he'll be upside down on it no matter which way you look at it. I got the heads off today, and my suspicions were confirmed. There isn't a lick of crosshatch left on the cylinder walls. None. I could shave in them (ok, not that bad) but it looks exactly like a ridden-hard-and-put-away-wet Corvette would. I immediately informed my writer that doing a head job on this engine was pointless, however he and the customer decided to press on. I've been told to "scuff up" the cylinder walls before I put the heads on.... yes, you read that right. "Scuff up". I was adamant that any "scuffing" I could do to a cylinder wall would last about as long as it took the engine to build oil pressure on first start, but that's what I've been told to do.
I have half a mind to just slap the heads on when they come back and call it a day. Why would I waste an hour or more on a meaningless procedure? All this thing has to do is run smooth and cool at this point, beyond that it's on it's own. I said my piece, I was overruled.
What would you do?
