Hello everybody,
I got a real good deal on an '88 GTA 5.7L TPI L98. Just under 80k miles. Great shape. Ran like crap but for the price, couldn't pass up. Had a real bad misfire in engine. I'm not a professional mechanic, but a fair shadetree one. Figured I could troubleshoot the problem and save big on the $$$.

I checked all spark plugs for spark and all sparking just fine. Timing was fine. Performed compression check and results are as follow. Driver side 1-3-5-7: No.1 cyl. was approx 135psi. No.3 and No.5 cyl. was less than 30psi. No.7 cyl. was 140psi. Cylinders 2-4-6-8 all were between 130 and 140psi.

Next test I did was a cylinder leakage test. Very minimum leaking from No.1 cyl. No.3 cyl had 100% leakage. I could hear the air leaking and could not find where it was coming from. Not throttle body, not exhaust pipe, crankcase nope, radiator notta. Where it was coming from was the spark plug hole on number 5 cylinder. Ok, blown head gasket. No problem.

I tear the heads off of car. Sure enough the head gasket is blown clean through number 3 and 5 cylinders. But, there is a small groove in the engine block and the head where the gasket was blown. Looks like it was burnt. The depth of the groove on engine block measures .034" and is about an eighth inch across. Depth of groove on cylinder head is .011" and also an eighth an inch across.

Was no oil in the coolant and no coolant in the oil. No leaking there. My question is, is there any product that could seal this? I heard of block sealers but I'm not blown where they would fix. Any alternatives to major machine shop milling or furnace/flame welding? Don't have a lot of money and looking for a cheaper fix to my problem. I know when I put new gaskets on, it will blow there again. A friend had mentioned copper gaskets and torque bolts 15 to 20 pounds more. I don't like the sounds of that. Any help or info would be greatly appreciated. Thank you.

Sincerely,
Errol

JB Weld. Just jokin. Not sure what to tell you. Good luck, I guess.

Might have more luck asking at an F-body forum.

i guess im not quite clear on where your talking about, post a pic...

The correct fix is not easy, but can be done. You can have a machine shop shave both block and head (actually called "edcking" the block IIRC) but unless you install shorter pistons you will have an interference problem big time. You are talking a total of .045" and then some in order to assure that both block and head are true. You will need to source a thicker head gasket or combination of gaskets and possibly a complete head shim, if they make such a thing, in order to keep moving parts (pistons)from hitting stationsry parts (heads) or other moving parts.(valves). Like I said, it can be done. Even the involved pistons can have their heads shaved to compensate but you run risk of losing too much material and could get a blow through of the piston if this engine puts out substantial power.

Now for the easy fix. Grind a groove between cylinders 4 & 6, .034 in block amd .011 in head, reinstall all removed items along with new head gaskets. Install shut-off plates in intake manifolds and exhaust manifolds between center pairs of cylinders. Oh, and toss away those 4 spark plugs and you can even downsize to a much smaller carb or TBI, and you will have yourself an AFM engine that works only in fuel conservation mode.

Good luck.

If you deck it don't forget the intake to head dimensions will change too and you will need thicker gaskets there also.

I'd go for the copper gaskets (if the burn is not too bad) or locate another used block.

Well, I just finished brazing the two spots. Had to get it pretty hot to stick but looks to have took pretty good. Don't see any cracking (Thank God). I'm a welder by trade. Ive done a couple exhaust manifolds before. Going to file it smooth tomorrow and reassemble.

Reason being, I really want to drive the car before I commit to spending any major cash. The car ran so crappy when I took possession, I was never able to really drive the car. Want to make sure car is worth the effort. Running good is one thing. Driving/riding good is another. If deemed "nice ride", then I might go have some fun for as long as the engine will hold. I'm certain the brazing and the new gaskets should hold for at least a test drive.

How I got the car was some guy broke down in front of my house. Tried to be the good guy and help diagnose problem. Could tell he didn't have a clue. After he bought new cap/rotor, wires, coil, and 8 new plugs (of only 6 were changed at the time), and I tried to tell him he didn't need any of it, there was no change in performance. I offered 1000 bucks or get it outta here. Couple days later, he was back with title.

Being it has headers, shift kit, 3" exhaust, maybe a cam, tells me someone has had their fingers in it and I think I should drive it to see as a whole package. Ive rode in some that would, damn near, rattle off the road. All gaskets needed were under 100 bucks. If its a rattlin turd, I will try to sell or trade in. Although, I hope its in as good of shape as it looks. Under 80k, no rust, and the guy was older... Might of gotten lucky... Always like this era TA.

Thanks to everyone who posted in reply. Hope to hear run/drive sometime this weekend. Will post results in a few days.

Brazing cast iron is always tricky. Preheating with a torch is a must, as well as using proper rod. I've welded cracked blocks in the water jacket but never at the head.