Hey guys, I have been looking for an LT1/LS1 car and ran up on a 98 Z28 M6 car. The problems is cylinder 4 only has 30psi. The car has 85k miles and a clean carfax. The guy wants $7200 for the car as is. It is at a carlot. Some of the local guys say they could possibly help me out. One guy with a 98Z (running mid 11's ) has 2 sets of valves just laying around that he says I could have/use. He also said he could possibly pull the head for me and put ones of his valves in it (for a little money). I guess worse case is I would have to replace the head, which seem pretty cheap on ebay btw (stock ones).

I found a nice 97 Z28 m6 but I think it would be smarter to go for an LS1 car. Do you guys think I should keep looking or should I investigate into the 98 w/ a burnt valve?

I only have around $8500-$9000 to spend.

 

How do you know it's a burnt valve? I've never heard of LS1's burning valves, but what I have heard (a lot) is bending pushrods, and also the factory springs aren't very heavy, so the guy could have over-revved the motor and floated a valve, which in turn hit a piston and bent the valve.

This is a tough call IMO.....on the one hand, I'd say get the LS1 and fix it, because an LS1 is a better engine than an LT1. BUT, maybe that car has been abused and might have more problems that you aren't aware of yet? Hopefully it would just be that valve problem though, then all would be well?

 

This is the story. This kid was looking at the car. His dad was going to buy it for him. The check engine light came on and they said they thought it was a bad O2 sensor. I guess the kid drove the car, not sure though.

They said that it was running lean. The dealer took it to the shop and found out that cylinder #4 only had 30 psi instead of 110 psi.

He said it misses at idle but runs fine on the highway.

So I guess it is possible if the kid drove the car he over reved it.

Edit: The guy that has the extra valves said he would take EFI Live up there to scan the car with. I was guessing if the Knock sensor isn't reading knock like crazy it is possible it's only a valve right?

 

If you can afford the LS1 and it's insurance, then I think you should get the LS1.

 

you need to look more into "why" the valve was burnt. The only time ive seen LS1s burn a valves is after shooting to much nitrous and leaning out. If that is the case, he could have also caused bottom end damage to the motor which is something you DONT want becaus the motor will have to come out. Where as if he burned some valves just the heads will have to come off. He could have messed up pistons, or burnt piston rings which would cause low psi in those cylinders as well... And its VERY hard to tell if its a valve or piston. I had 0 PSI in two cylinders and all it did to my car was burn big holes in the valves so i got lucky.. It could be both, you could do all that work putting valves in and get the car back together and it not fix the whole problem and then have to tear the whole top end back off and and take the WHOLE motor out and APART to fin a piston which isnt to fun.

Its ALOT of work to pull the heads off to fix a valve though. I doubt someone you just met would want to do something like that for a 'little' money. You have to remove the spark plugs, manifolds, might as well just take the headers and Y pipe off all together, all your sensors, wireing harness, intake, fuel rail, then the heads is simple but some of the back bolts can be pretty tough, serpentine belt, altenator, all that **** infront of the motor, and probabily some stuff im leaving out, but in the end everything comes out but the bare bottom end. Then you also have to spend around $200 in new gaskets, head bolts and fluids alone. It will take some time. If you pull the heads, it will also be a good time to get some better push rods. Scoogin DIggy is where i ordered all my gaskets, head bolts, push rods, an stuff from. Good prices..

 

I just thought about it, they have torque-to-yeild bolts so I would have to replace all of the bolts I take out.

I guess the better thing to do would be buy the 97 Z28, or look around for another cheaper LS1 car.

I probably wouldn't trust the dealers mechanic too much. If I did then I would defently get a warranty.

 

That dealer sounds shadey. Saying "Buy this LS1 for what its worth and ill have a 'mechanic' who does side work fix it for you for a little money'. Is that basicially the case? Id tell him since it dosent run he could sale it to you for cheap as a parts car or something, otherwise have it fixed. There are plenty of 98/99s getting into the 10K and under price range for you to think you have to jump on the first one you come across.