low compression, what to do?

[SaletOn4Wheels]

Well before I did any upgrade work to my 92 TT I took it up to RameyZ and had a little tune up and compression test done. As it turns out i've got bad compression in cylinder 6 (95psi) all other cylinders are decent (120-130psi). If this were a normal car I would probably have it torn down and begin a re build but the Z is no normal car and Mr. Ramey wants $1800.00 just to pull the motor and diagnose the problem, which he swears is a fried ring. I could afford the pull but then would have no money left over to fix the actual problem. Other than the compression loss, i have a coolant leak from dead center front of the block, and a moderate amount of smoking from the pipes (white) especially heavy when my foot is in it. The car is still running great even with all these symptoms. So here's my dilemma.. Do I say f*** the motor and drive it around while doing other mods (suspension, body and paint, reupholster seats etc.) or should I just park it for the winter and start saving for the motor build? My problem with option 2 is the price is staggering. I priced a build at about $6g, with labor about 10g. What are the chances of the problem not being a fried ring? I've been told by others it could be a blown head gasket or a bent valve.. Mr. Ramey says its a fried ring and bad turbos causing the smoke..

Thanks for any and all help, I really need your opinions and ideas.

[RED_DET]

Stop doing any more mods until you decide how you want to fix the problem. If that means saving up some cash over the winter like you suggested, then so be it. You could also source a low mileage JDM engine from tigerjapanese.com for $950. That would be my suggestion and build that engine to whatever specs you want while still being able to drive the car. If it is low on compression, signs of coolant and smoking, then we can probably say head gasket.

[es.biggs]

Could be a bent valve but that's not likely if the timing belt has always been on right. Unless you abuse the car and bounce it off the rev limiter all the time. You don't strike me as somebody who would do that though lol. Blown head gaskets usually affect more than just one cylinder - adjacent cylinders would typically be low as well, but not always. Did the guy do a wet test (dropping some oil in the cylinder, then testing compression again?) If the compression went back up to spec when there was oil in there, that usually indicates a ring problem, or a cylinder wall problem. I had a problem with my cylinder walls being out of round.

I'm with RED on this one...I would buy a jdm engine and rebuild it, and baby your current one while you can. That way there's no rush, and you can do it the way you want to. Will you being doing the work or will somebody else? If you have some mechanical background then I'd suggest that you do it and just get tech answers from here and Z1 and other online resources. It's not that bad...I just rebuilt mine this summer and I haven't ever rebuilt an engine before (and put it in a car, I did one in school but it stayed in the class)

One thing I found out is there is an almost endless supply of answers. This car has been around for over 20 years, meaning any problem or question you have, someone else has had and solved before, 99% of the time. There's a TON of helpful rebuild and motor pulling links and FAQs and even a guide that shows you step by step how to put the engine back together after it's been stripped down to the block. Pics, torque specs, and everything.

Anyhow, sorry for the book lol.

Ethan

[SaletOn4Wheels]

I don't abuse the car, I in fact only drive it about 3 days a week. And I have some mechanical knowledge but not enough to trust myself to build and swap motors. The 2nd motor idea is quite a possibility, but if my problem is a head gasket or bent valve than that is a quicker and cheaper fix. I just have no way of figuring out if this is the problem without paying for the $1800 pull... I will ask if he did the "wet" test when checking compression.

[es.biggs]

A good mechanic can leakdown test your engine. That will help you diag without pulling the motor. Using the leakdown tester you can inject air into the cylinder while it is at top dead center, maximum compression. When the air is injected, you can watch how fast the air leaks out. Also, you can listen to where the air is leaking - ears on the tailpipe (make sure its the right side) to check for a bent exhaust valve, ears on the dipstick to listen for leakage past the rings, and ears on the intake manifold (one of the balance tube holes would work) to listen for a bent intake valve.

I tried that when I fried my motor and it sounded like air was moving everywhere...it might have been idk lol. But it's worth a try to avoid pulling the motor just to diag it. Thats crazy.

[marty1mc]

I don't abuse the car, I in fact only drive it about 3 days a week. And I have some mechanical knowledge but not enough to trust myself to build and swap motors. The 2nd motor idea is quite a possibility, but if my problem is a head gasket or bent valve than that is a quicker and cheaper fix. I just have no way of figuring out if this is the problem without paying for the $1800 pull... I will ask if he did the "wet" test when checking compression.

Is this guy the only mechanic in your area that is any good? Because his labor rate is damn high. If you calculate his labor @$75/hr, he is charging you 24 hrs labor to just pull the motor. Not sure what book is, but I can pull a motor in under a day, and I don't rush because I am not as young as I once was. I know some can have it out in a couple of hours.

[SaletOn4Wheels]

Yes when it comes to this car, he is the only mechanic around worth a damn.

[es.biggs]

where are you?

This car is hard to work on, but it's not that hard. I'm sure you can find someone decent, who isn't going to rip you off.

[BigTDogg (MA)]

where are you?

This car is hard to work on, but it's not that hard. I'm sure you can find someone decent, who isn't going to rip you off.

2nd. 8 hours max for an engine pull, if it's your first time. That price may be to pull, take off heads, reassemble and reinstall. Otherwise, he's getting ripped off.

OP, for starters, have you poured a teaspoon of motor oil into the #6 spark plug hole and retested compression? If your number goes up, it's your ring. If not, it's your valves, or head gasket.

Do you have coolant in the oil? Does the oil look "milky"?

[SaletOn4Wheels]

I should have said tht but yes the $1800 is for a out tear down and back in, but thats still $1800 with out fixing anything. And no I haven't done any of the compression tests with oil etc and I'm not sure hoe Mr. Ramey did it when he did it either. And no I dont think theres coolant in the oil, last time I changed the oil it didnt look very milky but I guess i could check it again..

[es.biggs]

Well, maybe that is a fair price then. You won't really be paying for diag, because when its all torn apart it would be dumb to put it back in without fixing it haha. When he gets the heads off he will be able to measure everything and inspect the valves so you will be good to go. So get ready for some labor, machine shop, and parts bills out the a**

I would still do the wet compression test before taking the engine out, but it's probably going to need a rebuild anyways.

Good luck bud! If you have Q's post em up!

[SaletOn4Wheels]

Yes I feel its worth it in the long run BUT $1800 would pretty much tap me out...so I'd have the motor out and apart and no $ to fix anything. Back to my original question, knowing what you do, would you buy a 2nd motor and build it slowly?

[es.biggs]

I would. With $1800 you can bore and rebuild the bottom end (pistons, rings, bearings), and do some minor headwork (cut the valves, new stem seals, etc.) and you can replace a lot of hoses, mounts, clutch, and whatever else you might need.

If you can't afford new turbos and you don't know the condition of the turbos you get from the engine you buy, you could reuse your current ones. Of course, it is ideal to replace the turbos while the engine is out.

That seems like your best option though.

[SaletOn4Wheels]

Thank you very much! Keep an eye out for a follow up thread...

[Z-owned]

Why would you even be thinking of getting more mod's, paint etc before fixing the issue? Maint. should always be first before upgrades, power or cosmetic. It sounds like Ramey is giving you a good deal if that includes the pull, tear down etc. Plus he knows what he is talking about when it comes to these cars so I would have to agree it's likely a ring. I am guessing your on stock turbo's as well if you don't have alot of money get them rebuilt or find some used ones that are good, stock turbo's sell for a few hundred bucks generally. As for a rebuild both coz and z1 sell rebuild kits starting at around 1k so not sure where you come up with 6 to 10k if all you want is to get it back on the road reliably I say save the money spent on a jspec engine and just get yours taken care of. Your mod's and paint will be useless if the engine goes unless you just like to stare at the car parked.

[marty1mc]

I should have said tht but yes the $1800 is for a out tear down and back in, but thats still $1800 with out fixing anything. And no I haven't done any of the compression tests with oil etc and I'm not sure hoe Mr. Ramey did it when he did it either. And no I dont think theres coolant in the oil, last time I changed the oil it didnt look very milky but I guess i could check it again..

Knowing that it's a pull, tear down, rebuild and install, $1800 is a good price. I agree on that with Z-owned. I like the items Brett Ramey he has designed for the Z motor. I have a couple of things for my Z that he sells (idler pulley studs and sling). So, it's obvious he understands the motor and even how to improve it's reliability. I would trust him.

I think you need to understand something about your Z. It's not a Honda. The motor is complex and takes skill and patience to repair. The cost isn't determined by your wallet, but by the complexity of this motor. So, the amount of labor he is charging is reasonable to cheap. I wouldn't do that amount of work for $1800. With parts, you are looking at around $2.5k-$3.5k (without turbos). That is a good price for a fresh motor. If you look at Z1 and what their short blocks sell for, you can spend $2800 for just the short block, plus gaskets, plus labor to build the motor and installation. Unfortunately, many buy this car and never consider the amount of money it takes to keep it in good repair. I do all my own work. It's the only way I can afford to keep it and I have a good job.

The only way to avoid this kind of expense is to do the work yourself. If you don't have the expertise, then pay an expert and get the job done right.

[SaletOn4Wheels]

I agree with the fact the Ramey is a Z genious but if I have to pay $1800 to get the motor out, than im broke. If I attempt to pull it and do some work myself i can go ahead and start the build. And for Z Owned, $6g is for what I WANT to put in the car (build pack, injectors, turbos, few other knick knacks) I do understand the complexity of the car and thats why I bought it, I didnt wanna be Joe with a cool 240, I wanted to be me with a rare piece of japanese history/art.

[Z31toZ32]

just wondering what you decided to do? it is a tough situation for sure.

[vulcanrush]

i would do the rebuild, jspec engines could give you the same issues, low compression, etc.

[brandon1985]

i have low compression in my number 1 valve.. i tried new spark plug , a compression test, i blew out the valve to see if it was carbon but it still isnt working.. i pulled the coil and spark plug out and its still firing.. so it looks like a need a valve job.. is it possible it could be anything else?

[t.mcginley.jr]

You mean low compression in number 1 cylinder? And did you make sure to do the compression test with the engine warm and a fully charged battery? if not it will mess up the numbers