5# piston low compression PROBLEM, help

[diabloxx14xx14]

I would like to know what can be done to fix a problem with a 88 toyota supra turbo that has low compression on fifth piston. Do i have to replaced the whole engine? or rebuild it to fic the problem, could it be a spark plug problem/spark plug cable problem>?...No black smoke or anytyope of smoke,,The car sells for 700 dollars and since it hasn't sold i might get it for as low as 500 dollars,....anyways is it worth it, how much would it cost me to fix the car? (*about how much) thanks,

btw, i did research on the web but i can't find anything, therefor i came to u guys

[troy]

You sure its not a blown head gasket?

Just thinking with the most common problems for that year.

[Jeeves]

That depends.
1) What ARE the actual compression values (on all Cyls)?
2) Did you try adding a teaspoon full of oil to the cylinder then re-test it? This will test the piston rings. If the compression numbers rise it's a ring failure of some type.
3) If the number does not rise, the only other thing to do is a "leak down" test. This will be able to indicate where exactly the failure is w/o pulling the motor.

A rebuild in most cases solve the problem, but the cost of the rebuild can be upward of $1000 depending on the work required.

Like Troy said, if it's a blown head gasket it could also cause low compression.

Here is some tips on identifying a blown head gasket:

1.) Does youre car use alot of coolant?

2.) Does oil dipstick have any white&yellowish gunk on it? (Rare, indication of coolant in the oil)

2a.) Can you open the radiator cap, look at the coolant and see a rainbow? (More common method if finding oil in the coolant)

3.) Does youre cars exhaust have a sweet smell even running at normal engine temp?

4.) With youre rad cap off, Does youre car have little bubbles happening while idling?

5.) Does the car have issues w/overheating or not supplying heat when you turn the heater on?

These are all common symptoms of a BHG, and I've seen shops take customers on a $2500 joy ride. Now, that's outside the normal realms of cost, but not unheard of.

[diabloxx14xx14]

Well i been reading around and read that if a piston has a low compression of 0 or mow on 2 cylinders then it is likely that it has a head gasket blown but this supra only has a low compresion like 80 instead of 150 (normal right?) not too low. I guess i wont be buying the car, cheap but i dont think i want to do a whole engine over haul, it'll cost me like 400 dollars, I live in san diego, my bro has a mechanic friend in tijuana so it'll be cheaper, but a whole engine overhaul seems too much for me, i'll do a head gasket change but i cant know for sure that it's the head gasket and not the piston and/or piston ring in which case i would need a whole engine overhaul...thanks anyway

[diabloxx14xx14]

btw, if it is a head gasket blown wouldn't it spill out white smoke (i had this problem on my previous supra, and got it fix right away) just wondering, i thouhg that when u blewn a head gasket u'll ALWAYS get white smoke out because water and oil would mix, can u clarify this for me thanks again

[Jeeves]

Nope. I had a blown head gasket on my stock JDM Motor.
[img]http://**********s.com/supra/images/DSC05262.JPG[/img]
[img]http://**********s.com/supra/images/DSC05257.JPG[/img]

I smoked for about 3 seconds on startup, couldn't see any under boost ever. Everyone I talked too thought it was the valve stem seals. As you can tell, it was most definately NOT the valve stem seals. On top of that, I had a compression test around 75 on several cylinders.

Honestly, BHG's can disguise themselves in mannnny forms.

[diabloxx14xx14]

hey hardass why did u have to do a whole engine swap, what happened?..was it piston related or something else, but most importantly does that apply to my problem, ei low compression on piston?...thanks

[Jeeves]

Motors I've gone through:
1) Stock Block - Machined wrong, crankwalked. Bottom End = Dead.
2) JDM Block - Stock JDM Block, Popped the Head Gasket. Replaced HG w/Stocker + ARP Studs @ 85ft-lbs, machined head.
3) JDM Block - See Above. Determined to have excessively low compression ( < 10psi) in Cylinder 1, and low compression in #5. Burnt Valves (overly-lean) found on #1, Detonation/BHG beginning on #5.

I did a swap because my Stock block crankwalked, an unheard of thing in 7M's.

Either way. Yes, a motor swap would solve your problem. But that's a $1000 solution (when you figure in shipping, gaskets, beer, band-aids, etc.) not to mention the clutch that should be done if the motor's out...