Dorikamu

This is a b18b turbo setup.. with 450 injector, S-AFC
This engine a JE Pro Series 9.2:1 CR Forged Pistons

This is the situation,
When it's idling, it sounds rough. bouncing a little.
When it run in low RPM, it's "knocking"

I checked the spark plug, it's extremely dark (too rich)
I also did a compression test
~150
~140
~120
~160

My mechanic told me, there is something wrong with this engine... it's knocking. Now I am not sure what knocking sounds like, but the engine sounds like ****. If the engine is really knocking, what can be going wrong here?

Dorikamu

someone help

TurbodCX

Well bro,

I hate to say it but i beleive your motor is cashed, if your mechanic says it is knocking, and he is a trust worthy guy, i would trust him.

Also by looking at your Comp. #'s you have a problem in the cylinder with only 120Psi.

I think it is time to tear the motor apart before it gets any worse.

A rough idle can be caused by the large injectors also, and sometimes you can remedy this by turning the idle up just a bit.

HTH
Brian

ekb18c

Any check engine lights?
Looks like the cylinder with 120 psi isn't too good.

Any knocking is bad, really bad.

Next step is do a leak down and see what that shows.

Is this a new engine? Was it running fine before? What mods did you do to it before it started to go bad?

Dorikamu

ok, I just bought this car, the engine came with it. I called the seller and ask him about the 120 psi, and he said it's due to the JE piston.
and the ruff idling is due to the broke tranny.. however when I was testing this, I had the clutch press in - disengaged the engine with the tranny.. I really doubt it's the tranny.

can the ruff idling and knocking be the result of bad tuning?

the problem is.. I have a mechanic do this for me.. if I have to take the engine apart.. it's gonna cost me lots of money


[Modified by chusai, 10:23 AM 3/28/2003]

ekb18c

120 psi is too low compared to the rest of the cylinders. They should be pretty much even all across the board but since one is off track then that cyinder is going bad.

Idle has nothign to do with the tranny.

Rough idling and knocking could be a result of bad tuning.

I would get some money from the seller because he sold you a motor that is on it's way out, or it wouldn't perform as it shoudl be because the comrpession numbers don;t match. Ask your guy to do a leakdown test....

HTH

ahobbs

Just to give you an idea. I have the same compression as you and mine is 150 all the way across. You have a few problems. A good rule of thumb. if the numbers are very close then your cool. If you have numbers that aren't consistant you have a problem that needs to be investigated.

Dorikamu

Colin... once I get the car running(the car doesnt have a tranny now), I will make an appointment to have you guys look at the car (should be sometime next week)...

the seller also claimed that a compression ratio is not accurate on JE pistons? I should do a leak down test instead, is that true?


[Modified by chusai, 10:52 AM 3/28/2003]

ekb18c

That's a false statement!!!!! The numbers should be the around the same thing for all 4 cylinders. If it's around 150 all across then I would assume that the motor has low comp pistons and that would be fine.

Give us a call when you get it up and running and we'll fix it for you.

BoostedSi

I would think compression wouldnt affect the idle unless its under 100psi.

Sounds to me like those 450s arent tuned right. The knocking noise could be a spun rod bearing.

Dorikamu

that's exactly my guess.. but with that 120.... I have to agree with Colin, it's probably on it way out sooner or later

BoostedSi

Not always...u could just have some blowby. I remember the first time i rebuilt my motor with je 9:1 pistons i didnt hone the cylinders out or get them checked. Well to make a long story short, compression came out 110-130 across the board. I didnt really have time to tear it down again(only transportation to school and work) so i just left it and boosted on it for half a year w/ no problems but blowby out the breather

intekragsr

maybe check ignition timing? This helped my idle before my sleeve cracked.