Ive just done a compression test on my twin turbo here are my results wondering if good or bad but reading in tech section sounds like my rings are worn let me know what you guys think anyway here are my results. 1) 128 2) 125 3) 135 4) 135 5) 140 6)132 and with a small amount off oil for wet test 1) 150 2) 145 3) 150 4) 150 5) 160 6) 160 let me know what you guys think of the numbers cheers
does it drive ok? those figures, while not great, are at least reasonably even across all 6. you could hold out on the rebuild while you acquire some cash......if its still drivable.
Worn but not worn out..... I would not be pulling your engine down for a rebuild just based on those figures. Your rings are wearing evenly, which is a good sign...... you should determine other factors (valves/bearings/turbos etc) before embarking on a (very expensive) rebuild. If everything else is in fairly good condition, a tt with those compression numbers could still run pretty hard for a while yet. Another 12mths or so will give you time to save up the necessary dollars (lots of them) to do the job properly. If you're going to 'penny pinch' on a rebuild, you may as well not bother in the first place
is that a hot or cold engine test? figures would be ok if it was done on a cold engine compression test should be done on a hot engine
test was done on a operating temperature, it drives fine on boosts 12psi other then my det sensor is throwing code 34 its all good. but if i was to do the rebuild it will be engine,turbos ect as its all 21 years old and needs a refreshing. Do you think it will be safe to drive as its me weekend car i have a daily so only gets driven on weekends.
Also confirm your battery was fully charged and you're using a quality (read accurate) compression tester. Edit: got in while I was typing lol! I'd do a leak down test to verify.
yer had a battery pack on my battery to give it good charge isn't a leak down test by pouring small amount of oil in each pot and doing the test again and if the number rises from a normal test your rings are in fault?
yes what i wrote doesn't mean your engine is fubar. A friend of mine has an R33, had 47PSI on cyl 6 and 110 on cyl 4, the rest were around 150psi and the car ran fine for a few months after.
As everyone else said, the compression numbers are fine as long as they are even. Mine were 130 all around (although i was very low on oil if that makes a difference?) and i'm still making a safe 310rwkw, and driving it every day with no issues
No, a leak down test connects a device with a guage on it to an air compressor and pumps air into the cylinder and gives a read out of 'leakage'. From their you can diagnose by ear where the 'leakage' is, ie rings, exhaust valve or inlet valve. Key thing again is looking for consistency. If all cylinders are around the same then all good. If all are showing 20% and one is showing 40% there's a problem in that cylinder.
Ok thanks guys for the input ;-) going to save up the dollars and do rebuild once i have the money i cant part with my Z even tho it owes me alot of money i love it way to much will continue with weekend cruising ;-)
you dont need to rebuild,.. those figures just mean the engine is old (which it is) it could be fine for years.. ive compression tested many a motor.. only the ones that id say were rooted were the ones that only had 0-50 PSI on 1-2 cylinders id only rebuild it if you plan on upping the power significantly or it fails completely
I wouldn't be surprised... ...if you got a further 100,000k's out of it. Are you burning oil?.... topping up frequently?
Not burning oil but on start up around 15secs after its running its pretty smoky then all clears thats about all. Only did compression test to see what my results would be to be on the safe side as feels like its lost power but i think its because of code 34 as im doing pleneum pull replacing knock sensor good old code 34. Ill save and once i have the founds i will rebuild it as i would like to upgrade turbos ect ;-)
Code 34 isn't generated by the knock sensor - rather it is actually a break on the wiring circuit back to the main harness. Found it on here somewhere - may have actually been Eric's post.
checked my wiring shore enough it was broken fixed it now i have the loving code 55 thanks mate:zlove:
That's great happy to help! So you still going do that plenum pull?? You have to actually remove the lower plenum as well. So how's she going now?? Cheers Matt.
