Compression Test Results

[gtrboosting]

Hey guys got my compression test results on my Rb26DETT as follows.

176 180 177 155 150 170

There is a diff of 30 between cyl 2 and 5 :S Is it worth throwing on some aftermarket turbo's and power fc etc or does it look like rebuild time?

How long do you guys think the engine might last? Seems to run fine? Thanks!

[gtrboosting]

Hey guys got my compression test results on my Rb26DETT as follows.

176 180 177 155 150 170

There is a diff of 30 between cyl 2 and 5 :S Is it worth throwing on some aftermarket turbo's and power fc etc or does it look like rebuild time?

How long do you guys think the engine might last? Seems to run fine?

Should i get a leakdown test done next? Thanks!

[mad032]

thats not too bad but depends on whats type of power you are looking to produce.

And i would also suggest getting a leakdown test as this way you will know where you stand and where or what to do

[gtrboosting]

ok getting a leakdown and another compression test on tuesday.. ill let you guys know the results!!

[Beer Baron]

I would get the test done again. 180 is very high. and varience of 30psi is not good news at all.

[95SKY]

I would get the test done again. 180 is very high. and varience of 30psi is not good news at all.

Isnt 180 more then new from factory? i thought its meant to be 177 ?

[BNR32t]

Yeah, i would prepare for a rebuild... Or sell the car.

If you wont be power figgers now is your chance. I wouldnt push the engine to much, just run factory boost and she will last a little while longer.

[Beer Baron]

I wouldn't break out the cheque book just yet guys. there are a couple of things that can give incorrect results. I would be happy with 150 in all 6 cylinders as long as it's even. how was the test done? hot? how much time cranking? what type/brand of gauge? how good is the battery? throttle open?

[gtrboosting]

i wasn't there when the test was done but it was done by a reputable performance shop. I'm getting another compression test and leakdown done on tuesday so when i have the results ill post them up! I doubt the engine could be that bad.. the car is standard and runs very well! nice and smooth good pickup and idles perfect

[James_03]

Get the test done again, or better yet read how to do it then do it yourself.

The variance is too big there for that to be still running ok.

[BNR32t]

yeah agreed,

[SiR_RB]

isnt the RB26 170psi stock? so if you got more then 170 in some cylinders, definetly get it checked again

let us know how it went.

[gtrboosting]

the battery isn't very good! if i dont start the car for a couple days it wont start. think i should change the battery before the test?

[dk_fabiosantos]

I have done compression test on my rb25 and the numbers were 180psi,190psi,180psi,180psi,180psi,190psi, I was surprise with the #, then I went to check the fsm and the fsm says factory is 185 maximum and 150psi is minimum for the motor to be good and a difference (I don't remeber exactly right now) but I think was 15psi between them, so I was really surprised and I've checked to see if I had a rb25de turned to rb25det and my motor is for sure a rb25det not tuned to be a (t) so I went to check my cams and apparently they have been changed (new gasket all around the valve covers,I have to open to see what cams do I have still), so I think the best you to do is, do the compression again this time make sure if you have the battery fully charged no spark no fuel and wide open throttle, turn the ignition for about 5 to 7 seconds and make sure your tester is ok too.

This is what I have done, I'm not 100% sure about rb26 but that is what the fsm says to do for my rb25det.

I hope your motor is ok man!

gl!

[gtrboosting]

Thanks for all the comments! ill keep you guys up to date! This time the batt will be fully charged.

[wrxhoon]

Lower comp on 4 and 5 could even be a head gasket . Test again and do a leakdown to pinpoint the comp loss on 4+5.

Is it a re-built engine or stock? Dont forget carbon built up will increase compression.

[Richo]

190psi compression? shit that seems high to me, how about RB20s are they meant to have about the same compression?

[dk_fabiosantos]

If you have a rb20 or rb25 na they have high compression pistons if I'm not wrong.

[gtrboosting]

Hey guys well I am happy to report apparently my engine is fine. Wen't and had another compression test done at a very reputable place and also hot and cold leakdown tests done. Compression was 150 on all 6 cyl and on the leakdown just said "nothin to worry about all less than 10%"

I dunno why it came up with dodgy readings the first time but i'm happy with that result!

Cheers

[R.3.2.G.T.R]

good to hear all is good.. how much did the tests cost?