rb20 compression numbers

[doublejceballos]

Did you try checking the manual for the compression numbers?

If I remember, for the RB26, Nissan says new it should be like 180 and at 127 the engine is due for a rebuilt. I dunno about the RB20 though.

Well Ive been wondering if rb26's are different then rb20's when it comes to compression

was it a cold test or warm test...

make sure it was a warm test because more often then not the cold test turns out LOW numbers...and they mean ****....

try the warm test and then you may get results which are better....

for the difference on my RB26 when i did it....cold test brought up 140....warm brought up 165....thats quite a difference

Well, I dont know how it was done, TSS did it and i wouuld hope that it was done properly since thats their forte. BUt if it runs 130's and one 121 warm that Id say I better second guess purchasing this vehicle.

[love_boost]

I just finished testing my compression in my Gts (RB20DET) and my compression is running 1-130 2-160 3-160 4-160 5-160 6-160. All the 160's are roughly that high, some were a little lower.

i can be wrong but your engine is due, since there is one number thats 30psi lower than the other ones, could mean a headgasket or velve?

i was told by numerous mechanics, people that worked on different nissan motors for years say that it is fine to be that low, as long as all the cylinders are close to the same its okay and normal. to some extent of course, i also had numerous shops in calgary say its fine.

[doublejceballos]

hm........
i could live with all flat at 130
but 121 is pretty low

[dah_hunter]

^^^ Ya i would stay away from 121..

unless the car is rediculous other good value..

[kelaog]

I just finished testing my compression in my Gts (RB20DET) and my compression is running 1-130 2-160 3-160 4-160 5-160 6-160. All the 160's are roughly that high, some were a little lower.

Did you ahve the throttle down to the floor when you were doing the test?

You must make suer you did that for all six cylinders =].

If not it'll be off about 25-30 psi.

And yes Dahhunter you want to stay within about 10 psi of each other

IE: 135,130,125,130,132,134 would be some good numbers. A bit low, but good numbers.

[kelaog]

Do a leak down test and find out.

If it's a headgasket hell that's a pretty easy job on an rb20 . If it's a valve well...it's not too bad, but if you have to rebuild the bottom end I wouldn't buy the car =/

i can be wrong but your engine is due, since there is one number thats 30psi lower than the other ones, could mean a headgasket or velve?

i was told by numerous mechanics, people that worked on different nissan motors for years say that it is fine to be that low, as long as all the cylinders are close to the same its okay and normal. to some extent of course, i also had numerous shops in calgary say its fine.

[doublejceballos]

Did you ahve the throttle down to the floor when you were doing the test?

You must make suer you did that for all six cylinders =].

If not it'll be off about 25-30 psi.

And yes Dahhunter you want to stay within about 10 psi of each other

IE: 135,130,125,130,132,134 would be some good numbers. A bit low, but good numbers.

TSS did I it have no idea how well the test was done, Ill have to ask the guy Im supposed to go and see/drive it this week waiting for the seller to have a free day...Ill ask some q's

Do a leak down test and find out.

If it's a headgasket hell that's a pretty easy job on an rb20 . If it's a valve well...it's not too bad, but if you have to rebuild the bottom end I wouldn't buy the car =/

Thats my biggest concern.
I can live with having to do some top end work, I might end up upgrading some parts anyways, but I need it to last and be reliable untill the fall when the most of the driving is done, and I can think about doing some engine work.

Im going to insist a mechanical inspection so I can go and have the test done before my eyes
how do you do a leak test?
Something I can have the shop do during inspection I guess...

[doublejceballos]

Drove the car again today
Had TSS do compression check.
Apparently last time they did the check it was an old meter that always showed lower numbers, plus it was in shop so it may not have been warmed up
today I drove it there, and they did the test with a new compression meter, and it was warmed up and numbers were 1-6 in order 155, 150, 147, 150 150 150
So i am please.
But I still got to talk the guy down
Bald tires, body problems.
But yeah. Numbers turned out good.

[M13]

Those numbers are good.

Good luck!