getting compression checked on my engine

[Deadly BlaZe]

i'm getting the compression checked on the engine today, what kind of correct numbers should i be seeing? i would search..but i'm on a 28.8k modem right now so it's kind of hard to do much of anything on it.

 

[SinaiTSi]

For the 1g Turbo
Standard Compression: 164 psi
Service Limit: 121 psi

 

[bbigbrn]

you can search this easily. but ill tell you anyways, the correct should be between 120 and 130 and it can vary on each cylinder.

 

[SinaiTSi]

you can search this easily. but ill tell you anyways, the correct should be between 120 and 130 and it can vary on each cylinder.

Where did you get that from. Since the car is older it will lose compression over time but I'm pretty positive that 120 - 130 would be too low.

 

[Deadly BlaZe]

it turned out to be about 170 psi..is that normal?

 

[DSM MAN]

Ya, you could have carbon build up keeping compression in.

 

[bojanglesracing]

what if you are getting 190 psi

 

[Dream On]

My 92 read 170 across the board. Next time I change the plugs, I think I'm gonna run some seafoam. I hear nothing but good things about it, besides the smoke show.

 

[Deadly BlaZe]

so is 170 normal or not

 

[bojanglesracing]

yes its fine

 

[SinaiTSi]

I think that technically the car's factory compression is at like 165-170 psi. So, if you are at 170, I would only think that it's a good thing. Definitely better than being too low anyways.

 

[SpeedFreak03]

I think that technically the car's factory compression is at like 165-170 psi. So, if you are at 170, I would only think that it's a good thing. Definitely better than being too low anyways.

While that does make sense, "I would only think that it's a good thing", it can be a sign of excessive carbon build-up, which isn't good amd should be cleaned out. Either way, carbon or not, 170 is fine, nothing to worry about there. But too high of a number is a sign of carbon build up and that's not good.

 

[taloneagle]

is 210 good?????????

 

[vintagemuscle]

is 210 good?????????

since your a non turbo the compression of your engine will be higher due to your higher compression pistons.

 

[Splitpi]

According to the shop manual for a 2G 4G63:

Standard value (at engine speed of 250-400 r/min (starter crank speed)): 178 psi
Limit (at engine speed of 250-400 r/min (starter crank speed)): min 133 psi

Also, Measure the compression pressure for all the cylinders and check that the pressure differences of the cyclinders are below the limit. Limit max 14 psi.

If there is a cylinder with compression or a compression difference that is outside the limit, pour a small amount of engine oil through the spark plug hole, and repeat the test.

(1) If the compression increases after oil is added, the cause of the malfuction is a worn or damaged pistion ring and/or cylinder intter surface.
(2) If the compression does not rise after oil is added, the cause is a burnt or defective valve seat or pressure is leaking from the gasket.

 

[lasertim]

My 92 read 170 across the board. Next time I change the plugs, I think I'm gonna run some seafoam. I hear nothing but good things about it, besides the smoke show.

The smoke show is one of the fun things

I would recommend MCCC if you really want to clear the carbon out. Seafoam works pretty good too and so does water.

 

[Boosted Again]

I think that technically the car's factory compression is at like 165-170 psi. So, if you are at 170, I would only think that it's a good thing. Definitely better than being too low anyways.

yes factory is about 165, so being higher than that on a turbo motor means you probaly have a little bit of carbon build up...