Confusion with compression test???

[Boost95]

I have a 97 AWD with 160k+. I did a compression test and always would have thought if I had such low numbers on a cylinder I would be getting some smoke out the exhaust or something. The car runs amazing other than needing an Injector in the #1 cylinder. Heres how the test went. Compression- #4-200,#3-200,#2-150, #1- 50! The car can sit for 2 days and if I look under it there is not a drop of oil. It doesnt burn any oil and doesnt smoke at all out the exhaust! I just figured for having such low #'s in #1 that it would smoke or run shitty.. Can someone please explain? Thanks for any input.
Mike

 

[Myke Coxlong]

somebody before or you turned up the boost with out the proper fuel set up and most likely burnt something up in that cylinder hence its the furthest from fuel supply

 

[Boost95]

Why doesnt the car smoke at all?

 

[Boost95]

I forgot to post. The car is at stock boost level.

 

[Boost95]

Can I please get some more input???

 

[power=dsm]

redo the test. It seems like u have carbon build up, also if you really want to know bring you car to get a leakdown test and then you'll really see whats wrong. A compression test can be very inacreate,due to alot of factors such as the gauge, the car was it fully warmed up maybe some dirt got stucn in the gauge ect.

 

[Boost95]

Yes the car was totally warmed up. I did #1 and got 50PSI then I went and did all the other and came back to one and got 50 again. So the gauge was accurate. I dont understand why the car does not smoke at all or anything. IM confused

 

[91orangeGST]

You probably have a bad valve seal. Do the compression test again only drop a teaspoon of oil in the bad cylinder. If the compression goes up then it is a bad ring or a marked up cylinder wall. If it doesnt raise then it is either a bad valve seal or head gasket.

After I looked at your post again it looks like its a bad head gasket because the two cylinders that have lower compression are next to each other. Do the compression test over with the oil and post how it does! Also 200 compression seems really high for a turbo! new engines from factory have 165 psi

 

[Boost95]

Just did the test over again for kicks. With and w/out oil and results were the same. Heres teh results.

(4) (3) (2) (1)
200 200 150 50

I was also wonderin about those high numbers. Standard was about 178 or so. How are mine at 200?? You would think after having 4 DSM's I would be sick of dumping money into them :thumbdown

 

[PEN15]

I forgot to post. The car is at stock boost level.

Really? Stock boost levels with K&N and 3" turbo back?

Do you have an aftermarket boost gauge?

Sorry to ask. Your profile is not updated.

You might get more relevant help if you update your profile.

 

[Boost95]

Ill update the profiel after this post. What I meant by stock boost was that I did not turn it up. But once you install airflow mods the boost will go up naturally. It is running about 15psi now. And yes I have a boost gauge. Why does my car not smoke at all and run great? I have owned several DSM's and this one runs just as good as my other one.

 

[Boost95]

With it being something so major, why does my car run so damn good and not smoke a bit?

 

[power=dsm]

k do what everyone said, put oil in the cylinder and if the comp doesn't change it's the head or head gasket. But like i said get a leakdown test done and you'll be able to see where you are losing the compression. imo it's the next best thing to taking off the head and checking evrything.

 

[Defiant]

More than plenty of bumps in this road.

Your motor's very tired and due for a rebuild.