? about compression test

[LaN-]

Did a compression test this weekend and these where the results

165 135 150 150

they are all above the min which is good but i've been told if you have more then a 7% diff between them it can cause problems.

i checked my timing belt and its good

not leaking coolent so not the head gasket

what do you think it could be ?? rings, valves ect...

I also have an idle problem, when i rev it up past like 2k it comes down and drops to like 500 rpms or if i'm driving and go to come to a stop it drops to like 4 - 500 rpms then comes back up. SOMETIMES it does stall

 

[liquordrunk]

Did a compression test this weekend and these where the results

165 135 150 150

they are all above the min which is good but i've been told if you have more then a 7% diff between them it can cause problems.

i checked my timing belt and its good

not leaking coolent so not the head gasket

what do you think it could be ?? rings, valves ect...

I also have an idle problem, when i rev it up past like 2k it comes down and drops to like 500 rpms or if i'm driving and go to come to a stop it drops to like 4 - 500 rpms then comes back up. SOMETIMES it does stall

U can try to add a cap full to the 135# cyl and if it goes up then back down ur rings are gone in that cyl..

 

[LaN-]

cap full of what??

sorry newb could you go into more detail

 

[liquordrunk]

cap full of what??

sorry newb could you go into more detail

oil in to the spark plug hole after you take hte plug out.then redo the compression test for that cylinder

 

[Birdoprey]

A cap full of motor oil. This will seal the rings momentarily. If compression jumps up after adding the oil and then goes back down after a bit, then your rings are not sealing well in that cyl. If you don't notice a change, then could be head gasket or valves/seats not sealing...

 

[Hughes]

Well, when my ECU was toasted it idled horribly and I always smelt fuel. When I revved to 2 or 3k it would drop to 500 sputter and die after a few hard idles. Hope this helps, by the way I had full compression also.

 

[LaN-]

alright thanks guys i'll do that and see what happens

also how bad is this ........ is something gonna blow up soon

for example "if its your valve......this this this and this will happen to that and your gonna have to do this blah blah blah"

same thing for rings and such

(i'm trying to learn as much as i can so sorry for asking for so much fine detail)

 

[Hughes]

Everyone learns at one point and time.

No, nothing is going to blow up.

At worst it will be your rings which are expensive and just have to be replaced. You would have to take off the head, but if you don't know what they will do I would consider going to a shop and having it done, they are important.

If it is your ECU you can put that in easily. When you pull your plugs smell the end of it for fuel, if you catch a wiff as I did, then it could well be your ECU. Have you checked to see if you're throwing codes?

 

[LaN-]

i'm running a tad lean but no knock

i think i'm at .85 on the high way at WOT

no codes either

so that explains the rings what about if its a valve

and thanks

 

[Hughes]

Well, if it is a vavle you're going to have to buy a new vavle(s) and replace them. If you have smoke comming out then more than likely you're burning oil via your piston ring. You need to do the oil test and find out if your ring(s) are bad. A valve is the same concept, low compression readings but can be replaced. Just keep testing and see what happens form there.