Worn Piston rings?

Cbussilver01es · Post by **Cbussilver01es** » Fri Aug 13, 2010 10:38 pm

Ive been having problems with my car lately since I have put the turbo on. Ive been having weird Idle problems and now the latest problem Im having is the uncontrollable smoking that the car is doing right now, and the awful sound, that sounds like a Connecting Rod knocking. The idle is really bad and my vacuum is low. I did a compression test with the following results

Cyl 1. 185psi
Cyl 2. 135psi
Cyl 3. 175psi
Cyl 4. 180psi

^All of these results are from a dry Compression Test

Cyl 1. 210psi
Cyl 2. 150psi
Cyl 3. 185psi
Cyl 4. 210-215psi

^These results are after droppin oil in the Plug Tubes.

Now is this a sign of the rings being bad? I really think that this stock bottom end is done for so I think forged will be here sooner than I had wanted. I appreciated the help guys

ZeroChad · Post by **ZeroChad** » Fri Aug 13, 2010 10:59 pm

Sounds like they are shot to me. I don't know any other way besides that, or taking them out to check though.

OB · Post by OB » Fri Aug 13, 2010 11:37 pm

Valve seat/guide wear can also cause compression loss during a test, so rings aren't always the issue. Just something to think about.

Post by **occasional demons** » Sat Aug 14, 2010 7:15 am

Usually doing the oil trick will not improve things if the loss is at the valves. The oil film will help the rings seal better. It is one way to eliminate the valves from the equation.

The best way is a leak down test. But without a good supply of compressed air, it is difficult for the common person to do.

Cbussilver01es · Post by **Cbussilver01es** » Sat Aug 14, 2010 12:02 pm

Yea, I just think that this is a sign that I need to go with a forged bottom end since I have the turbo. I can hear the connecting rod knocking. Ive heard that sound in every single neon I have had, ive gone through 3 motors between 3 neons.

I guess Im just going to have to take the car to someone who knows what they are doing. cause I keep messing something up

fixitmattman · Post by **fixitmattman** » Sat Aug 14, 2010 1:16 pm

Compression numbers will normally go up with wet vs dry as wet always seals much better. In your case the change isn't dramatic enough to say you have worn rings IMO. You definately have issues on cylinder number 2 the difference between cylinders is quite large. Normally any variance of 25% between highest and lowest indicates problems. In a healthy engines I've seen they're all fairly consistant within 10%.

Cbussilver01es · Post by **Cbussilver01es** » Sat Aug 14, 2010 1:59 pm

fixitmattman wrote:Compression numbers will normally go up with wet vs dry as wet always seals much better. In your case the change isn't dramatic enough to say you have worn rings IMO. You definately have issues on cylinder number 2 the difference between cylinders is quite large. Normally any variance of 25% between highest and lowest indicates problems. In a healthy engines I've seen they're all fairly consistant within 10%.

See the only other thing that would make me think its worn rings is the amount of smoke that has been pouring out of the exhaust, some people say worn seals, but I really don't think that is the case. The car constantly smokes at idle, not to mentions the car idles REALLY rough with really low vacuum, but also when I accelerate , shift and hit the gas again nothing but blue/white smoke pours out of the exhaust to the point that I can't see cars behind me because its so dense. I mean its either that or the seals on the turbo have gone bad. Either way there is something seriously wrong with the car because I can hear rod knock.

fixitmattman · Post by **fixitmattman** » Sat Aug 14, 2010 2:21 pm

With the numbers and smoke, I would say you lost the headgasket, failure is in cyl 2.