Compression Test after a number of problems...

[Spyder4g64]

I finally got around to a compression test after running on 3 cylinders for about 3 days.. It doesn't look too pretty.

Starting with cylinder #1 - 170-60-160-170 (Yes it was warm.)

I poured 2 cap fulls of oil into cylinder #2 and then did the compression test again. The results led me to my answer. The compression went from 60 to 90. Bad rings.

I have never pulled a piston out, so any help or pointers would be great.

Tomarrow I plan on taking the head off the car. I'll check back here then...

 

[GORBS88]

I finally got around to a compression test after running on 3 cylinders for about 3 days.. It doesn't look too pretty.

Starting with cylinder #1 - 170-60-160-170 (Yes it was warm.)

I poured 2 cap fulls of oil into cylinder #2 and then did the compression test again. The results led me to my answer. The compression went from 60 to 90. Bad rings.

I have never pulled a piston out, so any help or pointers would be great.

Tomarrow I plan on taking the head off the car. I'll check back here then...

I would do a leak down test just to confirm, but either way sounds like it's got to come apart.

 

[Spyder4g64]

Alright, got the head off. To my surprise, the piston doesn't look bad at all. The edge looks a bit shot peened , but no scoring at all on the cylinder wall. I'm wondering if i really need to remove that piston at all...?

The head on the other hand. One exhaust valve has a chunk missing. Could this be what caused the smoking and the leak of compression?

I will post pictures tomorrow when it's not dark outside.

 

[Spyder4g64]

One other thing.. I'm going to take the head to a machine shop as soon as possible, but is it possible to replace the valves and seats for only one cylinder? or do you have to replace all of them together?

Any tips or advice would be great...

 

[Spyder4g64]

Yeah...

 

[airmail96]

haha, nice. And yes a valve missing a chunk could be the cause of some bad compression and some smoking.

 

[talontd92tsi]

You dont have to change them all, you can change the ones that are fubared.

 

[desolateboosted]

Since the turbo pistons on these cars are dish shaped, adding oil may or may not reach the ring sealing part of the combustion chamber. Therefore I would not completely jump to the conclusion of bad rings since oil is a fluid and will take up space it will increase your compression every time. However in your case that cylinder is awfully low. I would double check the valves in that cylinder.

 

[Spyder4g64]

I am going to just build the head ( - Cams due to $) while it's off the car. I'm going with 2mm o/s SI valves, and the Crower Springs and titanium retainers, Ferrea seals, and of course new seats + a 5-Angle Valve Job.

I took a flashlight to look around the piston, and everything seems to be fine. No scoring on the walls also leads me to believe it was just that valve that was causing the leaks..

I am going to put the head on and get everything into position for another compression test once the head is done, and hopefully that will show me something i want to see...

 

[Spyder4g64]

Well I am still waiting on parts, but i did, however, get the Valves in. Here are some pics I took with my phone (I lost my Digital Camera).

The micrometer is reading 3.6cm for the Intake Valves, and 3.25cm for the Exhaust Valves.





* I don't know if this thread is appropriate for "Bolt-on Tech" any longer. Maybe it can be moved to "Cylinder Head & Short Block"...

 

[Spyder4g64]

All my parts came in today. I took some pictures of everything. I have about ~$800 in parts sitting on my dresser right now..