DISI Compression Results

[Tokay444]

What percentage leak did you measure?

[DTKII]

Originally Posted by Tokay444 What percentage leak did you measure?

About 30% 75psi down to 55psi. I'm getting ready to email SPEEDPERF6RMANC3 for a quote on a short block.

[Nliiitend1]

Originally Posted by Nliiitend1 I checked my compression tonight. '08 MS3 with ~49K miles. From left to right, it was: 128 126 127 129 I need to check it again with a different gauge/tester, as I'm not too confident in the accuracy of the one I used. Related thread here: Oil Volume issues...

Finally got around to doing this again with my shiny new compression tester and here are the results (car now has 61,819 miles):

Again, from left to right (with the engine warm):

186
182
189
186

I feel a bit better about those numbers.

[Dano]

shitty tester was shitty

What you can take away from any test is consistency. even low numbers, if they are all in the same ballpark is a good indication the motor is healthy and the gauge is the problem.

[fivefingerdeathpunch]

bumpity bump

did a compression test today. did it how a friend said to do it. dont think the engine was warm by the time i did the test

anyway got from left to right.. 170, 157, 170, 157

one person said thats fine... do you guys agree? i liked the consistency but obviously two are lower than the other two. should i redo with the proper method from the first page?

[himurax13]

Originally Posted by fivefingerdeathpunch bumpity bump did a compression test today. did it how a friend said to do it. dont think the engine was warm by the time i did the test anyway got from left to right.. 170, 157, 170, 157 one person said thats fine... do you guys agree? i liked the consistency but obviously two are lower than the other two. should i redo with the proper method from the first page?

It isn't terrible but you should have done a wet test.

Sent via blown passenger side speakers.

[fivefingerdeathpunch]

Originally Posted by himurax13 It isn't terrible but you should have done a wet test. Sent via blown passenger side speakers.

yeah i shouldve done it exactly as mentioned on the first page but my friend said he knew how to do it so i did what he said haha. i may redo it and do a wet test too if its the same results

[Tokay444]

A compression test doesn't really paint a full picture.
For example, my compression has always been in spec (when I do it by the MSF disi standard testing procedure), but my leakdown shows 31% leak in cyl 3.
If you go to the trouble to do a comp test, do a proper leak test at the same time.

[sidekick]

Originally Posted by Tokay444 A compression test doesn't really paint a full picture. For example, my compression has always been in spec (when I do it by the MSF disi standard testing procedure), but my leakdown shows 31% leak in cyl 3. If you go to the trouble to do a comp test, do a proper leak test at the same time.

What is your compression number on that cylinder? It must be lower. That's a ton of leakage. How high does the gauge read on the first compression stroke when testing that cylinder? A low reading on the first stroke can also indicate issues, even if overall compression numbers are in spec.

[scubasteve711]

Agreed that a comp. test doesn't tell the whole story, but a cylinder that leaks down at 31% is going to have a variance in the comp test....

[Tokay444]

Originally Posted by sidekick What is your compression number on that cylinder? It must be lower. That's a ton of leakage. How high does the gauge read on the first compression stroke when testing that cylinder? A low reading on the first stroke can also indicate issues, even if overall compression numbers are in spec.

Compression at time of leak down was 182-176-178-180.

First pump is 90. Same as the rest.

[sidekick]

Originally Posted by Tokay444 Compression at time of leak down was 182-176-178-180. First pump is 90. Same as the rest.

Something isn't adding up. 30% leakage is significant. Did you find the source of the leakage? Rings, valves?


EDIT: Don't you have an issue with oil in your intact tract? Those compression numbers could be similar to "wet test" numbers if a significant amount of oil is entering your combustion chamber.

[Tokay444]

It's rings. Most likely a broken land. I burn a litre of oil/1000kms.

[sidekick]

Originally Posted by Tokay444 It's rings. Most likely a broken land. I burn a litre of oil/1000kms.

Very interesting findings. Maybe your rings still seal well, but the cracked ringland is the source of the leakage? Any plans for a teardown?

[Tokay444]

Not until after my wedding.

[btstarcher]

Fucking liters....WTF Canada.

[Tokay444]

Litres*

[silvapain]

Originally Posted by Tokay444 Litres*

Quarts*


Sent from my iPhone using Tapatalk 2

[BigRedSpecial]

*Furlongs

[Micha]

Fathoms*

[BigRedSpecial]

My car gets 16 rods to the hogs head, and that's the way I likes it

[Dano]

^^^^ fagots*

[theurgy]

Originally Posted by btstarcher Fucking liters....WTF Canada.

You realize the rest of the world uses the metric system now right?

[btstarcher]

'Merica. Fuck you.

[Tokay444]

Originally Posted by Dano ^^^^ fagots*

faggots*

Originally Posted by silvapain Quarts* Sent from my iPhone using Tapatalk 2

almost.

[Dano]

Originally Posted by Tokay444 faggots*

Thanks for the spelling correction...I knew a faggot would know how to spell it...you fell right into the trap

now rebuild your POS motor already.

[Tokay444]

tarp*

[Dano]

negative...you did in deed fall into my T R A P !

[Tokay444]

i really just want you to wrap me up in your tarp.
baby oil?

[Dano]

hahaha

not right now...maybe later?

[azazelthegreat]

Cylinders 1 3 and 4 were around 180
Cylinder 2 was at 60

Looked for leaks
Hooked my compressor to c2
No air from anywhere

[himurax13]

Originally Posted by azazelthegreat Cylinders 1 3 and 4 were around 180 Cylinder 2 was at 60 Looked for leaks Hooked my compressor to c2 No air from anywhere

How did you look for leaks?

[azazelthegreat]

Originally Posted by himurax13 How did you look for leaks?

w
Air compressor hose where the cylinder 2 plug goes

Listened for air from intake oil cap area abx exaust

Came from intake at first but my friend told me to crank the motor once and it went away.


Going to his house in a few days to redo it just in case

[btstarcher]

I thought that leakdown test required you to be at TDC? Anyway also check around injector seals and dipstick. If it's coming from intake, is that intake valves?

[Dano]

Yes TDC compression stoke otherwise air just goes out the valves.

Tappin

[ms3blackmica]

Checked Compression again @ 73,000 miles yesterday. Motor was warm but not hot.

Still looking good.

203 202 202 205

https://www.youtube.com/watch?featur...&v=h_c66_ZHe4E

[btstarcher]

Originally Posted by ms3blackmica Checked Compression again @ 73,000 miles yesterday. Motor was warm but not hot. Still looking good. 203 202 202 205 https://www.youtube.com/watch?featur...&v=h_c66_ZHe4E

I want to borrow your tester.

[ms3blackmica]

Originally Posted by btstarcher I want to borrow your tester.

I would gladly send it over to you Ben but it isn't mine!

[ArmanRus]

I need to do this. I'm at 102k miles and although she's pulling strong and not burning any oil, I want to for the peace of mind.

[LatinKraze]

2007 106,000 miles
Fully Bolted +BNRs3

119-121-120-121

On two different gauges (HF and O'Rileys). Wet test gave me an extra 2-3 psi. My buddy is letting me borrow a tester where he hits 180 psi. We'll see what his gauge yields and we'll also be doing a leak down