SS Specific Service Issues/Repairs Service/Repairs specific to the SS. Turbo-Brembo Brakes-2.0 Engine-Limited Slip Differential-Programmable Display-MU3 Transmission

Compression test, piston rings, head gasket

Thread Tools
 
Search this Thread
 
Old 01-21-2023, 01:09 PM
  #1  
Premium Member
Thread Starter
 
hhrumadbruh's Avatar
 
Join Date: 03-17-2012
Location: Bay Area, CA
Posts: 1,004
Compression test, piston rings, head gasket

I've purchased a harbor freight compression tester for $30.

Do I just unplug each coil and one spark plug to check each cylinder?

How hard is it to replace the rings?

If only one cylinder has low compression, should I still swap out rings on the rest?
hhrumadbruh is online now  
Old 01-21-2023, 01:48 PM
  #2  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 7,814
Better to take all the spark plugs out. Are there instructions included with the tester?

If the results are good, then you're good. If there's too much variance, then you'll want to do a cylinder leak down test to determine where the compression is leaking out. https://www.chevyhhr.net/forums/how-...-engine-56053/
RJ_RS_SS_350 is offline  
Old 01-21-2023, 01:56 PM
  #3  
Premium Member
Thread Starter
 
hhrumadbruh's Avatar
 
Join Date: 03-17-2012
Location: Bay Area, CA
Posts: 1,004
I haven't opened the box yet.

Thanks for the link.

I was also suggested it could be turbo related. If all cylinders have good compression, would the turbo be the next place to look? Or could the leak down test tell me if it's the head gasket?

The cloud of smoke only happens after I've given it throttle. But does have some small idle smoke and smell.
hhrumadbruh is online now  
Old 01-21-2023, 03:17 PM
  #4  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 7,814
If the compression is good on all 4 cylinders, that would be good news, the basic engine is in good condition. The turbocharger could be leaking oil, could also be the PCV valve stuck open (there was a lot of sludge in the engine, right? ). After those 2, I can't think of anything else.

But before you'd go after 1 of those, you'd want to be sure it's oil that's getting into the exhaust. Could be coolant. So keep an eye on the fluid levels.
RJ_RS_SS_350 is offline  
Old 01-21-2023, 03:47 PM
  #5  
Senior Member
 
PulpFriction's Avatar
 
Join Date: 12-05-2014
Location: Northern Ohio
Posts: 2,372
Don’t open the box. You can get a loaner from Autozone. (Basically you pay full price for their used loaner and return it for full credit.)

You’re learning a lot with all the work you’re doing; why not invest in on-line access to a real shop manual?

Last edited by PulpFriction; 01-22-2023 at 04:26 PM.
PulpFriction is online now  
Old 01-21-2023, 04:16 PM
  #6  
Premium Member
Thread Starter
 
hhrumadbruh's Avatar
 
Join Date: 03-17-2012
Location: Bay Area, CA
Posts: 1,004
I'll just keep it or say it didn't work. Only $30.

Do you have a link?

First 2 are at 135~psi each. Is this normal?
hhrumadbruh is online now  
Old 01-21-2023, 04:54 PM
  #7  
Moderator
 
donbrew's Avatar
 
Join Date: 01-23-2009
Location: Fredericksburg,VA
Posts: 24,719
HF rarely asks questions on returns.
You have to check all 4; you are looking for less than 15% variation. If 3 are 135 and 1 is 125 you know which one to look at.
donbrew is offline  
Old 01-21-2023, 04:56 PM
  #8  
Premium Member
Thread Starter
 
hhrumadbruh's Avatar
 
Join Date: 03-17-2012
Location: Bay Area, CA
Posts: 1,004
They all measured 130/135 (can't tell on this gauge)
And yes I reset it each time

hhrumadbruh is online now  
Old 01-21-2023, 05:42 PM
  #9  
Moderator
 
donbrew's Avatar
 
Join Date: 01-23-2009
Location: Fredericksburg,VA
Posts: 24,719
Are the plugs oily or steam cleaned or just a nice brown. https://www.mobil.com/en/lubricants/...ck-spark-plugs
donbrew is offline  
Old 01-21-2023, 05:42 PM
  #10  
Moderator
 
RJ_RS_SS_350's Avatar
 
Join Date: 05-01-2014
Location: California
Posts: 7,814
Even with variations in readings if you were to try a different tester, that's pretty low compression. A healthy engine would be around 180, plus or minus. 100 would be bad.

Let's see what the other cylinders say, but I'm guessing you're heading to a leak down test.

Have you tried a "wet" test yet? That's usually good for diagnosing rings.
RJ_RS_SS_350 is offline  


Quick Reply: Compression test, piston rings, head gasket



All times are GMT -5. The time now is 09:37 AM.