Compression Testing - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

376LS3 · 11-23-2013, 10:34 PM

Hey guys,
I pulled my headers off the other day to take them to get ceramic coated. When I pulled the plugs out, I noticed a good amount of oil on the plug for cylinder 1, and a little bit on 4. I was hoping it would be a valve seal. I took the springs off, and the seals looked good. I replaced them anyway. I wanna do a compression test but since I have most of the engine torn down, is it possible to do a compression test without the rockers on? The only thing I can see going wrong, is the lifters turning sideways if the tray were to drop one. Has anyone done this before? The reason the rockers wont be on is because while they are off Im gonna put my trunion upgrades in, finally. My dad can only come over in the morning to help with the compression test so I wanna get that out of the way, then worry about the rockers. Is this a bad idea? Thanks!

White_SS/RS · 11-23-2013, 11:09 PM

You will need the rocker arms on. A compression test simulates the cylinder pressure generated thoughout the engine cycle. You could do a leak down test though!

Also if you look at the top of the piston if the oil/carbon build up is around the edge of the piston its most likely rings. If its intake valve you should see fairly clean oil on the back side of the valve. How much oil does it use? Any pics??

376LS3 · 11-23-2013, 11:53 PM

I dont have the heads off so I cant see the pistons. Ill prolly end up pulling them to send them off to AI. Just didnt think I was going to do it now. Lol!! Here are some pic of the plug and the hole it came from.....

Nutro · 11-24-2013, 12:03 AM

Damn dude those plugs are oil soaked. You burning any oil?

376LS3 · 11-24-2013, 12:08 AM

Not sure. Its hard to say when I only drive the car twice a month and I only have 300 miles on this oil change. I was REALLY hoping it was a valve seal but like I said, they looked good. I may pull the heads tomorrow and check what WHITE was talking about above. My 418ci maybe happening sooner than expected.

firestone_ss · 11-24-2013, 12:23 AM

the picture seems to show oil on the outside of the cylinder not inside

376LS3 · 11-24-2013, 12:25 AM

I couldnt get the camera to focus on it, but the base of the plug has wet oil on it. Not on the electrode, but on the very bottom.

White_SS/RS · 11-24-2013, 11:54 AM

Do you have the intake off? If you do, look down the port at the back of the intake valve and see if it looks similar in condition to the plugs. How many miles are on the engine?

376LS3 · 11-24-2013, 02:27 PM

Did a compression test and results are pretty inconclusive. Here is what it looks like:
#1 215 @ 5 revs
#3 181 @ 4
#5 212 @ 5
#7 175 @ 4
#2 180 @ 4
#4 175 @ 4
#6 168 @ 4
#8 193 @ 4

Cylinders 1 and 5 shot up quite a bit further than the rest. Once I had completed all cylinders, I went back and redid 1 and 5 and got:
#1 168 @ 4
#5 181 @ 5

What Im thinking is there was oil on top of the piston that was sealing the rings, and after several engine cranks, it cleared out. The engine has 44k on it and the car is the most pampered car out there. Its not abused by any means. The manifold is not off but I am going to take it off to check in the intake valves. Anyone have any feedback? Thanks!

Jmar · 11-24-2013, 03:05 PM

Try squirting a little oil in the spark plug hole and crank the low reading cylinders again. If the reading jumps up it's ring seal.

Or put air pressure in the low cylinders while the rockers are off and check for leaks. If air is coming out the intake or exhaust you have valve problems. If air is coming out the PCV tube it's rings.

Iam Broke · 11-24-2013, 03:23 PM

I had oil on the threads at the top of the plug right by the hex when I changed plugs but the plugs were perfectly clean and white. I suspect when I changed the rocker covers the oil seeped down the outside of the head and pooled around the plugs in the head but I'm not sure. I don't use any oil and the catchcan is collecting water vapor only so I'm at a loss also. Don't know where else it can come from. Are there oil channels through the head that can weep past the head gasket and collect oil at the plugs? Perhaps at 9 psi I'm forcing it out somewhere in the area by the plugs?

Keep us updated.

376LS3 · 11-24-2013, 07:41 PM

I know its not a rocker cover. There was no oil trail going down into the plug. Here are some pics with the manifold off. Im wondering if the head is cracked?

376LS3 · 11-24-2013, 08:36 PM

Could all this be a PCV issue? I was just talking to my dad and looking at the pics, and all the ports are pretty oily. Since the PCV is right behind the throttle body, is it possible cylinder 1 is just getting the grunt of the oil the PCV is ingesting? Im ordering a catch can now. That would be great if thats all this is! But thats just a lot of oil for a PCV system, at 8,000 miles.

iPODFAN11 · 11-24-2013, 08:59 PM

Quote:

Originally Posted by 376LS3

Could all this be a PCV issue? I was just talking to my dad and looking at the pics, and all the ports are pretty oily. Since the PCV is right behind the throttle body, is it possible cylinder 1 is just getting the grunt of the oil the PCV is ingesting? Im ordering a catch can now. That would be great if thats all this is! But thats just a lot of oil for a PCV system, at 8,000 miles.

There was plug fouling/cracking on truck engines prior to 2011.

Quote:

PCV pullover that adds additional oil to the cylinders that can foul out or damage the spark plugs

There was an updated valve cover for the Vortec Gen IV engines. I wonder if this might be what you are experiencing.

11-24-2013, 02:27 PM	#9
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	Did a compression test and results are pretty inconclusive. Here is what it looks like: #1 215 @ 5 revs #3 181 @ 4 #5 212 @ 5 #7 175 @ 4 #2 180 @ 4 #4 175 @ 4 #6 168 @ 4 #8 193 @ 4 Cylinders 1 and 5 shot up quite a bit further than the rest. Once I had completed all cylinders, I went back and redid 1 and 5 and got: #1 168 @ 4 #5 181 @ 5 What Im thinking is there was oil on top of the piston that was sealing the rings, and after several engine cranks, it cleared out. The engine has 44k on it and the car is the most pampered car out there. Its not abused by any means. The manifold is not off but I am going to take it off to check in the intake valves. Anyone have any feedback? Thanks! __________________ 2010 Camaro SS LS3 - No Modz

11-24-2013, 03:23 PM	#11
Iam Broke PHAT B33 Drives: 2012 TF3 Camaro 2SS/RS M6 Join Date: Jun 2012 Location: Dark of the Moon Posts: 1,460 View My Garage	I had oil on the threads at the top of the plug right by the hex when I changed plugs but the plugs were perfectly clean and white. I suspect when I changed the rocker covers the oil seeped down the outside of the head and pooled around the plugs in the head but I'm not sure. I don't use any oil and the catchcan is collecting water vapor only so I'm at a loss also. Don't know where else it can come from. Are there oil channels through the head that can weep past the head gasket and collect oil at the plugs? Perhaps at 9 psi I'm forcing it out somewhere in the area by the plugs? Keep us updated. __________________ Another 1 of 371 '12 T3 LS3 M6's built.

11-24-2013, 07:41 PM	#12
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	I know its not a rocker cover. There was no oil trail going down into the plug. Here are some pics with the manifold off. Im wondering if the head is cracked? Attached Images __________________ 2010 Camaro SS LS3 - No Modz

11-24-2013, 08:36 PM	#13
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	Could all this be a PCV issue? I was just talking to my dad and looking at the pics, and all the ports are pretty oily. Since the PCV is right behind the throttle body, is it possible cylinder 1 is just getting the grunt of the oil the PCV is ingesting? Im ordering a catch can now. That would be great if thats all this is! But thats just a lot of oil for a PCV system, at 8,000 miles. __________________ 2010 Camaro SS LS3 - No Modz

11-23-2013, 10:34 PM	#1
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	Compression Testing Hey guys, I pulled my headers off the other day to take them to get ceramic coated. When I pulled the plugs out, I noticed a good amount of oil on the plug for cylinder 1, and a little bit on 4. I was hoping it would be a valve seal. I took the springs off, and the seals looked good. I replaced them anyway. I wanna do a compression test but since I have most of the engine torn down, is it possible to do a compression test without the rockers on? The only thing I can see going wrong, is the lifters turning sideways if the tray were to drop one. Has anyone done this before? The reason the rockers wont be on is because while they are off Im gonna put my trunion upgrades in, finally. My dad can only come over in the morning to help with the compression test so I wanna get that out of the way, then worry about the rockers. Is this a bad idea? Thanks! __________________ 2010 Camaro SS LS3 - No Modz

11-23-2013, 11:09 PM	#2
White_SS/RS Drives: 14 1LE Join Date: Mar 2013 Location: Spokane, WA Posts: 1,567	You will need the rocker arms on. A compression test simulates the cylinder pressure generated thoughout the engine cycle. You could do a leak down test though! Also if you look at the top of the piston if the oil/carbon build up is around the edge of the piston its most likely rings. If its intake valve you should see fairly clean oil on the back side of the valve. How much oil does it use? Any pics?? __________________ LMS Engineering

11-23-2013, 11:53 PM	#3
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	I dont have the heads off so I cant see the pistons. Ill prolly end up pulling them to send them off to AI. Just didnt think I was going to do it now. Lol!! Here are some pic of the plug and the hole it came from..... Attached Images __________________ 2010 Camaro SS LS3 - No Modz

11-24-2013, 12:03 AM	#4
Nutro Drives: 2011 2SS Synergy Green Join Date: Nov 2011 Location: Austin, Texas Posts: 3,670	Damn dude those plugs are oil soaked. You burning any oil?

11-24-2013, 12:08 AM	#5
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	Not sure. Its hard to say when I only drive the car twice a month and I only have 300 miles on this oil change. I was REALLY hoping it was a valve seal but like I said, they looked good. I may pull the heads tomorrow and check what WHITE was talking about above. My 418ci maybe happening sooner than expected. __________________ 2010 Camaro SS LS3 - No Modz

11-24-2013, 12:23 AM	#6
firestone_ss Drives: 2010 camaro ss Join Date: May 2009 Location: Tacoma WA Posts: 779	the picture seems to show oil on the outside of the cylinder not inside

11-24-2013, 12:25 AM	#7
376LS3 Eh, that'll happen Drives: 2010 2SS Join Date: Apr 2012 Location: Mesa, Arizona Posts: 1,841	I couldnt get the camera to focus on it, but the base of the plug has wet oil on it. Not on the electrode, but on the very bottom. __________________ 2010 Camaro SS LS3 - No Modz

11-24-2013, 11:54 AM	#8
White_SS/RS Drives: 14 1LE Join Date: Mar 2013 Location: Spokane, WA Posts: 1,567	Do you have the intake off? If you do, look down the port at the back of the intake valve and see if it looks similar in condition to the plugs. How many miles are on the engine? __________________ LMS Engineering

11-24-2013, 03:05 PM	#10
Jmar Drives: 2012 LS3 CRM, V8 Healey, Mini Join Date: Jun 2012 Location: MI Posts: 103	Try squirting a little oil in the spark plug hole and crank the low reading cylinders again. If the reading jumps up it's ring seal. Or put air pressure in the low cylinders while the rockers are off and check for leaks. If air is coming out the intake or exhaust you have valve problems. If air is coming out the PCV tube it's rings.