Compression test results...do these indicate worn rings?
Thread Starter
Racer
Joined: Aug 2001
Posts: 499
Likes: 0
St. Jude Donor '10
Compression test results...do these indicate worn rings?
#1 185
#2 180
#3 185
#4 180
#5 190
#6 185
#7 187
#8 180
We don't have the equipment to do a leak down test. But these are the results....I was told by another shop that my rings are worn, and that I needed a new engine. I think they were trying to hose me. Thanks to everyone here, that won't happen this time!!!! BTW, this is a continuation of an earlier thread I posted)
#2 180
#3 185
#4 180
#5 190
#6 185
#7 187
#8 180
We don't have the equipment to do a leak down test. But these are the results....I was told by another shop that my rings are worn, and that I needed a new engine. I think they were trying to hose me. Thanks to everyone here, that won't happen this time!!!! BTW, this is a continuation of an earlier thread I posted)
Burning Brakes
Joined: Dec 2000
Posts: 1,023
Likes: 0
From: Marietta, South Carolina, USA
Re: Compression test results...do these indicate worn rings? (ladyinblack)
The cam and the compression will have a lot of effect on the number that you get when you are checking the compression.
I dont know what engine you have, but the numbers dont really look that bad and they look really even to me, I think your rings are ok.
I think a stock engine is about 190 to 210 so that is not to bad, maybe somebody on here can tell you what the right numbers for your engine is if you give more info.
Just my 2 cents
Jay
I dont know what engine you have, but the numbers dont really look that bad and they look really even to me, I think your rings are ok.
I think a stock engine is about 190 to 210 so that is not to bad, maybe somebody on here can tell you what the right numbers for your engine is if you give more info.
Just my 2 cents
Jay
Drifting
Joined: Mar 1999
Posts: 1,931
Likes: 1
From: Norcross GA
Re: Compression test results...do these indicate worn rings? (ladyinblack)
Those numbers don't show an engine that is "wasted". As stated, they are all close, so you don't have a "bad cyl".
As you probably know, it will still run. Run at bad-azz performace,... that would be a judgment call.
Can't say you are being hosed or not. This info seem slike fleeting comments.
Does it burn oil? (Because of rings or Vseals?)
As you probably know, it will still run. Run at bad-azz performace,... that would be a judgment call.
Can't say you are being hosed or not. This info seem slike fleeting comments.
Does it burn oil? (Because of rings or Vseals?)
Burning Brakes
Joined: Feb 2000
Posts: 958
Likes: 1
From: SF Bay area, CA USA
Re: Compression test results...do these indicate worn rings? (ladyinblack)
The easiest way to determine if the rings are worn is to do a compression test with the cylinders dry and then squirt a big shot of motor oil into the cylinders (one at a time) and measure the compression wet. If the compression increases a large amount then you probably have worn rings. The numbers you listed sound pretty good for compression and most importantly they are all fairly even.
Instructor
Joined: Jul 2001
Posts: 198
Likes: 0
Re: Compression test results...do these indicate worn rings? (weekendwrench)
Compression indicated by a compression test is somewhat misleading, it can be influenced by cranking speed etc. the true measure is that they are all nearly the same ( within I believe 15% is the rule of thumb). :seeya
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
Re: Compression test results...do these indicate worn rings? (ladyinblack)
point of reference:
My stock 80K mile 9:1 CR 350 had about 150psi per cyl. Now at 10.5:1 CR with a longer cam, i have about the same as you. My rings are a little worn and my car burns some oil, but i definitely don't need anew engine.
Like someone said above, there are a lot of things that can effect the reading you get during a compression test, but at 180+....it doesn't sound bad.
My stock 80K mile 9:1 CR 350 had about 150psi per cyl. Now at 10.5:1 CR with a longer cam, i have about the same as you. My rings are a little worn and my car burns some oil, but i definitely don't need anew engine.
Like someone said above, there are a lot of things that can effect the reading you get during a compression test, but at 180+....it doesn't sound bad.
Burning Brakes
Joined: Dec 2000
Posts: 1,161
Likes: 0
From: Orangeburg, NY
Re: Compression test results...do these indicate worn rings? (ladyinblack)
The numbers look good, and no real deviations between cylinders. If you are not burning any oil, I wouldn't worry about it.
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Safety Car
Joined: Jun 2000
Posts: 4,870
Likes: 25
From: Long Island, NY
Re: Compression test results...do these indicate worn rings? (ladyinblack)
No smoke, no oil consumption...just a spot or two or the garage floor. Its a 91 with 94,000 miles on it.
Compression numbers look good, sounds like you just have a small oil leak.
Vic
Drifting
Joined: May 2001
Posts: 1,297
Likes: 0
From: Edmond Oklahoma
Re: Compression test results...do these indicate worn rings? (ladyinblack)
I wonder if the 1st shop was going to be willing to at least give you a "reach around" as they pulled your "wasted" motor, put in a "who knows what" and installed your "wasted" motor in one of their cars.
Anyhow, seems your original issue was the failure of the intake manifold gaskets. Was this at the front and/or back or on the sides? If it's the front/back, what was used for the seal? Is it possibe the surfaces weren't prepped properly or improper sealant was used?
For sure I'd make sure the PCV is working. With the motor running, pull the PCV valve out of the valve cover. If you put your finger over the PCV valve, it should have pretty good suction.
In all, I'd bet you are 1 each happy camper.
Mark
Anyhow, seems your original issue was the failure of the intake manifold gaskets. Was this at the front and/or back or on the sides? If it's the front/back, what was used for the seal? Is it possibe the surfaces weren't prepped properly or improper sealant was used?
For sure I'd make sure the PCV is working. With the motor running, pull the PCV valve out of the valve cover. If you put your finger over the PCV valve, it should have pretty good suction.
In all, I'd bet you are 1 each happy camper.
Mark
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: Compression test results...do these indicate worn rings? (ladyinblack)
The compression numbers look fine. You just needed a new mechanic, not a new motor. Get the new mechanic to put in a new PCV valve and make sure the rest of the PCV system is clean. :)
Drifting
Joined: Jun 2000
Posts: 1,765
Likes: 0
From: na
Re: Compression test results...do these indicate worn rings? (AquaMetallic94LT1)
Yes the even compression numbers are good.
Did you take it to a Chevrolet dealer? If you did not that's where I would go next. It sounds like the engine ventilation system but something else could be clogged also.
Did you take it to a Chevrolet dealer? If you did not that's where I would go next. It sounds like the engine ventilation system but something else could be clogged also.
