Testing engine - Leakdown, Borescope, compression
04-10-2003, 10:44 PM
#1
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Testing engine - Leakdown, Borescope, compression
On my 86 951, 100k miles.
I just had to play with my new Borescope today. At the same time, I did a compression test. I didn't like the results.
115-115-120-133 cold
120-115-115-120 hot <img border="0" title="" alt="[Eek!]" src="eek.gif" /> (what's with this?..)
My question has to do with the leakdown. If I can connect my air compressor to the compression tester (had a connector), how much air should I put to the cylinders? I can run the compressor for a minute or so and get the pressure down to whatever I need. 10psi? 20psi?
A check of my theorys:
Hissing in oil filler cap = rings
Hissing in intake or exhaust = valves
Bubbling in the coolant = Headgasket ( or crack)
Back to the Borescope. It's a cool tool, but I should have bought the smaller diameter one. It easily fits into the spark plug hole, but the hole is angled to one side of the cylinder and it won't bend around to see the other side of the cylinder walls. This one is just about .4" the other is about .23"
Here's the link if you're wondering what I'm talking about.
<a href="http://www.provision100.com/" target="_blank">http://www.provision100.com/</a>
Here's where I bought it.
<a href="http://store.yahoo.com/bradystools/borescope.html" target="_blank">http://store.yahoo.com/bradystools/borescope.html</a>
What it did tell me is that there is a drop of fluid in the #2 cylinder. Could be gas leaking from the injectors, (But I don't think it would stay there very long). Or water from either a head gasket or leftover from my water injection that I just installed.
Overall the engine is running strong, but doesn't hold the car on a slant as well as it does with my 2nd 86 will hold by just putting the car in gear.
TIA
DanD
I just had to play with my new Borescope today. At the same time, I did a compression test. I didn't like the results.
115-115-120-133 cold
120-115-115-120 hot <img border="0" title="" alt="[Eek!]" src="eek.gif" /> (what's with this?..)
My question has to do with the leakdown. If I can connect my air compressor to the compression tester (had a connector), how much air should I put to the cylinders? I can run the compressor for a minute or so and get the pressure down to whatever I need. 10psi? 20psi?
A check of my theorys:
Hissing in oil filler cap = rings
Hissing in intake or exhaust = valves
Bubbling in the coolant = Headgasket ( or crack)
Back to the Borescope. It's a cool tool, but I should have bought the smaller diameter one. It easily fits into the spark plug hole, but the hole is angled to one side of the cylinder and it won't bend around to see the other side of the cylinder walls. This one is just about .4" the other is about .23"
Here's the link if you're wondering what I'm talking about.
<a href="http://www.provision100.com/" target="_blank">http://www.provision100.com/</a>
Here's where I bought it.
<a href="http://store.yahoo.com/bradystools/borescope.html" target="_blank">http://store.yahoo.com/bradystools/borescope.html</a>
What it did tell me is that there is a drop of fluid in the #2 cylinder. Could be gas leaking from the injectors, (But I don't think it would stay there very long). Or water from either a head gasket or leftover from my water injection that I just installed.
Overall the engine is running strong, but doesn't hold the car on a slant as well as it does with my 2nd 86 will hold by just putting the car in gear.
TIA
DanD
04-10-2003, 10:56 PM
#2
Burning Brakes
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I have the SnapOn leakdown tester, and it needs 100psi to perform the test.
YOur pretty much on with your checks and results.
I have the same scope, its a couple years old but works well. Your right, its a little tight to check the cylinder walls at the top, but I manage to get a good look at everything starting about 1/4 the way down, good enough for scoring checks and fractured rings.
Take Care!
YOur pretty much on with your checks and results.
I have the same scope, its a couple years old but works well. Your right, its a little tight to check the cylinder walls at the top, but I manage to get a good look at everything starting about 1/4 the way down, good enough for scoring checks and fractured rings.
Take Care!
04-11-2003, 01:22 AM
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John,
You put me on the right track. I did some research and found this site for the rest out there. Made my own leakdown tester and will try it out tomorrow.
<a href="http://www.xs11.com/tips/misc/misc3.shtml" target="_blank">http://www.xs11.com/tips/misc/misc3.shtml</a>
Thanks,
Dan
You put me on the right track. I did some research and found this site for the rest out there. Made my own leakdown tester and will try it out tomorrow.
<a href="http://www.xs11.com/tips/misc/misc3.shtml" target="_blank">http://www.xs11.com/tips/misc/misc3.shtml</a>
Thanks,
Dan
