Compression check
CF Junior Member
Joined: Dec 2007
Posts: 31
Likes: 0
RE: Compression check
line
Bro, thats a cylinder head right?? If not, what is it called again?? btw, good research
ORIGINAL: NoBrakes
I am no expert but try this. And good luck
Interpreting Compression Test Results If all cylinders are performing equally and engine performance is acceptable, the engine passes the test.[*]Variations in compression between cylinders should be no more than 20%.[*]When two cylinders next to each other have low compression, a blown head gasket is usually indicated.
[ul][/ul]
A blown head gasket.[*]One or several cylinders with low compression and no apparent pattern of loss often indicates burned exhaust valves.[*]Rough idling is a symptom.[*]At higher rpm, the rough running from the burned valves disappears.
[ul][/ul][align=left]NOTE [/align]On an engine at idle, a burned exhaust valve will cause a dollar bill to be sucked against the end of the exhaust pipe every time the bad cylinder's piston has an intake stroke.
Wet Compression Test If any cylinders auto body part show poor results, perform a wet compression test.[*]Squirt about a tablespoon of oil into each low cylinder.[*]The oil makes a seal around worn rings, boosting the compression reading.[*]When cylinder readings that were low increase to normal during a wet test, a piston ring problem is indicated.
[ul][/ul]
[ul][/ul][align=left]NOTE [/align]Adding too much oil takes up volume and raises compression. When the compression test is completed, install the spark plugs. Be especially careful not to strip the threads on an aluminum cylinder head and use anti-seize compound on the spark plug threads. To more accurately diagnose engine problems, use a cylinder leakage tester to perform a cylinder leakage test on the engine. [align=left]NOTE [/align]A compression test will not tell the condition of oil control rings, only compression rings.
I am no expert but try this. And good luck
Interpreting Compression Test Results If all cylinders are performing equally and engine performance is acceptable, the engine passes the test.[*]Variations in compression between cylinders should be no more than 20%.[*]When two cylinders next to each other have low compression, a blown head gasket is usually indicated.
[ul][/ul]
A blown head gasket.[*]One or several cylinders with low compression and no apparent pattern of loss often indicates burned exhaust valves.[*]Rough idling is a symptom.[*]At higher rpm, the rough running from the burned valves disappears.
[ul][/ul][align=left]NOTE [/align]On an engine at idle, a burned exhaust valve will cause a dollar bill to be sucked against the end of the exhaust pipe every time the bad cylinder's piston has an intake stroke.
Wet Compression Test If any cylinders auto body part show poor results, perform a wet compression test.[*]Squirt about a tablespoon of oil into each low cylinder.[*]The oil makes a seal around worn rings, boosting the compression reading.[*]When cylinder readings that were low increase to normal during a wet test, a piston ring problem is indicated.
[ul][/ul]
[ul][/ul][align=left]NOTE [/align]Adding too much oil takes up volume and raises compression. When the compression test is completed, install the spark plugs. Be especially careful not to strip the threads on an aluminum cylinder head and use anti-seize compound on the spark plug threads. To more accurately diagnose engine problems, use a cylinder leakage tester to perform a cylinder leakage test on the engine. [align=left]NOTE [/align]A compression test will not tell the condition of oil control rings, only compression rings.
CF Beginner
Joined: Apr 2008
Posts: 8
Likes: 0
RE: Compression check
if you want to look at the rod caps and all drop your oil pan. and just look at them. and all so just a little tip. on the cylinder that is reading 120 put a small amount of oil down that cylinder and do the compression test again if it goes up. that is a sign of worn piston rings.
Thread Starter
CF Beginner
Joined: Nov 2007
Posts: 14
Likes: 0
RE: Compression check
Update
We took off the heads bout 2 weeks ago, removed the valves, then took them into my work. There we media blasted the heads and intake manifold, cleaned all the parts in the parts washer after, along with the valves, springs, and retainers.Painted the heads and intake, re-assembled the heads. This past weekend we re-installed everything, new gaskets and seals, got new plugs, started it up, and it runs like new now.
When i drained the oil, it was quite watery, but smelled strong of fuel.
Thats all for now,I wont be home for 2 weeks to get back to 'er so in the meantime,thanks to everyone thats given advice/suggestions, much appreciated
We took off the heads bout 2 weeks ago, removed the valves, then took them into my work. There we media blasted the heads and intake manifold, cleaned all the parts in the parts washer after, along with the valves, springs, and retainers.Painted the heads and intake, re-assembled the heads. This past weekend we re-installed everything, new gaskets and seals, got new plugs, started it up, and it runs like new now.
When i drained the oil, it was quite watery, but smelled strong of fuel.
Thats all for now,I wont be home for 2 weeks to get back to 'er so in the meantime,thanks to everyone thats given advice/suggestions, much appreciated
Thread
Thread Starter
Forum
Replies
Last Post
Rdaniels
Silverado, Sierra & Fullsize Pick-ups
11
Jun 3, 2013 8:19 PM
