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Joined: Aug 2008
Posts: 36
Shade Tree Mechanic
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OP
Shade Tree Mechanic
Joined: Aug 2008
Posts: 36 |
I have a 29 i took a compression test on all the cyclinders starting at the front of the car the #1 92 #2 71 #3 70 #4 90
#5 93 #6 93 if the car is running there is bubbles in the cooling system but no oil if you had to guess would you said head gasket or rings
thanks john vukovich
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Joined: Oct 2009
Posts: 1,294
ChatMaster - 1,000
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ChatMaster - 1,000
Joined: Oct 2009
Posts: 1,294 |
Rings would not make bubbles in the cooling system. Might be head gasket or cracked head.
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Joined: Jul 2005
Posts: 3,192 Likes: 8
ChatMaster - 3,000
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ChatMaster - 3,000
Joined: Jul 2005
Posts: 3,192 Likes: 8 |
Remove the two spark plugs from the low pressure reading cylinders , and see if there is any leakage of coolant into those cylinders. Mechanics now use a fibre optic camera to look into the cylinders for a quick check. Spark plugs are usually rusty also.
JACK
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Joined: Nov 2001
Posts: 19,758 Likes: 64
ChatMaster - 15,000
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ChatMaster - 15,000
Joined: Nov 2001
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Bubbles might also be air drawn in past the shaft on the water pump.
How Sweet the roar of a Chevy four!
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Joined: Feb 2011
Posts: 3,136
ChatMaster - 3,000
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ChatMaster - 3,000
Joined: Feb 2011
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How about doing a "leak down" test on each cylinder?...I suspect head gasket leak or crack...Maybe you'll see bubbles without running the motor...
1947 Fleetmaster Sport Coupe VCCA # 47475
If it's not wearing a Bowtie...It's not properly dressed...!
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Joined: Dec 2001
Posts: 10,379 Likes: 1
Technical Advisor ChatMaster - 10,000
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Technical Advisor ChatMaster - 10,000
Joined: Dec 2001
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As a refresher, give us a summary of doing a "Leak-Down" test.  
RAY Chevradioman http://www.vccacolumbiariverregion.org/1925 Superior K Roadster 1928 Convertible, Sport, Cabriolet 1933 Eagle, Coupe 1941 Master Deluxe 5-Passenger Coupe 1950 Styleline Deluxe 4-Door Sedan 1950 Styleline Deluxe Convertible 2002 Pontiac, Montana, Passenger Van 2014 Impala, 4-Door Sedan, White Diamond, LTZ 2017 Silverado, Double Cab, Z71, 4X4, White, Standard Bed, LTZ If you need a shoulder to cry on, pull off to the side of the road. Death is the number 1 killer in the world.
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Joined: Jul 2005
Posts: 3,192 Likes: 8
ChatMaster - 3,000
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ChatMaster - 3,000
Joined: Jul 2005
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A leak down test on a cylinder is performed by filling the cylinder with a pressure of compressed air through the spark plug hole, with a gauge connected to read the pressure dropping rate. It will determine if the leakage is past the rings, valves or another area( head gasket , cracked head etc) You can hear the air escaping, say in the exhaust or intake manifold if either valve is leaking. Or into the sump if the rings are bad/ worn. See the link. http://autos.yahoo.com/maintain/repairqa/engine/ques057_1.html
JACK
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Joined: Dec 2001
Posts: 301
Backyard Mechanic
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Backyard Mechanic
Joined: Dec 2001
Posts: 301 |
Gday John I have seen the same type of readings on several motors where consecutive cylinders have similar low compression readings and every time the head gasket has blown between the two cylinders, that would be the first place I would look. You will have to remove the head either way regardless of what the problem is, and if the head gasket is ok and the valves are adjusted properly and look ok then it will be lower down. Best of luck Michael
"Never give up" Louis Chevrolet
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