Is there anything that could cause comression loss that is a cheap fix?
Dear Car Talk | May 01, 1999
Dear Tom and Ray:
belt turn, there is spark at the spark plug wires, but the engine feels like it's freewheeling. I can actually turn the engine over by hand by pulling on the A/C belt. The
symptom occurred catastrophically on a very cold morning (minus 10 degrees) when my wife tried to start the car. It labored the first time, and then the second time she
tried she got this symptom. It's been like this ever since. What could have happened? -- Joe
TOM: Well, I think you DO have no compression, Joe. And there are two things I can think of (that is, two cheap things) that could cause it catastrophically, as you
describe.
RAY: One is that you have "wash down." That's a secondary symptom of flooding, where so much gas pours into the cylinders that it washes down the film of oil on the
cylinder walls. That prevents the rings from doing their job and maintaining proper compression. And when that happens, you have, what? No compression!
TOM: You can test that theory by squirting a shot of oil into each of the cylinders. Just take off each spark plug and drop a thimbleful of oil into each cylinder. With the
spark plugs still out, crank the engine over for a few seconds. Then replace the plugs, and if the car starts, wash down is your problem.
RAY: If that doesn't work, then my next guess is that your timing belt jumped. If the valve timing has been thrown off, valves can be open when they're supposed to be
closed. And when that happens, you get, what? No compression!
TOM: So start with the oil shots, and if that doesn't work, have the car towed to your mechanic and ask him to check the valve timing. I can't think of any other naturally
occurring phenomenon that would cause a catastrophic loss of compression while sitting in the driveway, Joe.
***
Wait! Don't buy another car before you read Tom and Ray's pamphlet How to Buy a Great Used Car: Things Detroit and Tokyo Don't Want You to Know. To order it,
send $3 and a stamped (55 cents), self-addressed, No. 10 envelope to Used Car, PO Box 6420, Riverton, NJ 08077-6420.
***
?(C) 1999 by Tom and Ray Magliozzi and Doug Berman
Distributed by King Features Syndicate, Inc.
belt turn, there is spark at the spark plug wires, but the engine feels like it's freewheeling. I can actually turn the engine over by hand by pulling on the A/C belt. The
symptom occurred catastrophically on a very cold morning (minus 10 degrees) when my wife tried to start the car. It labored the first time, and then the second time she
tried she got this symptom. It's been like this ever since. What could have happened? -- Joe
TOM: Well, I think you DO have no compression, Joe. And there are two things I can think of (that is, two cheap things) that could cause it catastrophically, as you
describe.
RAY: One is that you have "wash down." That's a secondary symptom of flooding, where so much gas pours into the cylinders that it washes down the film of oil on the
cylinder walls. That prevents the rings from doing their job and maintaining proper compression. And when that happens, you have, what? No compression!
TOM: You can test that theory by squirting a shot of oil into each of the cylinders. Just take off each spark plug and drop a thimbleful of oil into each cylinder. With the
spark plugs still out, crank the engine over for a few seconds. Then replace the plugs, and if the car starts, wash down is your problem.
RAY: If that doesn't work, then my next guess is that your timing belt jumped. If the valve timing has been thrown off, valves can be open when they're supposed to be
closed. And when that happens, you get, what? No compression!
TOM: So start with the oil shots, and if that doesn't work, have the car towed to your mechanic and ask him to check the valve timing. I can't think of any other naturally
occurring phenomenon that would cause a catastrophic loss of compression while sitting in the driveway, Joe.
***
Wait! Don't buy another car before you read Tom and Ray's pamphlet How to Buy a Great Used Car: Things Detroit and Tokyo Don't Want You to Know. To order it,
send $3 and a stamped (55 cents), self-addressed, No. 10 envelope to Used Car, PO Box 6420, Riverton, NJ 08077-6420.
***
?(C) 1999 by Tom and Ray Magliozzi and Doug Berman
Distributed by King Features Syndicate, Inc.
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