What causes one or two cylinders in an engine to have less compression then the others causing loss of power?

Question

My friend's car can hardly to up an incline of 25 degrees even with no other passenger than the driver, and he not having to use first gear. You change gears (its standard shift) ath the bottom of the hill, and with enough momentum which should take it up such hill but as you press the accelarator it just crawls and you have to make first gear in time otherwise it will stop and roll back.

Answer 1

It doesn't really matter. Anything that causes compression loss requires pulling the heads off. Then you can check valves, ring gaps and look for signs of a blown head gasket.

Answer 2

If it a high mileage car, the best thing to do would be to start looking for a rebuilt engine. It may be head gasket, valves, or even bad rings, but with a high mileage motor, if you fix one problem(say leaking valves), you may cause other problems(blow rings), in which case you would have been as well off to have gotten a motor to begin with, because you will just have to dump more money into it because you will be tearing it down twice.

Answer 3

I had a car (mazda 626) with the same problem. The head gaskets were shot. After replacing them, the compression did go up but still not high enough. Ended up needed new rings. They were just worn too much.

Answer 4

Valves not seating or rings worn usually. If the two cylinders are side by side it could be a gasket problem.

Answer 5

if there side by side,,on the engine,,it probably has a blown head gasket on those two cylinders for it,,that's what usually causes this to happen on any car,,good luck hope this help,s.

Answer 6

The problem could be a leaking head casket or leaky valves