Jim Grant's Tech Tips
'94 Ford Ranger, Timing Chain Failure
Q: I have a 94 Ford Ranger with a 3.0 engine. It has 122k miles on it. For the last couple days it lacked power. I was pulling a trailer and I was running about 55 MPH when I heard a pop and engine stopped. I assume I have a broken timing chain. My question is can this also mess up the valves or push rods? I have had several people tell me it could.
- Sam P.
A: It is possible that the valves could have been damaged. But you should know that there is a test that can be performed before disassembling the engine. The test is called a leak down test and in your case, performing this test would be useful before starting any repairs. To perform this test requires a piece of equipment called a leak down tester. The leak down tester applies a metered volume of air into a cylinder to measure the rate of leakage. All cylinders will leak but there is an acceptable amount. If leakage is above a specified amount its an indication of damage or wear. If your timing chain has failed, you will have to remove the valve covers and then the rocker arms to correctly seal each cylinder for testing. Performing a leak down test will allow you to know just what repairs are, or are not needed, to get your truck back on the road.