Why might the check engine light go on in your Isuzu Rodeo and the engine knock while driving and have some trouble starting the car even though you have always used regular gas and the oil level is fine?

Answer 1

Your ignition timing might be advanced too much which would cause knocking as well as the hard starting problem. This could also trigger the engine light to come on so having a competent shop check the ignition timing would be a good place to start.

The answer can depend on the year. What year is it, and does it have a Distibutor or a DIS ignition? If it has a distributor then the hold down could have become loose and the distributor could have turn and advanced the timing. I don't think any of the Isuzu engines used distributors, the 91 and 92 with the Chevy V6 does, the timing is 10 degrees before TDC, you will need a timing light to check this. Put the light on plug wire one and from the driver side look down at the crank with the light pointing at the balancer, and make sure the line is at the 10 degree mark and not moving much at idle. If it moves a lot, then check the distributor, or change the ignition control module in the distributor cap. But if you don't have a distributor then there is a chance the timing chain or belt jumped. I'm pretty sure that the Isuzu engines (93+) had a belt, These belts can break easily or stretch and jump if not changed out every 2 years. Timing chains can last on average ten years.