Hi - My 1995 b2500 had slight pinging/knocking when going up hills, higher octane gas didn't help. Installed new wires, plugs, distributor cap, now problem is worse - engine pings even when it switches into a higher gear, and on long steep hills, the knocking almost becomes a banging sound, so I'm afraid some real damage could occur. Haynes manual says that timing is not adjustable on 1995 and newer models, so that's out of the question. I guess I could put all the old parts back in, but then I'd just go back to the lesser problem. There's no pinging on level grade, when the engine isn't under stress it runs beautifully. The engine only has about 200,000km on it, so it should have quite a bit of life left in it. Any ideas? Thanks. Peter

 

First the intake has to come off. Flip it over and you will find a metal plate bolted on. The gasket for this plate leaks and oil gets drawn into the intake and the cylinders. It's the oil vapors in the combustion process that is causing the pinging.

Here is TSB #09-05-00 that describes the issue and the test.
http://dodgeram.info/tsb/2000/09-05-00.htm

 

That is the belly pan gasket? Right?

 

According to the TSB, the technical term is: "intake manifold plenum pan gasket".

 

Thanks very much Alloro, I would never've thought of that. I'll give it a go.

Peter