Engine knocking

A few more particulars are necessary.
MAKE
MOCDEL
ENGINE |
YEAR
Without any more info the only thing I can say is try changing the KNOCK SENSOR if your rig has one. Most do.

Moved from Forum Technical Support

Without more info, I'd add check the fan clutch and the water pump shaft for loose bearings. It would be helpful to break out whether this is engine spark knock...

Try using premium fuel and see if that helps. Cost more but may be worth it.

2003 Tiffin Allegro Engine is a Workhorse 8.1. Thanks!

Loose, cracked flex plate?

How many miles on the engine. It may be a carbon build up in the heads and is causing pre-ignition. Premium fuel will help.

Have the engine checked for proper timing and advance.

Ken

There are about 60K miles on the engine. The most important thing, I think, is to note that you have to have your foot on the accelerator for the knocking to happen. Also, the knocking is quite loud...certainly not a "tapping" if that means anything too. I can't tell you how much I appreciate your help. I'm female and know nothing, and my mechanic doesn't seem too "in the know" about RV's...so I'm concerned.

I agree with a post above, to start try a full tank of premium fuel. See if that changes anything. If so it is spark knock (preignition, engine ping). Then post back and we can go from there.

Rereading I wonder could the vacuum advance be screwing up as in the vacuum line be collapsing