Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

What to do w/a '99 rodeo

my faithful 1999 isuzu rodeo has 182978 miles and now has a decided TAT TAT TAT…" when she’s running. i know its probably fatal but her exterior is perfect and her interior intact but grimey. what should i do? i hate the thought of giving her away i’m not up to dismantling her & selling off piecemeal.

It sounds like it could be “piston slap” or possibly a valve/lifter problem, neither of which is an inexpensive fix. I’d just keep running it until it doesn’t run any more. In the meantime, you could have a trusted mechanic listen to it and try to diagnose the sound.

It’s possible that some “miracle additives” could make the sound go away (though not fix the underlying problem). For example, you could try adding some Marvel Mystery Oil or other “top end” lubricant to your regular engine oil.

Thank you, but the problem starts with the fact there is no “trusted mechanic” in the picture. it’s shady mechanic or money-grubbing, worst-case scenerio dealership.
i KNEW there was a way to stop the noise temporarily. thanks

OK, in that case, it’s time for your own “do-it-yourself” science project. Go to your local auto parts store and get a can of Marvel Mystery Oil. Follow the instructions on the can for adding some to your engine oil.

I haven’t looked at a can in a long time, so I don’t remember what they recommend. But you could probably add up to 1/2 quart or so without needing to drain any oil from the engine. You can Google “marvel mystery oil” and read Q&A’s on their user forum. That should help you out.

Be sure you know where the oil fill cap is, right on top of the engine!

got it!

Hi, I have the 1996 Rodeo in the other posting about my alternator problem. However, your problem is a very comonon problem with Isuzu’s. Unless the engines are totally different, you have HLA’s…Hydraulic Lash Adjuster. Think of it as a sponge which sucks up oil to expand and take up the slop like old fashioned mechanical springs did for rocker arms and pushrods. the HLA’s get covered with gunk, and no longer act like a spring and you end up with the tap tap tap that a lot of Rodeos get. I’ve had it for years and other than the alterator, the engine is still running great with tap tap tap…at 188k. it comes and goes. I read of this trick online and it works OK. drain your oil, refill with tranny fluid, run for 200 miles and the tranny fluid acts as a detergent and cleans the HLA’s. then change your oil again, maybe twice. It seems to always help keep them quiet for a while, but because the HLA is a poor design IMO, it’s bound to keep happening over and over. Careful not to run too many miles on tranny fluid…overheating could cause you bigger problems…I’ve heard. Izusu wanted $3500 to replace the HLA’s, and there are a LOT of them. 36 or so. Good luck!