I have a 1999 Cherokee that I rebuilt the engine on about a year ago. I've changed the oil regularly. After my last oil change I've noticed a tapping noise at cold start ups. The noise goes away after 20-30 seconds.

I've read that it might be a piston slap or a noisy lifter but I'm not sure.

any thoughts?


thanks

 

They all do that.

Or many of them do, anyway, by judging how many people post on that very topic.

Most call it a "dry start". Usually lasts 2-3 seconds. Yours seems too long. Better start looking real hard at the actual oil pressure at startup.

Some say changing to a different brand/viscosity of oil or oil filter brands seemed to help.

But there is no clear consensus on this it seems.

 

Thanks for the reply. Actually it might be like you said or more like 5-10 seconds. I just realized that the tapping noise dissipates quickly.

I will try to do an oil change this weekend. I'm thinking of using 5 QT of Castrol GTX and 1 QT of Lucas engine oil stabilizer.

is that a good idea?

 

It will make some noise untilled the lifters "pump up" when the oil reaches them. This is normal on older engines.

 

Oh, we got into a big discussion about Lucas a couple of weeks ago. The feeling is that it is too thick.

I think a good grade of 10W-30, either conventional or synthetic, and a good oil filter would suffice.

Wix, Mopar, and Mobil 1 are some of the better ones it seems.

Personally, I think it is lifters losing a little of their prime, causing them to clatter against the pushrods a little until they pump up.