Tapping from engine when driving

[joebren]

Hello all auto-gurus,

I have a 2001 3.1L V6 SE Grand Prix. Since I bought the car in 2002 it's had a slight ticking noise coming from the engine. It's almost like a valve tapping. For years it's only seemed to happen in cold weather and only until the car warmed up. Once the car was warm the engine sounded fine. Nowadays there is a different story. It makes this tapping noise all the time when driving. When idling it's fine. It has 128000 KM (I'm from Canada) on it and I haven't had any timing belt/chain work done on it. It's had regular oil changes and I run synthetic through it. The noise is awful because the car sounds like a junker. This is misleading because the car has been great to us for the past 5 years. Anyone able to diagnose based on this info (or at least possible problems)?

Thanks.

Cheers!

[GTP Dad]

There are many causes to a tapping noise although the original tapping was probably a lifter that once the engine oil pressure increased and the oil got hotter it went away. The issue you have not is probably a failed or bad lifter. You may have to replace the lifters and adjust the rockers to get the noise to go away. It isn't a hard job to do but you will need some time since it will take about 8 hours. And since you will be removing the lower intake manifold this will be a good time to change the gaskets.

If you remove the valve covers you may be able to find the bad lifter since the push rod may be loose or the valve not moving to full compression on the valve spring when the engine is rotated. Either way you will probably need to replace at least that particular lifter.

Good Luck!

[joebren]

Thanks GTP Dad. I will have a look into that.

Cheers