Hello Forum,
I have one more concern about my 3800. Whenever the temperature gauge reads 200 degrees, my engine begins to make a slapping noise from cylinder 1 or 2. When I drive it cold this doesn't happen, but after a long drive it makes that noise at idle. Is this piston slap or a serious problem? I'll post a video with sound so you can understand my situation.

Thanks
Martin

What weight of oil are you using?

10W-30 Half Synthetic. Stock oil weight

When I rev the engine it goes away or when the temp drops. I had this slap before but it wasn't as noticeable as it is now.

I'm not familiar with the internal configuration of the 3800, so please forgive me if I'm totally incorrect, but is it possible that the noise is being made by the timing chain, or the oil pump?

Still waiting on the vid so diagnosis can be confirmed. The nature of the sound you describe can also describe a harmonic balancer failure as well.

How long has this been happening, and did it suddenly appear, or has it been getting worse and worse?

Sorry for not posting the vid, I was busy with schoolwork. I got a new computer so I'll probably post the sound file later cause I got ALOT of stuff to do. The slapping noise got louder after the head gasket blew. I've had this car for 11 years and that'* the only thing that'* worrying me since I drove it from my house to Tucson and back.

The slap seemed to stop after two trips on the Freeway. I was pushing 65 on the needle and when I stopped at the exit ramp, the slap couldn't be heard. I also took advantage and replaced my heater core which was leaking coolant into the interior. After that, the engine stopped leaking coolant and idled a bit better. I don't know why my 3800 did this, but I'm happy that it'* back to normal.