Thread: Another problem...

I hate to be the guy with all the questions, but I guess somebody has to be.

Last night while driving home from work, I stopped at a light with my windows down. It became apparent that there was a rattle coming from the front of the car. I experimented on the rest of the drive, and noticed it went away when I increased the throttle, but still happened when stopped and at idle. I looked under the hood when I got back but didn't notice anything unusual, but it sounded like it was coming from below or behind the engine, not up top. Any thoughts guys? I'll be glad to give more info if you need.

After driving it some more and inspecting, it almost sounds like a lifter problem. Anything thoughts?

Originally Posted by MattGTP04

After driving it some more and inspecting, it almost sounds like a lifter problem. Anything thoughts?

Have you done any top end work on it lately?

None at all. The previous owner didn't either.

Will the noise change speed with throttle? Like if you give it some gas will the noise get louder or faster?

See that's the weird part. I work mostly on small engines so I'm not as good with diagnosing larger engines. But it is a rhythmic rattle at idle, like tick-a-tick. (Sorry lol) but when I increase the throttle it goes away

Check your coolant and your oil level and see where they are. Both make ticking noises when they are extremely low.

Oil is full, and coolant is a little low, but nearly full

Did you check them with a cold engine? Dumb question but still...haha

Haha yeah. Both seem normal.

Hmm. Anything seem weird before you noticed the noise?

No, that's why this is so weird. It seems to get louder as the engine gets warmer though

Well if it was a lifter noise, it would be coming from the top of the motor. Are you sure it's not coming from the top?

It's very possible. It really just sounds internal, but closer to the top

Well looks like it might be time to tear into it and take a look at the LIM

Well actually that's what I would do. Somebody else might chime in and say to try something else before tearing into it. Can you post a video of the noise?

Aren't the 3800 injectors known to be really noisy? Mine are always ticking away like crazy.

I'm not sure if they'd be loud enough to hear with the hood closed and in your car with the windows down though...

Finally got a video of it. It's not the best example though. It's so sporadic. Some days it will be 3x as loud, others it can't be heard at all. Today it was somewhere in between. More on the quiet side for sure. You can start to hear it around 0:40 into the video.

2004 Grand Prix GTP Mystery Sound: http://youtu.be/O7CkiRYoh50

Anybody have any ideas?