Ok, I will try to keep this brief and accurate.....

It is a 97 1.8tq, 85k on the clock. have had it since november.

Drove to work today, no problems. Got to work, driving in the parking garage, noticed the car seemed a lot louded than normal. but, it drove like normal.

So. I park, and listen to the engine with hood up. Sound like either something is vibrating very badly, or the valvetrain is about to bust through the top of the engine. But, the car is idling normally, running smoothly. So, I rev the engine up. At about 2-2.5k, the noise completely goes away. I does this a few times, at anything less than 2k, car sounds awful but runs fine, at 2 - 2.5k car runs fine and noise goes away. WTF?

So, I work all day, go to the car, hoping for the best. Same thing is happening. So, I pull out my brass *****, and decide to drive the car. I drive around the garage, seems to drive fine (except for the noises), so I decide to drive it home. Its about 15 miles, mostly highway. Well, since on the highway the car usually runs about 3k rpms, I figure this should work. I drive the car home. The car has no noticable loss of power. The car drives great and sounds normal the whole way home on the highway, nothing out of the ordinary. Of course, as soon as the revs are below 2k, here is the nasty noise. Its really bad sounding.

So, I am about to look closer now. I am just guessing at this point. Loose bracket somewhere? Loose spark plug? what could this be? Ok, I am no noob, and do a lot of work on cars. I have a fair amount of wrenching under my belt, and general knowledge of how things work. i am getting ready to start tearing things apart.

Could this be a possibility: The car needs a timing belt, i was planning on doing this soon. Could the tensioner be going bad, such that at low rpms the timing is off and banging the valvetrain up? And when I rev it the belt tightens up and everything sounds normal? If this was the case, wouldn't the car idle rough and run like crap in the low rpms (which it is not)?

Im really stumped here. Anyone out there had a similar issue? i am getting ready to start taking stuff apart to see what is going on. Any advice or similar experiences would be much welcome at this point. I am hoping changing the t-belt will fix this, but I want to know if anyone has had a similar problem.

The strange thing is that there is no loss of power, the car idles fine, and drives fine, no roughness at all. but it really sounds like the valvetrain is coming through the top of the engine at idle.

Thanks for any input you can give.

Onepoint8tee, if your around this weekend, I might need your help if you might be able to stop by with the vag com and help me troubleshoot. I will pm you later if I see you on. I think you are pretty close to where I live.

thanks everyone! i will post anything I find here later on tonight.

 

maybe be an exhaust leak, or your valves need adjusting

 

I was thinking that, so an exhaust leak could do it? That could be it.............

 

is it coming from your exhaust area at alll??

 

I was thinking that, so an exhaust leak could do it? That could be it.............

 

Ok, I am getting a code now, p1338 - camshaft position sensor, open circuit or short to b+ (bank one)

Any ideas, I am about to search and see what I can find.

 

Ok, Im not finding anything.

I think my timing belt needs replaced, maybe the camshaft sensor as well.

My haynes says that to replace this sensor you need to remove the timing belt, how convenient.

Any other ideas? Its running like **** now, i am afraid to start it again.

looks like a vacation day or two is in order.....

 

by the way, I dont see/hear/feel an exhaust leak. I just hope the valvetrain is not hosed.

 

If it was an exhaust leak it would not go away at higher rpms.

 

What do you guys think?

Do the timing belt and check the camshaft position sensor and hope for the best?

How can I tell if there is valve damage?