Help I just picked this car up. I drove it for 2 hours at 75 mph and had no problems with this 3800. After getting home with it I noticed an engine noise when you rev it up. I changed the oil and it made no difference. When the engine is idling you do not tend to hear it. When you increase the rpms from 2000 – 3000 it is very pronounced and sounds like a diesel engine. It appears that the noise is coming from the intake. Oil pressure is about 40 pounds. Please help with some good news. Thanks

Welcome to Bonneville Club! Here are two possibilities. If you are lucky, it could be a bad harmonic balancer (crankshaft pulley) - They are only about $100. The clatter they make can be pretty loud and is usually not as regular in frequency as, say, a rod bearing. But it could also be a rod bearing going out - they do sound like you have described. In that case, you will need to pull the engine and purchase a crank kit for about $200, and then spend another $200 for gaskets and seals. Maybe it'* the HB.

I did look at th HB and everything seemed fine.

Lots of things can make a tap tap tap sound, but many of them typically are loudest or only make noise on start up, like piston slap, balance shaft bearings, or valve train noise. I have a bad piston pin that makes a very light click that is loudest when the oil is thin and hot but comes and goes as it rolls around within the piston boss. Drain the oil and check it very carefully for sparkly stuff. Tapping rod bearings will often produce this kind of debris that can be seen when the oil is drained.

From his description it can't be the HB. They make a clatter, but NOT during accelleration or revving. Only at idle or decell.

I'd get a mechanic'* stethescope on that thing and narrow it down. The noise you describe is rarely good news.

Guys, I listened to it ( I know Dumppicker)the upper intake. Its a very noticable meatlic rattle that sounds like its on the passengers side or maybe in the middle of the intake any rpm above 2000-2500. Its fairly loud. Its not the belt tensioner and its not louder coming out of the oil filler hole but rather sounds like its right inside the upper intake.

It had the upper intake redone because the date is 2003 on the intake and it doesnt seem to be smoking or loosing any coolant..Ideas ?? Thanks

Do PCV valves ever make a noise? It'* right inside the UIM and on the passenger end.

No, not a rattle noise.

Without hearing it myself, it'* impossible to diagnose. Shoot a vid please.

Where you describe may indicate a lifter, but you can't go by that. Sound travels through the engine in odd ways. Anyone that has used a stethescope after initial audible diagnosis will tell you the same thing. And a lifter would still indicate internal damage from a failure.

Could it be a cam problem ? What does a wrist pin sound like ?

My wrist pin sounds lighter than a lifter tick and varies in amplitude from quiet to about as loud as a lifter. It is loud enough that the knock sensors picked it up and retarded my spark advance to the max until I disabled them.