I have a 1988 Volvo 740 GLE with 286,000 miles which I put all on except 27,000 of those miles. It has been a great car. Approximately 3 years ago, I noticed a grinding noise coming from under the hood (either engine or transmission) when it was cold out (less than 40F) when I first started the car and the car was idling or just started to move. Once the car warmed up, the grinding noise went away. Over the past 3 years, the grinding noise is getting worse to now it even occurs in the summer when it is warm out. There is a slight grinding noise and a slight hesitation when I first start moving even after the car warms up. However, the grinding noise is definitely louder when the car is cold. If I put the car in neutral and slightly depress the accelerator, the grinding noise will go away. Does anyone have any idea what my problem may be? Thanks in advance.

 

Well, this could be many things but I'd go with pullies/accessories/belts area. So, not serious, probably. The question would be what knd of "grinding", which is somewhat general. With these miles it could be something like a P/S pump bearing, or any bearing for that matter. You should just try to eliminate them one by one.