Occasionally on freeway driving, I hear high pitch hissing noise which seem to come from under the car. It follows with smell of belt or rubber burning. The transmission seem to work fine - nor problem with gas supply to the engine. The noise seem to diminish at lower speeds (and RPM) at street driving.

Visual Inspection shows no abnormality from under the car. My mechanic suggest the fuel pumps may be the culprit.


Any suggestions please.?

 

I really would appreciate any useful advise.

 

does it change if you turn on off the AC? does it sound different with a full or empty tank of gas?

 

what year is this guy?

 

I haven't tested it under these circumstances. Next time I will try it.

The only way so far I have seen noise go away is when I take my feet off the throttle and let rmp go down to 1000 or so.
As I mentioned before, noise seen to occur only during highway driving.

 

1996. 2.9L 146,000 Miles. I am the Only owner
(The car is in excellent condition and I hate to get rid of it though).

Thanks

 

the lone fuel pump is in the gas tank - should not be the noise

 

At 154000 miles (in past 10 years I have been using only Chevron gas). Is that a good idea to replace it now? - rather then get caught on highway 100 miles from home.

The problem is, the noise starts about 4-5 miles after I start driving. Then when I reduce speed (and rpm) it goes away for a while, then comes back.

Recently I have been noticing that, while driving 60-70 Miles /hr, the tachometer stays at 3300 rpm, then while at steady drive it drops to normal 2600 rpm.
Maybe they are related - I am not sure.

 

I tested it with AC off for few miles. No difference. I always fill up when gage show 1/4 tank. What should I expect driving with near empty tank?.

The problem is, noise generates only during hwy driving.

 

Replaced the pump. While there, also replaced the Drive Belt as well. So far no noise heard.

Thanks www.carparts.com.