Car Question Please ?

Question

I just bought a 1991 3000GT SL 141,932 miles. New Clutch and new Transmission, 5-Spd. I was wondering what noise is coming from my car. Under heavy acceleration or med acceleration the car sounds like it's hissing/making a psssssssss noise from the engine. I drove it from Atlantic City to the Philadelphia Int Airport. To drop my brother off, and came back, constantly checking the gauges no overheating. It dosen't make it while i'm sitting or idleing barley makes it if i'm reving it to 7rpm(i don't race the car but i'm trying to figure out where this came from.) I have an exhuast leak in two spots but other than that i know of nothing else. Mabey belts of something anyways help is greatly appreciated . Thanks

Answer 1

The leaks in your exhaust due to the preassure at which the air is flowing make a little sort of whistle... I can say this because the preassure of the air in between 3000rpm and 6000rpm is very high and since OEM exhaust have a lot of restrictions the same preassur makes the exhaust gasses try to find another way out and they obviously go through those little holes.

The effort that the engine is doing during idleing and reving on the same place at 7000rpm is nothing compared to when it comes to moving the whole car so more exhaust flows through the pipes.

Answer 2

a hissing sound, you say? maybe a vacuum leak somewhere, like vacuum line or brake booster.

Answer 3

fix the exhaut first. then look for noise..

Answer 4

If you own a 3000gt, check out www.3si.org It is a world wide group of owners. Spend some time reading around the forum. Any question you have will be answered there. Those guys have saved me tons of money and time.

Answer 5

some components that make this noise.

a/c leak... even though you have cold air, it will make that noise.

blow off valve from turbo.

cone shaped intake filter.

and vacuum leaks.

exhaust leaks...hint, hint.