Engine Noise

[avmedco]

1998 Sc400 w/90k miles.

I've had this noise since I got the car with 65K miles. When the car is accelerated under load and you then ease off the throttle then moderately throttle up again there a gurgling/rattling engine noise as if low octane fuel is used. Only happens after agreessive acceration is let off and the throuttle is slightly reapplied to tack along. I always use 92. Changed plugs and did full 60k service on car when I got it. Never went away. Mileage is good, engine codes check good.

I'm having the timing belt done so while they are in there what should they look for? Only other symptom the car's idle in drive seem just a little low.

Any thoughts ideas appreciated.

[djspawn00]

gurging? maybe coolant circulation? rattling? maybe a heat shield?

[arielscar]

Exhaust noise? Bad cat or muffler can give you that noise.

[avmedco]

Definitely not the exhaust. It sounds like the knocking you get with low grade fuel.

[92Lex]

So is it a gurgling sound or a knock? Does it seem to be coming from the engine compartment, cabin or rear end?

[Jevon]

Hey did you ever find out what the noise was b/c I have the same noise on my 93 sc300

1998 Sc400 w/90k miles.

I've had this noise since I got the car with 65K miles. When the car is accelerated under load and you then ease off the throttle then moderately throttle up again there a gurgling/rattling engine noise as if low octane fuel is used. Only happens after agreessive acceration is let off and the throuttle is slightly reapplied to tack along. I always use 92. Changed plugs and did full 60k service on car when I got it. Never went away. Mileage is good, engine codes check good.

I'm having the timing belt done so while they are in there what should they look for? Only other symptom the car's idle in drive seem just a little low.

Any thoughts ideas appreciated.