Hello,
I bought GS300 2006, and since that im dealing with this:
And thats how the exhaust sounds:
It only happens when the engine is hot.
Also when im driving and keeping him under about 50 km/h and less it sounds like this:
Sometimes that sound happens when I brake but rarely. Accelerating even a tiny bit or letting the gas off completly silences that for some time. So basically my driving style now when I have to go 50km/h or less is "accelerating until I hit 50,40 etc - letting the gas off - and repeat" to never hear it.

 

yeah that sounds bad. any error codes? how many miles on your car? checked compression?

 

I had check engine error with too rich air-fuel mixture once but after reseting IT never came back. 275000 km, never checked compression but shouldn't that be connected with bad engine performance and problems with engine start? It's a speed demon for me and never had problem with starting even in -10 C temps. It is smoking white quite a lot though.

 

is it steam coming out the exhaust? have you checked to see if you have coolant in your engine oil?

 

Sounds like a lot of knocking! Maybe rod knock? A rod knock can come and go! You really need to put it on a lift while running, and visually that should help determine whats going on. If its a rod knock, maybe you can get away with dropping the pan, and replacing the worn bearings. Thats the easy bandaid fix! If the crank is damaged then you will need a new engine. What mileage did you change your oil at?

You never know, it could be something stupid like a damaged water pump. Goodluck, hope its an easy fix for you