howling noise

Dear Uli,

       Your howling noise story is very similar to the mysterious noise that plagued me for months.  The source was the throw out bearing.  It had completely failed.

               Warmest regards, Chuck Engles

Here in Arizona, it would be ascribed to chupacabras…

Good luck with the fix!

Rocky

forgot to mention, we extended the ratio of the 5th. gear and herewith new needle bearings and  synchronizing (?) rings. gearbox is ok. the noise was once in a standing position, engine of....

thanks, Uli

@uli posted:

I have replaced nearly all parts of the engine in the last years. include cooling system, water pump etc. Last replace were the bearing of the rear wheels. we hear sometimes at a certain speed a howling noise, which come up and disapear again. It happens once, (standing and not driving) that I turned of the engine and it was heard 2-3 sec. after turning off the engine. So, I think it may by caused by the cooling system, expansion or pressure barrel vessel. any idea what could cause the noise ? the thermostat ?

reg. Uli

I think you are on the right track with the assumption of being cooling / water related! I would try one of the additives for the coolant that rises the boiling temperature…..  “radiator cap” pressure blow by would make that sound…

try a new cap… higher psi rated.. just to pinpoint where it’s coming from..

once you turn the engine off it increases pressure as the water doesn’t move anymore and a hotspot may give you the blow off after a few seconds..

I don’t think a thermostat can make that noise..

yes, will try and come back,

thank you, Uli

I think what cengles was getting at was the throwout bearing in the bell housing.

It can spin with the clutch disk, and could keep spinning for a short while after the engine is shut off if it was in contact with the clutch disc…

But maybe you have checked this…

Rocky