Diagnosing a noise when braking

lisa strahle — Wed, 29 Jul 2009 18:31:09 GMT

While applying brakes the engine automatically downshifts,and a mysterious clunking noise occurs,i thought it might be a broken motor mount. Any input would be appreciated!

RE: Diagnosing a noise when braking

curiousOne — Wed, 29 Jul 2009 20:10:41 GMT

If by clunking you mean sort of like a squeel

The breaks under your two front tires should be checked.

Once a year or maybe even sooner, they should be replaced, then they squeel for a while too, and then it becomes a more silent squeel, but they still squeel

RE: Diagnosing a noise when braking

olddad — Thu, 06 Aug 2009 01:22:17 GMT

your problem is puzzling. if the engine is running higher than idle speed (maybe your foot its lightly on the accelateor) and the brakes are applied, some cars will downshift (especially if you are going slow and up hill such as truning into a steep uphill driveway). The clunking could be play in the drive train as the engine revs up. if you can get it to duplicate the problem at will, a good mechanic can probably find the problem.

RE: Diagnosing a noise when braking

Dick P — Tue, 22 Sep 2009 13:10:58 GMT

Not familar with the vehicle I'll venture a few guesses. Most transverse engines have a center motor mount that attaches to the engine top center and the core support (radiator support) In a reverse torque situation this could cause a clunk if worn. (Reverse torque: whenever the transmission is put into reverse or whenever it applies pressure in the oposite direction. A worn part in the drive shaft will do the same thing.

If regular maintenence has been neglected, tune ups especially this, will cause the engine to faulter resulting in a hesitation. This really puts the reverse torque into play. My wife drives a Ford Taurus and keeps track of her gas milage every tank full. If it drops make sure I hear about it. This prevents a lot of serious and costly repairs. There are quite a few neglected parts in our cars of today that are missed. One of the cheapest that can cause big $$ problems is the thermostat. Cars running hot let you know. Cars running cool don't (usually). A lot of people, some mechanics included, think cooler is better. It's not. Just one of the items affected are the pistons and block. When the engine heats up the cylinder expands in all directions making the hole smaller. The piston gets bigger creating the fit the manufacturer wanted. Any thing less causes problems. Oh I said the thermostat was inexpensive, didn't mention the labor involved. Better check, expecially if you are prone to fainting.

I could go on a lot more but I hope what I have written helps enough to point you in the right direction. Dick P