Noise when put into D mode

Any chance you can give us a tiny hint as to how the noise sounds?

Tom

 

Let me suggest a couple of tests:

1) apply parking brake - shift between "R" and "N" and "D" and "B"

2) hold with foot brake - shift between "R" and "N" and "D" and "B"

This isolates the vehicle braking system from the mechanically simpler parking brake system. It also lets us map the noise to each transaxle shifter selection.

Bob Wilson

 

Are you sure it's not the brake accumulator pump? That makes a rattling, grumbling sound, and often occurs when you press the brake.

Tom

 

Are you sure, or could it be that you only hear it when stopped? The easiest way to check the brake accumulator noise is to repeatedly press the brake pedal. About every third time you will get the rattling sound from down behind the driver's foot well. The sound should only run for a few seconds. On the other hand, a pressure leak in the brake system can make it run longer or more often.

Tom

 

sounds like the brake accumulator pump.. mine does it just about all the time. some complain about it.. others just live with it. i noticed it really early on.. i'm now at 107k miles with no ill effect... although i did get a brake fail alarm on a long distance trip... but i'll save that for another topic..

 

I don't think so. The OP just ruled that out.

Tom

 

Off hand, this suggests it is some sort of brake system noise. Since it has shown up in 'cold weather,' I would probably start by:

• checking fluid levels
• checking fluid quality - Doug has mentioned many shops have the ability to test for dissolved water in the fluid
• having third party locate sound - with the wheels blocked, open the hood and repeating the test, see if the exact source can be located (maybe at a brake shop?)
• check front and rear brake areas - look for evidence of leaks or abnormal rust patterns
• back-up adjustment - try a series of reverse and hard brake actions to 'tighten up' the rear brake shoes. Then repeat your 'noise test.'

Your testing points to the brake system and pretty much rules out transaxle or engine issues. The best thing is it sounds reproducible so it should be easily resolved.

GOOD LUCK!
Bob Wilson

 

I just wanted to add that I hope the OP keeps us updated on this when he gets the issue resolved.

 

If I may offer a tidbit: I've noticed the same phenomenon but I don't think it is brake related. On a few occasions when it's cold and the engine first starts, while the car is still in park and the engine is idling, the engine idles very roughly. That is, I feel occasional bumps and shakes just like it has a bad ignition miss - although it never throws any codes. Other days it seems to idle very smoothly at first startup. I also notice very low level 'grumbling' sound that occurs only in park, neutral, and reverse. As soon as I put it in drive, the grumbling sound goes away. If I put it back in neutral or park, the grumbling sound comes back.

Again, this only happens once in awhile.... I'd say 10% of the cold starts in the morning.

 

mine does the same thing..i was curious about it and have not been able to find much more out about it ill have to see if my car does this tonight adn see if i cant get some audio/video of it

 

Could it be the Coolant Heat Storage Water Pump?

 

I doubt it highly.. but not sure. From inside the vehicle, it sounds like the noise is coming from the right (passenger) side.