What might the sound be and caused by?

Okay this is an interesting issue I am having with my 2002 kia sadona mini van. Every time I first drive it after it has sat for a good long time (more then 5 hours) when I put it into gear, either D or R i hear a sound from the engine area until I fully accelerate. I can leave the car in park or neutral and rev the engine and don’t hear it. Once the car warms up I never hear it at all. The only time I hear this sound (like a grrrr sound) is when the van is cold and between idle speed and say 5 miles an hour, because as I excellerate the sounds goes away. What might this be?

Possibly transmission - have you check the transmission fluid level? Has it been changed?

If the GRRRR noise is heard only briefly each time, then it is very possible that you are just hearing the ABS self-test. This noise, which varies considerably from one make of car to another, is typically heard on a “cold” start, after driving about 10-30 feet.

If i put it into drive and don’t touch the pedal I will hear the sound, but as soon as i begin to excellerate it goes away and is never heard once the car has been running for a while even at idle. The sound is a little lowder if I am in reverse at idle speed over shifting into R and then backing out of my driveway. Again this only occurs when cold.

Trans fluid is good, it’s a redish color, not sure when it was last changed.

[i] Trans fluid is good, it's a redish color, not sure when it was last changed.[/i]

Being reddish in not a bad sign, but it is not much of a test for the transmission fluid. Since it is a 2002 model and you don’t know when or even if the transmission fluid has ever been changed I would suggest today would be a great day to do it.

It seems many if not all manufactures have written off transmission maintenance as if it was not important. To me the cost of a new transmission is a good reason to change that fluid. Generally I recommend every 30 - 40,000 miles. It will not break the bank and it may save you a lot of money.

It is on my list of to-do’s, but it is second behind the more expensive timing belt replacement. The dealership is telling me NOT to have the pan droped and cleaned and such but to just have the system drained and refilled, while the trans places I call say the only true way to do it right is to drop the pan, change the filter and such. not sure which way i am going to go.