2003 XC70 Transmission noise when turned off

[hansenjg]

I recently got this 2003 XC70, 5 cylinder, automatic. Tranny seems OK, but sometimes shifts a little hard. Fluid is not as clean as I'd like, but not too terrible. And I'm always leary of flushing old transmissions that might never have been done (150K on this one).

After I drive the car (especially for long distances), when I turn it off the car makes a short "buzzing" sound (just a few seconds long) periodically over the next 10 minutes or so. I opened the hood and it sounds like it's coming from the transmission. The sound is almost like the sound made by cars with load leveling shock absorbers (if you know what I mean). A short buzz or almost the sound of a small pump coming on for a few seconds. After doing that a few times, it stops. No driveability problems, except the occasional hard shift or downshift.

Any ideas on what my noise is? Do I need to do anything about it? Thanks in advance for your help.

[jimmy57]

The turbo control valve that should be clipped to back corner of air cleaner box is likely your buzz and is normal.

[scot850]

+1 with Jimmy on this. Our '06 does the same.

I can understand the reluctance to flush the tranny, but the symptoms you describe are normal with a fluid change being required. If the previous owner had it serviced at the dealer, it should have been done at 60,000 miles service. There have been a few issues with the 5 speed auto box, but a flush should not be a problem. Do some research on this forum.

Good luck,

Neil.

[hansenjg]

Thanks for the feedback Jimmy and Neil. Glad to hear I don't have a scary tranny problem. Neil, I will take your advice. I agree, my symptoms would indicate a flush would be helpful, but I've heard so many people say "tranny was a little off, flushed it, now dead"! I know I shouldn't be so scared of it!

Thanks to you both!

[vtl]

No flush, google for gibbons method!

[hansenjg]

I saw this method on Youtube I think. I was going to do it, but saw someone below it suggest that simply drianing off the 3 liters that come out of the drain plug at every regular oil change might be just as good. So last week I drained the 3 liters and put in 3 new. Next week I'll do it again. Thereafter at every oil change. I feel good about cleaning the system up without the "shock" of a full blown flush. My wife says she thinks it is already shifting smoother with just the 3L replacement. The old stuff looked pretty bad. I know this will never completely clean the system, but it's gotta be better than nothing.