A sound like a relief valve blowing off !??

[donnyb Lurker Find all posts View Profile Close donnyb]

Hi fellow Toyota Tragics ,

My 2002 3.4L petrol V6 Prado that Ive owned from new, has developed a strange noise. 167,000klms.

This may be a coincidence, but I first noticed it a little after I had done an auto transmission pan screen and fluid change a month ago. I also changed the diffs and transfer case oils and was very careful with quantities going back in.

The sound is not loud, similar to a relief valve in a pressurised air system just popping off a little. So, just a very short psssht!

It occurs just now and again, as far as I can hear. And seems to come from the driver's side engine bay area, but it comes and goes so quick I cant really place where its happening by ear.

I haven't started to try to investigate the source yet, but I may start with the brake booster area.

Any ideas.... anyone ?

Thank you,

Don

[CoreyTroy Member Find all posts View Profile Close CoreyTroy]

I wonder if there is air in the transmission oil after the change.
Maybe try a few gear changes with the dipstick out, to let any air out that may be trapped.
Other than that, i have no idea.

[pradosteve97 Junior Member Find all posts View Profile Close pradosteve97]

I'd be looking at the brake booster?

[donnyb Lurker Find all posts View Profile Close donnyb]

Thanks Guys ! Will try both places. Don