E46 rpm fluctuations when driving

[Smac01 12]

Hey guys,

My E46 ('01 325i touring) has a strange quirk - when cruising at a constant speed, the rpms fluctuate every couple of seconds (by about 200rpm).

It does this at various speeds, but when going up hills, it's accompanied from a metallic rattle at the rear.

No codes are being thrown.

I wasn't too nervous until google suggested its the torque converter dying.

http://forum.e46fanatics.com/showthread.ph...&highlight=

Any thoughts or experiences with this?

Edited May 13, 2012 by brunch

[yng_750 247]

would guess as you say its the torque converter

anything else would actually cause the car to lurch slightly

unlikely that it is it could be the odd air bubble making its way through the systems

my first thought would be to check the fluid level and see if it smells funky

[BM WORLD 1283]

yes sounds like torque convertor.

get the trans fluid level checked/changed

with a new filter

[HELLBM 1555]

Time for a manual conversion. (or we can sort torque convertor etc. for you.

Regards Ray

[330iMSport 0]

Does sounds like torque converter. My Passat is currently in pieces having it rebuilt. Not a cheap job if you have to pay someone for it

[Smac01 12]

Thanks guys - the car is up with Ray now.

Here's a video of the RPM drops at cruising speeds (sorry for the unsteady video!)

Will update with the fix once done.

[yng_750 247]

i wonder if someone with the same car can tell us what revs it should sit at

it is possible its trying to go into overdrive or lock up the torque converter but failing

this lowers revs and lowers resistance for better cruising efficiency by effectivly deleting the torque converter

im sure ray will tell you soon enough though

[Smac01 12]

All sorted thanks to HellBM - it was the torque converter.

Once again, thanks Ray!