Transmission question

[Jbombdizzle]

So first off the transmission is still the same one from 168,000miles ago and the engine was rebuilt about 35,000 ago. So when I start the car I hear this rattle/knocking noise. and when I hit the gas its starts doing it even more and it does it the whole time im driving but once I get past third and 2k rpms it goes out but its still somewhat there. It sounds like it could be the torque converter, because the transmisson isn't slipping really only a little in the begining when I first get going. So would you think its the torque converter? and where can I check the transmisson fluid for gunck?

[Jbombdizzle]

anyone??

[jmenacker]

and when I hit the gas its starts doing it even more

Does the rattle knock noise occur only when the car is in motion?

where can I check the transmisson fluid for gunck?

With the transmission fully warm (approx. 15 miles of driving), park the car on a level surface. Put the transmission in park but leave the engine running. Transmission fluid level can then be checked using the yellow dipstick. The trans fluid on the dipstick should be bright red. If the fluid is dark red or smells burnt, then the transmission may be on its way out.

It's not too difficult to drain the transmission fluid and change the filter. There is a hex head drain bolt on the bottom of the transmission pan to drain the fluid. A half dozen or so bolts with clamps hold the pan to the trans body. The biggest issue is loosening the filler tube compression nut. I took my car to a friendly mechanic to break the compression nut loose and then drove the car back home to complete the fluid/filter change. There are a couple of magnets in the bottom of the pan where detrius can be observed. The filter is fastened to the bottom of the valve body with torx head bolts so make sure some torx drivers are available before getting good and dirty.

Once reassembled the trans fluid goes in via the fill tube. A long, thin neck funnel is indispensible for refilling. I think about 3-1/2 quarts of Dextron III fluid is needed to refill after dropping the pan.

Joe M in WV

[Jbombdizzle]

Does the rattle knock noise occur only when the car is in motion?



With the transmission fully warm (approx. 15 miles of driving), park the car on a level surface. Put the transmission in park but leave the engine running. Transmission fluid level can then be checked using the yellow dipstick. The trans fluid on the dipstick should be bright red. If the fluid is dark red or smells burnt, then the transmission may be on its way out.

It's not too difficult to drain the transmission fluid and change the filter. There is a hex head drain bolt on the bottom of the transmission pan to drain the fluid. A half dozen or so bolts with clamps hold the pan to the trans body. The biggest issue is loosening the filler tube compression nut. I took my car to a friendly mechanic to break the compression nut loose and then drove the car back home to complete the fluid/filter change. There are a couple of magnets in the bottom of the pan where detrius can be observed. The filter is fastened to the bottom of the valve body with torx head bolts so make sure some torx drivers are available before getting good and dirty.

Once reassembled the trans fluid goes in via the fill tube. A long, thin neck funnel is indispensible for refilling. I think about 3-1/2 quarts of Dextron III fluid is needed to refill after dropping the pan.

Joe M in WV

First The rattle is consistent when not in motion, in motion, and out through any of the gears.

So there is a pan on the bottom of the transmission that I can take of and check for stuff? but I have to drain the fluid first? Where is the compression nut at and what do you need to get it undone? sorry to hound you with questions im just curious. if you want you can PM me back. I aprreciate the information. thanks.

[Jbombdizzle]

oh and where is the yellow dipstick?

[jmenacker]

First The rattle is consistent when not in motion, in motion, and out through any of the gears.

So there is a pan on the bottom of the transmission that I can take of and check for stuff? but I have to drain the fluid first? Where is the compression nut at and what do you need to get it undone? sorry to hound you with questions im just curious. if you want you can PM me back. I aprreciate the information. thanks.

Pan on bottom - yes! Drain fluid first - yes!

Compression nut is at front of pan -- holds fill tube to pan. Nut is large -- better than 22 mm. I used a large adjustable wrench on it so don't know exact size.

There is no need to PM. Forums are here for all to learn, me included. Please note that the transmission is extremely sensitive to contaminated fluid. It is essential to clean the bottom of the tranny before opening anything up and keep it clean when reinstalling. For $150 or so a shop can change your fluid and filter including flushing out the fluid not accessible via the pan.

Transmission dipstick has a yellow handle and is close to the firewall:



Again, the trans fluid should be fully warm, with the car on level ground, engine running and trans in park or neutral to check fluid level.

Joe M in WV

[Jbombdizzle]

haha good point about learning. well this is rather weird I dont have a yellow dipstick. its capped by some black thingy that I dont think comes off. I have an auto trans is that why?

[jmenacker]

haha good point about learning. well this is rather weird I dont have a yellow dipstick. its capped by some black thingy that I dont think comes off. I have an auto trans is that why?

Perhaps a previous owner lost the dipstick and plugged the fill tube If that is the case, then finding a replacement is highly recommended.

Earlier you mentioned that the noise occured even when the car was stopped. I've never experienced an automatic transmission that made noise when parked. Have you put an ear under the car to locate the noise source?

Joe M in WV

[Jbombdizzle]

Perhaps a previous owner lost the dipstick and plugged the fill tube If that is the case, then finding a replacement is highly recommended.

Earlier you mentioned that the noise occured even when the car was stopped. I've never experienced an automatic transmission that made noise when parked. Have you put an ear under the car to locate the noise source?

Joe M in WV

Yeah that kinda sucks that its not there. I might call him and ask him why the dipstick isnt there. But yes it does it while it is idleing in park. It is really awkward for me too because I have never heard a noise like that before. and it doesnt seem to be affecting the drive train in anyway(being slipping and such) No I havent been under the car running but I was on top listening around. it sounds to be coming from inside the TB to be totally honest and its more on teh drivers side than the passenger.

[jmenacker]

An experienced ear may be required to locate the issue in a timely manner. The diagnostic cost from a trusted independent mechanic might be worthwhile in this case. I know of a couple decent mechanics out here but its a bit of a trip for you just for a diagnosis.

Any Baltimorons around that might help?

Joe M in WV

[Jbombdizzle]

I Know a place that will work on it, and I am going to take it there, its just that I wanted to see if I could figeure out what it would cost me because like most BMW owners I am kinda short in the money department lol.