Hi all, I am hoping someone has some insight here. I recently changed the manual transmission oil and rear differential oil on my wife's 2005 RX8. Both procedures went well; no problems, nothing strange. I just drained them both and filled with fresh oil.

Since then there has been an awful smell inside the car (inside the cabin, windows rolled up). It smells just like used rear differential oil. It's really bad. And it isn't getting any better.

It's been over a week since I did the work. I checked and there are no leaks. I even re-torqued the drain and fill plugs to be sure. There is no excess oil pooled anywhere on anything that I can see.

Anyone have any ideas why I'm getting this terrible oil smell inside the car?

Thanks!

 

did you fill the trans through the shifter? did you spill any espically on the exhaust? did you replace the rubber boot aroung the shifter?

 

I filled the trans through the upper plug on the side of the transmission, not through the shifter. I didn't even know you could do it that way.

 

curious, did you give the underbody a good washing? I have a feeling that you may have dribbled some over onto the transmission/engine and it is just heating up and releasing odors.

 

I haven't yet. That's my next step. The car has been driven a lot since the work was performed, I would think any spilled oil would have burned off by now.

I've been trying to avoid the washing step because we live on a hill. Anywhere outside of the garage will be very difficult to jack up the car to get to anything with the hose or pressure washer. But I may have to get creative and find a solution.

I'll give it a try later this week. I welcome other ideas between now and then.

 

Update for anyone interested: I did some research on this forum about tranny oil. Almost unanimously the community recommends Motorcraft manual transmission fluid, which is a GL-4 type. So I pulled the receipt for the oil I bought and checked. The oil I bought is a GL-5 type of fluid (It's what the guy at the auto parts store told me to buy) Everyone on this forum said to use GL-4, not GL-5.

So over the weekend I switched to the Motorcraft GL-4 fluid (at over $20 per quart). So far there is less smell, and the car shifts considerably better.

I've never really believed that there is much difference from one oil to another. I always use quality oil, but I don't go out of my way to buy one brand versus another. This experience is making me rethink that opinion.

 

interesting ... not sure that using a GL5 oil would actually cause a significant smell difference, but glad you fixed your issue.