I crawled under the vehicle this morning to change the oil and filter when I noticed the following leak:


another view:


and one more for good measure:


Looks to me that this is where the engine mates to the transaxle. I'm hoping like hell that this is not a rear main seal leak, or, for that matter, a transmission seal leak. The leak is a slow one, so I cannot tell if the fluid is transmission or engine oil.

Last summer I had the transaxle fluid flushed at a Mit stealership and I'm wondering if the wet bolt pointing downward toward the floor was loosened to perform that procedure.

Thanks for any speculation.

 

Well it def is transmission fluid. Can't tell if it's the main seal or something else until you open it up and see. Remove that little access cover in the middole and see if you can see something in there.

 

How do you know that it definitely is transmission fluid? I should have said that some of the bolts are red because for some reason they've been partially painted/marked red. For example, that bolt that points downward to the floor has for some reason had it's top painted red. You can see some red paint on other bolt heads in the area.

Is it the location of the leak that makes you think it's transmission fluid?

Thanks.

 

Red fluid is a dead giveaway for tranny fluid leak. that's the only fluid that is red...unless you spilled wine in your engine bay.

if I were you, I'd torque those exposed bolts to specs, even if you have to loosen them. Afterwards, get some de-greaser and clean it up so you can watch for more leaks.

honestly, it doesn't look that bad of a leak. if re-torquing the bolts don't work...I'd run with it. Be glad we have a dip stick and can check fluid level.

which reminds me...I need to add a qt of oil to my truck and my glass of wine is getting low too!

 

Again, the fluid is not red. The head of the bolt pointing downward has for some unknown reason been painted red and gives the impression that the fluid is also red. You can see that parts of a few other bolt heads in that area have also been painted/marked red. We've owned the vehicle for only one year, so I have no idea why or where that was done, but regardless, those bolts having been marked in red is suspicious, especially now that there is a leak in that area.

After more examination of the photos, I believe the the oil/fluid comes out from under the upper left hand corner of the small cover and then flows mostly outward and downward and finally "gathering" on the head of that red-headed bolt.

After starting this thread I sent the photos and an explanation to the service managers of two local Mit dealerships -- one closeby that replaced a rear axle seal a couple of months ago and another more distant one that flushed the transmission last July. They both replied amazingly quickly to my email and both managers say that it's a situation that should be dealt with sooner rather than later. The vehicle is still under bumper-to-bumper warranty, as well as the extended drivetrain warranty, so whatever is causing this leak will be covered. (But nevertheless, because this is our only vehicle, a possibly-lengthy repair will be terribly inconvenient.)

The closer manager suggested that I add a dye to the engine oil which, after about a week of waiting, should either appear or not appear when exposed to a black light. If the dye shows up, it's engine oil. If it doesn't, likely it's transmission fluid.

I've added the dye.

The other manager said that it could be a leaking transmission input shaft seal, but he thought the dye was a very good idea to nail things down. He also suggested that I wash off the whole area so as to make the dye stand out, or not stand out, better.

I have very mixed feelings about washing off the area. Removing irrefutable evidence of a leak may be counter-productive in the end, for all too obvious reasons.

Next week I'll post what the dye test reveals. Because I have never owned a vehicle that had a rear main seal leak, I'm betting that it's a transmission leak of some type. (Then again, I've never owned a vehicle that had a transmission leak, either. I hope this vehicle doesn't continue to present a lot of "firsts".)

 

I would follow the leak stains towards the front of the truck until they stop n check around there. With traveling speeds that would run quite some way and make it look like you have a leak somewhere else.. It's free and ya just might find something...

 

Good idea, but at this point I'll just take it in next week and see what the "professionals" have to say. Whatever is leaking, it seems to me that it is much more than amazing that all of the leaked fluid has "just happened" to accumulate right on, or closely adjacent to, the "seam" at which the engine and transaxle meet.

 

BTW, I would be very interested to know if any other members have noticed the same situation where the engine meets the transaxle and, also, whether any of the bolt heads in that area have been fully or partially marked in red.

When you have the opportunty for whatever reason, please take a look and post what you find.

Thanks.

 

the only other leak I've had in the engine area was between the upper oil pan and the engine. Some "Right Stuff" and some elbow grease fixed that. it did leak down a bit like that, but of course oil wouldn't be that color.

you could always dab the fluid with a white paper towel to truely determine the color.

 

I just got back from the dealership where our vehicle was examined.

The leak, which, according to the service manager is engine oil, is more of a "weep" than a leak. The tech removed that small panel. By looking into the opening underneath, one can see the shaft of the long bolt that has the red-marked head. It is a long one indentical to the one to the left of the number 6 in the diagram below (the middle bolt with the long shaft), but out of view on the other side of the little door.




It is the rear-most (the left one in the photo below) of the two M6 x 124 mm (4.9 inch long) bolts that secure that end of the aluminum upper oil pan to the engine block.


The tech could not detect any dye in the "weeped" oil, but nevertheless declared that it was indeed engine oil that had accumulated from a very slow "weep" between the upper oil pan and engine block above those two bolts. So he tightened the two long bolts and removed all of the oil-soaked grime from the entire seam area, as well as removing the red markings on two bolts that secure that end of the pan to the block. They're all bright aluminum now.


The service manager said that he believed the weep had been stopped but for me to "keep an eye on it" and to let him know if any more weep occurs in the future.

There it is. I was not charged any of the normal $130 diagnostic fee.

I'm tentatively happy, but I will definitely examine that area far more frequently than I have so far. Whatever the leak is, both the engine oil and transaxle fluid are at normal levels even though it's been almost a year since both were changed, so the leak or weep must be very slow.