Oil leak
 

2.5 V6 Auto
I was changing the oil today and while I had the undertray off I saw what appeared to be a bit of oil along the join between the two casings marked in yellow on the picture.

The picture is looking upwards under the car just behind the front bumper. The silver coloured casting is the auto box, and I am not sure what the black casing is. The join between the two appears to have some kind of black sealant visible.

When I wiped the oil off (the picture is just after I had cleaned it) it appeared to be the colour of engine oil (brown). (I may be wrong about that, but I would have expected auto trans fluid to be more red, and this was changed less than 5000 miles ago). Having said that, I had not noticed the engine oil level changing since the last oil change. I couldn't really tell whether there had been a consistent leak because the upper (inner) surface of the undertray is quite grimy anyway,

I put a socket on each of the 10mm bolts that you can see outlined in yellow and they each fairly easily tightened about a quarter turn. (I have no idea what the torque setting should be).

After the oil change I ran the car for a few minutes and the leak seemed not to be happening.

Not being familiar with what the black casing is (my mechanical abilities do not extend much beyond simple things like oil changes), I don't really know what I might have just fixed, or indeed might not have fixed.

Any observations or advice?

https://live.staticflickr.com/65535/...518906dd_c.jpg

Have you checked that the oil is not running down from above?

Its unusual for the gearbox to leak fluid from there unless someone has been in there before and not sealed it correctly.

Thank you for your comment - I have checked and can't see anything running down from above. I guess I'll have to keep an eye on it, although with the undertray on its a bit tricky to see the bit that was wet.

I'LL HAZARD A GUESS AND SAY TIGHTENING THOSE BOLTS WILL HAVE CURED THE LEAK CAUSED BY THEM BEING NOT TIGHT ENOUGH.

Sorry about the size of the letters. Caps lock was on.---:duh::duh::duh:

Hello David,

ATF has a distinctive smell so that's the easiest test! ;) I expect that what you have there is engine oil which has been drawn into the throttle body and run down into the air cleaner hose and slowly seeped out through the Jubilee clipped joint. Mine's the same. "They all do that Sir". :D

Simon

A quick clean down of the area where the oil is seen and above with a good engine de-greaser and a hose down with care, then leave the undertray off for a week or so with the occasional glance to see where it fist appears may give a clue as to where it is coming from.


When, if, it does appear, you will then be able to follow the leak upwards to the source.


Easier said than done I'm afraid in a crowded engine bay, the use of inspection mirrors, good lights and an inspection camera may help, but it can be a guestimate if the area of the leak isn't accessible.

thank you for all the helpful comments