4.4 M62 serious oil leak

mikeaj · Post by **mikeaj** » Wed Jan 25, 2023 10:20 pm

This X5 ate it's timing chain tensioner. It rattled a bit, but no serious damage was done as we caught it in time.
There is now a serious oil leak at the back of the engine. It's MOT ran out while being repaired and during the new MOT it dumped at least a litre of oil on the floor. The garage were adamant it was transmission fluid because it was "clear"and seemed to be coming from the filler plug. It would be clear after the amount of flushing etc. to be sure all the tensioner bits were out. It was driven about fifteen miles so it cannot be transmission oil at that rate of loss, The dipstick is dry which is a bit of a clue!.
So, where is this coming from? I can't see anything obvious or wet from above.
While doing the tensioner, all the front and top gaskets were replaced as well as the crank oil seal.
Nothing was knowingly disturbed at the back.
I am baffled. Could we have left something off, or inadvertently disconnected something?
Any ideas?

X5Sport · Post by **X5Sport** » Thu Jan 26, 2023 5:22 pm

Could be a failed head gasket, failed rear crankshaft seal, failed valley-pan gasket (between the heads). I think there are oil pipes back there as well and I’m also certain it has happened to others on the forum too.

mikeaj · Post by **mikeaj** » Fri Jan 27, 2023 12:21 pm

Thanks for this, all suggestions gratefully considered.
There are no symptoms of failing head gasket, so unlikely, but possible if there is an oilway at the back.
Far too much for crankshaft seal, but this would dump the oil into the convertor housing, and then it would come out of the bottom.
Bought the car very cheap with failed valley pan gasket, but it's coolant. Some prat tried to repair it with bathroom sealer, not even silicone! all that work and skimp on the genuine modified part!
That leaves the pipes and the oil separator. I just can't reach in there. I am going to roll up some kitchen towel like a sausage and poke it down the back all accross it, to see what happens. It might show the source. Tomorrow?
You can see my cry for help on the forum.

mikeaj · Post by **mikeaj** » Fri Jan 27, 2023 12:25 pm

I tried to search for this problem accross the forum but surprisingly got no results .

X5Sport · Post by **X5Sport** » Fri Jan 27, 2023 2:17 pm

This was a 4.6 rebuild and has images to show you the engine….the pipes at the back may well be where your issue is hiding. It’s basically the same lump (M54).

viewtopic.php?p=161448&hilit=Oil+breather+m54#p161448

mikeaj · Post by **mikeaj** » Sat Jan 28, 2023 12:09 pm

That link was really helpful. Even with the scuttle removed it's hard to see what's in there and what might be wrong,
This has to be something to do with oil separation as there isn't any thing else oily back there.
Time to pull it all out. Just like the video, mine is lpg which complicates it all a bit.
My skilled mechanic friend, very skilled, not a "technician", sadly is over two hours away. He says he just pulls the engine out first!

mikeaj · Post by **mikeaj** » Sun Feb 05, 2023 4:14 pm

Finally found the problem, mainly by logic, elimination and the pictures from "X5Sport". Very many thanks.
The bottom vent pipe on the oil separator which runs to the left hand cam cover was flapping in the air with no clip on the cam cover end.
It was a bit oily around there.

X5Sport · Post by **X5Sport** » Sun Feb 05, 2023 4:17 pm

That’d do it. Glad you’ve got it sorted.

The useful thread wasn’t down to me though. Just happy to help out.

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