Oil leak

F

flybobbie

Elite
 Stourbridge
So have replaced the oil/water filter heat exchange o ring twice.
First was after market but leaked shortly after.
So tried again with BMW original, all fine.

Then started to see odd tiny drip on floor.
Asked Mot guys, they said could see anything.

I looked back at seal around filter, reasonably dry.
Looked slightly wet along the cylinder head gasket, sort of grey rubber.
But behind looking between inlet manifold the engine wall was wet with oil.
Washed it off.
Now i can see patch forming on cast rib.
Hard to see where it originates.

So just lying in bed thinking i wonder if the engine not getting up to temperature driving to work 7 miles daily.
Temp. barely reaches 90. I know we can see 110-120 mid summer.
Wondering if a good run will tighten things up and stop leak...or make it worse!

In the old day i would put sheet of cardboard in front of radiator to get temp. up.

Does the 35i version have shutters on the radiator.
Tried to access realoem but seems blocked.
 
7 miles I would say doesn’t help the engine at all…

N54 doesn’t shutter the radiator..

N54 has oil to air cooler not oil to water
 
So had another look today.
Oil stain is back after washing off dry, but hard to find where it is from.
Oil doesn't normally rise up from a leak, almost like a fine squirt from somewhere.
Removed the manifold again to get a better look.
Something i will recheck tomorrow, once the manifold is off, where it sits on engine small amount of oil, as though from the manifold.
I'm wondering if pcv valve has gone.
Cam cover was replaced at 95k, now at 110k.
Other clues are fine smoke on starting, have been passing off as water vapour being winter, strange smell i guess was cat. burning off..
Instability of rpm on first start first 5 odd seconds, idle hunts upto 1100, down to 900, back up to 1000, then slow down as normal 600, before it settles.
Could the after market pcv gone already in the cam cover.
Part No.977C0002 cam cover from Autodoc
 
  • Like
Reactions: B21
Looks very much like the cam cover gasket is leaking and oil finding its way onto the exhaust and burning, hence the smoke. Usually fails and you see oil on the exhaust heat shield. I always use Elring Gasket sets that include the round rubber cover seals that fit under the cover bolts(15) of them. These should always be replaced when putting a new gasket in. Also some sealant around the half moon shapes front and back where the gasket changes direction to ensure a good seal. Those round seals do go hard and don't compress to seal enough and ensure the main gasket is tightened enough. Oil leaks from these will also let air in and upset fuelling. The only other oil leak place is the small gasket between the oil filter housing and the engine block so check that side of the engine as well to see if there is and oil on that side.
 
No not that side is perfectly dry. Grey-ish smoke from exhaust on starting.
Got me thinking it was some blow back oil on first start burning off.
Want to see today how oily wet the inlet tubes are.
Wish weather would dry out as that would eliminate moisture in the exhaust.
Just ordered a set of the 6 manifold O rings.
 
Assuming oil doesn't generally travel up hill, i'm trying to see if it drips from inlet 2 and follows arrow path.
 

Attachments

  • drip.jpg
    drip.jpg
    328.3 KB · Views: 7
My thought now is the inlet O ring leaking.
Poor pcv design allows too much vapour to get into manifold and oil condenses, then drips out.
Would explain smoke haze and the oil consumption.
I noticed since the last change it needed oil topping up at 3500 miles, about 3/4 of a litre.
Normally get away with no top up in 5k miles between changes, but usually burnt off 1/2 litre.
Also reason exhaust is so black.
I know people fit catch cans on turbo cars, anyway on a N52?
But better to cure the excessive blow back. Is the pcv faulty already or just normal.
 
Leaking O rings might explain the strong smell of petrol on start, the unstable idle for a few seconds and month ago looking at fuel trims one bank, can't remember which bank, one had around normal the other minus signs in front of numbers.
On start pumping in too much fuel because it thinks excess air going in, possibly?
 
Take a better picture of the engine so we can see where the leak is showing, not really clear exactly where your small photo is showing.
 
  • Like
Reactions: B21
Actual oil now runs under 3 inlet tubes.
Plan now is wash and dry all and use powder like flour to see where it gets wet first.
 
Do check the joint between the oil filter housing to the engine block, that gasket fails and leaks oil, could be coming from there and finding its way to where you see it pooling. Cam cover gasket is higher than the inlet tubes and further back, that looks clean along that side in the picture.
 
Well dusted area, run engine....... oil filter gasket, again!!:mad:
It leaks on the lower run above the alternator.
Then follows the head gasket seal.
What a crap design.
First i replaced with after market seal.
That lasted 3 months, probably lot less before i noticed leak again..
So bought genuine BMW, that has lasted a year. Maybe a lot less as it has always dripped.
One assumes on second attempt it was done and fixed.
I knew when i fitted the genuine i should have backed it up with some silicone or similar sealant.
The bolt layout is poor with little clamping along the lower edge.
Forward bolt hard to get to without removing a coolant hose to the block.
 
flybobbie said:
Well dusted area, run engine....... oil filter gasket, again!!:mad:
It leaks on the lower run above the alternator.
Then follows the head gasket seal.
What a crap design.
First i replaced with after market seal.
That lasted 3 months, probably lot less before i noticed leak again..
So bought genuine BMW, that has lasted a year. Maybe a lot less as it has always dripped.
One assumes on second attempt it was done and fixed.
I knew when i fitted the genuine i should have backed it up with some silicone or similar sealant.
The bolt layout is poor with little clamping along the lower edge.
Forward bolt hard to get to without removing a coolant hose to the block.
Click to expand...
Did you put fresh bolts in the cam box..
 
Not rocker cover cam box. That came with new bolts.
The oil filter housing sealing face must be bowed or the old seals etched into the old surface not sealing.
So here's screen shot of someone replacing the seals showing the mating face.

You can see where the seal has "burnt" into the flat face probably antifreeze..
The bottom edge is quite a long run with no extra bolt clamps.
The burnt section looks like the water side, the three round holes oil, looks ok.
The beige at the bottom is the cylinder head gasket.
 

Attachments

  • fil.jpg
    fil.jpg
    65.6 KB · Views: 2
Last edited:
So had apart and this time used some orange seal stuff.
The seals on the heat exchange when removed go back to new shape, given a good seal when reattached. That wasn't leaking.
The body to engine though take up squashed compressed shape.
So used some vtr gasket stuff around the seal, see how that goes.
Be careful taking hoses off you don't lose any O rings, one dropped out, took stripping off belly pans to find ...:mad:
 
You must log in or register to reply here.
Back
Top Bottom