Philippe db
Well-Known Member
Please have a look at my fuell pump. It’s leaking some thick black oil. Don’t supose this is normal. Should I look for a new one?
Many thanks in advance.
Fuel pump trouble
- Thread starter Philippe db
- Start date
Please have a look at my fuell pump. It’s leaking some thick black oil. Don’t supose this is normal. Should I look for a new one?
Many thanks in advance.
I assume that is the same as the oil on your dipstick. Somehow leaking around the pushrod. Mech pump prices are all over the place, should be able to find one for 100 bucks or less. Yours looks like the newer type, but the older is the same ( and at one time, could be repaired but repair kits cannot be found).
Agree with bavbob; there obviously is a seal somewhere along the path the pushrod travels to separate the engine oil from inside the valve cover from the gasoline inside the pump, and on your pump that seal has failed. I believe I have a pump laying around somewhere, but given shipping costs you probably should see if you can source one in Europe.
Philippe db
Well-Known Member
Thanks guys.
Cleaned up the oil and will keep an eye on it to see how fast it will be dirty again. So far the car drives just fine.
If I'm not mistaken I think I ones bought a spare original fuel pump from DQ. Will go on a search expedition for it tomorrow.
Cleaned up the oil and will keep an eye on it to see how fast it will be dirty again. So far the car drives just fine.
If I'm not mistaken I think I ones bought a spare original fuel pump from DQ. Will go on a search expedition for it tomorrow.
Oil is separated from the fuel by the diaghram, that cavity has engine oil from the push rod for lubrication. Unusual that it would leak on that rod.
something strange,
looking at your pic the black fluid seems to go not vertical which is strange, i would expect the trace to be more vertical
i found this pic to explain it a bit,
you see the push rod, well the tolerance in diameter between the hole in the cylhead and the rod gives you the lubrication, using the same engine oil that fills the cylhead
point is that the oil accumulated will be very little and will not go anywhere
to have that oil spilling from the mech rod there might be three reasons:
1- there is too much oil in the chamber and it exerts so much pressure that it has to leak, and provided there is not a seal in that rod, it comes out (here it comes my recommendation to wipe clean it and see how much it leaks)
2- there is a strong deterioration of the balance mech that actuates the pump membrane and it has eaten the pump wall so the oil has found a way out (i had a completely destroyed internal brass bush in my old pump, forces are small but very repetitive there)
3- your membrane is broken so some fuel comes into the chamber, mixes with oil and, being more thin, makes the fluid come out through the rod
the third one is the most critical, as the leak in the membrane will grow bigger every cycle, at the end you will have gasoline coming into the cylhead
question, can you tell that the black fluid smells to gasoline ?
looking at your pic the black fluid seems to go not vertical which is strange, i would expect the trace to be more vertical
i found this pic to explain it a bit,
you see the push rod, well the tolerance in diameter between the hole in the cylhead and the rod gives you the lubrication, using the same engine oil that fills the cylhead
point is that the oil accumulated will be very little and will not go anywhere
to have that oil spilling from the mech rod there might be three reasons:
1- there is too much oil in the chamber and it exerts so much pressure that it has to leak, and provided there is not a seal in that rod, it comes out (here it comes my recommendation to wipe clean it and see how much it leaks)
2- there is a strong deterioration of the balance mech that actuates the pump membrane and it has eaten the pump wall so the oil has found a way out (i had a completely destroyed internal brass bush in my old pump, forces are small but very repetitive there)
3- your membrane is broken so some fuel comes into the chamber, mixes with oil and, being more thin, makes the fluid come out through the rod
the third one is the most critical, as the leak in the membrane will grow bigger every cycle, at the end you will have gasoline coming into the cylhead
question, can you tell that the black fluid smells to gasoline ?
From my P.O.V, you can answer deQ's questions when you change your pump. Alternate is to find Leslie Wong's blog on his E3 where he shows how to switch to an electrical pump.
A bit strange to see exhaust nuts on an intake manifold.
Philippe db
Well-Known Member
Thanks for all the input guys.
Drove 50km this morning and couldn't see any extra spill. To be on the save side I think I better replace it.
Drove 50km this morning and couldn't see any extra spill. To be on the save side I think I better replace it.
Philippe db
Well-Known Member
Perfect match but without the BMW logo.