Backflush Oil pump and pickup tube ?

[SpiritofBavaria]

Hi everyone,

The oil pump in BMW engines are crank driven by chain. It is located just above the oil pan. It has an oil pickup tube with screen sticking into the oil in the pan, and the oil picked up is first sent to the oil filter directly above for filtration before being channeled to the rest of the engine, valvetrain, pistons, etc.

What do you do if your oil pickup pipe and screen gets clogged ? You can't remove the filter and put a stick down the hole at the bottom to clear the pipe....it does not go right through that way. However, can you remove the oil filter, fill up the filter housing with oil or solvent such as paraffin or diesel, and rotate the crank THE OTHER WAY manually with an appropriate socket wrench ?

Would the solvent or oil flow backwards from the filled oil filter housing, down through the pump, and out to the oil pan via the oil pickup tube ? Would this work to backflush the oil pump and help to clean out the oil pickup tube and screen ?

Of course we can't make much pressure at all if we do this by hand but would it help ?

Is there a valve or something in the oil pump that prevents oil from moving in the opposite direction ?

Whether it works or not, could anything go wrong by doing this ?

If there is a way to backflush the oil pump, it could save you the hassle of dropping the oil pan and cleaning the pickup tube and screen manually.

Thanks.

Spirit

[Aradaiel]

There is a checkvalve built into the oil pump, won't work. You can just clean it off with brake clean.

There isn't a reason to do it, unless the motor blew up or ate something.

[SpiritofBavaria]

There is a checkvalve built into the oil pump, won't work. You can just clean it off with brake clean.

There isn't a reason to do it, unless the motor blew up or ate something.


Gotcha, thought so. Thank you.

How would I clean it off with brakekleen ? I'm trying to avoid dropping the oil pan and do that kind of cleaning if the oil pickup screen and tube gets clogged. Thanks Aradiel.


Spirit

[Aradaiel]

You're funny.

There is no way that it will clog unless something catastrophic happens to the engine. At that point a clogged pickup tube is the least of your worries. You should drop the lower oil pan at your first oil change and change the o-ring on the level sensor (depends on motor if it has one, m60s do) and check the oil pump bolts.

[MissileMech]

As Aradaiel stated you need to drop the pan on an M60 to check the security of the pump bolts. I found one laying in the pan when I changed a leaky O-ring on the sensor. Two other bolts were loose.

[K Fox]

As Aradaiel stated you need to drop the pan on an M60 to check the security of the pump bolts. I found one laying in the pan when I changed a leaky O-ring on the sensor. Two other bolts were loose.

I think I had 7 in the pan, and the other 2 were completely loose. The only reason they hadn't fallen down was that they were captive - they couldn't fall...was unpleasant.

Fox

[SpiritofBavaria]

I think I had 7 in the pan, and the other 2 were completely loose. The only reason they hadn't fallen down was that they were captive - they couldn't fall...was unpleasant.

Fox

How is it possible for bmw to build an oil pump with bolts that come loose over time ? Especially for a device in such a hard-to-reach place ? Or is something else the factor ?

[K Fox]

How is it possible for bmw to build an oil pump with bolts that come loose over time ? Especially for a device in such a hard-to-reach place ? Or is something else the factor ?

They didn't use loctite on the bolts?? :dunno It is a known issue with M60's that the oil pump bolts work loose over time. As far as I've read, it was somehow addressed and the M62's don't do it, but there are several threads on here about it. When I started seeing my oil pressure light come on with hard braking on my 94 540, I dropped the pan and found what I describe above - everything was loose. It's one of the major symptoms of it to see that pressure warning light on hard braking - the braking action throws the pump forward, and it bleeds more oil off than it does otherwise, causing low pressure for a few secs. Not pleasant to have happen, and scary when you get in the pan and see bolts everywhere. S'why we always warn everyone about it - better to check it before you get the the point of low pressure warnings. ;)

This was what greeted me when I dropped my lower pan on the '94:

http://imageshack.us/a/img638/1918/oilpumpbolts.jpg (http://imageshack.us/photo/my-images/638/oilpumpbolts.jpg/)

Fox

[ross1]

Hi everyone,

The oil pump in BMW engines are crank driven by chain. It is located just above the oil pan. It has an oil pickup tube with screen sticking into the oil in the pan, and the oil picked up is first sent to the oil filter directly above for filtration before being channeled to the rest of the engine, valvetrain, pistons, etc.

What do you do if your oil pickup pipe and screen gets clogged ? You can't remove the filter and put a stick down the hole at the bottom to clear the pipe....it does not go right through that way. However, can you remove the oil filter, fill up the filter housing with oil or solvent such as paraffin or diesel, and rotate the crank THE OTHER WAY manually with an appropriate socket wrench ?

Would the solvent or oil flow backwards from the filled oil filter housing, down through the pump, and out to the oil pan via the oil pickup tube ? Would this work to backflush the oil pump and help to clean out the oil pickup tube and screen ?

Of course we can't make much pressure at all if we do this by hand but would it help ?

Is there a valve or something in the oil pump that prevents oil from moving in the opposite direction ?

Whether it works or not, could anything go wrong by doing this ?

If there is a way to backflush the oil pump, it could save you the hassle of dropping the oil pan and cleaning the pickup tube and screen manually.

Thanks.

Spirit


I'm hoping this is a hypothetical situation. Any engine with enough sludge or debris in it to clog the oil pick up deserves to be torn down.

[K Fox]

I'm hoping this is a hypothetical situation. Any engine with enough sludge or debris in it to clog the oil pick up deserves to be torn down.

I'm guessing that it was forgotten that there is a replaceable filter in the system, designed to prevent the above situation from happening, unless as you say it gets 'really grody' in the engine and it needs to be pulled apart. Just my guess.

Fox