Cars / e32 / Engine / E32 / E34 Fuel Filter Replacement

E32 / E34 Fuel Filter Replacement

Article by: Paul Axford

Applies to: all e32 and e34 models (this article was written with a 730i).

The filter provided to me by BM Warehouse in Hamilton as an “OEM part” looked nothing like the stock filter. It has a slightly smaller overall diameter and does not have the flow direction indicated on it.

It seems to be an unbranded aftermarket filter with a BMW part number label stuck to the box – not a good way of doing business in my opinion and probably illegal if it was in the USA.

This job required raising the right-rear corner of the E32 body and removal of the wheel. Lift at the rear jacking point, not under the suspension.

A 10mm socket will remove the clamp around the filter unit and a 5mm socket (or #2 phillips screwdriver) will loosen the hose clamps. A pint or so of petrol spilled out before the flow stopped.

Be aware, the fuel will be under pressure, up to 45 psi.

After cleaning the hose ends and attaching the new filter I squirted a touch of CRC lubricant (like WD40) on each hose clamp to allow the rubber to compress evenly as the clamp is tightened.

The clamps really only need to be a touch tighter than is needed such that you cannot rotate the hose around the nipple.

Shortly after doing the job (but before starting the car) I researched the filter a bit as I became uncomfortable with the lack of labeling and subsequent risk.

I could read the original p/n on the box under the BM Warehouse label “Z168.”

Apparently it’s manufactured by the Australian firm Ryco and seems to be a reputable aftermarket part at half the price of a real OEM unit.

I also found out on the web site that the outlet is at the crimped end so I had to do the job again.

Why they didn’t label it is beyond me, but that’s one reason why I usually buy OEM. The photo below shows the filter backwards.

I decided to prime the filter rather than just crank the car for a period of time, avoiding beating the starter motor to death and having the neighbors thinking I’ve buggered-up my car.

The fuel pump only runs when the engine is turning over so you need to bypass the fuel pump relay. It’s so easy (and fun) that there is no excuse not to do it.

I opened the “E-Box” (computer box) with a #3 phillips screwdriver and pulled out the orange relay.

Then identified terminals 30 and 87 from the schematic on the relay body and jumpered them with a short piece of bare wire after turning on the ignition.

There is no drama here provided you are careful to correctly identify the contacts.

The fun part is that you can hear the air rushing through the tubes and then the liquid flowing through the pressure regulator. It took about 30 seconds to purge the air.

I did notice on the first drive that the fuel pump makes a cavitation-sort-of-noise for the first few miles. I was initially alarmed about this but it cleared up quickly.

The jumper is shown here:

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