oil pressure light slow to go out on 325

[xsstigger]

Hi all,

I have noticed the oil light can be slow to go out on cold start up, with trial and error i found that certain makes of filter are responsible. I noticed that there was a big difference if the car was facing up hill or down or whether the car was hot when stopped or just warm.

I put it down to the oil draining back out of the filter, therefore there is a delay in the system pressurizing, if the car is on a hill the filter is tilted back and prevents most of the oil escaping likewise if the oil is still relatively thick from a warm engine apposed to thin from a hot engine then it is less likely to escape past the non return valve.

This is my third E30 325, all three have had the same issue, Fram & ufi filters did not suffer from this but both are no longer made. My question is, oil cooler pipes aside, is there any reason that i can't rotate the oil filter housing 90 degrees to make sure that the oil never drains back with the added benefit that i can pre fill the filter with oil at change time to reduce the delay in the system being pressurized.

The m20 is known for wearing its cam, i wonder if it could be due to this frequent delay in oil pressure on start up.

Opinions appreciated.

[reggid]

how much delay are you talking about? in seconds? the light goes out at 7psi (IIRC) so it should only take a second or two to go out

the cam wears because people dont use oil with proper antiwear additives or they dont change oil frequnetly.

just use a genuine oil filter they are the best and they cost the same as crappy ones.

i have heard of people rotating the housing but only to give better access when using a 6 branch exh manifold

[aimlessrock]

my first port of call would be to remove the switch (mounted on the sump) and give it a good clean. I removed mine when I replaced the sump gasket (pig of a job) and I was surprised how much crap was in it.

HTH

[treeman]

my first port of call would be to remove the switch (mounted on the sump) and give it a good clean. I removed mine when I replaced the sump gasket (pig of a job) and I was surprised how much crap was in it.

HTH

Hi aimlessrock. How do you go about cleaning it? Physically with a pin or carefully with a bit of petrol?

Cheers.

[aimlessrock]

remove it from the sump (drain the oil first) and then use a cleaner like petrol or paraffin, let it fill up and then swirl it around..etc.

Personally, unless you use your car on a track I would be looking to remove the oil cooler and associated pipes.

[Brianmoooore]

I think there may be a bit of confusion here, between the oil pressure switch and the oil level switch, but as aimlessrock says, the oil cooler is little more than an ornament on a non track 325i.

[pianist]

+1 I think aimlessrock is talking about level switch not pressure one but I would replace the pressure switch and see if it fixes it

[Yeti]

+1 as the oil switch goes in the block just above the sump

[xsstigger]

Thanks for all the replies.

The oil light delay is definately related to the filter as a change in make has made the problem disappear.

I always used gen BMW filters until i had this problem, i rang the BMW workshop manager and he said that he has also come across this problem more than once. From there i rang Fritz Bits, they told me they used Fram filters with no problems, when i used Fram the problem disappeared, that was until they stopped making them, the same happened with UFI filters a few years later.

I found BMW, Mann and Bosch filters all gave a delay of approx 3 - 4 seconds on cold start, (no delay if the car was parked on a steep hill with the filter tilted back) with the UFI/Fram the light went out within a second of the engine running every time.

By keeping the oil cooler/oil filter housing and rotating it 90 degreed the oil filter can never drain back.

I would remove the oil cooler for reasons already mentioned, i have never stripped a oil filter housing but i see no reason why i can't remove the pipes and put in blanking plugs/bolt (as thought the stat was always closed) or connect the feed and return with a short pipe ? - thoughts please would be helpful.

I still use my 1989 325 tourer every day, it is the only transport for me and the Mrs, are other E30s still being used as daily transport ?

Happy spannering.

[aimlessrock]

apologies, i did indeed confuse the switches...sorry for any confusion.

If you do decide to remove the oil cooler it would be wise to replace the housing with a non oil cooler attachment from a 320i. A advert in the wanted section should soon solve that.

[xsstigger]

I assume you mean use the attachment which lets you screw the filter directly onto the block.
The down side to that is, I will not be able to rotate/hang the filter from the housing preventing my oil drain back problem,.

[reggid]

i use a BMW genuine filter and the light goes out in less than 2 seconds and my pressure switch is 13psi which is almost twice the stock 7psi one. ive heard of aftermarket cheap filters causing oil pressure issues but dont exactly recall the nature of the issue

[paultv]

Interesting,

I had a replacement filter fitted by Fritz about 10 months ago. I've been concerned for a while about why my oil light takes about 4 seconds to go out, didn't do this before ( only when cold )

So now I want to change the filter but I can't find a genuine BMW one, anyone know who made them originally? or what I should buy, I can find Febi, Mann, Bosch, Viaco, Mahle - any opinions?

Paul

[reggid]

ive used mann a time or two when i couldnt get a genuine one at short notice, never had issues

[biffer]

continuing this thread, my car is a 1987 325i, 120000 miles,with a good service history,including recent oil/filter change.iv'e owned it for a year.

all the time iv'e owned it,during a cold-start,the oil-light has always taken 3-4 sec. to go out- not ideal.

at first i guessed it might be sticky oil-press. switch,this was cleaned in white-spirit,but with no change.

oil press. switch was replaced- again,no change.

"maybe it's a sticking press.-relief valve in sump" i thought,so added wynns hyd. tappet-treatment to the sump-full of new oil and went on some long journeys-still the same.

along with these attempts i'd swapped the oil-filter twice,so the car had had 2x mann and 1x bosch filter,to rule out a faulty one.

rotating the oil-filter and housing anti-clockwise from its usual position under the manifold,down so it nearly touches the engine-mount below,even though its only a few degrees,made all the difference- oil-light now goes out immediately.

even tho. fault is now fixed i'm gonna go further and rotate filter 90 deg. so it hangs vertically,well away from exhaust.-iv'e found the heat from manifold makes filter very hard to unscrew after a time. am hoping oil-cooler lines have enough slack for this.