New to BMW and E30’s

[Werda24]

Hey guys just bought my first E30 last week it’s an 85 325e last owner had it for 19 years but hasent taken the greatest care of the car I can see. Needs lots of tlc. Any advice for first time owner. I have had an old air cooled beetle and many vws. To start first issue I’ve been having is oil pressure light which I see is a somewhat common issue I have changed oil to 20w50 Castrol checked connections for the pressure switch and the relay for my oil pressure gauge everything is in working order. When engine is cold oil pressure is above 30 psi but when engine gets hot it’s dipping under 15 psi and the light is coming on. Any help would be awesome picked the car up just for a daily summer driver hoping it’s not an extensive issue!

[Speedtouch]

Welcome to the Zone! How many miles has the engine done? Maybe you can use some engine flush, then top up again with fresh oil, which may cure your problem; of course, it could be just a faulty oil pressure sender/wiring to it or sticking oil pressure relief valve, so check those first before jumping to conclusions about the engine.

Perhaps try whacking the instrument cluster with the engine warmed up and running, to see if it causes any variation in the reading...

The Zone Wiki is a mine of info:

http://www.e30zone.net/e30zonewiki/index.php/Main_Page

[martauto]

Welcome to the zone mate !!
As above really and of course you changed the filter as well?

Mart.

[Werda24]

Did filter as well yes engine seems to be running just fine and getting oil to the head. Pressure just dipping low on idles. Possible low idleing? I’m shooting in the dark here at any thing. I will try an oil flush this weekend. Engine has 151,000miles

[aimlessrock]

Before you spend much more on the engine I would pull the plugs and to a compression test.

[Werda24]

So just an update drove to work today everything was good till about 10 minutes into the drive oil light started coming on at idle again. My oil pressure gauge is showing that is dropping. Switch relay seems to be working.

[Speedtouch]

Perhaps fit a new oil pump as a precaution?

http://www.e30zone.net/e30zonewiki/inde ... 0#Oil_Pump

[Werda24]

Perhaps fit a new oil pump as a precaution?

http://www.e30zone.net/e30zonewiki/inde ... 0#Oil_Pump

Not sure seems like a lot of work for somthing that not sure that’s the issue. I have been reading these engine idle at like 10 psi of oil pressure and that’s normal. My pressure gauge is t dropping under 15 psi, the warning like just starts coming on at idle when that pressure drops a little. Is someone able to tell me what the oil pressure should be at when idling and the engine at running temp?

[aimlessrock]

you need to check the internal health of your engine before changing parts on it- do a compression check to start with and post the results.

[Speedtouch]

What speed is it idling at when warmed up, and does slightly raising engine speed make the light go out?

[Brianmoooore]

the relay for my oil pressure gauge

What ?????

I'd replace the oil pressure switch (second hand will do). AFAIK, these shouldn't switch until about 7 PSI, so you may be chasing a non existent fault.

The "New Members" forum is intended to be just for you to introduce yourself, and possibly post a couple of pic. Threads like this need to be in "E30 Tech help" to get exposure to those likely to be able to help, so I'll move it to there.

[Werda24]

the relay for my oil pressure gauge

What ?????

I'd replace the oil pressure switch (second hand will do). AFAIK, these shouldn't switch until about 7 PSI, so you may be chasing a non existent fault.

The "New Members" forum is intended to be just for you to introduce yourself, and possibly post a couple of pic. Threads like this need to be in "E30 Tech help" to get exposure to those likely to be able to help, so I'll move it to there.

Appreciate it was just getting acquainted figured it would be good to introduce and explain why I here haha

[Werda24]

Pressure gauge works fine but the switch is lighting on my dash at idle but gauge is reading above 15 psi at idle. After oil change and looking at the bottom side I noticed the drain plug is the actual pressure switch not sure why it is there I’m assuming it should be mounted on the side of the block where the T for the pressure gauge is?

[Brianmoooore]

What exactly have you got here? It sounds like this car may have been fitted with a few pretend competition parts.
No E30 ever had an oil pressure gauge fitted, and if there's an electrical connection to the sump drain plug, then this is the sensor for an aftermarket oil temperature gauge. The oil pressure sensor can only be fitted to the gallery on the RH side of the block, like you say.
An item that often gets fitted in cases like these is a "competition" oil pressure switch which is set to switch at a considerably higher pressure than the standard type, and I strongly suspect this is what you have fitted.

[Werda24]