350i oil transmitter

[dukeenfield]

I want to change the oil transmitter,but I have looked and there seems to be two.I just wondered which one it is,the one towards the front on top of oil pump or the other one farther back.It has a wire going from one to the other one.The reason I want to check it,is because the oil pressure seems quite low (when ticking over cold just under 2 bar and when hot about 1 bar going up to 1 1/2 bar when increase rpm) and and the chap I bought car off,says he had it checked at garage and pressure was ok.It has a vdo oil gauge measured in bars,also been told the transmitters are not very acurate.

[paul gotts]

dukeenfield said:

I want to change the oil transmitter,but I have looked and there seems to be two.I just wondered which one it is,the one towards the front on top of oil pump or the other one farther back.It has a wire going from one to the other one.The reason I want to check it,is because the oil pressure seems quite low (when ticking over cold just under 2 bar and when hot about 1 bar going up to 1 1/2 bar when increase rpm) and and the chap I bought car off,says he had it checked at garage and pressure was ok.It has a vdo oil gauge measured in bars,also been told the transmitters are not very acurate.

The unit towards the front of the engine like a minature oil filter is the sender for the oil pressure gauge, the other smaller sensor further back is the switch for the warning light. You should be looking at something like 40 psi hot when over 2500 rpm, although at idle mine drops to c. 20psi. I don't find the standard gauge very easy to read, so have fitted a Racetech capiliary type oil temp/pressure gauge where my clock used to be- this is t'eed into the warning light outlet on the pump, and reads in psi, which I find far more useful.

[dukeenfield]

Thanks for imformation ,that gauge you have fitted sounds a better more reliable idea,are they very expensive?.I probly best to try and fit one of them or similar.

[paul gotts]

dukeenfield said:

Thanks for imformation ,that gauge you have fitted sounds a better more reliable idea,are they very expensive?.I probly best to try and fit one of them or similar.

These are the guys I got mine from:

www.raceparts.co.uk/racetech/instruments.htm

I found them v.helpful. The dual gauge I have was c.£60 plus the adaptor and lines. Although I can't see an oil pressure gauge only on their site, its listed in the Demon Tweeks catalogue at c. £30, so I'm sure Raceparts must do it. As my clock had stopped working, I replaced with this new gauge, which is the same 52mm dia.

[shpub]

I have used the Racetech unit inn the 520 for several years. I have the dual pressure/temp version. The temp sensor uses a housing that fits in the oil line to the remote filter.


The oil pressure sensor will probably require some adapters which will vary on where you fit it. Either teed off the pressure switch or as a replacement for the transmitter.

PS Rally Design sell them www.raldes.co.uk

Steve
www.tvrbooks.co.uk

>> Edited by shpub on Monday 6th December 07:15

[dukeenfield]

Thanks for your help

[adam quantrill]

Yeah mine reads 1/2 a bar on tickover when hot, and has done for years. I just put it down to inaccuracy and a little engine wear.

So long as the engine oil warning light stays out (though it's OK if this flickers on real low revs and very hot) there should be nothing to worry about.
You should also see approx 2 bar at 2000 rpm (I get
1.75 or thereabouts) when hot.

A note of caution when replacing either the sender or switch, don't tighten it using the body or you can cause an oil leak from the housing, and don't overtighten or you could snap off the brass thread which will then require a bolt extractor to remove!