M50 B25 temp gauge problems...

[Eddy]

Hello!

I ve done a swap drom M20 B20 to M50 B25,and my temperature gauge will not cooperate with the M50 engine...

What to do?

[Andy335Touring]

M20 temp sender ?

[Eddy]

A little late but: yes,have thought bout that,but the M50 has 2 senders....how do I know whitch one to replace...

[Andy325i]

Hi mate, just saw your post.

There are two senders as you point out on the M50. The Black one is the one for the temp gauge, the Blue one tells the ECU what temp the engine is. You need to replace the Black one for a Brown one from an E30 6 cyl (M20) I am 99 % these are the same thread (M14x1.50) so it should be a straight swap. The reason for this is that the M20 sender has a much lower resistance (about 130 ohms vs the M50 sender which has a resistance of about 1300 ohms at the same temp (84C)), hence the gauge doesn't move with the M50 sender.

Hope this helps. Let me know if you get any more issues with it

Kind regards

Andy

[Eddy]

Hi mate, just saw your post.

There are two senders as you point out on the M50. The Black one is the one for the temp gauge, the Blue one tells the ECU what temp the engine is. You need to replace the Black one for a Brown one from an E30 6 cyl (M20) I am 99 % these are the same thread (M14x1.50) so it should be a straight swap. The reason for this is that the M20 sender has a much lower resistance (about 130 ohms vs the M50 sender which has a resistance of about 1300 ohms at the same temp (84C)), hence the gauge doesn't move with the M50 sender.

Hope this helps. Let me know if you get any more issues with it

Kind regards

Andy

After some time off I`m back in the E30 customing,and I whould like to thank you for this post,cuz it works the temp gauge does move

[Andy325i]

No problem mate, funny as today I saw that this is now available:

Water Temp Sensor Wiring Adaptor


Andy

[ian332isport]

No problem mate, funny as today I saw that this is now available:

Water Temp Sensor Wiring Adaptor


Andy

That's a nice idea, but still won't work. The dual temp switch used on the later engines is the wrong resistance for the E30 temp gauge.

Ian.

[Andy325i]

Ah! sorry didn't look at it closely, thought it had the two temp sensors (of the right value combiened included). So like you say it won't work on the E30 conversion anyway

Hijacking the thread a little my temp gauge on the 2.8 sits a little high, (once fully warmed up) at idle its about a needle width over the center line then when you give it a run it goes up to half way between 1/2 and 3/4 quickly returning to just above the centerline within a min or 2


Andy

[DanThe]

Hijacking the thread a little my temp gauge on the 2.8 sits a little high, (once fully warmed up) at idle its about a needle width over the center line then when you give it a run it goes up to half way between 1/2 and 3/4 quickly returning to just above the centerline within a min or 2


Andy

Mine sits bang on half way, coming to a stop after a blast it does rise above a bit.
Ive got the fan switch wired in permanent so it still runs on after switching off the engine.
I do like the way the engine warms up so quick though, no more wiping the screen in the winter

[ian332isport]

Andy & Dan,

My gauge sits a little over 1/4 on the gauge most of the time. Sometimes gets a bit closer to half way if the aircon is running. It rarely goes above half even in traffic.

Ian.

[Andy325i]

what are we doing wrong I am running an E36 325i M50 rad

[DanThe]

M20 rad and expansion bottle on mine, both brand new, the first rad I was using had a slight blockage.
I want to get hold of a front panel with 2 cut-outs, I reckon the upper one will give a lot more air flow.

Do you have this on yours Ian?

[ian332isport]

what are we doing wrong I am running an E36 325i M50 rad

Not sure to be honest

Is that the rad with the expansion tank on the side ? My rad is from an E36 M3 and is wider than the ones with the expansion tank on the side. Did you also remove all the plastic cowling in front of the radiator. That tends to block a lot of the larger radiator as well.

Ian.

[DanThe]

Thermostats?

The 2.8 and M50 have 2 temps of stats, 88Ԛ° and 92Ԛ°
http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

Looks like the M3 is 80Ԛ° though
http://www.realoem.com/bmw/showparts.do ... g=11&fg=35

Think I will be putting a 5mm drill through mine

[ian332isport]

I want to get hold of a front panel with 2 cut-outs, I reckon the upper one will give a lot more air flow.

Do you have this on yours Ian?

I don't, but could probably use one. This is one of the differences between cars with and without aircon.

Ian.

[Andy325i]

Good work there Dan but Ԛ£37.91 for a thermostat!!! Drill bit it is then :D:D

When you mention about the front panel, is this the one cut out above the one for the oil cooler?

I also have a brand new E36 M3 oil cooler which I think I will fit but think I need an E36 M3 oil filter housing to get the pipe connections

Andy

[DanThe]

That M3 one looks a bit different to me,

I bought a non-gen one for about Ԛ£15.

Thats the cut out I mean yeah, as Ian says its for cars with air-con, I may just go at mine with a grinder for the time being as its covered by the vallence

There is a non-gen oil filter covering (lid) with oil cooler outlets, its in one of the engine swap threads, I will have a look and post it up

[Andy325i]

That M3 one looks a bit different to me,

I bought a non-gen one for about Ԛ£15.

The thermostate dude? Did you buy an M50/M52 one or S50?

There is a non-gen oil filter covering (lid) with oil cooler outlets, its in one of the engine swap threads, I will have a look and post it up

Sounds interesting

Andy

[DanThe]

M50

[Andy325i]

ah cool

Andy

[DanThe]

Drilled a 5.5mm hole in the top of my thermostat today, its an 87Ԛ° one, warm up was longer but it made no difference to the running temperatures at all
What a crap idea that was

Im going to cut a big hole in my front pannel tomorow to get some more air flow around the rad, if that doesnt work im just going to have to cram an E36 M3 rad in the bay.