m30 temperature

[devinwwu]

I just finished gettin my m30 e30 all running and my temp gauge won't work. I tried changing the sensor out for the old m20 sensor but either i have the wrong plug or it won't work.
I'm just going to wire in a universal temp gauge but i was wondering what temperature was 1/2 way in terms of degrees and what is considered overheating in terms of degrees for this motor...?


Thanks in advance

[Toby_Unna]

hi

sorry if this is obvious - but as i remember the E34/32 temp sender and harness has two wires - have you connected the right one to the m20 sender?

did the gauge work before the conversion? try grounding out the sender wire to check the gauge is operating.

[DRIFTBOY]

Click on this!

http://www.bmwe34.net/e34main/trouble/overheating.htm

Then click on the picture of the temperature guage!

[devinwwu]

the gauge supposedly worked before. i'm just going to buy a universal gauge and plug it in somewhere.
thanks driftboy i hadn't ever noticed that picture was a link...

[DRIFTBOY]

Don't wish to be rude or tell you what you already know, but have you used the correct 1-pin sender? It's the brown M20 one, uses the black M30 plug and goes in the M30 'stat housing nearest the top hose.

[devinwwu]

that's the problem, i don't have a black plug from my m20 harness. i had to use the engine harness off of a 1987 325i and there is a brown one and a blue one but no black on from the injector harness. Is it the really long wire with one pin that has a black plug?
According to strictlyeta.net that was for oil pressure...?

THanks!

[devinwwu]

http://www.blinkfile.com/1602/e30%20m30 ... %20135.jpg

[devinwwu]

^^ This is what it looks like right now^^^

[DRIFTBOY]

You need to use the M30 engine loom with an M30 engine.

The car will most likely run by just plugging that engine loom into the M20 body loom at the C101 connector (that big multi-plug on the bulkhead). I'm not sure if year changes between models are important though to be honest.
What year was the donor car/engine and the car it's going in?
Are you also using the M30 ecu?
Got any more pics of the conversion?
There are several threads on here covering this conversion that might be worth reading!

[devinwwu]

I am using the m30 ecu. the m30 loom didn't work because it was all the drive by wire throttle and couldn't be reused for this application. I'm using the full harness from a 1987 325i so that it had the 3 rows of pins to mate up with my m30 ecu. people have done this before with the m20 eta conversion.

the car is running and working fine. i just cant get the temp gauge to work...

[DRIFTBOY]

Aaaah, I see.

Sorry dude, didn't realise the M20 loom could be used on an M30 engine!
I stand corrected!

I've heard of drive by wire being used on this conversion though.

I'm afraid youv'e done something that my knowledge on the subject can't cope with!
I'd like to help but I can't think of an answer at the moment! Will let you know if I do.

Or Brianmoooore might know! He's a whizz with the electric stuff!

[Brianmoooore]

Not sure I'm following this.
You've used a M20 E30 loom in an E30 with a M30 engine? Everything works except the temp. gauge?
The temp gauge circuit is extremely simple. Just a single wire from the gauge to the sensor.
In the picture in the link I can see the brown connector for the temp gauge, and what appears to e an unused two pin white sensor near it.
The brown connector should only have one pin in it, and the white sensor needs to be replaced by a M20 one with only one terminal.

[devinwwu]

funny thing. i posted this at work and then got in the car to go home... did nothing all of a sudden the temp gauge works!!!!

no idea why it wasn't before but oh well must be a loose connection somewhere

[gareth]

if only everything was that easy! may have just been a corroded connector terminal or something...

[Brianmoooore]

On closer inspection of the pic, I see the brown plug is connected to a sensor, presumably the M20 one.
Most likely place for a poor connection is the multipin round plug and socket for the injectors under the inlet manifold. This carries the signals for both the brown and blue sensors, as well as the injectors.

[gareth]

good call, didn't think of that as i'd never had problems with one! bet i will now though, i've gone and jinxed it!

[devinwwu]

Hey one more question for you guys. I have a 14" electric fan mounted as a pusher on the front of the radiator. This is a fan that claims 2950cfm of air flow. The car is still overheating in traffic even with the heater on full blast... shouldn't the 2950cfm be enough to cool the motor?? or do i have a overheating issue?
thanks!

[DRIFTBOY]

It's very easy and common for the fans to be wired wrong and draw hot engine air back through the rad!

I'd check that first!

[gareth]

i reckon about 2/3 of M30 conversion on here had that slight mishap! me included!

mine was ok in traffic as it sucked so much air out forwards through the rad but overheated once moving as it held the air still!

[devinwwu]

no the fan is definitely wired correctly as i just have it hardwired with an on/off switch straight from the power block. I have it on the pusher setup, it just doesn't seem to cool off the big motor.

how many cfm are you guys running in yours without cooling issues??

I'm starting to wonder if it has something to do with my motor, like a headgasket or something

[gareth]

do you overheat at a steady speed or just while going slow?

[devinwwu]

just while going slow, once i'm on the freeway i'm ok it stays about 1/4. but i just don't get why it would overheat if others aren't having this issue with just an electric fan and no heater. i filled the full system when the car was totally cold and waited till it was spilling out of the bleeder valve with the resevoir lifted up. i was pretty sure i got a good bleed on it, but i guess that's my next step.

i was just wondering if the electric fan alone has worked and what cfm rating they were at. i also don't have a shroud made yet for the fan but it is connected to the radiator, and the radiator mounts pretty much flush with the radiator support beams vertically so there is no air escaping from the sides...

thanks for your help

[gareth]

mine ran fine for a few weeks with no fan. i only ever stopped the engine to keep the heat down while stuck in traffic for a while.

i've never had any real trouble bleeding though a few of the other M30 owners have done.

is it hot where you are?

it is possible to left the rear of the bonnet to help hot air escape. this may be worth a go, even as a temporary fix to keep things cool and reduce risks. you can either redrill the bonnet roller catched on the wing or shim up the rollers on the bonnet and use longer bolts. removing the rear engine bay sealing strip will also allow some air out.

[devinwwu]

yes i can drive around with the hood lifted up, i would just prefer not to. it is only like 50 - 60 here during the day so no its not hot and in the morning its is around 45. i can't remember if you guys are F or C so celsius would be about 10-15 degrees during the day and only just over 7 in the morning...

[m10man]

Hey one more question for you guys. I have a 14" electric fan mounted as a pusher on the front of the radiator. This is a fan that claims 2950cfm of air flow. The car is still overheating in traffic even with the heater on full blast... shouldn't the 2950cfm be enough to cool the motor?? or do i have a overheating issue?
thanks!

My 16inch fan flows 2120cfm and keeps it cool, so 2900cfm should keep yours cool, unless it is the diameter (14inch) isnt quite cooling enough of the radiator area.

[m10man]

just while going slow, once i'm on the freeway i'm ok it stays about 1/4. but i just don't get why it would overheat if others aren't having this issue with just an electric fan and no heater. i filled the full system when the car was totally cold and waited till it was spilling out of the bleeder valve with the resevoir lifted up. i was pretty sure i got a good bleed on it, but i guess that's my next step.

i was just wondering if the electric fan alone has worked and what cfm rating they were at. i also don't have a shroud made yet for the fan but it is connected to the radiator, and the radiator mounts pretty much flush with the radiator support beams vertically so there is no air escaping from the sides...

thanks for your help

Did you bleed it again a couple of times once the thermostat opened? That is also important (as I learnt the hard way) and air can be still trapped. I have found using gareth's mouth to mouth technique works good.

[DRIFTBOY]

I had to lift my (original M20) expansion tank higher uo to properly bleed my cooling system on the M30. My 14" Spal blow through fan has no trouble keeping it cool in traffic and it's fine fine without it above about 25 mph.
What radiator are you using?