bmwe21.net forums

Happy new year to everyone!

Here is the news!

Took the head off after new year (car got me to the north-west of France
and back again, only using about six litres of water!).

Anyway, head gasket looked fine! Sent head off, no cracks.

Anyway put the whole car back together with anal detail (didnt realise it
was twin chain, and those cogs were a headache!) only took me two days.

The car now runs perfectly, and as far as I can tell it has not used any
coolant!

The only problem I am having is that, when cold sometimes it is seriously
lumpy and idles around 400/500rpm, once you get it moving and it
warms up slightly it idles at a constant 850rpm (needle at the bottom of
the 1 on 1,000rpm with no hesitation.

I have read some posts and am thinking about changing the temp switch.
I found some pipes under the intake plenum (Idle control valve) that had
cracks so taped these up with electrical tape.

If anybody has any imput that would be great, dont think it is vacum
related as used some E34 M5 paper gaskets on my rubber ones.

Otherwise the part No: for the right sensor.

I have two numbers, I dont want to get the one that is for the dash as this
wont help in any way, right?

PN 1 : 13621709966

PN 2 : 12621710512

Thanks in advance.

Luke

QUOTE

Man man man all these forums I have to watch 

It's the rear sensor of the 2. You can do some measurements:

+10 degrees centigrade should give abt 3.5-4 K Ohms, warm engine at abt 80 degrees centigrade should give abt .3-.36 K Ohms of resistance.

If you pull the connector at idle with warm engine, idle should go up, that's a simple road side test to keep in mind as well.

But I suspect the ICV more... did you test it with the vacuum hoses disconnected? Should buzz, if you stick your finger inside you should also feel that it's keeping the valve in a certain position. Otherwise, clean thoroughly with carb cleaner and also check if there's 12V on the connector.

Base idle is well adjusted (with all 3 wires on the throttle switch shorted)?

Just some first thoughts!

BTW in case you didn't notice... changed my own forum as well... see www.bmwe21.net/forum hmmm is this kind of publicity allowed?

Rgds,
Jeroen

Hey Jeroen, thought I would also post this on your new forum, very impressive!

I cleaned out the ICV with carb cleaner and that seems to have worked!

When I pull out the blue connector though the idle does not speed up but it makes the car run rough! Does this mean I need to replace?

Thanks

Luke,

Thanks... and I'm glad it helped! I'd check with an ohmmeter or multimeter first but there is a chance the temp sensor broke down as well of course... another point of improvement!

But, if I understand correctly you did not find a clear cause for the coolant loss??

NO! It is not my favorite topic at the moment, must go for a fast drive today to make sure it is not leaking!

The head gasket looked fine, head had no cracks, etc

I did see some slight rust residue one of the cylinder walls! Really thinking about putting some of this sealing stuff into the coolant!

Anyway will let you know.

P.s. what is the part no for the sensor?

Part no is 12 62 1 710 512 according to http://m3bmw.com/parts.html

Quote "If you pull the connector at idle with warm engine, idle should go up, that's a simple road side test to keep in mind as well."


Jeroen are you sure this is true. When I disconnect this blue sensor the idle goes down to about 500rpm!
It also does this with a new sensor!

Hi Luke,

Hmmm strange but I could have been wrong... even though I'm quite sure!!?? The car running any better at the moment? Did U check the intake air temp sensor?

Problem found. It turned out to be the e34 m5 paper gaskets.

All good now. Also loosing no coolant.

All in all pretty good.

Also mines when you put out the blue valve is getting down.What was the reason?

I think Jeroen got mixed up! when you pull the plug on the blue sensor the idle should drop.
When you disconect the sensor on the throttle butterflies the idle should go up!

If your engine is not running well when warm or cold it is an intake leak.
I have had so many problems from intake leaks.

Mine is ok with temperatures and no cooland loss.Is not working the idle valve.Everythink seen ok but idle valve is not moving and it has power

Exquise me! Was out of the country and I seem to have left my mind behind (next to my car I guess)... hope it's all solved now!

Except... I need some time to look into the not functioning ICV... what controls it... I'll be back!

I have one question:in the thermostat it is two sensors,the one is for the fun i think,the second i dont know for what is.Who can tell me?Also my idle valve is not functioning

I believe there is one with 2 wires, that's the sender to the temp gauge on the instrument cluster. The one with the 3 wires switches low/high speed for the electrical fan.

Your ICV is still giving me sleepless nights but I didn't find a clue...