Blue Water Temp Sensor

Post Mon Mar 17, 2014 11:27 am

Ello,

Looking for a new temp sensor for 1989, 325 cabby, getting different quotes from diff people (quite varied), I'm new to these cars, can anyone help with where to buy and how much i should spend please?

Cheers

Bini

Post Mon Mar 17, 2014 11:30 am

I have found that pattern one's from GSF/ECP tend to be unreliable,so I am prepared to pay dealer price.

Are you sure the sensor has failed?
How did you test it?

Post Mon Mar 17, 2014 11:39 am

Long story, but local garage noticed the choke always seemed to be running on the car, mechanic thought it was air flow meter, briefly spoke to Marc who suggested checking the temp sensor which sorted it out. They simply just took it off and it runs much much smoother.

You suggest I should just get in touch with BMW direct? So far seen prices for £6 off ebay, or £39 from Cotswold BMW

Post Mon Mar 17, 2014 11:53 am

Before buying anything,you would be best advised to check the wiring,as this could be a simple,cheap fix!

Using a meter,check the resistance at the ECU plug,engine cold,engine hot.Repeat the test at the sensor.This should determine if the sensor is faulty,or you have a poor connection in the wiring.

If this is a proper engined car(6 cylinder!

)a likely place for wiring damage/corrision is the C191 connector underneath the inlet manifold.

Post Mon Mar 17, 2014 12:02 pm

Wicked, thanks for the tip mate, will speak to the chaps or just wait for Marc to be free next (around April).

Is it safe to drive around the car without the sensor? Only a weekend drive at mo.

Post Mon Mar 17, 2014 12:16 pm

Assuming that it is just unplugged(and NOT removed

0)your only problem may be with cold starting and poor running until warmed up.

Post Mon Mar 17, 2014 12:42 pm

Cool.
Surprisingly it starts and runs a lot smoother now.

Post Mon Mar 17, 2014 1:25 pm

daimlerman wrote:Assuming that it is just unplugged(and NOT removed 0)your only problem may be with cold starting and poor running until warmed up.

Wrong way around! A car with the sensor unplugged, and, importantly, no other mixture weakening faults, will start normally when very cold, but will misfire and run progressively worse as it warms up. It will be difficult to restart when hot and eventually foul the spark plugs completely.

The difference in price between ebay copy sensors and the genuine article is likely to be swallowed up many times over in increased fuel consumption if the copy doesn't follow the exact temperature/resistance graph of the genuine article.

Post Fri Mar 21, 2014 7:29 am

Thanks for your input guys.

Quick update, the mechanic, without asking, ordered the temp sensor but said it didnt make a difference, car is still the same and it runs like its constantly running with the choke out, engine is running at 10%, when it should be only around 6-8% (if that makes any sense).

Anyway, they said this is something out of their depths so they have recommended a Bosch eletricitcian, who works on all their car wiring. Ive also found a local chap is apparently good with older cars.

I wanted to quickly ask, apart from what daimlerman recommended above with the wiring, are there any other things you guys recommend so the chap can go direct to that rather than searching around and charging me for hours of work, please? It's going in tomorrow.

Thanks, your help is massively appreciated.

Post Fri Mar 21, 2014 9:40 am

Roll your sleeves up and get to work!

Post Fri Mar 21, 2014 11:28 am

Are you refering to the CO test,where a probe is placed in the exhaust?

I had problems 12 months ago when my summer car went straight to the test station following it's winter sleep.The exhaust reading was way too high,I discovered that all it needed was the spark plugs removing,cleaning and re-gapping....

Half an hours work...

Post Fri Mar 21, 2014 11:33 am

Yeah, what you suggest above. Hopefully it's something simple, fingers crossed.
Thanks for your input.

Post Fri Mar 21, 2014 5:51 pm

You could have diagnosed the temp sensor in 10 minutes with a 5quid supermarket multimeter, rather than take it some "mechanics" who don't know how to put two probes onto an ECU plug.

Let's move this to the Tech Forum.

Post Fri Mar 21, 2014 8:19 pm

Cool - Is there a link to a step by step guide? I'm absolutely shit at this at this kinda thing but if there a guide, I'll give it a go tomorrow.

Post Fri Mar 21, 2014 8:44 pm

Get to grips woth the Wiki, it covers most things:

http://www.e30zone.net/e30zonewiki/inde ... emp_Sensor

Post Fri Mar 21, 2014 8:54 pm

Grrrmachine wrote:Get to grips woth the Wiki, it covers most things:

http://www.e30zone.net/e30zonewiki/inde ... emp_Sensor

Im trying to figure out how to use the Wiki page correctly searched for the likes of this earlier to no result, See my OP in the Technical area.

My problem is my gauge isnt working so if this test works within spec does this lead to the gauge it's self being at fault

Post Fri Mar 21, 2014 9:03 pm

Wiki search is a bit useless, so you either have to click "All Pages" and read the index, or try and use the Front Page. I designed it to try to make it intuitive, but it's not perfect.

1) Access the Wiki
2) Click "Instruments" on the E30 diagram box
3) Click "Temp Gauge" from the Table of Contents
4) Read the description. There's a link for when things don't work properly, which takes you here:

http://www.e30zone.net/e30zonewiki/inde ... ot_Working

As a short answer, the Blue Temp sensor has nothing to do with engine cooling or the temp gauge in the car; it's purely to control fuel management. If you've got cooling issues, click "Cooling" on the Wiki main page.

Post Fri Mar 21, 2014 9:05 pm

Temperature gauge? This has nothing to do with the blue sensor. The gauge has its own dedicated brown sensor.
Only connection between the two, is that both signals run through the infamous C191 plug and socket.

Post Fri Mar 21, 2014 9:09 pm

Grrrmachine wrote:Get to grips woth the Wiki, it covers most things:

http://www.e30zone.net/e30zonewiki/inde ... emp_Sensor

Nice one - will give it a go, cheers

Post Fri Mar 28, 2014 2:14 pm

*Update*

Car has been sitting on drive for two weeks, the mechanic changed the temp sensor, but if anything the car is in a much worse state as, it starts up but making a choking kind of noise and when you put gas on pedal, it cuts out, which it never did.

I'm out of my depths and dont know anyone reliable who is free to look at car, so got a mate to have a look, who took a reading of the car and came up with the following errors:

1) Temp sensor
2) Error on EME control unit

Too much fuel is being pumped out, engine is being over worked and the spark plugs are also quite filthy.

He said, as it has had a different engine (registered 320, has 325), it could have been incorrectly re-mapped with wrong software?

Spoke to Marc, who said it may have the wrong temp sensor, also check for air leaks too.

I need some advice on what my next options are, buy a new temp sensor from official BMW, let the mechanics send it to Bosch to get electrics checked?

Appreciate your input.

P.s. Anyone fancy driving up to Hertfordshire for a job, would be brilliant. At least I know it be worked on by someone who f**king knows what they doing.

Post Fri Mar 28, 2014 2:19 pm

Did you check the blue temp sensor from the ECU plug pins, as detailed (probably) in the wiki?

Post Fri Mar 28, 2014 2:22 pm

No, i havent checked that. I'm far from technical, any chance you have the correct link or a utube vid that i could learn how to do that?
Thanks

Post Fri Mar 28, 2014 2:59 pm

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

Ben

Post Fri Mar 28, 2014 3:16 pm

You are massively overthinking this problem. The M20 engine in your car is one of the crudest, most basic EFI systems out there, and there really isnt much to go wrong.

1. Open the bonnet and check everything is connected. Make sure the AFM is plugged in, and that no-one has left any rubber hoses or pipes dangling and disconnected.

2. Make sure the blue plug connector is actually plugged in. Spastic mechanics yank it off and pull the wires loose, so unplug the connector and make sure the terminals inside are in there properly.

3. Kick your mate with the code reader in the bollocks. Code readers dont work on this engine.

4. Find the Ecu and tell us what number it is.

If you dont understand any of this, read the Wiki.

Post Fri Mar 28, 2014 4:04 pm

Point 3 cracked me up! ha ha

Thanks for the link and the info, will attempt it and let you know how i get on. Appreciate the help.

Post Fri Mar 28, 2014 8:30 pm

Take care to identify the two ECU pins in the plug correctly, and use a permanent marker to mark them.
Pin numbers (end of rows) are marked on the ECU itself, and don't force the meter probes right into the buckets of the plug, or you will permanently bend the springs apart.

Post Sun Apr 06, 2014 3:40 pm

Thought id update this.

Tried to get a reading from ECU and couldnt get anything, got my neighbour to help me out and neither of us could get anything from the multimeter, but could do from the Temp Sensor which read as ”“ 1789.

Anyway, got a Bosch electrician to collect car and he diagnosed with the following problem:

Cause of fault, fuel pressure ”“ wrong fuel regulator was installed, which is now replaced, cleaned out plugs, tuned and re-set air flow meter, engine oil contaminated, changed oil & filter.

Car seems to be running much smoother.

Thanks everyone for their input, hopefully this bloody resolves this issue.