I seem to have a 190E that runs extremely cool. The ambient temp is only 59*F and the car only seems to warm up to 60 (second notch from the bottom) maybe a little bit above it when I'm stuck in bumper to bumper traffic with the A/C on.

I'm gonna check the water temperature sender - if my research is correct it is a single prong sensor right?

Where is this on the M103? Is it behind the valve cover?

Thanks in advance,
Holson

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2008 BMW 335i Coupe

It should be a single pin sensor towards the rear on the drivers side of valve cover, between the 2 pin aux. fan switch and the CIS temp. sensor.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Check the sender values before replacing
It is a Negative thermistor.

OHM 110 = 60C
67 = 80C
38 = 100C

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A Dalton

Can anyone explain what he means by negative and how do I do the test...

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James A. Harris

Maybe it's right, it could be the thermostat. I always thought changing them should be part of regular maintance. If you've never changed it now would be a good time.

And the replacement thermostat cover is now metal.

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5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)

Look at the chart....negative means as the temperature goes UP , the resistance value [ Ohms] of the sensor goes DOWN [ negative].

So , you measure the ohms and compare it to the gauge ..
I have a 38 ohm resistor in my tool box for checking these real easy..if you sub that resistor for the sensor, the gauge has to read 100C... just like the chart I posted says............simple.

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A Dalton

Thanks Jim, I just got the car actually. I'm not sure if the previous owner changed it but the thermostat cover is metal. I was wondering about that because in the Haynes manual that also came with the car it shows a picture of a plastic cover.

I'll try shorting the connector to the temp gauge and see if it'll spike to overheat

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2008 BMW 335i Coupe

I will buy some resistors to test the gauge this evening. But I took some readings and it came back as 800ohms and the gauge read 40*, maybe a hair above it.

It did fluctuate wildly between 400-800 though.

I sprayed some electric parts cleaner on the sensor and its surrounding area (including the harness connector) and now the gauge jumps around more but does read above 60*

will try to clean the contact points of the sensor and see how that goes.

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2008 BMW 335i Coupe

UPDATE: I cleaned and sanded down the connecting surfaces of the harness and sensor. The gauge is now consistent and not dancing around.

I grounded the harness to the ground and the temp gauge shot to 120+

So the gauge works, the temp sender is fine.

The temperature was still at 65-70 on the highway and between 75-80 when I'm idling in a warmer place (a garage).

I guess it's the Thermostat - I wonder if it even has one

Thx for all the help guys

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2008 BMW 335i Coupe

you have a stuck open thermostat.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

That's what I'm thinking too, is there a way to check it? Say when the car is just starting to warm up, basically the line from the t-stat to the radiator should be cold right?

Btw, is it enough to just siphon out some coolant from the expansion tank (just so the water level is below the t-stat) to change it?

Thx

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2008 BMW 335i Coupe

just replace it, its cheap and easy.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

There's a drain cock on the bottom side of the radiator, and I think you can get awayt with only draining partially.

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Prost!

Right. Mine was like you describe. It never warmed up all the way. When I took it out I expected it to be stuck open but it wasn't. However the new one fixed the problem and now it works right. There was a certain brand I was advised to get. But I don't remember which one it was!

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Behr is excellent.

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A Dalton