Hot running (not)ish

Kinky

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All sorts of odds n sods
I've seen a million and 1 postings on various sites (this included) regarding the temp gauge and high temperatures, etc ....

I have a specific problem which I've not seen documented elsewhere but would be interested in anyones thoughts.

Casually moseying down the M3 at varying speeds of a morning or evening my temp gauge will happily sit at anywhere between 80 - 100.

However, as quick as a flash it'll jump up to 120+ (I say + coz it looks like the needles goes as far as it can.

And you can sit there watching it literally jump up and down between 80 - 120+ like it's on a spring bouncing up and down. There's no (apparant) correlation with revs, speed, throttle, what electrics I have on, having heater on full hot blast, air con, etc.

There's no apparant or obvious leaks anywhere - the coolant is a nice kind of minty artic blue colour, and the oil cap is nice and clean and as expected. The oil (from what I can see) is nice and clean.

When I got the car I was told about this and the fact that the dealer had it pressure tested and it was ok.

As I've now got the car going in for a main dealer service on Saturday - any pointers on what to check for - or what I should have replaced?

Fortunately it's under warranty so if it's major - it "should" be covered.

Many thanks in advance,

K

[Edited to say it's a '93 L E280 estate with 122k on the clock]

[and re-edited to say that it's been serviced pretty much bang on the nail every time - but not by an MB dealer - or even an 'expert' from what I can guess]
 
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jimmy

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Sounds like a faulty sender switch or some other electrical fault. You could actually get a thermometer and check the accuracy of the gauge, if its reading 120+ surely you would see steam rising from the bonnet?
 

Steve_Perry

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I had exactly the same on my previous '86 190E only in that case it was the pressure gauge that read from 0-3 (bar?). It was jumping around like a yo-yo, the problem was caused by a faulty sender unit. The replacement unit was quite cheap too :)

Heh with the current car I wouldn't get that problem as they did away with the pressure gauge, and the economy gauge has disappeared too. That's progress for you :rolleyes:

S.
 

fuzzer

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My car does not have a temp gauge on the dash , you have to go through the computer to get it on screen and ive not got a dipstick either , its all done through the dash cluster.:confused:
 
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RichardM

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I've got a temp gauge, although its an electronic bar chart, no dip stick though.
 

kid-jensen

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I'd suspect the gauge itself.

If it's under gaurentee, get them to replace it, or explain EXACTLY why it can't be that ;)
 

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