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Discussion Starter #1
Is it normal for the temperature to fluctuate between 80 and 100 while driving casually for about 20 to 30 minutes? I just got my 129 and want to take it for a longer run and wonder if it will eventually overheat.
is the thermostat causing this and should I replace it?
Thanx
 

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Vogon constructor fleet.
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That is kind of high, based on my experience. I suggest to perhaps swap in a new thermostat and do a basic cooling system check while you're at it....flush out the cooling system just in case you've got some gunk in the radiator or passages in the block, check that your aux fans are operating....that sort of thing. Also just curious....what year's your car? My '95 was doing all SORTS of crazy things until I swapped out the "designed to rot" engine harness. Take a look at the connectors.

Get back to us afterwards.
 

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Discussion Starter #3
That is kind of high, based on my experience. I suggest to perhaps swap in a new thermostat and do a basic cooling system check while you're at it....flush out the cooling system just in case you've got some gunk in the radiator or passages in the block, check that your aux fans are operating....that sort of thing. Also just curious....what year's your car? My '95 was doing all SORTS of crazy things until I swapped out the "designed to rot" engine harness. Take a look at the connectors.

Get back to us afterwards.
Will do and I appreciate your response, mine is a 1994 with 54,000 miles so I will keep an eye out for the wiring...Thanx again
 

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Vogon constructor fleet.
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Since your car's a 94, it falls within the danger zone as far as the "bio-degradable" upper wiring harness is concerned (MY 1993-1995 for sure).Trust us on this one. Mileage doesn't matter, engine heat and the model year does. If your car still has the original harness on it, it's not a matter of "if" you'll have to replace it but WHEN.

It's not a hard job and the swap is pretty much a "plug and play" affair. Look on Ebay for a "DELPHI" tag on a replacement harness for your engine.. They aren't insanely pricey. My car's also an SL320 and it took me all of 90 minutes start to finish. Be grateful you don't have a V-12. I've heard they're a PITA to replace.

Do a search for "R129 wiring harness". Very enlightening reading.
 
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