Thermostat for V6 Cologne engine

[Jon280]

Well, I have now got the thermostat out from my car, and am looking at replacing it. However, I am a bit unsure about what to fit. Some places say to fit an 88 deg (some though seem to be 87) thermostat for the V6 Cologne engine in the 280i, other places (including the car manual) state to use an 82 degree one.

On taking the one currently in there out, it is a Motorcraft 81TF-8575-CA, and the markings on it would seem to indicate that it is indeed an 82 degree one (marked with 82/95). On testing it in a pan of water, I don't think its working quite right, as it doesn't start to open till shortly before the water is boiling, and even then it does not seem to open that wide (although to be hones, I'm not sure how wide they should open, the system is pressurised after all so maybe this is not too critical?)

So what advice would people who have changed theirs give? Stick with what I had (i.e 82) or see what happens with an 87/88 one?

Also, any places recommended to get one from, would rather avoid some random one from ebay. Seen some on Burton Power, and there is quite a big price difference between the 82 and the 88 ones (82 over double the price!)

[mrzigazaga]

Hi Jon..The reason for the difference in opening temperatures is so the lower opening temp one can be used for summer and the higher for winter..I have an 86-88 in mine and that works fine..The proper ones are brass so if you have a silver looking one then it might have failed as even new ones of them do!..save the outer sealing rubber..Some go round the outer edge and some have a lipped one that the thermostat rest's on..Try tickover for a replacement..These do not come with gaskets but they do sell them..They are not cheap but you dont want cheap!..Ziga

http://www.tickover.co.uk/shop/contents/en-uk/p612...

[RCK974X]

Sounds like thermostat is knackered.. it should be fully open when water is boiling.

I've seen both 82 and 88 degree ones in the various Cologne engines I've messed with, and to be honest there doesn't seem to be much difference in running temps on the guage... I tend to put the cooler one in if I have to buy a new one, just for that little extra margin, but I'ts probably me being paranoid.

My 2.8 Wedge ran just fine at normal with its rad about 20% blocked !! I only found out when it sprang a leak.

[Grady]

Make sure you have a thing like a small loose rivet to allow any trapped air out. (Or drill a small hole - 1/8th") Also be careful when reassembling, the thermostat can slip out of place and snap, you'll break an ear off. Use gasket tack to hold everything in place. Grady

[RCK974X]

Maybe I've been lucky, but if you assemble the rubber ring into the moulding on the water pump it's tight enough to hold the thermostat in whilst cover assembled....just be careful not to disturb it..

PS. And do put the thermostat in the right way round - I've seen one the wrong way round, and beleive it or not you can still tighten the covers up without leaks..