Xsara thermostat housing?

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boroboy

Xsara thermostat housing?

Post by boroboy »

Have mk2 1.4 Xsara, is the thermo housing located off the top rad hose?

Could I get away with not draining all the coolant before changing the thermo? Just undo the top hose, as I've just changed the coolant.

Just bought the car, runs well, not loosing any water (I think), temp sometimes seems to run quite high 90 - 100 C. Thought it may be a sticking thermostat? Had the mk1 Xsara 1.4, temp never rose above 90.
Last edited by boroboy on 13 Oct 2006, 19:18, edited 2 times in total.
jeremy
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Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
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Post by jeremy »

Before you start dismantling make sure it is the thermostat - as it could be a blocked radiator. If the radiator is blocked you may be able to feel cold patches - especially at the bottom.

What happens is that modern Citroens have crossflow radiators with the tanks at the ends. In days gone by the tanks were at the top and bottom and sludge would collect harmlessly in the bottom one - now it collects and blocks the bottom tubes which is no problem until one too many gets blocked and the car overheats.

Worth investigating what temperature the fan is supposed to cut in at - as when the car is atationary its temperature will rise to cut in point then drop back by 5 or so as the fan does its job.

If the thermostat is doing its job the top hose should feel cold as the engine starts and warms up - then rapidly warm up as it opens at (85?? - don't know exactly)

I rather think if it were stuck shut the car would have boiled by now - as the heat output from the engine at 70 MPH would boil it very rapidly with no water circulation at all.
jeremy
boroboy

Post by boroboy »

Jeremy,
Thanks for the info, I'll check the rad tomorrow. Just thinking the thermo may be sticking or perhaps not opening early enough?
jeremy
Posts: 3959
Joined: 20 Oct 2002, 16:00
Location: Hampshire, UK
My Cars:
x 2

Post by jeremy »

In answer to your original question opening the thermostat housing will just make a mess with water everywhere but that's all. The system may need bleeding again when you top it up.
jeremy
boroboy

Post by boroboy »

Thanks Jeremy,
Going to change the thermo tomorrow, hope CHG is OK, can't believe I'm messing around with a 02 car. The coolant water was slightly low when I bought the car from a dealer, 1 previous lady owner with fsh. Hope luck is on my side? Have done a CHG before myself (punto). Hope my hunch is right though (thermo)? Time will tell. Got car at a good price without warrantee. Part X'd my previous 99 Xsara with small CHG oil leak, which I pointed out to the dealer. Think I'm now a little paranoid after buying the car when the coolant water was slightly low, did that with my previous Xsara, but was a slight leak on the top hose, tightened jubilee clip up & no further trouble.

My car so far has not actually overheated yet, just in my opinion coolant temp running a little high. Haven't yet really tested the car though.
boroboy

Post by boroboy »

Jeremy,
Changed the thermo, made no difference. No cold spots in rad & not loosing any water, no air locks. Still runs between 90 - 100 C. Do you know if the mk2's have a more economical rad than the mk 1's?

Just found out that the thermo starts opening ar 88 C & is fully open at 95 C, so that sounds about right.

Taking the car for a long run this weekend, 300 mile journey, so that'll be the big test.
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