help with changing thermostat

revlimit

Guest
hi im having trouble with my 1.8 20vt leon. i want to change the thermostat but not sure where it is.
can some one please help, also any pics would be good.
how much do they cost ?

cheers guys
revlimit
 

revlimit

Guest
most of the time it sits on 60 and sometimes goes up to 90 and aslo varies inbetween
 

andycupra

status subject to change
the reason DPJ is asking as it could be a few things.
temperature sensor/sendor.
possibly water pump, although probably not in this case :) (thank god thats expensive)
or thermostat.

id say its most likely the temperature sensor. A common fault and usually replaced with an updated green sensor. about £16 i think. Fiddly but not overly difficult job i understand
 
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revlimit

Guest
got the new one the otherday it is the green one and it cost just under £30 !!!!.
but still does not seem to be quite right, how long does it normlly take to warm up to 90 from a cold start ?
 

andycupra

status subject to change
got the new one the otherday it is the green one and it cost just under £30 !!!!.
but still does not seem to be quite right, how long does it normlly take to warm up to 90 from a cold start ?


in what way is it not quite right?
is it still doing the same as before?

my lcr tends to be up to temperature within 2-3 miles. although this clearly depends on how its driven during warm up. If its a case of getting in and driving with no stop starting or traffic etc then 4 miles would be about right id say.
 

sebasti0n

Active Member
Nov 6, 2006
81
0
Same probs with my 1.8t LC....

From cold temp goes up to just below 90... then drops half way... after a while it does climb back up to 90....

Had a new collant temp sensor & water pump changed within the last 6 months, so keen to find out what the fix is for this....

The wierd thing is, if your at a stand still for along time, it will climb to 90 failrly quickly, then drop as soon as you start driving.... then it wiil climb back to 90 and stay there.
 

Dodge85

Guest
very good guide here for thermostat replacement

http://forums.audiworld.com/tt/msgs/1304805.phtml

mine was doing exactly that before i replaced it. took ages, or sometimes never got to 90, and if it did it would suddenly drop down to 65-70. replaced it and has been fine since.

edit - as long as the temp isn't going over 90, i wouldn't have thought it was the pump.
 

Feel

Veedubya 'velle
Jun 12, 2003
4,918
2
Midlands
I don't think it's your thermostat - I think it's your temperature sender (in fact I'm pretty sure).

The Temp Sensor you changed (to the green top one) IS NOT used for the temerature gauge on the dashboard.

The temperature sender for the gauge is located in the thermostat housing (I understand).
 

steelyglint

Guest
seen a few threads on here discussing how to diagnose "thermostat" problems. The old way of doing it i.e. pre vagcom etc. is to start your cold car , and hold onto the radiator hoses. If they gradually start warming up straight away then your thermostat has failed open and needs changing,
They should stay cold until the thermostsat opens at which point they change from cold to pretty hot in a matter of seconds.
Just a thought for those in doubt what part to change first.

p.s. my 2000 reg 1.8t cupra is on about 90000 miles and I think the stat has failed open . ie. takes ages to get warm and doesnt stay at 90. I will now try my own diagnosis!!
 
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traumapat

Leon Cupra IHI
Jul 24, 2005
5,925
4
sunny sussex
seen a few threads on here discussing how to diagnose "thermostat" problems. The old way of doing it i.e. pre vagcom etc. is to start your cold car , and hold onto the radiator hoses. If they gradually start warming up straight away then your thermostat has failed open and needs changing,
They should stay cold until the thermostsat opens at which point they change from cold to pretty hot in a matter of seconds.
Just a thought for those in doubt what part to change first.

p.s. my 2000 reg 1.8t cupra is on about 90000 miles and I think the stat has failed open . ie. takes ages to get warm and doesnt stay at 90. I will now try my own diagnosis!!

good post.
 

Black TDI Turbo

Shussssh Its A Diesel ...
Oct 2, 2005
1,175
0
North East
my old mk3 cupra 1.8t had thermostat problem. It took ages to warm up from cold, then when sat stationary the gauge would sit at 90 start driving and it would drop to 60, stop again and it would rise to 90 again, this is because the thermostat is stuck open slightly thus taking time to warm up as its circulating the coolant through the radiator instead of just around the engine until it get up to temp. The temp falls from 90 to 60 whilst driving because the radiator is cooling the temp and the thermostat cant open and shut to regulate the temp. I replace the thermostat which wasnt too bad you can get through the gap in the front of the inlet manifold and the thermostat is just next to the alternator. Retested and warmed up quickly and always stayed at 90. :)
 

benngunn

Guest
hi guys have been reading about the temp probs my leon mk1 had the same probs the temp sender and the stat were changed under warranty it fixed the prob, hope this helps
 

heathred

Guest
Good work lads, had the thermostat replaced twice and water pump / cambelt done a couple of months ago on my LCR.
Does anyone know how to replace a temp sender - easy or hard?
 
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