Coolant temp problem on LCR

[tonyjo]

This is an odd one, although I am sure its Coolant Temp sensor related.

I have previously had Coolant Level sensor issues on my LCR which was cured by cleaning the prongs in the coolant water chamber and the coolant level sensor. Since doing this, the flashing amber light next to the coolant gauge on the dash has stopped occuring.

However, recently I have noticed that the car is taking a long time to reach running temp of approx. 90'c. Well, according the coolant temp gauge that is.

When it does eventually show 90'c, which takes about 15mins, the gauge fluctuates between 65 and 90 when driving. It tends to drop when the car slows right down for a junction, when I speed up, the gauge goes up. This surely is not correct and I am hoping its just the coolant temperature sensor giving false readings.

Anybody seen this occur on their LCR? Is the coolant temp sensor easy to replace and how much are they?

 

[Willie]

The coolant sensor is at the RHS of the block as you look at it, low down.
Looks like it's a case of unplug old plug in new.
Strange issues, not too sure of a possible solution.
Usually when the water pump is going it goes up in temp when standstill and drops when drivin

 

[andycupra]

sounds like a potential thermostat problem. (eg its not closing properly).

 

[tonyjo]

Umm, it shouldn't be the water pump as this was replaced during timing belt change 10 months a go.

I will have to get VAGCOM on it to see if there are any reported fault codes. There is no indication of errors on dash.

It definitely drops when slowing down. If I stop and let the car idle for a little it rises back to 90 or if I drive off and speed up it goes back to 90.

The car is a late 03 with 41k on the clock. Any other suggestions?

 

[andycupra]

thermostat amkes sense as when you are at a standstill and get no cooling it goes up to 90.
when you are moving but not quickly, you are getting cooling effect but with no big demands on the cooling so it drops.
when moving quickly there is more demand on the cooling.

so id definately say thermostat or thermostst controller. (i think its one unit anyway)

 

[LEE69]

Mines did this so i replaced the sender, it still did it so a new thermostat was done.
How to replace thermostat
Sender is the same as an Audi TT
http://blog.carrel.org/2005/08/replacing-audi-tt-coolant-temperature.html

 

[tonyjo]

OK, cheers guys.

It does sound like a thermostat problem, although if the temp sensor is cheap, I might as well replace that as well to ensure a fix.

How much I am I looking for parts for a DIY job?

Thermostat part no' and price?
Coolant Temp Sensor part no' and price?

 

[LEE69]

Sensor is about £10 of ebay and thermostat less than £10 from even halfords.

 

[Holdup]

I had a similar issue on my Astra, i replaced my temp sensor, ever since it has also taken along time to get to 90 and would go down on journeys then go up when idleing but i never found a cure for it and havent really let it bother me as it seems to work fine.

Have you tried unscrewing the cap on the coolant bottle (when cold of course) to see if it has any air in it? if so it should sound like you have just opened a fizzy bottle of drink

 

[LEE69]

I had a similar issue on my Astra, i replaced my temp sensor, ever since it has also taken along time to get to 90 and would go down on journeys then go up when idleing but i never found a cure for it and havent really let it bother me as it seems to work fine.

Thermostat, it isn't holding the temperature at 90.

 

[Holdup]

Okie kokie, astra not my problem no more goes on wednesday for my 1.6 leon

Hope you get it sorted tonyjo