Dash temp gauge and coolant bottle.

[ADAM_84]

Hello, before anyone screams at me to use the search button i have and can't find the answers i need.

Since having my front mount i have noticed that the car temp gauge has been known to sit just below 90 degrees on long motorway journeys at night. Driving round town once it warms up it used to sit at 90 degrees which is all fine and dandy but at the moment as soon as i start to do any speed the temp drops to like 75 degrees, so in the morning on the way to work mostly sitting at 70mph the temp doesn't reach 90 degrees i know its been cooler in the mornings and the heaters have been on but after looking under the bonnet the coolant level is sitting much higher then it used to, about 5cm from the max fill line.
Been trying to find out if its a faulty temp sensor which would mean that the valves aren't opening allowing the coolant around the block hense there being more fluid in the coolant bottle when the cars cold? Also would this affect the secondary air pump on start up?
Any help would be much appreciated.

Cheers Adam

 

[techie]

First up you need to establish if the coolant is actually cooling down on the move or if the gauge is reading incorrectly. Do both top nd bottom rad hoses get piping hot?

It sounds like you have a stuck thermostat to me.

 

[adam cupra 20vt]

After fitting my FMIC I had problems to, my temp gauge kept moving between 75-90.

I first changed the CTS but it turned out to be the thermostat, fitted last week and its fine now.

 

[ADAM_84]

Cheers for the replys I'll have a look in abit and see if the hoses warm up, just thought it was strange the coolant bottle had so much in it when normally I look and it sits pretty much on the maximum line.
Take it warming the car up on fast idle should do ok to check the hose temps?

 

[ADAM_84]

Just had a little drive in it and both top and bottom hoses got hot and could also see the little hose that drains back into the coolant bottle draining fluid back in, also just spoke to a mate and said it could be the new manifold helping get rid of the hot exhaust gases keeping things cooler

 

[adam cupra 20vt]

It must be getting hot or the thermostat would not open and the pipe would not get hot.......unless its stuck open.

 

[techie]

Usually they do fail open, this is why you get over cooling when moving at speed as the circulation doesnt shut off.

 

[ADAM_84]

So what be the first thing to change then? Or is there another way to narrow down where the fault is

 

[adam cupra 20vt]

Genuine thermostat is about £16 + coolant, genuine green CTS is about £30 I think?

CTS is 2 min job, thermostat is PITA!!

 

[xr2turbo]

bumper less pic please

bugger sorry

 

[xr2turbo]

yeah just noticed

 

[ADAM_84]

Cheers Adam, I read the thread about eBay coolant temp sensors lol found it amusing ;-) shame there isn't a clear cut sign of the two parts failing, if one of them is dead will it make the coolant light flash?

 

[adam cupra 20vt]

If you want I can send you a good CTS to test as long as you send it back?

No not as far as I'm aware.

 

[techie]

If the temp is dropping when you at speed then its 99% a faulty thermostat.

 

[cupraluke]

Hi, I have the same problem with my LCR. Can anyone telll me where the thermostat is situated on the car?...cheers!

 

[adam cupra 20vt]

Hi, I have the same problem with my LCR. Can anyone telll me where the thermostat is situated on the car?...cheers!

Behind the alternator in that black plastic pipe the water hose connects to.

 

[cupraluke]

Cheers for that. Also can you tell me what a CTS is and where that is as I going to replace these parts to hopefully cure the problem?

 

[adam cupra 20vt]

Cheers for that. Also can you tell me what a CTS is and where that is as I going to replace these parts to hopefully cure the problem?

In the radiator hose that runs beside the block on the passengers side, kind of behind the battery/airbox along side the engine..

Held in with a horse shoe clip takes 2 mins to change.

 

[techie]

Coolant Temp Sensor

Any specifics would depend on you telling us what car you actually have.

 

[cupraluke]

Ah right, thats the dual temp sensor I take it! Changed that already. Ill have a go at the thermostat tomorrow, thanks for your help. Ive got to stop paying dealers OTT to do these simple jobs.