Thermostat Problems

[DW]

Hi,

For about 2 years now the temperature gauge has been playing up. Often the line stays on zero and only moves when it feels like it (usually once in about 3 months!). I drive everyday.

The red light constantly bleeps at me when I start moving, reminding me of the fault, but I have never bothered to sort it out because everything seems to run fine.

I decided to take the car to the SEAT garage the other day to see what they can do. They did all the checks and everything is working normally. They explained it is most likely the thermostat and made out it's a pretty simple job I could do at home. He told me what to look for when I see the thermostat and probably that I need a new one.

So when I got home I unscrewed the thermostat cradle and straight away loads of coolant, I think, gushed out. Is that normal? It stopped after about 20 seconds.

I was told to look for a hole in the thermostat. I couldn't really locate one. With no new thermostat at hand, I put it back in.

Needless to say, the temperature gauge still doesn't work, and the warning light comes on all the time now and I can't get rid of it which I could before after about 2 minutes of driving.

So now it's bank holiday. What should I do? Is it safe to drive? Do I need a new thermostat or is there something I have failed to do which is easy to do.

Many thanks.

 

[LEE69]

The beeping is the low coolant or the sensor/prongs in the header tank needing a scrape.
A hole in the thermostat??
Chances are it as stuck open so not holding temperature, bung in a new one.

Safe to drive.
Remember the coolant is G12 and can't be mixed with other coolant

 

[DW]

Cheers Lee,

Is the coolant spilling out when taking off the cover normal?

 

[LEE69]

Yeah as the level of water is higher than what you have removed

 

[DW]

That's a relief!

Another thing if I may...

over the last few week I have noticed creaking noises coming from under the car (possibly around gear stick or seat?), which only creaks when I start a journey (usually getting out of driveway - only when car hasn't been used for a few hours - and at no other times). It sounds bad as if something is loose.

Again, is this a problem I should get looked at? A service is due next month.

 

[LEE69]

The seat does creak some have removed them and found nothing wrong, next time put your and and try to narrow the creak down.

 

[DW]

Today I got a replacement thermostat through the post. All looks good, with the needle going in and out. I took out the old and placed this one in place. I noticed that the coolant had gone completely, apart from that left in the tube which came out when I replaced it.

After getting coolant and fulling to the maximum mark, I gave it a half hour run. The red light now acts like normal, with it coming on initially without making a sound and then going out straight away. Unfortunately, the needle never moved off the bottom (60)!

After the journey I lifted up the bonnet to find that the coolant had dropped significantly below minimum. I have spare but am reluctant to pour in if I'm going to lose it again. There is no obvious sign of where the coolant is going though as none has appeared to be draining out under the car or around the thermostat.

Any suggestions on what I should do to get the needle to work again? Could it be a case that I haven't installed the thermostat correctly?

Also, what do I do about the coolant?

I'm planning on driving again in just over an hours time. Is it safe in your opinion?

Many thanks.

 

[LEE69]

You need to bleed the system, top it up and run it increasing the revs watching the level and topping up as required.
Put the lid on go for a drive and when it settles top it up to the level on the side of the header tank.

 

[sambryant]

may i also add. you could have a air lock aswel. with the coolant top removed and squeeze the water pipes for a few mins, just gets rid of the air in the system

 

[DW]

Thanks. I will try those things shortly (currently looking after baby!) and get back to you to let you know how I got on.

 

[DW]

Ok. I filled up the coolant again, going slightly higher than I intended. Had engine going for about 5 minutes with the lid off the coolant container. The level stayed the same but the needle on the thermostat still didn't move.

Any suggestions?

 

[LEE69]

yeah drive it, will take more than 5 minutes at idle to move

 

[DW]

Will do in half hour. Going for another 30 min drive. I'm not getting my hopes up on the needle moving. If it still doesn't, what do you suggest I do?

 

[LEE69]

what do you suggest I do?

Cry?
lol


Should be fine on a run, if it doesn't move after a new stat it can only be the sender the CTS

 

[markbrum]

to be honest i think it was always going to be the CTS at fault here, thermostate only opens and closes due to temp of water, the temp needle in the dash is controlled by the CTS thats why we see cases of the needle being erratic sometimes...good luck mate also when buying the CTS remember to get the o ring (if not in the box) and the plastic horse shoe clip just incase your one breaks when removing..

 

[DW]

Cheers guys,

Hopefully all is fine now. The coolant levels are now right and the needle on gauge started working finally after about 3/4 hour driving. I expected it to kick in before but hopefully when I drive to work tomorrow everything will be normal again. If not, I will look into getting a CTS (whatever that is!) lol

 

[markbrum]

its the coolant temp sensor (CTS) its a green sensor that sits in the water pipes this is what controls the temp needle in the dash its a sensor that tells the dash how hot the water is and also tells the ecu aswell...not very exspensive most on here have to change theres at some point

 

[sambryant]

sounded like there was an airlock that needed to clear though, should be all sorted now

 

[DW]

The CTS is now fitted and all in working order. Very fiddly to installed though.