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GTI not getting warm, thermostat replaced

fungist

Passed Driver's Ed
Location
norway
Hi.

Its winter over here, yesterday it was -18c. Today its -7c.
Even at days with just -1c right at the freezing point my engine doesnt seem to get
The right operating temp.

But first lets travel 2 months back in time:



My check coolant lamp came on. I had to top the coolant level.
It was obvious i had a leak but i was glad to see it was not the head gasket.
It was a hose that leaked. It was under the battery area.
I had the mechanic doind some cleaning and repair.

Then 2 weeks later the problem came back.
This time leaking even more.

The cold came and the leak got alot worse. I had to top every day. At this point i also noticed my engine didnt get warm so i went back for a repair and had the thermostat replaced.
I also got it confirmed that the old stat was stuck open. At the same time he repaired a minor leak near the stat and also told me the other location he repaired leaked again.

Im going back to have the entire hose for that leak location replaced soon.



So i just wounder... i keep topping my coolant so i have enough at all times, the stat is replaced and my car wont get hot!

I can drive for 15 mins getting max 70c of optimal 90c. If im going downhill for a while at low rpm my temp can go down to almost 20c.. ice cold.
It seems to be wary though and its hard to know when and why,
But sometimed i might get the right temp for a little while and then 5 mins later it will drop again even if my driving patterns hasnt changed.

It also seem that when i put the blower on to get some heat inside the car the engine will get much colder and stay cold. It might rise a bit in temp if i turn off the blower..

I have vagcom... no codes on temp sensors or anything..


Any thoughts?
It cant be the leak?
 

707Stang

I'm Hella From Nor*Cal
Location
Nor*Cal
Are you positive the coolant isn't getting up to temp? I would, just to check, get your coolant temp sensor and stick it in cup of boiling water and see if the temp rises normally. At least you would be able to eliminate that part of the equation.
 

fungist

Passed Driver's Ed
Location
norway




After 1 hour.


Its blowing cold really. Its cold inside.


If a temp sensor were gone, would that cause the car to actually never get hot?
 

avenali312

Autocross Champion
Location
Mableton, GA
Car(s)
2015 GTI
If a temp sensor were gone, would that cause the car to actually never get hot?

If the temp sensor was reading in a way to where it thought the car was hot already, it may. This is me theorizing though. Someone with actual facts should chime in haha.

My car showed these problems once, but it was the thermostat stuck open.
 

fungist

Passed Driver's Ed
Location
norway
Ups. That picture was huge... xD

Yes my thermostat was stuck open too. Thats why i replaced it. The mechanic tested the new stat
And confirmed the old was open and the new were closed.
 

GTI's

Drag Racing Champion
Location
MD
You said you have vagcom , so why not check what the engine sees as the temp and compare to cluster.
 

fungist

Passed Driver's Ed
Location
norway
-21c now. Temp down to under 50c on gauge. Funny cause i bought a cold drink
2 hours ago to have inside the car. The drink is still ice cold and refreshing. Nice tip if you want cool drinks.
 

707Stang

I'm Hella From Nor*Cal
Location
Nor*Cal
Crazy thought, but, maybe the thermostat was installed backwards? If the thermostat is brand new and nothing changed, and it doesn't sound like the cooling fans are running all the time either...

Or, it's too cold of a thermostat, as in it opens too soon.
 

eurocars

5/17/15 - Never forget
Location
Indianapolis
Car(s)
2006 GTI
Crazy thought, but, maybe the thermostat was installed backwards? If the thermostat is brand new and nothing changed, and it doesn't sound like the cooling fans are running all the time either...

Or, it's too cold of a thermostat, as in it opens too soon.

FSI thermostat cant be installed backwards. Its an enclosed unit:

 

fungist

Passed Driver's Ed
Location
norway
Hmmm. I read up on mk5 that they had 2 temp sensors. One near the stat and one right under the engine cover possible to reach. Then i found a post somewhere else that the mk5 gti has only 1 sensor. I wanted to check if maybe they forgot to plug the connector. Wwhere is it located
 

merkeyterkey

The Real FLATTIRE
Location
Pawnee, IN
My car takes forever to heat up too, thank god for seat warmers because not having heat is brutal.

Hopefully you find the issue so I can fix my car too...
 

eurocars

5/17/15 - Never forget
Location
Indianapolis
Car(s)
2006 GTI
Hmmm. I read up on mk5 that they had 2 temp sensors. One near the stat and one right under the engine cover possible to reach. Then i found a post somewhere else that the mk5 gti has only 1 sensor. I wanted to check if maybe they forgot to plug the connector. Wwhere is it located

There is one just below the thermostat housing and one on the transmission side of the cylinder head.
 
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