Engine temp problem...

[Mr.Sline]

Hi all,

Problem I have is the car is taking longer than average to warm up, during this process with the
blower on low and on max temp and if I'm in traffic the temp will go down back to cold.

Once warm on 90degrees again if in traffic or stationary the temp will drop down again.


I have changed the thermostat with a genuine replacement, filled the cooling system with
antifreeze/water and blead accordingly...the problem is still there

So I have also changed the engine coolant temperature sensor, lost a few litres of coolant so
repeated the process of filling the coolant and blead again.

Unfortunately the problem still persists!

Any advice/feedback will be appreciated
Many thanks
Car in question is a Audi A4 2.0 tdi sline 2007 B7

 

[V6 Quatt]

May be temp sensor?

 

[Craig Cull]

I had a similar problem when bleeding mine last week. I found it had an air lock. I left it running for a while, turned it off, then left the top off the coolant and let it bleed its self, when I came back out the water had sunk to the bottom, I then filled it up, fired it up and continued to bleed as normal. Heaters got warm and the problem was solved. Took me nearly 2 hours like but it's worth a blast

 

[Mr.Sline]

May be temp sensor?

Change it again?..

 

[Mr.Sline]

I had a similar problem when bleeding mine last week. I found it had an air lock. I left it running for a while, turned it off, then left the top off the coolant and let it bleed its self, when I came back out the water had sunk to the bottom, I then filled it up, fired it up and continued to bleed as normal. Heaters got warm and the problem was solved. Took me nearly 2 hours like but it's worth a blast

Iv more or less blead the car with the process you mentiioned...
but worth another try...

 

[Mr.Sline]

Blead the cooling system again still the same...
It takes average time for the car to warm up to 90degrees
providing the blower is off, with them on and stationary it will fall down
to 60degrees but what i find strange is the heaters are blowing piping
hot air all around the cabin regardless of the temp.
The rad hose is not getting as hot as it should and the thermostat housing is
cool...

 

[joinerman]

Thermostat in wrong way round !!!

 

[Mr.Sline]

Thermostat in wrong way round !!!

Lol i wish it was!
Its defiantly in the right way!

 

[Giosabcsl]

May be worth noting that there are 2 cooling sensors. One is green the other is grey.

Best scan the car if you can and see if anything is coming up.

 

[Mr.Sline]

Iv had the car scanned no codes, apart from my parking sensors as one has given up.

I assumed there is only one coolant sensor on the back of the block?...cannot find another one...

Water is not circutlating around the block im now assuming my water pump is weak and looking into that..

 

[Mike B]

There s/b another sensor on the rad to control the fan but that wont be your prob.Thing is if the engine is warming up in a reasonable time not overheating and the heater is 100% then all is as it should be apart from the gauge itself.These are not accurate devizes

 

[Mr.Sline]

There s/b another sensor on the rad to control the fan but that wont be your prob.Thing is if the engine is warming up in a reasonable time not overheating and the heater is 100% then all is as it should be apart from the gauge itself.These are not accurate devizes

Agreed, but the the engine is staying cold, the lower pipe coming off the rad and leading onto
the thermostat is always ice cold even after driving for a few hours the water is not circulating
and the engine is luke warmish...not hot as it should be
jus came back from the garage...changed the waterpump and while i was at it changed the
timing belt aswel...so new water pump, thermostat and cooling temp sensor...
going to send the radiator off to get flushed out on monday and pressure tested...
will post results...

 

[Craig Cull]

Hope you manage to find the problem mate :/