Instrument panel and coolent temp having an tiff

[myneek]

I've had both the one on the right of the head and one in the rad replaced. Anyone know which of the 2 is Engine Coolant Temp. Sensor G62? Being that both are 2 wire not 4 wire.
I am tryig to fix the error which is still resent after replacing both sensors.

 

[myneek]

So to add some more info. I've been driving round with VAGCOM running, logging the coolent temp, and a number of other blocks.

The ECU light came on and i marked the log. When I reviewed the log there was no issue with the temp sensor sending any strange signals, no sudden spike or drop in temp.

Next I look at the instrument panel temp. This was way out. Coolent was about 50-60 deg c, instrument panel was 90 deg c. This was confirmed by VAGCOM.

Also I set the internal heating temp to HI (I've obviously got climate control!), yet cold air came out, I'd been driving the car for around 20-30 mins. I switched off the car. REstarted it and VAGCOM reported the instrument panel temp to be 24 deg C.

How can it move from 90 dec C to 24 deg C in a matter of 10 seconds. VAGCOM also confimed this. It say the coolent temp was 69 deg C the instrument panel was 24 deg C. Any yes, I'm not confusing the outside temp with the car temp... checked it mutiple times!!

So, I guess I'm after what could be the issue. As previously mentioned the two wire sensor in the housing, right side of the car has been replaced. The two wire sensor in the Radiator has also been replaced.

Is there a third on which contols the instrument panel and effects the climate control. I thought the climate control used the main sensor right of the engine.

Seems the garage started to wonder why by sensor only have 2 wires I'm not holding out much hope they know what their talking about, had some one else explain there was an additional temp sensor in the rad.

If no one can point me toward the issue. can u answer 1) where does the instument panel get the temp from, 2) is there a third temp sensor for climate and/or instrument panel?

 

[Nath.]

I think you have a faulty thermostat.

The thermostat closes when the engine is cold to keep the water in the engine only so that it heats up quick. then when the water is up to temp (90 deg) the thermostat opens and allows the now hot water to go through the heater matrix and the radiator to be cooled. If your thermostat is sticking or opening and closing randomly it will cause these problems.

The thermostat has a kind of wax inside it that expands and contracts with temp changes and mechanically opens and closes the water flow like a tap.


Maybe the ECU monitors both sensors and some sort of average is calculated ???

Good luck.

 

[myneek]

Yeah, thats the conclusion I've come to today, thermostat is knacker. Temp was moving from 50 to 90 to 70 to 60 to 80 to 90, all in the space of 10 minutes or so. No real heat via the heating exchange to the climate control even on hot and pumping air like a wind tunnel.

Have NOT managed to find where the instrument panel gets it temp from. Disconnected the coolent temp sensor and got -48 on the coolent sensor as expected, but instrument panel remain working. removed the cable from what I suspected was knock sensor, was the closest to the thermostat housing I could find, still working, removed cable from temp sensor in the radiator that was just replaced, still working. God know where it gets it temp from. If anyone know there's a beer in it for them as I'm perplexed.

Anyway looks like thermostat is the only option to take, that or we're looking at something more deadly like head gasgit (git being the word), but I've got no other sympoms that point to that.

Any other views or idea appriciated. Also anyone know the ££ of a thermostat £10 is my guess.

 

[Nath.]

I would agree with £10 for a 'stat

 

[myneek]

AVS Car Parts quote £15 wit the seal and postage. Will give a third part a call tomorrow.

 

[Skywalker80]

I had a similar fault when I bought my Ibiza, temp gauge would go up as normal but the warning light and buzzer would go off even though levels were fine and sensor and thermostat were replaced.

Turns out the whole instrument panel was knackered as the fuel gauge worked when it wanted to as well, and also the outside temp would dissapear from the climate control and dash.
I hope for your sake it's not as bad as this as I got mine done under warranty and cost the garage £400, and it's apparently common on ibiza's.

 

[myneek]

I hope so too! Everything else is ok with the instrument panel. No other issues. Am convinced it has something to do with the thermostat. Thats gonna get replace for the sake of £15, then see how we go. Still no idea where the temp gauge on the panel gets its readig from, seperate post coming for that one

 

[myneek]

Here's a story on this one. Removed the housing for thermostat, guess what, no thermostat in there!! Sort of suspect that might have been the problem.

New one fitted, no light as yet. Been like that for 3 days which is a record.

Lets hope the car doesn't have an overhearing problems in summer. Temp currently doesn't go above 105c which is fine

 

[mea02mr]

Hi, I also have a similar problem which would appreciate some help with.

My car appears to heat up as normal reaching 90 on the dash board in a normal time and does not deviate from this in any sort of driving conditions.

However in the climatronic diagnostic menu, the engine coolant reading stays around 25 and because of this the climatronic system is not turning the fan on in automatic mode and i am not getting any heat from the vents.

Here is the strange bit, monitoring it whilst someone else is driving i have noticed that when turning right the coolant temp on the diagnostic menu of climatronic briefly goes up and the fan comes on and i get heat. As soon as the car is going straight again the temp drops fan slows down and i loose heat.

Any suggestions?? i have tried draining the system several times and refilling with no joy.

 

[myneek]

Just getting the jist of this.

Your saying that you don't get any heat from then climate control yet the temp of the car is normal.

If you have a VAG-COM check what i belives the car temp is, it should be 80-110c.

If you don't (there are people who have got it who might be able to help) then I'd go for the thermostat in the housing and replace that, about £10 from CAF. That solved my problem