Tdi temperature will not exceed 81 degrees.

[Rickpercy87]

My temperature sensor has not worked for a few months but the car still runs fine. I have been using the torque app to monitor the coolant temperature the past week.

Whenever it reaches 81 degrees it will drop back to about 78 and then increase to 81 again. It's been very hot weather, too.

I'm thinking it must be a thermostat somewhere but considering my temp sensor isn't sending the signal to my dash could it be this?

[Skezza]

My sdi was running at bang on 80 according to torque yesterday

[danoid]

Usually if it's solid, then it's most likely to be thermostat not opening properly.

My passat was on 80 on for about two years, until I noticed the engine breather pipe at the back didn't have an o-ring, as it was a bit oily there, since fitting it it's been bang on 90. Probably just because it's stupidly hot, bit coincidence never the less

[lupo 1.7sdi]

....... thermostat not opening properly.

+1

[Rickpercy87]

Cheers guys, I'll get a new thermostat and coolant sensor done at the same time I reckon.

[danoid]

coolant temp sensor is easy peasy to replace yourself, if you want to try that first, just in case. That's only a few quid as apose to £100+ for thermostat. If your going to replace both anythoo, I'd start with coolant tempo

[Rickpercy87]

coolant temp sensor is easy peasy to replace yourself, if you want to try that first, just in case. That's only a few quid as apose to £100+ for thermostat. If your going to replace both anythoo, I'd start with coolant tempo

Where is the coolant temp located?

[danoid]

Not too sure, on the tdi. But it should be front right of your engine (as you look at the engine) slightly under the flap, it'll most likely be green.

You'll need a new sensor, o-ring* and plastic clip* - * may not, but I recommend it

[Rickpercy87]

Not too sure, on the tdi. But it should be front right of your engine (as you look at the engine) slightly under the flap, it'll most likely be green.

You'll need a new sensor, o-ring* and plastic clip* - * may not, but I recommend it

Cheers mate, ill have a look tonight and try to pick a new one up.

[Rickpercy87]

Iv'e just had a look now, there's two wires close to each other. I think i'l just the buy the sensor and improvise from there.

Also, Iv'e had a look for a new sensor. It seems some are two pin and some are four pin. Is there any way to find out which is mine without removing it?

Edited July 11, 2013 by Rickpercy87

[danoid]

Two wires, hmm. Is it possible you can take a picture.

[Rickpercy87]

Two wires, hmm. Is it possible you can take a picture.

I'll get on it. I have a 1.0 arosa i'm breaking so i'm experimenting on that. I removed the temp sensor (which was exactly where you said it should be on the 1.0 lupo)

and had a alot of coolant lol.

It's this one http://www.ebay.co.uk/itm/Water-Coolant-Temperature-Gauge-Sensor-059919501A-Temp-Sender-Clip-O-ring-/171011609482?pt=UK_CarsParts_Vehicles_CarParts_SM&fits=Model%3AArosa&hash=item27d116138a

But I removed another sensor aswell which looked like this:

http://www.eurocarparts.com/search/223440310/p/home

I located the temperature sensor on the 1.4 tdi, it is on the right hand side of the engine towards the back. A bit harder to get to.

[danoid]

Doh, it';s on my back on my passats too, stupidly awkward.

Personally I'd get a genuine one from the dealer, I've heard that cheapos usually die quicker

[Rickpercy87]

Here is what I puled from the 1.0 petrol

<iframe src="//instagram.com/p/boRG__FU2S/embed/" width="612" height="710" frameborder="0" scrolling="no" allowtransparency="true"></iframe>

[Rickpercy87]

Doh, it';s on my back on my passats too, stupidly awkward.

Personally I'd get a genuine one from the dealer, I've heard that cheapos usually die quicker

Haha, no problem, mate. I googled the part number of that other thing I pulled out. Turns out its just a flange plug to block off a hole :/

Cheers for the advice, mate. I reckon i should be able to get it done myself. It will be a little fiddle to get out, though.

[Rickpercy87]

I found some interesting information:

http://www.volkspage.net/technik/ssp/ssp/SSP_223.pdf

Looking at the temperature sensor on page 54:

"The coolant temperature sender is located on the coolant

connection of the cylinder head. It informs the engine control

unit about the actual coolant temperature."

"The engine control unit uses the coolant temperature as a

compensating value for computing the injection quantity."

"If the signal fails, the engine control unit uses the signal from the

fuel temperature sender as a default value."

This sounds interesting, do I read correctly that if the temperature sensor isn't working, it makes a guess to the temperature using the fuel temperature?

[lupo 1.7sdi]

the coolant temperature sender has 2 sensors inside. one sends informations to engine control unit (about this write in ssp) and one sends informations to dash.

If you want to know if the coolant temperature sender is gone you need a VCDS and compare the temperature displayed in Engine section with the temperature displayed in Instruments section. Or, if you have a multimeter (ohmmeter) you can measure the resistance of the 2 sensors and compare.

But I still belive that your problem is the thermostat (I had this problem some time ago).

[Rickpercy87]

the coolant temperature sender has 2 sensors inside. one sends informations to engine control unit (about this write in ssp) and one sends informations to dash.

If you want to know if the coolant temperature sender is gone you need a VCDS and compare the temperature displayed in Engine section with the temperature displayed in Instruments section. Or, if you have a multimeter (ohmmeter) you can measure the resistance of the 2 sensors and compare.

But I still belive that your problem is the thermostat (I had this problem some time ago).

Yeah I know for sure my temperature sensor is buggered, but also think my thermostat is aswell. It opens at 81 degrees celcius for sure, cools to about 78 degrees and the repeats the process. The other thermostats I can see online open up at 87 degrees. But that still seems too low. I want one that opens at about 92 degrees.