Ongoing low coolant temperature issues

Gary Woolston

Gary Woolston

Member
Hi all, I'm here to pick your brains again 😅
I was having some issues with my TDI 75 taking ages to get upto full temperature, so I bought this thermostat,
www.ebay.co.uk

Genuine VW Coolant Thermostat 044 121 113 | eBay

Find many great new & used options and get the best deals for Genuine VW Coolant Thermostat 044 121 113 at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk
And this temperature sensor,
www.ebay.co.uk

Genuine OE 4 PIN Engine Coolant Temperature Sensor 059 919 501A | eBay

Find many great new & used options and get the best deals for Genuine OE 4 PIN Engine Coolant Temperature Sensor 059 919 501A at the best online prices at eBay! Free delivery for many products.
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And had them fitted,
Now it's even worse, on my stop start city ring road, and some 60mph A road driving the car only got upto 74oc on the colour DIS, and 82oc oil temperature, any ideas?
Thanks
 
Hi Gary,
Sorry to her you are still having issues, in my experience 'original' parts on ebay, I have found might not be. I bought a 'original' thermostat from ebay and it was never right, it went in with a proper original temp sensor from the dealers for best part of £50.
I've gone from ebay 'original' thermostat, to a Euro's Circoli thermostat for under a fiver and all has been good for a while now.

As your just up the road from me, if you need any help changing these bits, just come round, I can do a 'stat without loosing much coolant now and I've just bought one of the really short wera sockets mentioned on here 👍

Regards

Andy
 
Have you got ac? I have a tdi 75 with no ac and boy do they run cold. There was a thread whereby a member logged temps on a run of this sort. I’ll try and find it. Might be in my coolant thread. This doesn’t sound too bad! I run with no thermostat and the car is currently running 55 58 deg and that’smotorway and lanes. Try turning heater off and see what happens, I doubt you have any issues.
 
CrispyEdd said:
Have you got ac? I have a tdi 75 with no ac and boy do they run cold. There was a thread whereby a member logged temps on a run of this sort. I’ll try and find it. Might be in my coolant thread. This doesn’t sound too bad! I run with no thermostat and the car is currently running 55 58 deg and that’smotorway and lanes. Try turning heater off and see what happens, I doubt you have any issues.
Click to expand...
Yes it's got ac, set on Auto 22oc, yes I did see the temperature logging post👍🏻
 
Sidewinder said:
Hi Gary,
Sorry to her you are still having issues, in my experience 'original' parts on ebay, I have found might not be. I bought a 'original' thermostat from ebay and it was never right, it went in with a proper original temp sensor from the dealers for best part of £50.
I've gone from ebay 'original' thermostat, to a Euro's Circoli thermostat for under a fiver and all has been good for a while now.

As your just up the road from me, if you need any help changing these bits, just come round, I can do a 'stat without loosing much coolant now and I've just bought one of the really short wera sockets mentioned on here 👍

Regards

Andy
Click to expand...
I did wonder if the parts were genuine or not, I've got a long run on Saturday to the start of season meal Silverstone, so I'll see how it goes, I may have to buy genuine from Audi and try again👍🏻
 
Try in a pan on the hob the thermostat starts opening about 85 ish it will have temp printed on it that it opens up usually 87. Test it before replacing as you can catch the coolant and pour back in minding some dirt,
 
If the temp sensor has the Audi logo on it as in its picture, it's probably genuine. But the 'stat is stated as valid for several makes even if it's the 'correct' one for Audi, so probably not the OEM one. A little embellishment on the part of the seller I feel.
 
Proghound said:
If the temp sensor has the Audi logo on it as in its picture, it's probably genuine. But the 'stat is stated as valid for several makes even if it's the 'correct' one for Audi, so probably not the OEM one. A little embellishment on the part of the seller I feel.
Click to expand...
I had an experience with thermostat with Audi logo on it and it was a fake... The "fake one" - came in VAG box etc., costed around 12 euro, while the genuine one cost around 50 euro.
In my case after the replacement with the fake, engine was cold all the time (on the road at about 90 km/h the engine temperature was ~75deg), while in traffic it risen to 90).
I went for an Vernet thermostat and now I get 90 deg after about 3-4km of driving (depending of outside temperature) - and when it gets to 90 deg it never drops down.
 
I bought 4 temp sensors.
All were advertised as OEM, around same price as yours.
And they weren't. Most barely worked/fit.

Then I made the lemon face and paid £60 for one from Audi website.
This one has worked the best, without a doubt, apart from the rubber ring, I had to use the old one, because none(!) of the sensors came with the right size one. No joke.

This probably applies to the thermostat as well.
 
Last edited:
In the interests of sharing diagnostics I thought it might be helpful to add the following to an older post. A while back I had temperature issues and chose to have both the sender (sends readings both to dash and ECU) and the thermostat changed at the same time. The parts were direct from Audi. I continued to have issues with the engine failing to warm up then occasionally (but rarely) rising to 90 degrees as it should. I suspected that the replacement parts might be faulty (or fake as discussed above). It was established that an internal 'rib' piece of the thermostat cover had broken off and got stuck in the thermostat holding it partly open. The conclusion is that the plastic thermostat cover may become brittle with age and heat. It is worth considering replacement of the cover when the thermostat is changed. Alternatively (and in any case) take care with the cover during intallation of the thermostat. (Photo shows piece of plastic in left of thermostat and gap in ribs in the cover).
 

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