Why does my VW (or Audi) never get to full operating temperature?

[@cubleycat]

We replaced the expensive one thinking that was the problem but seeing your video may well solve the problem. thank you for this

[@cubleycat]

Well we repalced the small thermostat today and we now have a warm car so thankyou so much for this

[@Beparepa]

I wish I had known to do this when I changed out my alternator. It was right there. But it is not as problem yet. My problem was my upper hose on the rad reservoir has a baffle in it and was plugged .it fix my issues imidiately

[@dopiaza2006]

You can save a lot of labour in the DSG thermostat job by just swapping the copper/wax module. No need to unclamp any hoses etc. Good idea to still check the actual temps you are reaching though as you kight be just above 75C, not the 88C+ it needs to be at.

[@PetesWorkshop]

Hmm I do not agree. If you separate the thermostat it is difficult to get back together again because of the spring tension. Also you risk damage to the sealing O ring, then you may get a coolant leak. Much much easier to remove 2 hose clamps and replace the complete unit. Less risk in my opinion. Can you even purchase the internal parts without the housing?

[@dopiaza2006]

@@PetesWorkshop I've done quite a lot of these. The main reason I use this method is that often the thermostat is stuck hard to the rubber pipes and while manipulating it to separate them a few times I've had the plastic elbow break where the rubber pipe joins near the front of the engine. It seems at the age of these vehicles the plastic is getting brittle. By not removing the whole thermostat it lessens the chance of that. No, you can't buy the internals indivisually - I just take the new one apart and remove the capsule. Never had a leak. But either methodis fine, whatever works for you.

[@Mind-your-own-beeswax]

My passat is exactly the same after a new thermostat. Ah yours is the auto whereas mine is the manual so doesn’t have that secondary thermostat

[@egidijusmontvilas9532]

Yea I got manual 2.0tdi Passat and temperature is up and down all the time between 70C-85C. Sometimes reaching 90C I just noticed in the winter never seen this in the summer months

[@LuisFilipe21]

Mine is an Audi 2.0 tdi manual gearbox and it has the second thermostat. Some people call it EGR thermostat.

[@ravagerslb]

Manuals do have that secondary termostat. Check the hoses that go into the EGR cooler.

[@mateuszlasek2777]

w samochodzie zskrzynia manualną również znajduje się ten termostat , tak jak i zawór dławi,ący

[@jonhjartarson4968]

Coolant temp sensor is also a known cause for those symptoms.

[@PetesWorkshop]

I have had a coolant temp sensor fault and it did not present itself the same as this at all. Sensor failure usually appears as non linear movement of the gauge that does not make sense for normal coolant heating/cooling.

[@leandrocarvalho2702]

I have the exact same issues with my dolf gtd

[@dopiaza2006]

75C on the gauge is more like 65C actual. The gauge reads 90C from 75C to 105C.

[@PetesWorkshop]

This is true. ‘Operating Temp’ is a temperature range. The gauge on the dash is designed to make it easy for everyday humans (that may not understand the inner workings of a complete engine assembly). I’m ok with this approach by VW.

[@dopiaza2006]

@@PetesWorkshop Agreed, although the engineer in me does get rather annoyed by a gauge marked with numbers that has little relevance to the actual temperature! Just have a cold/normal/hot range!

[@shabbirabdulhussein8748]

I have this same problem but im confused because at the end of the video you said you changed the thermostat and it didnt make a difference? Whats the part called that you actually changed? I rawatched the video and it and like there's two thermostats? One is for the engine coolant and another one is the main thermostat?

[@PetesWorkshop]

On the left of the thumbnail is the main thermostat that bolts to the engine block. The small ‘in-line’ thermostat on the right side of the thumbnail was the cause of the problem. This is the DSG thermostat.

[@HeadshooterGTAS]

@@PetesWorkshop i asked chatgpt, both thermostat work independantly no ?

[@korisnik4888]

Had the same problem on an audi a4 b8, changed the small one, temp does raise and stay at 90 but raises slow. Drops at +5C and lower if i drive downhill for 5 minutes with cabin temp at 21C Are there 2 or 3 thermostats in the 2009 model?

[@rsscott5672]

Exact same problem on my wifes audi tt tdi. Ill need to get it changed

[@yengel7442]

hi I have a 2.0 tdi cr manual gearbox I also have the problem of the temperature going down I changed the thermostat twice and I would like to know if it is normal for them to go down to 75° and to go up to 90 ° and I have heating and when cold it takes me 20 minutes for it to reach 90° with an outside temperature of 3° thank you for reply

[@PetesWorkshop]

This does not sound like normal operation. Try to find the cooling system diagram for your car and find a possible reason for coolant to bypass the main thermostat.

[@markrogers7398]

I’ve got the same issue on a golf, I feel like my mpg is suffering as a consequence did you notice that?

[@PetesWorkshop]

This is possible because when the engine is cold (or the ecu thinks it’s cold) the ecu adds more fuel to help it run better.

[@sergiygeo.7035]

Good day dear, I have a similar issue, in the morning on the highway the temperature drops down and error code came - cooling liquid too low. I have Audi TT MK2. Please advise if I can install the same small thermostat as a second one. Thank you!

[@PetesWorkshop]

I have a mk2 TT with 6 speed manual transmission. It does not have the same thermostat. The Stronic (dsg) may do, I don’t know. ‘Cooling liquid too low’. If the reservoir is full you probably have a sensor fault.

[@Spirit-88]

I have changed the water pump, thermostat and the sensor, unfortunately nothing has been changed. i am getting crazy

[@Alexdbre]

Mine was an B8.5 audi, changed both thermostats, EGR Cooler, Coolant, did coolant system with Headgasket check, waterpump with timing belt, Coolant Cap (there is a valve too) and both sensors to no avail, still not getting above 75°C

[@deividasivanauskas5561]

hello, the same problem passat b8 2015 manual I'm not sure if this car has such a thermostat?

[@PetesWorkshop]

I’m not sure either. Most likely it does though.

[@slavenkomsic1613]

i have exactly the same problem on my 2011 cc 2.0tdi 4motion…what do you think, is it the same thermostat or?

[@PetesWorkshop]

Very highly likely it is the same thermostat causing the problem.

[@isaactinacci4758]

water pump flange could be stuck open.

[@PetesWorkshop]

What is the ‘water pump flange’? More information please.

[@deleted.6743]

Heater on high should always drop the temp. This isn’t unusual.

[@PetesWorkshop]

I agree.

[@ethandavison6552]

I have same issuie temp goes up to u0nand stays there unless i out my foot down and already changed thermostat, where did you order this thermostat from and would it work on 2l tdi audi a5 2010 , wngine code is caha

[@PetesWorkshop]

The part number is in the description. Search it in eBay. I don’t know if the A5 has the same thermostat.

[@mateuszlasek2777]

tak , to ten sam termostat , polecam zamówić mahle th 5 80 , który otwiera się przy 80 stopniach.

[@2_CR1T1CAL]

does a5 2009 2.0tdi have this one? or only main one?

[@PetesWorkshop]

@@2_CR1T1CAL if the A5 has a DSG transmission, it will most likely have the additional thermostat. Although I don’t know for sure.

[@radulepg]

Please, can you tell me what multimedia is in Passat? I have same car, and want to replace rns510, but want to keep MFD function, as your car. Thnx in advance!

[@PetesWorkshop]

@@radulepg the head unit is an Eonon brand.

[@radulepg]

@@PetesWorkshop many thanks! I can see, from your video, that MFI (MFD) is integrated with this android media. It's show compas, as it would with the original media (rns510). Other android are not capable of such a thing, as far as i know...

[@iepurelavolan85]

On the engines with one thermostat there is no solution.

[@mateuszlasek2777]

2.0tdi posiadają 2 termostaty oraz zawór , nie ma różnicy czy auto z skrzynią manualn, czy automatyczna

[@sabinislami8884]

Just put a new thermostat and still have this issue…

[@PetesWorkshop]

@@sabinislami8884 which thermostat did you replace?

[@sabinislami8884]

@@PetesWorkshop the big one

[@Kiko6Kiko]

I have changed both main and the smaller thermostat and it still drops low when im idling or just waiting for the traffic lights. Any tips? Audi a6 c7 2012 tdi 2.0

[@Sinister_abc123]

If you have replaced both thermostats the only culprit left would be the temperature sensor...cheap easy fix if it is...

[@paulclaeys7631]

I've had the same issue on both my A4s (B7 & B8.5). When in Drive, the temp goes up to 90C, when in S, temp goes down. And as it so happens, today the temp gauge didnt even reach 70C... while yesterday it reached 90C easy. I guess it's fluctuating. A bit unnerving, but nothing to worry about.

[@Kiko6Kiko]

@@paulclaeys7631 I mean in the summer it's ok, but in the winter it's always drops when I let go of the gas pedal

[@paulclaeys7631]

@@Kiko6Kiko ok, that shuts me up. Never had such an issue before...

[@Kiko6Kiko]

@@paulclaeys7631 ye it stays at 90 when I'm on highway and when there is slight downhill and I let of the gas pedal so just coasting it drops after a minute to 70/80, in the winter it even dropped to 50 after like 5 minute downhill only.