Jo88Mak

A little update to this topic. So I changed my thermostat on the weekend and also flushed my coolant system with distilled water to get the old G13-coolant off the system and filled it with new G12 Evo-coolant. The issue that i was having with the engine running a bit cold in my opinion was the cause of the original thermostat stuck partially open, so the coolant didnt ever warm up over about 85 Celsius even when there was hot summer days with outside temps at 30 Celsius and driving on motorway at 140kmh. Also the oil temp hardly never reached over 100 Celsius in Summer. So after changing the thermostat the coolant temp reaches 92 Celsius when the outside temps at the moment in September are at between 6-15 Celsius and the oil gets to just about over 100 Celsius. Also the car gets up to temp faster in my opinion. So problem solved👍

Hello everyone! A little update to this topic. We have had our first very warm summer days here in Finland and I remembered this temp issue that i wrote about at winter time. So yesterday it was almost +30 degree Celsius outside temperature and i was driving for about 1,5 hours with driving speed 80-120kmh most of the time. I was watching my coolant temp with OBD11 and after the car had warmed up, the coolant temp would stay between 80-85 Celsius most of the time with a maximum temp reading being 87. The temp gauge on the dash was showing 90. And the oil temp was between 95-105. I havent yet changed the thermostat or the coolant temp sensor. Both still original from the factory and the car has now 218tkm on the clock. What do you guys think? Are my temps on the cold side and is my thermostat faulty, partially stuck open perhaps?

Also heres the diagram for my cars coolant system.

Hmm, interesting. So maybe i should try to change the coolant temp sensor first...its a cheap part and also easy to replace. If I remove this part will I lose a lot of coolant and do I need to bleed the coolant system afterwards? Also it would be a good idea to measure the coolants real temp with an IR-thermometer and see what the real temp is. Dont have one of my own though.

My car is a manual. Hmm, maybe the coolant temp sensor could be faulty? Not an expensive part to replace also like the thermostat isnt.

Sorry about the earlier post, dont know how to edit it. Ok so a little update. I drove today for 1,5 hour straight with most of the time at average speed of 100-120 km/h...also did some hard accelerations aswell. I was monitoring the coolant and oil temps with OBD11 the whole journey. I preheated the car with webasto for 25 min and the ambient temp was 7-8 Celsius the whole time. So when i started my journey the coolant temp was according to OBD11 and also the temp gauge about 70 degrees Celsius. Oil temp wont show under 50 degrees on Maxidot. I had my A/C set at 22 Celsius. The coolant temp lowered a bit at the beginning to close to 60 but started to rise back after 5 min drive. Webasto was off when driving also. So the highest coolant temp that OBD11 would show was 76 degrees Celsius and it would stay at 75 almost the whole drive when "warmed" up. The cars temp gauge would show 90 at this point. Oil temp was at highest about 96 and would stay between 87-93 most of the time. Also noticed that the Maxidot shows exactly the same temp for oil as does OBD11. So what do you guys reckon? Do I have a faulty thermostat? Should the real coolant temp be more than 75 degrees, in my opinion, yes. Also would it be better to still use the windguard to get the oil temp higher, over 100 degrees?

Ok so a little update. I drove today for 1,5 hour straight with most of the time at average speed of 100-120 km/h...also did some hard accelerations aswell. I was monitoring the coolant and oil temps with OBD11 the whole journey. I preheated the car with webasto for 25 min and the ambient temp was 7-8 Celsius the whole time. So when i started my journey the coolant temp was according to OBD11 and also the temp gauge about 70 degrees Celsius. O

Also, does a faulty thermostat have an effect to the oil temperatures in some way?

Another question just out of curiosity, what kind of oil temps are you all getting when its colder weather like below +10 Celsius? Especially in the diesel engines? I usually never get the oil temp over like 90-93 Celsius with normal 50-100 km/h driving for 20-30 minutes, if I dont have the windguard in place at the lower grille. With the windguard in place I can get the oil temp over 100 Celsius and even to 112 Celsius max if driven hard. That makes me wonder that should I keep the windguard in place for longer time of the year and take it off after the ambient temps get over 7-8 Celsius regularly. The reason for this is to get the oil temp over 100 to get rid off condensation in the oil...dont know if under 100 degrees is enough to get it off?

Thanks for the reply. So you say that your car reaches 90 Celsius after 20 min highway driving no matter what. Is this the temp gauge reading on the car or have you watched live data readings from Vagcom/OBD11 etc. I have noticed that with my OBD11, it shows lower readings than my cars temp gauge by about 5-10 degrees. Also is your car also a VRS model, because it has really open front grilles that let a lot of air through to cool the engine. Will check that hose going to the radiator. So if the thermostat is fully closed the radiator hose should be cold and the coolant temp under 92 Celsius which is the opening temp for the thermostat. When the coolant temp gets over this 92 degree mark the thermostat opens and the hose to radiator would get warm, right? Can't really say is the webastos heating weaker than normal, havent noticed anything, but will try that what you said, that heat the car with webasto and then try the radiator hose before starting. I have a 1,5 hour drive later today with mostly 80-100 km/h limits and the ambient temp is going to be 5-7 Celsius. I will monitor the coolant and oil temps with OBD11 to see how they behave. I'm starting to think that I may have a partially stuck open thermostat, the spring in it getting weak perhaps.

So if water boils at 100C then the oil temp is best to be little bit over that 100C mark to get rid off condensation. So when its colder weather and the oil wouldnt get over 90 without the windguard in place, is not good because the condensation doesnt boil off. Thats also a good reason to keep the windguard in place, engine gets to temp faster, stays warmer easier, oil stays good and fuel consumption and emissiona are better also.

I am using webasto and windguard when its below 0 Celsius. I have just noticed that on a longer trip with the windguard in the lower grille installed the oil temp in the maxidot would get as high as 110 Celsius. Is this too high oil temp, if you drive like 2-3 hours straight. Without the windguard the oil temp stays at 90-93 max below 0 Celsius ambient.

Ok, thanks for the info.

Maybe the G13 was used in the Euro5 diesels, i have the CUPA-version of 2.0 Tdi. Heres a bulletin by North America Volkswagen that I found from the web. MC-10170208-0001.pdf

Hi. I wrote in the first post that i have a factory webasto in the car that I use when the ambient temp is below 0 Celsius. And I also have a windguard installed in the lower grille also when its below 0 Celsius. What I was wondering is, that if its normal for the car to get to operating temp when the ambient is like 5-8 Celsius, in the descripted manner that I wrote in the first post...starting from cold without any preheating and without the windguard.

Thank you all for the feedback. Im going to monitor the temps for a moment and when the weather gets warmer if the car doesnt seem to get to the normal operating temp, im going to change the thermostat. Btw has anyone flushed your coolant system and completely changed from G13 to G12 Evo-coolant? Do i have to change the coolant to G12 Evo because i dont have the expansion bottle that contains the silica bag anymore? My timing belt+water pump was changed 2020 with 125k km on the dash, thats when a lot of coolant was changed to new, but not all i think.

I would really like to hear from fellow diesel owners what kind of coolant temps they are getting in chilly weather? Im holding back on buying new parts, because still dont know for sure is my car faulty or not. The upper and lower grilles are pretty open in Vrs and when its cold weather, it cools the engine for sure with the cold air blowing. I have had this car for 2 years now and the two winters that have been, i have used a windguard in the lower grille and that helps to keep the engine warm below 0 Celsius. Theres only one thermostat and its a mechanical one not electric, so no fault codes coming from that one either i would think. Also the coolant temp sensor when read with Obd11 live data, shows in my opinion reasonable readings even though they differ from the cars temp meter by showing 5-10 Celsius lower readings when the needle starts to rise from 50 Celsius. I would think that if this was broken it wouldnt show nothing or off the scale readings, also there would be a fault code registered. Both parts are original from the factory. Am I correct that a faulty thermostat would fail so that its spring gets weak or breaks so that it stays open completely or partially?

Ok, thanks for the reply. So you are saying that your petrol car reaches over 90C after a 5 mile run, even in colder weather like 0-5 degree Celsius? Petrols do run warmer and also warm faster, yes?

And what I really want to know is my cars behaviour and the coolant temps normal before I go changing parts?

Thanks for the reply. I have watched videos and read from the web instructions how to change the thermostat and coolant temp sensor. They dont seem to be hard to replace, but the coolant bleeding process is pretty akward in this engine type. I have Obd11 but dont know if I can bleed it right with it? Any other suggestions for the possible fault? And tips for bleeding the coolant system?

Hello! My car is a late 2014 2.0 Tdi Vrs, engine code CUPA and 6-speed manual gearbox. Mileage at the moment is 210k km. Yesterday i noticed that my cars temperature gauge wouldn't reach the 90 degree mark. It was +5-7 Celsius outside when driving. I had just the day before yesterday removed a "windguard" from the lower grille in the front bumber. The windguard helps to get to operating temp faster and keep the engine warm during winter time here in Finland, i dont use the cars auxiliary heater/webasto when driving, only before starting the car when its minus degrees outside for like 15-30 mins. Ok, so today i took a drive and connected my Obd11 to the car and followed the coolant temperature while driving around. I was driving for 60-90 km/h for like 20 minutes and the coolant temp wouldn't rise over 70-71 Celsius according to live data in Obd11, the cars temp gauge read about 80-83 at the same time. I then went off to motorway and accelerated hard a couple times from 100-140 km/h and also drove in the motorway for maybe 10 minutes with a constant 120 km/h, Obd11 showed that temp wouldn't rise over 75 Celsius and the cars temp gauge was reading 90 Celsius, just in the middle of the temp gauge. The maxidot display showed that oil temp was 87-93 Celsius when driving in the motorway. I also put the heater on max temp and full blow from the top vents, the air was warm but not hot. The temp gauge and obd11 readings would drop by a few degrees this point, but would come up after putting the heater setting back to 22 Celsius and Auto-mode blowing. The outside temperature was also this day 5-7 Celsius when driving around. Do I have a faulty thermostat/stuck open, a faulty coolant temp sensor or something else? Or is it a normal operating temp for 2.0 Tdi when its early Spring outside temperatures here in Finland. Searching the web says that normal coolant temp is 75-105 Celsius, but i would have thought that if the car is Ok, it would reach about 90 Celsius real temp in normal driving when ambient temp is over 0 Celsius. The cars coolant level is ok and I have replaced my coolant bottle with the version that doesn't have the silicate-bag in it. I also don't loose coolant. Is there something wrong with my car or is this normal temps this time of the year? Thank you!

Check this out. I changed tired ten year old original struts to these. There is a Youtube installation video how to do it. Also i calibrated the boot to not open full lenght of the struts so they will last longer. But the issue of the original struts having too short wires is non-existent in the linked struts+they are more robust in my opinion also. https://power-tailgate.com/electric-tailgate-actuators-set-skoda-octavia-2012-2020-deffner-s52-left-right

Any more info or opinions???

Check my post above, i can recommend those what i linked earlier, if you have electric boot.

Anymore info/opinions about this topic?