Klippmann

Now thats some good information! Thanks heaps. With reference to the algorithm displaying temperature, this explains quite a few things. Yes, this is a DSG and I completely agree with replacing the thermostat first due to ease and cost of replacement. However, this vehicle is still under warranty for another year, and while it is under warranty, I cant touch anything myself without upsetting the service centre who will deal with any warrany claims. And I certainly wont get my money refunded if I take it to a third party and ask them to replace the thermostat in order to troubleshoot a problem that will most likely end up with the water pump being replaced. I guess my issue is this, I know there is a problem because since the overheating issues which fixed themselves, it doesnt behave the way it used to..... how can I convince the service center that there is in fact a problem with the cooling system when they take a 10 minute look at it and tell me "There are no fault codes and the system appears to be functioning normally."

Thanks! Why was the water pump changed?

Thank you! The first person who actually answered the question! Thanks also for the other very relevant info. Good input from everyone else though.

Avocet, this is exactly what I suspect, however I have no way of proving it...... and yes, the diagnostics would have no clue that there is an issue. This is why Im looking for information from other 2.0 TDI owners as to how long a 'normal' warm up is.

Thanks for the input. As stated in my post, other than the first overtemp notification, its never gotten that hot again, and now it doesn't fluctuate, it just takes forever to reach normal operating temperatures. I spent quite a many drive with the camera in hand to try and capture the moment. The problem is my service center is not very switched on...... 😞 i have to explain everything 3 times, then get passed onto the next person etc.....then they still get it wrong. Im looking for information that they simply cannot explain away with "no fault codes found, system operating normally" Such as a normal warm up time when idling.

Hi Guys, looking for some information from the Kodiaq community. Specifically the 2.0 TDI owners. Owned the Kodiaq since new (2018) Tropical Cairns Australia. Mechanical Engineer by trade, so very familiar with cooling systems, thermostats, water pumps, old engines, new engines etc. As expected, towing a heavy load up the mountain range leads to elevated cooling system temperatures (not into overtemp) until good airflow and flat ground is restored. At this point the cooling system is at full flow capacity, whatever heat is extracted from the radiator is where the engine temp will settle. So some increase in engine cooling system temperature is expected and also observed. Other than towing a trailer up the range, the temperature needle always sits right in the middle where it should. HOWEVER.... A while ago, I noticed that while sitting at the traffic lights (quite a cool morning, only about 12Km down the road from home and this was the first drive of the day) not towing anything, only driving up a very small hill, the water temperature all of a sudden began to rise quite quickly. I proceeded to drive at the green light, all the time temperatures increased until overtemp warning sounded only about 200m down the road. Within about 2 - 5 seconds, the warning went away, temperatures dropped back to their normal indication and no abnormal indications for the rest of the day. Following this strange occurrence, I reported this to my service center, who proceeded to find nothing (as expected). This strange behavior repeated itself many times after that (other than the first overtemp warning, there have been no instances of it reaching the red zone on the gauge), always with the same outcome, "no faults found, cooling system operating normally". Even stranger, I would observe the engine water temperature to increase while driving along straight flat ground with no obstructions to the airflow (like when closely following a truck), then decrease back to normal again with no change in engine load, vehicle speed etc. This persisted for about a year, and its now been quite some time since it has repeated the strange temperature spikes. Then about 3 months ago, funnily enough, in our winter (18 Deg C) I noticed that it took significantly longer for the engine to achieve normal operating temperature. It used to take maybe 1.5 Km down the road, and the temperature needle is bang in the middle where it should be. Now it takes over 10 Km for the engine to be at a stable operating temperature. Once normal operating temps are acheived, it behaves very normal with no temperature fluctuations. After doing a fair amount of Googling the subject, Ive got a fair idea of what the problem is, however I cant prove it to the service center who continues to find no fault with the system as it is "functioning normally and no fault codes were logged" In my opinion, based on DR Google, the problem lies with the water pump design. From what I understand, the cooling system temperature is no longer regulated by a bi-metallic spring thermostat, however it is regulated by a sleeve in the water pump which is actuated by the engine management computer. It appears from what i have read, that there are plenty of others out there who have had the water pump replaced due to the sleeve sticking and therefore not properly controlling the temperature anymore. In my case, I believe that it is not closing properly, allowing water to flow when it shouldnt during the warm up process. I have even gone to the trouble of downloading a workshop manual so I can do some diagnosing, however the manual seems to be quite light on how long it should take to acheive normal operating temperatures. Also I dont have a vehicle diagnostics tester so that makes it pretty difficult to do certain things. If there is anyone out there with the same experience, could you please share. If there is anyone interested who owns a 2.0 TDI, would you be able to record the time it takes to achieve normal operating temperatures from a cold engine? Ideally just while idling in the driveway, however, I guess distance travelled would also suffice.