whizznbyu
Veteran Member
- Joined
- Jul 11, 2006
- Location
- Waxhaw, NC
- TDI
- 2015 Golf Sportwagen 6 speed manual. B5 died at 302k miles.
How many miles in this car that overheats?
TDI “Slowly” Overheating
- Thread starter Huckfinndy
- Start date
Highwaylizard
Well-known member
Encountered a new twist to my overheating issue today while sitting in line at the carwash to get the winter salt washed off DasAuto.
Idling, I watched the coolant temperature per the Scanguage slowly climb and top at 204 degrees. Car was not doing a regen. The temperatures went back down to 188 once I got inside the car wash - water on the radiator? Driving on the highway the coolant temperature dropped to 161 degrees. Sitting at stoplights I watched the coolant temperatures begin to climb as high as 175. Got home and popped the cap off the coolant reservoir and didn't see any coolant moving in the globe at idle. I didn't have anyone available to run the revs up while I watched the reservoir but I will see if I can get someone to help me with that tomorrow.
Any thoughts here? Not sure if it is related but the car has developed a very pronounced diesel engine sound over the past couple of days - not quite a knock but kind of a rattle while under load. Mileage is also down over the last two tanks. No codes. Air temperature was right at 50 degrees.
Idling, I watched the coolant temperature per the Scanguage slowly climb and top at 204 degrees. Car was not doing a regen. The temperatures went back down to 188 once I got inside the car wash - water on the radiator? Driving on the highway the coolant temperature dropped to 161 degrees. Sitting at stoplights I watched the coolant temperatures begin to climb as high as 175. Got home and popped the cap off the coolant reservoir and didn't see any coolant moving in the globe at idle. I didn't have anyone available to run the revs up while I watched the reservoir but I will see if I can get someone to help me with that tomorrow.
Any thoughts here? Not sure if it is related but the car has developed a very pronounced diesel engine sound over the past couple of days - not quite a knock but kind of a rattle while under load. Mileage is also down over the last two tanks. No codes. Air temperature was right at 50 degrees.
AverageAndy
Veteran Member
- Joined
- Sep 14, 2020
- Location
- Phoenix, AZ
- TDI
- 2013 Passat TDI SEL, 2013 Golf TDI 6MT, 2013 Jetta TDI 6MT (R.I.P.)
My car was overheating, usually up to 108-109C, sometimes as high as 112C if performing a regen. I kept it in check by using the cabin heat on high to blow off some of the heat. I planned to replace the thermostat and thought, I should just replace the oil cooler with a metal one while I'm in there, because of all the parts that need to come off. I did not have issues with my current one leaking, or so I thought. When I got to the oil filter housing, it was obviously a few miles from exploding coolant all over the place. The seal on the block was partially baked on and tore when I removed the housing. It took quite a bit of 3M scouring pads to get it all clean.
Good news is that replacing both the thermostat and oil filter housing solved my overheating problems. Now temps are 95-97C under normal driving, up to 99-100C under heavy load or active regen. No more fans running when I shut the car off!
Good news is that replacing both the thermostat and oil filter housing solved my overheating problems. Now temps are 95-97C under normal driving, up to 99-100C under heavy load or active regen. No more fans running when I shut the car off!
travelfreak
Well-known member
I had same issue. Replacing radiator solved the issue. Before it was 100 C during bumper to bumper traffic. Now most 85 C
TDI914
Well-known member
- Joined
- Jul 10, 2001
- Location
- Eastern Tennessee
- TDI
- Drive 50k+ a year. Have owned 7 diesels. 80 Rabbit 190k 82 Peugeot 505s 165k 87 Jetta Turbo Diesel 278k Volvo 740 turbo Diesel 245k 97 TDI Passat 249k '03 Jetta TDI 255k. Currently own '14 Passat SEL 140k Church, Autocross, Mountain Biking
I always stay at 190. I have 147K miles with new timing belt-water pump-heater core at 130k. I run 70-75 on the interstate. But I have always had the problem that on a long rise or hill on the interstate the gauge would creep up to 200. My Bug Shop (40 years in business) told me not to worry, just don't go up into the red. This is the 5th VW diesel that I have owned, all of which I drove until the 250k mark. This is a 2014 SEL Passat. Love the Car. IT troubles me to see 200 degrees. Is there a chance of warping or cracking a head? It easily cools down to 190. I just don't want to trash a motor. All the fans work, it regens like normal. No leaks in the system. What think you?
First off, I would recreate the climb, but use VCDS to scan the actual coolant temp. The gauge is dumbed down and may be peaking to 200 even though it's only at 195...
Other than the other common cooling system items, (T-stat, rad etc) I would proactively change the coolant temp sensor to ensure that it's at lease reading correct. Have seen more than one car "overheat" when it was only the temp sensor reading 10 degrees high...
Other than the other common cooling system items, (T-stat, rad etc) I would proactively change the coolant temp sensor to ensure that it's at lease reading correct. Have seen more than one car "overheat" when it was only the temp sensor reading 10 degrees high...