Overheating Problems

F

Florida_TDI

Well-known member
Joined
Sep 16, 2004
Location
FL, USA
TDI
Passat, 2012, White
I have a 2014 Passat TDI with 70 K miles that has experienced an overheating problem. I was on a trip and the check engine light came on with a P2457 code (EGR cooling performance) but the car ran fine. I also experienced a plugged heater core which may be related to the P2457. When I got home my VW dealer said my car overheated and damaged the Intercooler pump and the coolant reservoir. They based this on data from the OBD2 scan. However, the temperature gauge never went above 190 degrees. How can an engine overheat without the temperature gauge going up? They said the thermostat was stuck shut and changed it along with the other components mentioned. The bill came to $2400 which really surprised me. Labor for changing the thermostat was over $1000. How is this possible? The car runs fine but I still have the same "burnt antifreeze" smell from the engine bay that I had when the fault light came on. I am not confident that all my problems are fixed. Any thoughts?

As for the clogged heated core, they replaced that under my extended warranty. If the EGR cooling was at fault should that have been covered under the warranty for the emissions system?

Confused in Florida!
 
VeeDubTDI

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Florida_TDI said:
I have a 2014 Passat TDI with 70 K miles that has experienced an overheating problem. I was on a trip and the check engine light came on with a P2457 code (EGR cooling performance) but the car ran fine. I also experienced a plugged heater core which may be related to the P2457. When I got home my VW dealer said my car overheated and damaged the Intercooler pump and the coolant reservoir. They based this on data from the OBD2 scan. However, the temperature gauge never went above 190 degrees. How can an engine overheat without the temperature gauge going up? They said the thermostat was stuck shut and changed it along with the other components mentioned. The bill came to $2400 which really surprised me. Labor for changing the thermostat was over $1000. How is this possible? The car runs fine but I still have the same "burnt antifreeze" smell from the engine bay that I had when the fault light came on. I am not confident that all my problems are fixed. Any thoughts?

As for the clogged heated core, they replaced that under my extended warranty. If the EGR cooling was at fault should that have been covered under the warranty for the emissions system?

Confused in Florida!
Click to expand...
My two cents:

Your dealer is wrong. You are experiencing these issues because of Volkswagen's coolant problem that is plaguing several TDI-powered vehicles, especially the NMS Passats.

The coolant forms solids in it that clog the small passages in the heater core - I'm sure you're familiar with the heater core recall by now. In addition to clogging the passages in the heater core, these solids also clog passages in the EGR cooler and likely in the oil cooler (both coolers have similar sized passages to the heater core). To date, Volkswagen has refused to acknowledge issues with these latter two coolers.

The coolant gauge will move above 190F when the actual measured coolant temperature reaches 226F. If you didn't see the gauge move, then the engine didn't overheat (as long as there was enough coolant in the system for the sensor to read the temperature).

I would put serious pressure on Volkswagen to reimburse you for the work performed. If they refuse, I would consider selling your car back to them since its entire cooling system has been compromised and it will likely continue to cause you grief, even after replacing the EGR cooler at your expense.
 
Last edited:
oilhammer

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Thermostat assembly on the CKRA engine is about $80, and the labor time is 4.7hr. So, depending on what their labor rate per hour is, plus some coolant, I could see it approaching $1k. :(

There are some reports of cooling system debris or something with these, though. You are not alone there.
 
T

tdiatlast

Top Post Dawg
Joined
Jan 21, 2009
Location
Fort Worth, Texas
TDI
2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
"...They said the thermostat was stuck shut..."

Wouldn't this alone have caused a catastrophic overheating event?????
 
R

Rico567

Top Post Dawg
Joined
Jun 13, 2003
Location
Central IL
TDI
2013 Passat TDI SEL Premium (Turned in 7/7/18)
Now driving on our first replacement heater core under the extended warranty, hoping it holds up until we turn the Passat in next year.....
 
7

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
VeeDubTDI said:
The coolant gauge will move above 190F when the actual measured coolant temperature reaches 226F. If you didn't see the gauge move, then the engine didn't overheat (as long as there was enough coolant in the system for the sensor to read the temperature).
Click to expand...

Wheres the temp sensor that feeds the gauge, is it in the block coolant loop or external in the thermostat or some other place?

Also if these chunks are floating around, you think there may have been a change one of these chunks got stuck on the sensor to block a true reading?

I do agree I don't think the OP exceed safe temps of the engine but with a known issue in the coolant it may be tough to say the sensor was operating correctly.
 
W

wsc

Well-known member
Joined
Jan 3, 2015
Location
Cypress Texas (Houston)
TDI
99.5 Jetta, 06 Jetta (Totaled), 14 Passat.
My 14 Passat with 65 k just eroded a hole in the heater core inlet fitting after indicating insufficient EGR cooling. I replaced the fitting and it again coded insufficient EGR cooling at the same time making a burning odor inside the car. Had it towed to the dealer, I printed out my VCDS run for them, let the games begin.
 
W

wsc

Well-known member
Joined
Jan 3, 2015
Location
Cypress Texas (Houston)
TDI
99.5 Jetta, 06 Jetta (Totaled), 14 Passat.
Service Bulletin on coolant issue

https://static.nhtsa.gov/odi/tsbs/2016/MC-10106581-9340.pdf


The Service Bulletin says the coolant is becoming acidic with time and causing the formation of solids. Doesn't say anything about increasing the frequency of coolant replacement. Only says to change it if the heater core plugs up.

IMO, need to change out the coolant in these cars more often to prevent failures on the road. Other problems like water pump seals being worn out prematurely from the fine solids, or thermostats getting stuck, other coolers being plugged, fittings being eroded out (like happened on mine) can be reduced. I'm thinking I'll change mine every 30 k miles or so.

The video link from jrm above https://www.youtube.com/watch?v=sG7ni0lEr94 says a lot about what the problem is and how it is relatively easy to change the heater cores in these cars. Still, you don't want to have one plug off on a long trip at 80 MPH because it will blow the EGR coolant discharge hose and leave you stranded.

Alert! on 2.0 TDI's flush and change your coolant every 30 k miles, no guarantees but it might help.
 
Last edited:
W

wsc

Well-known member
Joined
Jan 3, 2015
Location
Cypress Texas (Houston)
TDI
99.5 Jetta, 06 Jetta (Totaled), 14 Passat.
06bluebeetletdi said:
I love the production solution, don’t make that motor anymore, that doesn’t exactly fix the problem VW.
Click to expand...
Me too. It's not the factory's problem any more. Just ship lots of heater cores and wait till customers bring the cars in. The thing is, it is not just about loosing heat in the car, it causes bigger problems.
 
You must log in or register to reply here.
Top