High elevation, hill climb, high load overheating?

ChadS99SVT

Veteran Member
Joined
Jul 17, 2012
Location
Parker, CO
TDI
2013 Passat TDI DSG
Always remember that your diesel is very different than the gasoline fueled engine you grew up with. You naturally shifted down when your gasser ran out of revs or torque. The thing is that your diesel does neither. You'll be buzzing along at highway speeds and find that you're climbing a rather steep grade. Your engine will seem to be quite happy and will be pulling well. You'll notice, though, that your foot is pressing the go-pedal closer and closer to the floor and if you have a scan gauge you'll note rapidly increasing exhaust temps. Simply shift down and watch things return to normal.
This is pretty much exactly what I do. When I see my temps start to spike I shift it into sport mode and that removes a gear (If I remember correctly) amongst other things...but that usually does the trick and at least keeps the temps from continuing to climb and usually they stay near 225*

fwiw I do still drive the mountains often and I see temps above 230* each season.

I have over 80k miles now and no problems to speak of:cool:

*knock on wood*
 

Brad95

Veteran Member
Joined
Aug 9, 2012
Location
Arizona
TDI
2013 Passat TDI SE Manual since 09/28/12-04/05/18, 2015 Passat TDI SE Manual Since 03/29/2018
hi chad!
i am in the same boat, i do not have ScanGauge, but seeing high temp (needle moves bit on right) when outside temp between 40-50 on steep hill. dealer flushed coolant still the same. dealer scan for codes but there was none.
 

Brad95

Veteran Member
Joined
Aug 9, 2012
Location
Arizona
TDI
2013 Passat TDI SE Manual since 09/28/12-04/05/18, 2015 Passat TDI SE Manual Since 03/29/2018
Resolved!

having same over heating problem as needle moves towards right @10 on uphill, had a thermostat that started to open at too high a temperature. The first symptom was the cooling fans were always on. Then it started to overheat under load.based on my home work from TDI club and other sites, found thermostat was the culprit. thermostat sticking, opening late.

symptoms/solution:
1) problem started in last week of February right after i had 1k mile round trip. never had this before. during trip it was driven 70 ~ 85mph for minimum 4.5 hours without stop.

2) when ever driven under load specially in 6th gear, even on light uphill between 65 to 75mph. temp needle drifts towards right and slowly comes back in middle. sometimes needle moves back to middle right a way.

3) had around 59k miles on odo and it was due for OC.i had dealer flush the coolant as well, in hope that radiator flush would rectify this overheating issue!. coolant flush reduced some what of needle movement. but was not enough for me to say resolved!

4)one thing i noticed! from last week in February, right after driven to operating temp, when ever it was parked , fan always kicks on after 1 second of ignition turned off,without missing a single day!. and i know it was not in regen.

5)to rule out other possibilities like head gasket ,WP. to rule out head gasket did hydro carbon test came out negative. WP was working fine since never missed slightest heat in cabin as well as did check reservoir hose that connects on top coolant reservoir,it had steady flow. upper radiator hose from engine to radiator felt pressurized and it was getting very hot to touch, the way it supposed to be.

6)one thing during this ordeal "bottom radiator hose that connects to thermostat housing never felt warm" or for sake Luke warm. it was always remained cold or enough for me to say dead cold. last checked @ dealer after 1.5 hr drive while ambient temp ~ 90F. "cold".

7) t-stat housing ordered thru dealer, made an appointment to change thermostat. in CKRA passat it's whole thermostat housing, dealer ask, if i want them to diagnose overheating instead of me telling them to go ahead and replace thermostat, as they have been aware of it since my last visit for OC & coolant flush. but according to dealer from last visit, as long as needle does not move to red zone it;s not considered overheating. second thing is for dealer to duplicate this, they need to drive under load on hilly area, which is not possible by them and i knew they'll come back stating can't duplicate issue. diesel engines are so heat efficient, even if they leave car running for several hours in their shop temp needle will not move past midpoint.

8)Changed t-stat, drove under load on the same road, needle did not move a bit from 190F. Stayed steadfast @190F. upper rad hose very hot, bottom very warm. while A/C off & engine running Fans are not constantly running (it cycles on/off though) while idling. got relief from daily occurrence of having car parked & rad fans were keep running, after ignition off, not any more!. - problem solved!!

8)for me, the key indicator for bad t-stat was the cold lower radiator hose that connects to t-stat with a hot upper radiator hose (at any given time no matter what ambient temp was!).-thanks
 
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740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
whats the part # and what'd they ding you for labor?

I've always thought the wifes passat was sticking open, seemes to take longer to get up to NOT than the jetta on the same stretch of road.
 

Brad95

Veteran Member
Joined
Aug 9, 2012
Location
Arizona
TDI
2013 Passat TDI SE Manual since 09/28/12-04/05/18, 2015 Passat TDI SE Manual Since 03/29/2018
whats the part # and what'd they ding you for labor?

I've always thought the wifes passat was sticking open, seemes to take longer to get up to NOT than the jetta on the same stretch of road.
part#03L121111Q, total $846.33, 6hours) had to remove alternator & intake cooler,Coolant flush etc have not claim geico's maint break down yet! i was still shy of 60K.

Following thread post #28 by DanG144 helped a lot:

http://forums.tdiclub.com/showthread.php?t=234002&page=2

-thanks
 

ChadS99SVT

Veteran Member
Joined
Jul 17, 2012
Location
Parker, CO
TDI
2013 Passat TDI DSG
part#03L121111Q, total $846.33, 6hours) had to remove alternator & intake cooler,Coolant flush etc have not claim geico's maint break down yet! i was still shy of 60K.

Following thread post #28 by DanG144 helped a lot:

http://forums.tdiclub.com/showthread.php?t=234002&page=2

-thanks
While I'm not disagreeing with you I do think it's overkill and possibly just coincidence at this point.

I like you went after the dealer, called VWOA, made the tech drive with me for a 45 minute drive in a brand new Passat TDI off the lot to replicate. that car got hot, not quite as hot as mine but went over the standard dummy gauge reading. (as noted in this thread).

I'm now at nearly 82k miles with countless times I've seen 230+ temps and no problems to speak of.

VW and all the techs have continuously said working as designed....

The fans you're speaking of could be a number of things and I'd be willing to bet a majority of the time you're interrupting a regen.

I'm not sure how you can accurately log and measure your results without having a scan gauge or similar tool. simply relying on whether or not the dummy gauge moves is a very wide spectrum and hardly accurate. the times you didn't see movement could have been times you thought the car was up to temp when in fact it was sitting at well below 190 degrees as I believe the dummy gauge reads 190 when the temp is actually as low as 165(if my memory serves me right. Never pay attention anymore :) ). Then it doesn't move off until you cross 225. that's a huge spread....

Just saying. I'm glad you think you've fixed it but for $900 I'll pass....I hope you don't see that gauge move in the future because that will be a punch in the stomach after dropping the coin to get that "fixed"

in all seriousness thank you for sharing your results though. :D:cool:
 

Brad95

Veteran Member
Joined
Aug 9, 2012
Location
Arizona
TDI
2013 Passat TDI SE Manual since 09/28/12-04/05/18, 2015 Passat TDI SE Manual Since 03/29/2018
thanks chad!

i brought back old t-stat and i can see inside housing where t-stat resides, seems like bottom round plunger slightly broke.possibly letting coolant pass through continuously!. i don't know where this bottom hose connects to, either EGR cooler or oil cooler!

according to dealer, as long as temp gauge does not go in red-zone and throw any codes, then it's normal. for me when gauge moves to 10'o clock, it's already passed 225 and overheating!. it supposed to run within 167~225 range.

as far as i know, only 2~3 times i have interrupted regen when i bought it initially,so i ruled out that possibility. also i always let it run for at least a 30 sec to minute or some time more than minute if time permits, after parking before turning it off!. another possibility for fans to run continuously after turning off is the t-stat opening partially and opening up very late.

after replacement, tested it on same roads with same criteria, where it was passing 190mark and now it does not!.

my goal was to inform members here! my case, i don't have skill nor sufficient tool to carry out this job my self.afterwards, i asked independent mechanic in town and he said he could have changed it in $250(labor only).

-thanks
 
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Reccekev

New member
Joined
May 21, 2016
Location
New Brunswick
TDI
04 passat and 2000 Excursion 7.3L
Help help help....anyone....I notice a lot on these forums about overheating so I am taking a stab at someone having an answer to this puzzle. I own a 95 golf diesel and recently bought an 04 Passat TDi with the 2.0l engine. The guy I got it from was a vw dealer and mentioned that his wife noticed that the temp was at the top of the range so I should change the thermostat. Shortly after getting it home and driving it the temp hit the high mark and the red STOP showed up on the dash.

Took it to a garage, they ran it....wouldn't overheat, hwy test... not for them...long story now short, changed the WP, T belt, Thermostat. They ran it in the driveway for 2hrs...no problem. I get it back drive it for a bit and low and behold still overheating. Seems to be overheating under load or the 110km on the hwy for any length of time.

I have heat from the heater core and cranking that brings the temp down. We noticed the aux cooling fan was not coming on when high heat, so we bypassed all the electrical crap and have it hooked direct to the ignition so it is on all the time to see if it can hold the temp......of course ...no luck...

we live on a hill and it was hot coming home but when we hit the incline about half way up the STOP came on again.

I have researched as much as I can on this and much points to the WP but this is starting to annoy me and I don't want this to be a mechanic special and just dump countless dollars at it, or god forbid a head gasket.

Any advice you could send my way would be awesome. Thanks for your time
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
My guess is that your radiator is gunked up and not cooling effectively.
 

Reccekev

New member
Joined
May 21, 2016
Location
New Brunswick
TDI
04 passat and 2000 Excursion 7.3L
thanks

Sweet...I'll get that checked. Is this something that can be remedied by a coolant system flush or is this the new rad territory?
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
You could try an acid flush if funds are tight. Personally, I'd just replace the rad. if it is clogged.
 

turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
I'd also check the exterior of the radiator for blockages.
 

Mechnurse

Veteran Member
Joined
May 17, 2005
Location
Pahrump, Nevada
TDI
97/2K/05/15 Passat 06 Jetta TDI
2015 Passat here

I notice the temps will climb from the usual 197 to 213 during a 7% grade climb with high throttle input and definitely go to jail speeds. But this car runs much cooler than others noted here.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
Yeah the new engine got a different thermostat style that makes it run cooler than the CKRA engines while under load.
 

Fixmy59bug

Veteran Member
Joined
Aug 1, 2009
Location
Las Vegas, NV
TDI
2015 Passat TDI SE
This last weekend I went down to Cali to visit my family. This was a 225 mile trip through some of the hottest mountain areas of Nevada and Ca.

Of course, it isnt "middle of summer" hot yet, but it was about 90 through most of the trip.

I had Torque going on my Andriod, and I saw the hottest coolant temp I have ever seen in my Passat to date (235*).

Thanks to Torque, I have learned that while the needle will stay solid until 225*, each line after 190 represents 5*. But that isnt important to my story.

So like I said, I saw 235* on my coolant. Should I be worried and have my technicians chase a ghost or is it safe to assume it was because I was climbing mountains in the heat?

I did have my cooling system cleaned and flushed about 5k miles ago at my 50k service in hopes of avoiding a clogged heater core.
 

VeeDubTDI

Wanderluster, Traveler, TDIClub Enthusiast
Joined
Jul 2, 2000
Location
Springfield, VA
TDI
‘18 Tesla Model 3D+, ‘14 Cadillac ELR, ‘13 Fiat 500e
This last weekend I went down to Cali to visit my family. This was a 225 mile trip through some of the hottest mountain areas of Nevada and Ca.

Of course, it isnt "middle of summer" hot yet, but it was about 90 through most of the trip.

I had Torque going on my Andriod, and I saw the hottest coolant temp I have ever seen in my Passat to date (235*).

Thanks to Torque, I have learned that while the needle will stay solid until 225*, each line after 190 represents 5*. But that isnt important to my story.

So like I said, I saw 235* on my coolant. Should I be worried and have my technicians chase a ghost or is it safe to assume it was because I was climbing mountains in the heat?

I did have my cooling system cleaned and flushed about 5k miles ago at my 50k service in hopes of avoiding a clogged heater core.
If that's at full load up a mountain, I think you're fine. While this is on the warmer end of what we've seen with the CKRA engine, it is still within the safe range for the coolant.
 
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