2015 Passat TDI EA189? Coolant hose issues

[Peytsdad]

Heater Core. Since 9/3/22 I’ve blown 3 of these fittings. I didn’t know there was no heat til the night before the last break on 10/23. The dealer fixed the 3rd one under warranty of his fix 2 weeks prior. I asked them to diagnose the heater core and the duct sys valves. They said the heater core is blocked cuz the louver things showed ok on their test. But they wouldn’t say the heater core blockage would cause the part to blow. They wanted $1200 for the heater core job. I had to say no thank you. I got a $70 Nissens 561819031C heater core cuz I read on a forum they had larger passages. It took 2+ hrs to replace following this Youtube video. I cut open the bottom end of the heater core to find 3/8in clumps of black clay. 3 dealer flushes had no effect on the heater core blockage. After I got it out and before I cut it open I blew hard in the lower hole to see what the resistance was. There was some but I displaced the clumps I guess. I’m a blowhard. I can’t figure how to paste pics from a iPhone. If there’s a blockage at the heater core would more heat build up at the fitting and blow it or is there more pressure at the fitting bc of the blockage? I hope this helps somebody.

 

[GlennW1173]

I have posts in another thread on this issue (and others have similar issues), but even with complaining to VW this is what I got covered and not covered on my 2015 TDI Passat - (In service date in Feb 2018 so post scandal but out of base warranty):

July 2022 - Water pump - Covered under TDI. - 61K miles - South Coast VW - Santa Ana, CA
Aug 2022 - Heater hose - Not covered - About 66K miles -VW Topeka
Aug 2022 - Heater core block - Not covered - About 66K miles - Emich VW Denver
Aug 2022 -Aux coolant pump - Not covered - About 66K miles - Emich VW Denver
Sept 2022 - Heater core - Covered under TDI warranty - About 67K mile - South Coast VW -Santa Ana, CA
Oct 2022 - Ground to Aux coolant pump not good (additional ground wire added) - Covered under TDI warranty - About 68K miles - South Coast VW, Santa Ana, CA

My out of pocket on the above non covered repairs was about $4,000.

Complaints were made to VW customer relations who worked with the dealer service manager in Denver. Dealer in Denver did not think that his uncovered repairs were warranty (even with the subsequent repairs) and would not unwind and re-submit as warranty. Denver had wanted to change my duct valves, but I didn't what changed (and the valves are functioning properly now - There was just no heat because of the partially blocked heater core).

Once this car goes beyond the TDI warranty I would replace with the heater core with the Nissan part, but because it was covered I stayed with the VW part.

2015 TDI is very tough on the VW coolant with the changes made in 2015 to warm up the engine faster. I think the VW changes that were done for the fix put even more pressure on the cooling system (for the 2015 cars).

This car was great from Feb 2018 to July 2022 but has been a nightmare since. It's probably had about 30 shop days in 3 months! This car will probably be up for sale in the next year or so, and certainly no more long trips with this car.

Glenn

 

[calimustang]

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Eroded heater core elbow II

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Eroded heater core elbow

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OC 4

forums.tdiclub.com

Erosion from Diesel Gate Grit. Solids forming in the coolant from excessive EGR temperatures. Flush your systems. Be ready to change more plastic parts in your system. It is emissions related, and covered if warranty is still in place.

holy NASTY! thank you for sharing!

 

[ssarg95]

This was my problem last winter for 2 months. Broke that plastic piece 3 times - all replaced by dealer under warranty. They tried replacing the EGR cooler as a fix, until I found a thread on heater core causing this issue. I replaced the heater core while it was broke, got it in to the dealer for them to replace their fitting that broke again. Only, they told me the heater core was covered under the Diesel gate extended warranty. So lessons learned is to attempt to get the heater core replacement done under warranty since it is apart of the coolant system before doing it yourself and ultimately "voiding" warranty.

 

[AJonathan]

Living this nightmare now. Wife had it crack on the day before memorial day in the middle of nowhere Oklahoma. Towed to nearest dealer. Drove it 300 miles, and this time it stranded me in the middle of nowhere Texas. Towing tomorrow. I watched the oil temp very closely today while driving it. I thought everything was fixed, but it seemed to run around 250F at 80 mph in 100° weather. Not sure if that is normal. I know the temp range VW specifies is very wide and this is well within it. I never watched the oil temp before, so not sure. I know in the winter the heat did not blow very hot, which in Texas wasn't much of a problem, but perhaps this is the symptom of a greater problem.

 

[740GLE]

if you had a regen during 100F outside temp while doing 80mph, i can see 250 oil temp as being a possibility.

Did the coolant gage move off center?

 

[AverageAndy]

but it seemed to run around 250F at 80 mph in 100° weather. Not sure if that is normal.

When I follow my oil temps I routinely get 240-250F running 80+mph in >100F ambient temps. Not saying that is normal, just giving you another data point.

 

[AJonathan]

if you had a regen during 100F outside temp while doing 80mph, i can see 250 oil temp as being a possibility.

Did the coolant gage move off center?

I don't know if it was doing regen.

I drove it about 3 hours in 90-100° temps, and it seemed to hang around 240, increasing to 250 with higher speed and temps. The coolant temp never wavered until *ding* the coolant light started flashing. I quickly took the next exit and turned on the heat. The coolant temp gauge only raised a bit (maybe one tick up) and I wasn't driving long. Added more coolant, got it to the next exit and gas station, and parked it. Came 1.5 hrs to dealer this am on a wrecker. That dumb hose stud is completely snapped off again.

Talking to service guy on phone and relayed info that I had learned here- that it commonly occurs multiple times and is related to heater core being clogged and is sometimes covered by TDI extended warranty. We will see what comes of it. So far their service estimate says $0 warranty covered.

 

[740GLE]

yeah thats not right, i wonder if the coolant shroud is sticking partially open on the water pump.

 

[Pianoforte]

Same issues as everyone has mentioned before me. My car was first at the dealership only 3 weeks ago to replace a hose. It had been holding coolant fine after repair until I took a trip from Fort Worth to Houston. Did fine getting there. One hour into my return coolant is gushing. Towed to dealership who replaced the top heater core hose. Get an hour down the road, red light comes on. I put coolant in but it is dripping out and car was towed to Waco dealership where it currently sits. What have you who have been thru this have found actually was the problem? Is it the heater core? My heat works fine, no coolant drips on floorboard, no fogged up windows.

 

[Rachelns]

How does this happen in a day and a half?

Yes !!! Same thing on my 2015 VW Passat TDI. Two times !!! About 600 miles apart/2 weeks. VW refusing to fix it with diesel-gate warranty! First time I can understand. But second time the check engine light DID come on! I took a picture but then it turned off when I fixed it again.
I’m thinking something in the engine is causing this to happen. I was not pushing the car at all. RPM at about 1.4 to 1.5. On the freeway. Driving at night when it happened both times !! Both times it ruptured in the same way with a hole that looks like yours.

 

[Rachelns]

Has anyone else have any Coolant hose issues? I have coolant literally gushing out of a coolant line behind the valve cover, against the firewall. Dealership is saying that it's cracked. Left me stranded...I am wondering if maybe my heater core is clogged?

Has anyone else have any Coolant hose issues? I have coolant literally gushing out of a coolant line behind the valve cover, against the firewall. Dealership is saying that it's cracked. Left me stranded...I am wondering if maybe my heater core is clogged?

Yes !! Same thing happened to my 2015 VW Passat TDI. It happened, so I had it fixed. Then it happened again about two weeks later. Same thing !! Have photos of both failures to show.

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• Rachelns
• Jul 12, 2024

2015 VW Passat TDI heater hose rupture two weeks after replacing it from when it did this the...

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• Rachelns
• Jul 12, 2024

2015 VW Passat TDI Heater hose ruptured. Replaced it and same thing happens again about 2...

 

[Rachelns]

I have the same leak on my 2015 Passat TDI EA288. I told the dealership when it was under warranty and they told me that they couldn't find a leak anywhere, but it was really easy to find. A TDI mechanic that does not work for a VW stealership, found it and told me that he had someone else had tried to get the work done under the dieselgate fix extended warranty, but to no avail.

Ya VW is refusing to fix mine as well and it’s happened to me twice now! My check engine light even went off the second time. I took a photo for proof. But then it turns off later. Does not matter. If they can’t see the check engine light and blame it on the engine then they will not fix it under the warranty. That’s how it was explained to me. Such BS!! Something is causing this… Plus the integrity of this part is horrible!!! It’s plastic !! It should be made of something stronger to prevent it from rupturing so easily. And look how thin that part is. I’ve been told by two different mechanics now that this part is problematic and a common failure. The 2nd time this happened I was stranded on the highway in the middle of the night with my kid, in the middle of GA for 15 hours before a tow truck showed up. So ya I’m NOT happy about it all.

 

[Pianoforte]

Has anyone tried a DPF delete to resolve this problem? I found someone who had had the same leaking hose issues and he said the problem was actually with the exhaust system.

 

[Rachelns]

IMG_7877.jpg

Eroded heater core elbow II

forums.tdiclub.com

https://forums.tdiclub.com/data/xfmg/thumbnail/149/149532-5d9b8e3759393e1219c51054997515ac.jpg?1661794570

IMG_7876.jpg

Eroded heater core elbow

forums.tdiclub.com

IMG_7948.jpg

OC 4

forums.tdiclub.com

Erosion from Diesel Gate Grit. Solids forming in the coolant from excessive EGR temperatures. Flush your systems. Be ready to change more plastic parts in your system. It is emissions related, and covered if warranty is still in place.

VW is refusing to fix it under that warranty for me. If check engine light does not go on and stay on, they are saying no. Not connected. It’s happened twice to me now too. What a nightmare it’s been dealing with breakdowns in the middle of the night in the middle of nowhere. 15 hours for a tow truck to get to us 300 miles from home. This was right after I replaced the first one too !!

 

[Rachelns]

Were you getting heat in the cabin evenly on both passenger and drivers side before the issue arose? If so, the core is probably not clogged.

It seems conceivable that a completely clogged core could burst or crack a hose due to excess pressure. If it was my car I would replace all the hoses between the radiator and the heater core (inlet and outlet).

This has happened to me twice now a couple weeks apart. I had the heater core checked and it was fine. Heat comes out well and evenly. So that’s not what caused mine to rupture two times. One right after the other!!

 

[Rachelns]

IMG_7877.jpg

Eroded heater core elbow II

forums.tdiclub.com

https://forums.tdiclub.com/data/xfmg/thumbnail/149/149532-5d9b8e3759393e1219c51054997515ac.jpg?1661794570

IMG_7876.jpg

Eroded heater core elbow

forums.tdiclub.com

IMG_7948.jpg

OC 4

forums.tdiclub.com

Erosion from Diesel Gate Grit. Solids forming in the coolant from excessive EGR temperatures. Flush your systems. Be ready to change more plastic parts in your system. It is emissions related, and covered if warranty is still in place.

do you know how to get it covered under the warranty ? Mine is still in place. I still have like almost 2 years and/or 35,000 miles left on my extended warranty from diesel-gate. Yet VW dealership is saying no it’s not covered, like those parts or failures anyways.

 

[calimustang]

why keep the emission? no inspection or testing here in Florida. go delete and never worry about it. I have 2015 Passat as well and troublefree. deleted at 40k miles in 2019 and now 162k miles. I'm in Florida as well.

 

[oilhammer]

Need to check the vent line assembly.... remove the whole thing and blow through it every which way with compressed air. Also make sure all the nipples the vent line assembly goes to are free and clear.

 

[Pianoforte]

Curious if replacing the heater core was the cure? $4,000…..replaced hoses and finally the heater core. Love the car but wondering if it is time to look for something newer.

 

[oilhammer]

Well if you want something better, then looking for something older will yield much better results.

 

[Pianoforte]

Has anyone kept their Passat after the heater core was replaced? Was the problem completely resolved? My heater core was replaced approximately a month ago. So far no problems and I have driven the car 1-2 hours several times since. Just questioning the reliability of the car long-term.

 

[oilhammer]

Until it is deleted, expect it to possibly happen again.

There are tunes that can back off the overly aggressive EGR duty cycle (but keeps all the hardware intact) that can help, too.

Bottom line is, it's a crap design. The coolant has too many hot spots, the EGR cooler being the main culprit. It boils the coolant so bad that the additives drop out of suspension, and the next stop after the EGR cooler is the heater core. Which ends up acting as a very effective filter, and all those particles that are no longer in liquid suspension just pack up in there.

 

[Pianoforte]

Until it is deleted, expect it to possibly happen again.

There are tunes that can back off the overly aggressive EGR duty cycle (but keeps all the hardware intact) that can help, too.

Bottom line is, it's a crap design. The coolant has too many hot spots, the EGR cooler being the main culprit. It boils the coolant so bad that the additives drop out of suspension, and the next stop after the EGR cooler is the heater core. Which ends up acting as a very effective filter, and all those particles that are no longer in liquid suspension just pack up in there.

Thank you for the information.