Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat

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Mon 29 Apr 2019 22:59
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Philflies

Hi,

VW Passat B8 Bluemotion Saloon, 2015, 94k miles.

My Passat is intermittently overheating, about once a week but under quite specific circumstances. The temperature gauge is initially rock steady at 90c and only whilst on motorway or fast dual carriageway around 15mins into the journey (from cold) the temperature will climb past 90c and upto 120+c fairly quickly.

If I notice it happening early enough and give the engine some higher revs 3000-4000rpm it seems to sort itself out, temperature will return to 90c and will be fine for the rest of the journey. It may not occur again for a week or so. It has not happened while doing slower, town driving type journeys.

Could it be the thermostat sticking closed? or maybe the waterpump giving in?

I've got it booked in with the garage to be looked at but want to be armed with some prior info if anyone out there can help please?

Thanks in advance.

Phil

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Tue 30 Apr 2019 01:25
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - elekie&a/c doctor
I suspect the temporary overheat is when the dpf is in regeneration mode.
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Tue 30 Apr 2019 15:13
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Philflies
I thought that too originally but a couple of times it’s made it to the red line, I’ve then got a beep and an overheat warning on the dash. I thought I’d also read that when the dpf is doing its regen you get a symbol on the dash?

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Tue 30 Apr 2019 15:36
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - dieselnut

I think this engine has the electric coolant pump sleeve.

It restricts coolant flow with an electrically operated sleeve until the engine reaches normal operating temperature, the idea being to improve engine efficiency.

Problem is that the sleeve sometimes sticks closed & stops coolant flow, then frees itself.

I belive VW will replace the pump FOC if you have a word with them.

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Wed 1 May 2019 14:25
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Philflies

Thanks for that info, much appreciated.

Having got to the point where it's overheated and come up with a warning on the dash will that have left a fault code anywhere?

Being an intermittent fault you can guarantee it won't perform when it's at the garage!

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Wed 1 May 2019 15:19
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - elekie&a/c doctor
If the car is fitted with an on demand water pump, not sure if this would flag the mil light if in trouble . It is only a 2 wire electro magnetic device, so would need to be open or short circuit to bring the light on . If it is stuck mechanically, the ecu can’t see that.
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Wed 22 Jul 2020 22:14
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Jamie Magee

Spoke to VW today and they mentioned the electromagnetic switch. Off to the garage tomorrow so I'll update the thread once I know it's solved. Hopefully that will be useful to others who come across this issue.

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Mon 13 Jul 2020 12:52
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - thom hayes
Hey - did this ever get sorted? Would be handy to know the outcome, as I’m having the exact same issue now. 2016 2.0 tdi, 100k miles. Cheers!
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Fri 17 Jan 2020 22:41
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Michael Molden
Hi , I have a 2016 VW Passat which has the exact same intermittent overheating fault as your car , just interested what the outcome was with your car ?

Edited by Michael Molden on 17/01/2020 at 22:42

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Wed 8 Jul 2020 12:18
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - thom hayes
Hey - I’m having this exactly issue too. Any chance of an update? What was the cause / fix?
Cheers
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Mon 13 Jul 2020 12:50
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - thom hayes
Hi Michael - did you get yours sorted? What was the cause / fix / cost!?
Cheers!
Thom
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Tue 21 Jul 2020 21:27
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Jamie Magee

I'm also having this issue. Anyone got a solution yet?

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Thu 23 Jul 2020 08:51
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Jamie Magee

So apparently it's coolant pump c on the go and will require a trip to be ??

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Thu 13 Aug 2020 21:26
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Eddjohn

Hello all! I work on these vehicles.. The intermittent over heating issues is caused by the main waterpump. ( on cambelt) the electronic pump has a sleeve that opens and closes. These can stick over the propeller. When the engine is cold it covers when the engine is hot it opens like a thermostat. So cut a long story short if it jams its equivalent to having no water pump. The ecu cannot pick this up as its a mechanical fault. Hence no stored fault codes. New cambelt and electric water pump job done.

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Sun 4 Sep 2022 16:40
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - Michael Merola

Thanks all for this update.

I have this exact issue, very similar circumstances. Dual carriageway, fairly low speed, 5th gear going about 40-50 (happens on my way to the motorway junction). So usually, at the start (2 occurences) of long journeys - c250 miles last Monday.

As soon as it happens, warnings all over the shop, so i ease off and well the temp usually drops quickly back to 90c

My car is a 67 plate B8 Passat 190 DSG - due very shortly for its cambelt and water pump service - on about 46k miles done.

Worth bringing it forward?

Edited by Michael Merola on 04/09/2022 at 16:41

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Mon 5 Sep 2022 17:38
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - ervin jason

I think this engine has the electric coolant pump sleeve.

It restricts coolant flow with an electrically operated sleeve until the engine reaches normal operating temperature, the idea being to improve engine efficiency.

Problem is that the sleeve sometimes sticks closed & stops coolant flow, then frees itself.

I belive VW will replace the pump FOC if you have a word with them.

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Sun 27 Nov 2022 04:18
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - thomas65

Spam deleted

Edited by Xileno on 27/11/2022 at 12:01

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Sun 27 Nov 2022 11:58
Volkswagen Passat B8 - 2.0TDI BlueMotion - Intermittent Engine Overheat - John F

This interesting thread is a good illustration of the tiny efficiency savings of clever electromechanical engineering being probably completely offset by the cost of repair (how much was it?) not to mention the hassle of being without the car while it's being repaired (well, I mentioned it!)

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