EA288 Water Pump Failures?

TurboABA

Veteran Member
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
2010 Jetta 6spd MT, 2014 Touareg Execline
Please God, grant me patience!

Do you have VCDS?
Can you use it?
Log\monitor a bunch of different temps in an attempt to see when\why it's overheating. I don't have your engine, so I can't tell you exactly which sensors you can read off it, but there should be a bunch. You should have coolant in 2 or 3 places, oil temp, IAT, etc. If you've already done this and your block temp is the only one that gets hot (I read this as oil temp), then you need to notice it's relation to the rest of the temps. (this is when logs help)

If your block\oil temp goes high at an accelerated rate or behaves wonky, it could mean a faulty sensor. If you have a flaky sensor, which reads way out of wack compared to the rest of the temps, it could cause the thermal management system to act up under certain conditions and lead to an overheating situation. If your WP isn't circulating, you should be able to easily tell by touching the inlet rad hose vs the outlet when your gauge is showing that you're overheating.... if both of these are near the same temp, then it verifies that there's no flow through your rad, and since you just had your thermostat replaced, we can safely assume that the WP isn't working.
 

sootchucker

Veteran Member
Joined
Sep 11, 2013
Location
Colorado
TDI
2015 Golf
Please God, grant me patience!

Do you have VCDS?
Can you use it?
Log\monitor a bunch of different temps in an attempt to see when\why it's overheating. I don't have your engine, so I can't tell you exactly which sensors you can read off it, but there should be a bunch. You should have coolant in 2 or 3 places, oil temp, IAT, etc. If you've already done this and your block temp is the only one that gets hot (I read this as oil temp), then you need to notice it's relation to the rest of the temps. (this is when logs help)

If your block\oil temp goes high at an accelerated rate or behaves wonky, it could mean a faulty sensor. If you have a flaky sensor, which reads way out of wack compared to the rest of the temps, it could cause the thermal management system to act up under certain conditions and lead to an overheating situation. If your WP isn't circulating, you should be able to easily tell by touching the inlet rad hose vs the outlet when your gauge is showing that you're overheating.... if both of these are near the same temp, then it verifies that there's no flow through your rad, and since you just had your thermostat replaced, we can safely assume that the WP isn't working.
yes i have VCDS.

yes i can use it.

i have monitored literally every coolant temp sensor available. i am not detecting coolant flow in the forward part of the system, as i explained. the thermostat was a logical thought, but ruled out after replacement. i dont claim to be the expert at all with this engine which is why i am here asking for thoughts but i have to believe that the TB driven pump is the last part i can replace. both electric pumps work as they should. i dont have any block in the system, my heater works way better than it should obviously. and the car seems to have a little more endurance before overheating with the heater on full blast, which runs the aux pump.

im going to move forward with replacing the TB/pump and go from there. i cant imagine its anything else UNLESS there is a head gasket failure symptom that i am not aware of. to recap, no water in oil, no oil in water, no coolant loss and no soot in coolant.
 

TurboABA

Veteran Member
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
2010 Jetta 6spd MT, 2014 Touareg Execline
So when it's overheating, both your inlet and outlet on the rad are hot?
Can you cycle the "N489 Cylinder Head Coolant Valve" (aka WP shroud) in VCDS?
According to literature, when this fails, the compression spring should retract the shroud so the coolant should still flow.... I guess it could be jammed or stuck in the "over the impeller" position, but this is why I'm suggesting you try cycling it to "free it up".

Effects of Failure If the N489 is defective, the modulating piston remains in its initial position and the coolant flows around the coolant circuit
 

whizznbyu

Veteran Member
Joined
Jul 11, 2006
Location
Waxhaw, NC
TDI
2015 Golf Sportwagen 6 speed manual. B5 died at 302k miles.
Regarding the water pump at IDParts: What is the difference between Hepu and Geba as far as durability and material? Do the solenoid and variable feature make them more prone to failure? As in something else to break? Are there metal impeller water pumps out there for the Mk7?
 

pedroYUL

Veteran Member
Joined
Sep 8, 2011
Location
MI, USA
TDI
2004 Jetta wagon BEW; 2015 Passat SE CVCA; 2015 GSW CRUA
It is in their website: " Geba water pump for the CVCA and CRUA engines. This is a non-variable pump and the sensor opening is blocked off."


Hepu is a variable speed pump that comes without the solenoid, or maybe it does bring a new solenoid 🤷‍♂️
 

sootchucker

Veteran Member
Joined
Sep 11, 2013
Location
Colorado
TDI
2015 Golf
So when it's overheating, both your inlet and outlet on the rad are hot?
Can you cycle the "N489 Cylinder Head Coolant Valve" (aka WP shroud) in VCDS?
According to literature, when this fails, the compression spring should retract the shroud so the coolant should still flow.... I guess it could be jammed or stuck in the "over the impeller" position, but this is why I'm suggesting you try cycling it to "free it up".
no, just the block temp is hot. im assuming the dash gauge pulls data from the block sensor.

will follow up on that test.
 

TurboABA

Veteran Member
Joined
Jul 24, 2010
Location
Kitchener, ON
TDI
2010 Jetta 6spd MT, 2014 Touareg Execline
The gauge in some of these more complex systems seems to rely on some combination of signals from a few sources. This is why it's important that you log all the temps at the same time so you can try to isolate\focus your troubleshooting on a specific area of the system. Sometimes you can unplug a sensor to quickly remove it from the equation.
 
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