Cooling Problem

malibuz16 · May 19, 2019

2002 Golf ALH 01M with an EGR delete. Dash reports 190°, Infrared reading at head/coolant flange 200°. Upper hose warm (150°), Lower hose (76°). Both fans work with AC on but I can't get the inlet hose (lower) to temp. I have tried three different thermostats 192° OE, 192° aftermarket, 180°. I have checked the water pump while the thermostats were out.

The EGR delete consists of block off plates and removal of the EGR cooler.

Nevada_TDI · May 19, 2019

I am confused, what is your cooling problem actually? 190-200 degrees is right in the ballpark for theses engines.

JETaah · May 20, 2019

The cluster gauge will report 190*F if the temp is anywhere between ~ 175-210*F
Its not an accurate source of information...It is just trying to not worry you about what the temp really is but lets you know when things are too far out of the norm.

If you want to know what the ECU makes it's engine management decisions upon you would need to read the coolant sensor at the OBD2 port with a scanner like ScanGauge or VCDS.

jmodge · May 20, 2019

" I can't get the inlet hose (lower) to temp. "

Lower hose is after the radiator has cooled the coolant and is returning to cool the engine. The 200 at the head is coming out and about as good as you will get. You are ok.

malibuz16 · May 20, 2019

My problem is that I don't see the thermostat open. The heater runs hot, and I see flow in the recovery tank. I will check with VCDS.

WildChild80 · May 20, 2019

These cars have one helluva good cooling system and diesels don't make much heat without a load...if you wanna see lower temp up a little, go for a spirited drive and pop the hood and watch the temp go down. The larger the difference between upper and lower hoses the better, it means your radiator is doing it's job

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Andrew Dale · May 20, 2019

by cooling problem you mean the dash gauge isnt being exact with the actual ECT? overheating is probably the least of your worries with a TDI

Vince Waldon · May 20, 2019

malibuz16 said:
My problem is that I don't see the thermostat open.

You won't, except on hot summer days stuck in traffic.

As posted above, TDIs produce very little waste heat. Also a factor is the heater core which always has coolant flowing thru it.

In general the temperature will sneak up to the t-stat's rated temp and sit there, t-stat barely open.

Also as posted above, you'll need VCDS or other scan tool to actually see what's going on... the dash gauge has a wide hysteresis band right around operating temperature.

Or are we misunderstanding your concern?

malibuz16 · May 21, 2019

Vince Waldon said:
You won't, except on hot summer days stuck in traffic.
As posted above, TDIs produce very little waste heat. Also a factor is the heater core which always has coolant flowing thru it.
In general the temperature will sneak up to the t-stat's rated temp and sit there, t-stat barely open.
Also as posted above, you'll need VCDS or other scan tool to actually see what's going on... the dash gauge has a wide hysteresis band right around operating temperature.
Or are we misunderstanding your concern?

That is my concern...after a 45-mile drive I can hear the coolant bottle bubbling, but no cooling fans. right now I'm trying to flush the cooling system to remove green coolant and install G12, but have no flow in the radiator. That is why I went to a 180° thermostat.

JETaah · May 22, 2019

Hmmm....I wonder if you don't have a head gasket breach.
You could be inflating the cooling system if the the temperature is normal.

JB05 · May 22, 2019

You may have a clogged radiator due to the green coolant. CoolAirVW has a u-tube video
with that same problem.

oilhammer · May 22, 2019

Yep, mixing coolant does some pretty awful things.

Cooling Problem

malibuz16

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