1992 VW t25 1.6TD

[Jeff9750]

Hello all, I'm new to the VW scene I have a 1992 VW T25 1.6TD, I have replaced all of the cooling system and heater box with new parts, I filled the coolant and started the bus and took it for a test ride and the bus runs beautiful but the Temp gauge hand only move 3mm still in the cold after about 60 mins of driving. I have no heat coming from the heater. I jacked up the front of the bus and filled the coolant tank until it would not take anymore coolant no coolant came out of the bleeder on the radiator. still no heat and the temp gauge hand still in the cold side. Every part of the cooling system is new. I need help!!!!!!
Jeff

[R0B]

No need to raise the front of your van up. Have a read of this. Bleeding the cooling system - The Brick-yard - Page 1

[multisi]

60 minutes for a coolant filling test drive is way too much, it could overheat the engine if the coolant system isnt working as it should.

[Jeff9750]

Hello ROB, thank you for all your help and the info. I will go out tomorrow and buy some more coolant and follow the instructions. Will keep you informed. I wish everyone a Merry Christmas and a Happy New Year.

Jeff

[Jeff9750]

Hi all, here is an update to my cooling system. Now the coolant temp gauge move to the half way point and the Bus drives very well but I still have no heat coming from the vents the blower motor is working well and all the controls are working well I even switch the heater matrix hoses to see if that fixed the problem, no luck still no hot air. The cooling system is completely new. No smoke coming from the tail pipe. I have a 1992 T25 1.6TD, the coolant in the main coolant tank is full and coolant tank behind the license plate is in the middle of min & max mark. no leaks. any suggestions would be greatly appreciated.

[Cecil]

I think you should drop the spare wheel so you can see the heater valve (under the floor of the van) ,have an assistant move the heater control on the dash and see if the valve moves properly.

[Jeff9750]

Hi Cecil, I just checked the heater valve and it is open. I checked all the hoses and bleed the system. The temp gauge was a little over the half mark but the fan never came on and I still have no heat. I took a temp of the heater core and it read 32.2 C
The hose going into the heater core were hot but the heater core was not. I put in Preston coolant, do you think I need to put in the G11 coolant? My radiator never got hot. I went to the engineering compartment and looked at the coolant tank in the engine bay, every time I rev the engine I see a few bubbles in the coolant tank. Is that normal. I'm new to VW Diesel engines. Need Help.

Jeff

[Oren Kipnis]

Seems that the heater matrix is clogged, and the best solution is replacing it.

For the coolant, Preston is a manufacturer which has different products. My practice with Preston coolants is so so. I would advise you to flush the system and use G12. The best is the original G12 EVO which is ready to use. Other wise mix a concentrate with distilled water in 1:1 ratio, or if purchasing a ready to use coolant observe that the freezing point is -36.

[Jeff9750]

Good Day Oren, the whole cooling and heating system are all new, even the heater core. Tomorrow I will drain and flush the system and I have 15 litres of G11 the Bentley book said to use. I even put on stainless steel coolant pipes, do you think that it that the stainless steel pipes are just not getting hot because it winter here where I live, it's about -5 today.  I ordered a head gasket tester, I hope it's not the head, I just don't know. Thank everyone for all your help in this matter.

Jeff

[Cecil]

Is the thermostat (by the water pump) new.
Air lock  (or combustion gasses) in the heater matrix caused by leaking head gasket is a possibility.
How about checking the main radiator remains free of air .I would do this by opening the radiator bleed valve after a run(when a bit of pressure has built up) you would get an instant squirt of coolant without hearing any air escape if all is well.I find with a good head gasket the radiator keeps itself free of air by itself.If the main radiator won’t stay free of air locks then neither will the heater matrix.
I would not be worried by the type of coolant you are using given you have the diesel engine.Different story if you had a wbx (petrol engine).
Was the reason for renewing much of the cooling system because of previous overheating problems?

[Aidan]

It is possible its the heater valve , it is not uncommon for the closure shaft to seize and strip the threads of the screw the shaft that the lever is fitted with so it looks like it is open, ie the lever moves, but the shaft inside doesn't; cheap component, especially now, aftermarket ones may not be all that reliable or quite as tough as the originals were - or it could be blocked, the shaft is an odd thing and even fully open is is only 50% open orifice so a largish flake of rust or a small piece of cloth could easily block the aperture

did you replace the valve ?

[Jeff9750]

Good evening, well here is and update: Today i pulled the heater matrix out and blew it out it was not clogged, I filled the heater matrix full and then reinstalled the heater matrix, started the van and checked. the heater matrix did get hot to about 57.6 c, tomorrow I will take the van for a test drive to see what happens. Can anyone tell me if the heating system get hotter if you drive or should it it get very hot just sitting at idle? I'm learning a lot about this van by doing all the work. Yahoooooooooooo
Thank everyone for helping me!!!!

[Oren Kipnis]

Sitting idle you can wait,,,wait   and wait. 
You will need at least 15 minutes of driving.