Cooling System Problems

[salgarfi]

Hello All,

I don't frequent the forum, perhaps, as much as I should, but I've got a problem. I've looked at the Wiki, but I am still confused, and secondly, I've put my problem in the hands of my local mechanics, but they might need some help.

My T25 has a 2.1 ltr waterbox engine, 1990. Coolant wasn't expanding from the header tank into the top-up tank (instead, it was boiling and seeping out through the cap) so I got a new 'Blau' dalek cap (and it 'quacked' when I blew into it). However, water is not passng beyond the thermostat as well, since after giving the car a run, water is still seeping out of the expansion tank, and the large pipe from the thermostat to the font of the vehicle is staying cold. The thermostat is new, so what do any of you think can be the problem? Another indicator of posibly strange behavior, is that the car heater is working very quickly. This car has always taken quite a while for hot air (no puns!) to go through the heater vents, so can this indicate something? Of course, the weather has been warmer of late, so perhaps this means nothing.

Again, if anyone has any ideas/suggestions it would be great.

Thanks,

Sal

[RogerT]

Could be a new but also faulty thermostat. Others on here have had that, and have recommended checking its operation by suspending it in a pan of water on the hob before fitting. Was planning to do the same to my new one before fitting.

A thermostat that stay closed, as you surmised, would cause those symptoms. Others may be along later with other suggestions, but I'd check your stat first?

[CovKid]

Split header tank? Not uncommon.

[salgarfi]

Split header tank? Not uncommon.

My local mechanics are tending to think that it's possibly the seal of the sensor unit with the tank, so they are going to fit a new one. They also think that they created a big air gap in the cooling system when they first replaced the thermostat (that was the first thing they tried), so they have now bled the system completely. If, however, the header tank has split, which one should I buy? I've seen on here that the JK ones might be suspect, so will one from Brickwerks be better? Or saying that, does VW still stock them?

Thanks!

[Jawin89]

https://www.vwheritage.com/type25-bus/t ... &top=13180&" onclick="window.open(this.href);return false;

[salgarfi]

https://www.vwheritage.com/type25-bus/t ... &top=13180&

Thanks! I got 'Honoria' back this afternoon. It seems that it was probably the seal on the sensor which went. She then lost more water than we thought, creating large air bbbles in the cooling system and lowering the header tank pressure, so nothing flowed into the top-up tank. She has now had a new seal fitted and she's been totally bled and she seems to run OK. I'll check the water level tomorrow and top up if required. Phew - what a saga it's been, for me and my local garage!

Sal