Vauxhall combo heater issues

[burts]

I have a combo van that has been giving Luke warm heating for a long time. I did have a split oil cooler a few years back and as you can imagine contaminated all the coolant side. I have tried flushing the heater core and coolant system a number of times. Just replaced the thermostat tonight and no better. Please help?
I'd imagine if it was the water pump the van would overheat?

 

[Burnerman]

Feel the pipes going to the heater matrix.....they need to be very hot to touch. Maybe there's an air lock in the system?
John

 

[burts]

I put my old stat in boiling water and it didn't open so I assumed that was faulty. With the old stat the heater matrix pipes were hot but not too hot you couldn't hold them. Now with the new one, one was hotter than the other. Is it possible the stat was broke and now I've an air lock?

 

[Burnerman]

Possibly, and an air lock has to be ruled out. I don't know if there any specific air bleed points on that vehicle but the usual trick is to remove (slightly) the top heater hose and see if any air escapes. Hot hoses means a working heater, usually.
John

 

[burts]

It's highly annoying, I'm no stranger to air locks as I am a heating engineer And they can be a pain. Old stat definitely doesn't respond to boiling or cold water so was faulty. Have to try eliminate air lock. With plumbing I know a pipe can be red hot but actually have no water in it, but I guess that's because metal conducts heat where as rubber hoses may not so

 

[Burnerman]

Hot hoses mean water is there, mate......let's know how things go. I don't suppose this car has a mechanical valve that reduces the water flow through the heater matrix - that's not common these days.
John

 

[burts]

Hot hoses mean water is there, mate......let's know how things go. I don't suppose this car has a mechanical valve that reduces the water flow through the heater matrix - that's not common these days.
John

I know of no mechanical valve, doesn't look like there is.
I know got hoses mean hot water, I was just saying, with copper pipes they can be hot but doesn't mean the water isn't airlocked and flowing freely .nust means the heat has travelled through the material. Will keep you updated and hopefully can guide me if I need it.
Is it possible that the cheap ECP stat is just crap also?

 

[Burnerman]

Does your van have a temperature gauge? There's no reason to suspect the thermostat at this time but if you feel the radiator and its cold, the stat is shut......when it opens, there's an immediate surge of heat through the rad and top and bottom hoses.
The ideal temperature for the coolant to be at is 90 degrees, give or take.
John

 

[burts]

Not had a chance to look too much, but it's doing the same as before. The old stat was definitely broke. Had no surge in to the rad and rad pipes were relatively cold. So annoying.Temp gauge is just above 80

 

[burts]

Update. Still not had much time to look, although when I stopped driving today afte 15minutes drive, the radiator or radiator pipes were not hot, radiator cold. Heater matrix pipes hot but not too hot to touch ....
New thermostat not working?

 

[DaveHerns]

How hot was the engine? I wouldn't discount the water pump.

 

[Burnerman]

If the radiator and hoses are cool then the thermostat is shut......if the temperature gauge is reading normal maybe you haven't driven long enough?
If the thermostat is faulty I would expect the engine and heater to be very hot indeed, and water would be expelled from the expansion bottle.
John

 

[burts]

How hot was the engine? I wouldn't discount the water pump.

I'm thinking the water pump. I replaced it about 3 years ago with a ****ty euro car parts one.
Would the van not overheat though if the water pump was dud?
How can I test a water pump?

 

[burts]

If the radiator and hoses are cool then the thermostat is shut......if the temperature gauge is reading normal maybe you haven't driven long enough?
If the thermostat is faulty I would expect the engine and heater to be very hot indeed, and water would be expelled from the expansion bottle.
John

It's the same as when I've driven longer journeys. Doesn't really make sense.

 

[Burnerman]

Broken water pumps cause overheating - at least that's the only symptom I've found!
If the radiator is cool.......the thermostat may be stuck shut - in which case the van temperature gauge reads high, more often than not.
If the radiator is cool.......the thermostat may be stuck open - in which case the van temperature gauge reads low.
One more possibility though - if there isn't a mechanical or electrical heater valve anywhere (not common now) then flaps are used to direct air either through the heater matrix in winter or to bypass it in summer. If these flaps are out of adjustment, due to cable or motor failure, you get poor heater control.
John
P.S I've just bought a new Peugeot Bipper van - and the heating is poor on that, too