Unusual overheating problem

[pauly8888]

Hello. I am hoping someone can help me here.
I have a 1982 T25 with a 1.9 diesel engine from a Seat Ibiza fitted (in it when I bought it). I can't seem to fix the overheating problem I have. The problem being that the water doesn't seem to circulate around the cooling system. Tbe radiator won't get hot.
The problem started when one of the long front to back water pipes decided to come unattached one evening, emptying the coolant all over the road.

Since then:-
1. I've fitted a new water pump, but only because I snapped one of the studs when refitting the perfectly good old one.
2. I've changed the thermostat, even after testing the old one which was ok.
3. I've tried running with no thermostat at all.
4. I've tried bleeding the system via the stud on the radiator.
5. I've tried drip-feeding the radiator via bucket on the roof.
6. I've fitted a new alternator belt.

I can blow water around the system by sticking one of the pipes in me gob! So I think there's no blockage.
The van starts first time every time I try her. A puff of smoke on start, like she always did before overheating.
I can't find any info anywhere that is any help.
I've bought 3 Haynes manuals, including the one for a Seat Ibiza.
Any help would be much appreciated.

Also, which way round does the thermostat go. Spring-side in or out of the water pump?
And, which way should the belt turn the water pump? I've fitted it so that it turns it clockwise (looking at it from the front).
AND, should I use gasket-glue when fitting the water pump and fitting the thermostat? I've read conflicting answers.
AND, even though I can blow down one pipe and watch water come out of the other pipe, am I actually not blowing water through the radiator and only blowing through the engine?
HELP

[camper]

Spring side of the thermostat goes inside the water pump.You may have a sludged or blocked up radiator try reverse flushing the rad with a hose.I run a 1.9 1y engine and have used gasket compound on the water pump and thermostat housing with no problem.Question are there any bubbles streaming into the expansion tank when the engine is hot.Have you tested the dialek cap on the expansion tank it should blow one way into it but out to the overflow tank only at high pressure.So if you can blow both ways easily its gone faulty.When you top up with coolent you need to run up the engine and check if the expansion tank coolent level drops do this in conjunction with bleeding air out of the rad .If the level drops then top up with coolent checking the bleed screw on the rad as air and coolent dribbles out.

[pauly8888]

Thanks for the reply Camper.
I've only got the one tank; the little round one with a blue cap. There isn't an 'expansion' tank. The system used to work fine, so I never stressed too much over the lack of another little plastic tank.
When I top up the engine when bleeding, the water just seems to bubble away in this little round tank as it gets hot.
What do you think?

[billybigspud]

have you done a compression test on your cylinders? if you keep the cap on and run it briefly so it soesnt get hot, does it pressurise the water?

[camper]

You need a overflow tank regardless if it seemed okay before.An expansion tank is the one in the engine compartment with the blue or black valve cap the overflow tank should be behind the number plate.Change the blue cap the valve may have gone faulty.

[pauly8888]

Billy: Haven't done a compression test. I haven't got the equipment. I can't say if it pressurizes the water, as I can't put mor than a couple of litres in and it gets hot within a couple of minutes. I would say there is no pressure until it gets hot. There certainly is then because water sprays all over when I unscrew the cap.

Camper: I'll have to look at fitting an expansion tank. I had worried about it a little, to be honest. It was the extra pipework which was putting me off.

[California Dreamin]

Your description sounds like a failed head gasket.....

Martin

[pauly8888]

Thanks Martin...cheered me up no end. I'll try and sort out a pressure test too!

[billybigspud]

Your description sounds like a failed head gasket.....

Martin

reckon so, fingers crossed it aint though mate.

[camper]

Billy: Haven't done a compression test. I haven't got the equipment. I can't say if it pressurizes the water, as I can't put mor than a couple of litres in and it gets hot within a couple of minutes. I would say there is no pressure until it gets hot. There certainly is then because water sprays all over when I unscrew the cap.

Camper: I'll have to look at fitting an expansion tank. I had worried about it a little, to be honest. It was the extra pipework which was putting me off.

The only pipe work you need is a length of cotton covered water hose aprox 1mtr running from the expansion tank valve cap to the overflow tank inlet .Overflow tank is tucked in behind the number plale held by two screws.And as said it does sound like a failed head gasket. Hope you sort it.

[pauly8888]

Cheers Camper.

Is there a photo or diagram anywhere that shows the connection of the piping for the expansion tank that is supposed to sit behind the number plate? I've looked at some for sale on fleabay and they have 2 pipe connectors.

So, how do I test to see if the head gasket is gone? I can't use the tester kit I've seen (the thing you stick in the radiator with the blue fluid that turns yellow)

Back-flushing the radiator this weekend too.

[camper]

If it is a cylinder head /gasket problem you could use this ebay seller.http://www.ebay.co.uk/itm/Volkswagen-Tr ... 1c0b557a02" onclick="window.open(this.href);return false; There carrier collected the cylinder head on a Monday and it was returned to me Wednesday the same week.Its a good deal with a good qaulity head gasket and bolt set included.The hose from the expansion tank cap is routed around the battery tray to the back of the number plate and is a push fit into the overflow tank nothing complicated.

[Oldiebut goodie]

First check that the water pump is running in the right direction - you wouldn't be the first to have it running backwards on a replacement engine. You will have to take it off to see which way the vanes go if there is no arrow cast into the body.

[pauly8888]

Thanks Camper. I've saved that fleabay seller to my favourites list.

Oldie: I looked at the water pump impeller and 'decided' it was turning the wrong way. I'm assuming it is supposed to 'cup' the water as it turns to 'push' it through the pipes. So, after struggling with the belt to make it fit around the water pump pulley the other way (anti-clockwise)...it still didn't solve my problem.

[Oldiebut goodie]

Damn! That would have been too easy!
As the problem reared it's ugly head after the water pipe letting go it then points to an air lock. Which as many will testify is a b***er to shift sometimes. (Been there and got the t-shirt)
It will not be helped by having the original Seat expansion system. Given the amount of coolant in these vans that is a lot to expand into a single small bottle.