Pinto 2.0 Cooling System help

[ThanasisPolitis]

Hello all,

 

I have been reading through posts regarding the cooling system on Pinto engines and the best diagram I found was this:

My pinto has a pressurised header tank, the radiator has no filler cap and there is no heater installed.

Based on the above diagram, and my configuration this is how it is connected:

The problem I am having is that the header tank is filled to the minimum line but overflowing when engine is warm and when the engine cools down all the coolant from the tank gets siphoned out to the point that the tank is almost empty! 
There are no visible leaks apart from when the tank overflows.

Do you think that there is an airlock in the system?

[Foz]

The Pinto in my 2B was piped up as your first diagram (with a heater). When hot the overflow bottle would be almost full but when it cooled down it would be almost empty.  It was a  0.7 litre bottle so I'm guessing there was about 1/2 a litre of coolant "expansion" between hot and cold.  It ran like this with no problem for years, including a number of track days.

How big is your expansion tank?  I'm guessing that you're going to have a similar amount of expansion so maybe you just need a bit bigger header tank?

 

[nelmo]

Is your coolant overflowing from the header tank when it gets hot?

I had that happen on my Zetec (which is setup like yours) and the problem for me was the cap on the header tank - it wasn't holding in the pressure, allowing the overflow. I just replaced the cap (£7) and it has been fine since.

It could, as you say, be an airlock but if your header tank is the highest point of the system (it should be), then less likely to be that.

[ThanasisPolitis]

Thank you all for your replies!

I have a VW expansion tank in it (Febi Bilstein 02205), not sure of its capacity…

I will go with the cheap solution of replacing the cap and if that does not solve it, I’ll grab a 2L header tank.

Based on some rough calculations, the engine takes 8L of coolant so ideally a 1.5L header tank will do the job…

Edited June 13, 2024 by ThanasisPolitis

[ThanasisPolitis]

Photo attached of the said expansion tank and its location.

[nelmo]

I don't think size is a problem (ooo-errr  ) - mine is from a Polo and is smaller than yours is now. 

[ThanasisPolitis]

49 minutes ago, nelmo said:

I don't think size is a problem (ooo-errr  ) - mine is from a Polo and is smaller than yours is now. 

Thanks Nelmo!

who said size matters?!
love the pun there! 

Edited June 13, 2024 by ThanasisPolitis

[Kenner]

I run a Volvo S60 tank on mine yours should be a problem. I also can fill my radiator from the top. If you can I would take top hose off radiator and make sure radiator is full of coolant and then at attach top hose top up coolant tank to full and then cycle the engine keeping it topped up so you try limit air bubbles in the system. if running a heater turn that on full blast on hot too so it it cycles water around heater matrix.  I got electric water pump so I could turn that on while keeping radiator full. 

 

[nelmo]

3 hours ago, Kenner said:

I run a Volvo S60 tank on mine yours should be a problem

I assume that is a typo and 'should' was supposed to be 'shouldn't'?  

[Kenner]

yep sorry shouldn't be an issue. lol 

[Jez Morton]

Where is the header connected to its not clear from you sketch, is it bottom Rad hose? 

[ThanasisPolitis]

17 minutes ago, Jez Morton said:

Where is the header connected to its not clear from you sketch, is it bottom Rad hose? 

Yes, that’s correct, sorry did the drawing on mobile phone…

[Jez Morton]

Do you have the 15mm hose fitted from water pump to inlet manifold? You need this on a pinto. I'd also tee this hose onto the degas pipe.

[ThanasisPolitis]

1 minute ago, Jez Morton said:

Do you have the 15mm hose fitted from water pump to inlet manifold? You need this on a pinto. I'd also tee this hose onto the degas pipe.

If you mean the hose in red colour on the graphic above, yes that’s installed.

[Jez Morton]

The basics of the system appear to be good, so with the amount of expansion and it drawing more back makes me think theres an air lock. Try running without the cap for a bit it the pressure may be holding the air lock. The expansion should be just under half a litre.