Co2 test kits

[Wobbo]

Are these kits accurate? They are £5 upwards. I've had coolant blowing out the expansion tank for a long time now and tried everything...well I think I have!
Can only think its overpressurising now. No overheating, just blows a small amount out the expansion tank every trip.
Did have a new headgasket about 8 years ago due to a blockage and overheating but been fine.
Is a manifold gasket likely to cause a leak into the coolant or just the head?
Kad32....
Thanks

 

[rafiki_]

There are several areas where exhaust gases could be pressurising the coolant. One of the easiest tests you could do would be to pressurise the coolant system and watch for pressure decay. Any pressure loss will indicate a leak into or from the coolant system, and might show the culprit. Could be the heat exchanger or an exhaust riser. Good luck!

 

[Wobbo]

There are several areas where exhaust gases could be pressurising the coolant. One of the easiest tests you could do would be to pressurise the coolant system and watch for pressure decay. Any pressure loss will indicate a leak into or from the coolant system, and might show the culprit. Could be the heat exchanger or an exhaust riser. Good luck!

Ok thanks. I do have a pressure tester (we inherited various tools!) So in best case scenario am I likely to see coolant oozing out under pressure, I just assumed this would be going on internally!? Hmmm....I guess I'd be none the wiser if I did get a positive test for co2, question is where from!!

 

[Momac]

To what level do you have the coolant on a cold engine?
The coolant level shown in the image below may prove to be too high (I later drained some off).........

 

[Portofino]

@ Martyn , you always put us to shame with your almost immaculate ER pics .
Winters coming on .
The red circles are corrosion and the blue line highlights probably the trickiest thing to detail cracked paint on rubber flexing pipes .
A a National concourse ( if such a thing were ever to exist in the VP world ) you would drop points so 95/100
That might not be enough to carry off the trophy fwiw

 

[Mr Googler]

Yeah Martyn.....get it sorted???

 

[Momac]

@ Martyn , you always put us to shame with your almost immaculate ER pics .
Winters coming on .
The red circles are corrosion and the blue line highlights probably the trickiest thing to detail cracked paint on rubber flexing pipes .
A a National concourse ( if such a thing were ever to exist in the VP world ) you would drop points so 95/100
That might not be enough to carry off the trophy fwiw

Its not bad for a 17 year old boat .
Will check out the corrosion bottom right as had not noticed that.
No way I will be painting hoses .

 

[Wobbo]

To what level do you have the coolant on a cold engine?
The coolant level shown in the image below may prove to be too high (I later drained some off).........

I've drained it and filled the correct amount which put it just below the max mark. I've tried it without topping it up on cold at low mark and tried it with it empty...temperature crept up at empty but it chucks it out a small amount at a time at any level!
Co2 and pressure test at the weekend.
There is a thread on here with a chap having the same trouble but the thread just ends with no solution!
Could the exhaust manifold allow gas into coolant....clutching at straws here!!?