Overheating, again!

Camalot

Camalot

Camalot

Soldato
Joined
7 Mar 2005
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Wolverhampton
Can't figure this out, my car (ford puma) is overheating again. It did stop at one point but its doing it again now.

If i turn the blowers onto max the temp gauge comes down, but then shoots back up to off the dial :(

My coolant level is at max, my fan also started to come on today, never heard it come on before!.

What can cause this? HCV?
 
Is the top hose to the radiator rock solid when the car is hot? Do the heaters blow hot?
 
Lopéz said:
Is the top hose to the radiator rock solid when the car is hot? Do the heaters blow hot?
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Sometimes blow hot, sometimes blow cold. The air con mostly is red hot.

Ive had a bad coolant leak the past few weeks but seems to have stopped with radwell.

Already ran the car with cap off for half an hour a month ago, issue still here.
 
Camalot said:
Sometimes blow hot, sometimes blow cold. The air con mostly is red hot.

Ive had a bad coolant leak the past few weeks but seems to have stopped with radwell.

Already ran the car with cap off for half an hour a month ago, issue still here.
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Radweld is probably not helping in this case and might be blocking the system up if you used too much.

When you took the cap off, did you have the nose raised with a jack?
 
MeEsH BaKkA said:
This, jack the front up take the cap off and run the engine for a while. If you squeeze the pipes are they solid or can your hear any bubbly sounds? Water in expansion tank?
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I can hear bubbles, shall i reverse car onto drive so the front is raised as my drive is on a slant.?

no mayo in oil, oil is pure black.
 
Im not sure why you would need the nose in the air. Where was the previous coolant leak from? Check levels in header tank and rad (if possible) and remove header tank (whilst cold) and let the engine run, giving the radiator pipes a good squeeze to hopefully expel any air.

Other causes could be knackered thermostat or waterpump. No dodgy looking mixing of oil/coolant in the header tank/oil cap? Is it using any coolant?
 
Liverpool-Lad said:
Im not sure why you would need the nose in the air. Where was the previous coolant leak from? Check levels in header tank and rad (if possible) and remove header tank (whilst cold) and let the engine run, giving the radiator pipes a good squeeze to hopefully expel any air.

Other causes could be knackered thermostat or waterpump. No dodgy looking mixing of oil/coolant in the header tank/oil cap? Is it using any coolant?
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coolant was leaking at an alarming rate until i put radwell in.
 
If the coolant is maxed it's not a coolant leak surely.

If the engine is overheated and coolant is maxed, the engine isn't using coolant.

Knowing nothing about cars - why does an engine not use coolant to keep cool?
 
Three things it could be Im guessing, head gasket, if you leaked out a lot before it may have warped the head when you overheated depending on how badly it did.

the radweld could have blocked up smaller pipes causing the flow to be severley restricted causing overheating, (on some cars, the honda 2.7 lump used in the legend specifically warns you not to use any radweld as the coolant system has pipes which will be blocked by it)

thirdly it sounds stupid but you're expansion tank cap might be buggered, if they dont properly release pressure they can cause leaks and major overheating.

Duhhh, forgot airlock, it can cause needle to fly up or drop off the bottom, especially since you said you had a big leak before, if you didnt bleed it correctly then chances are you have air floating about in the system
 
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Liverpool-Lad said:
Im not sure why you would need the nose in the air. ?
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Air is light than water, raising the car like this can encourage the air possibly trapped in the heater matrix or other parts of the system to make there way out :)

nose in air, heater on, lots of squeezing hoses listening for bubbling and gurggling, fun!
 
The fact that playing with heater settings had an effect on the temperature would lead me to suspect air in the system.

As above, bleed the system and report back.

Oh, and for the record Radweld (or any similar rubbish) = Bad.
 
Did you know that Subaru specify the use of radweld at every coolant change on the Legacy, in the US? They just call it 'Subaru coolant conditioner'. No ill effects.

Used Bars stop-leak myself before, worked perfectly and no issues - after getting the thumbs up from several people who've used it. Even the local truck depot recommended it as they use it all the time without issue, although they tended to use a more industrial version.

Most coolant passages are pretty wide so you'd have to be going some to block them up with anything.

If you're paranoid about it clogging your heater matrix then that's easily avoided too - simply turn the heater off, run it with the additive in the system for several hours, then flush it out, change the coolant and continue as normal.
 
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Lashout_UK said:
Did you know that Subaru specify the use of radweld at every coolant change on the Legacy, in the US? They just call it 'Subaru coolant conditioner'.
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Really!? :eek:

That's actually quite interesting, I wouldn't have thought a manufacture would advocate using that stuff.

Do you know the reasoning behind it, or do Subaru not have much faith in the quality of their cooling components? :D
 
I think they suffered from persistent minor leaks from the headgaskets and core plugs due to corrosion (usually due to the use of incorrect coolants) - and that's one of the things these radweld-alike products claim to prevent (as well as potentially sealing and small leaks that exist).

I just googled it again, apparently they advise it for all models built before 2009, barring the 2008 STi!
 
Lashout_UK said:
If you're paranoid about it clogging your heater matrix then that's easily avoided too - simply turn the heater off, run it with the additive in the system for several hours, then flush it out, change the coolant and continue as normal.
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Not one to be pedantic, but how does turning the heater off stop the solution reaching the heater matrix?
 
Because a lot of cars control cabin heat by restricting the amount of coolant flowing through the heater matrix - so by turning it off you're cutting the amount of additive (if not stopping it entirely) going through the heater matrix :)
 
Lashout_UK said:
Because a lot of cars control cabin heat by restricting the amount of coolant flowing through the heater matrix - so by turning it off you're cutting the amount of additive (if not stopping it entirely) going through the heater matrix :)
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Like a Landrover Defender and Discovery.
 
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