Hi all,

A couple of weeks ago I was driving my Ford Escort hard. When I stopped I suddenly smelled something sweet.
After opening the bonnet, I saw that some coolant had came out of the expansion tank. The temperature didn't rise while driving and the coolant level was fine.
The temperature stayed the same on the way home and I went through some gears. Not the brightest move because there was lots of smoke when I stopped. More coolant had came out of the expansion tank and onto the exhaust. The temperature still didn't rise on the gauge.

The day after, the oil was looking as it should and the coolant was clean. I've filled up the expansion tank with water to see what was causing this failure. But as soon as the car warmed up, the radiator started spraying.
Therefore I replaced the radiator with a brand new one from Ava Quality Cooling and fitted a new filler cap for the expansion tank. After installing it, I've filled it up with SP12 coolant. A hose started to leak but this was due a bad reďnstall, easy fix.

When driving before, the temperature stayed on 2/5 on the temperature gauge, shy below the middle. It did not made a difference when you drove the car hard, hitting the redline etc, the temperature stayed the same. But now, the temperature stays in the middle when driving normal and when you put your foot down it rises to 3/5 - 4/5 on the gauge. The fan still activates when the temperature gets too high.

What could this be? The thermostate is about 4000 km old so I don't expect that to be the issue.
Ideas and suggestions are more than welcome!

Kind regards,

Cor

 

- i had this problem on different occasions different components causing similar issue -

1) 1st problem radiator was too small (not same car but ford) and the flow wasnt enough for full throttle -
2) expansion cap: which reservoir are you using? OE or aftermarket - major leaks caused al sorts of pressure issues for me especially spillage from cap - i never got to bottom of issue as the problem has gone away
3) My heater matrix leaking was causing the fans to come one whilst driving at any speed - never assume brand new parts are perfect -
4) water pump housing leak caused the worst problem with temps rising like the radiator not flowing...

this was my experience my cooling is now fine although rs mk1 focus runs very hot lol

let the car idle and feel around which pipes are getting hot and which are not ( wait till fans come on IF they do that is)

IVE JUST REMEMBERED SOMETHING: My heater matrix pipes were plumbed the wrong way round so check that too -ah this is what caused the expansion cap spillage/ overflowing issue

 

Nope i am still getting expansion tank leakage after any sort of drive BUT my temps are much more stable when driving 87-99 Celsius mostly - so more investigations

 

If your header tank is leaking it's either overfull finding its own level, a faulty tank or cap or to much pressure being made and blowing it out

We've just repaired an engine with a cracked cylinder head it wasn't overheating but it was useing water