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2.0 zetec expansion tank problem!!
ross05 - 14/7/12 at 09:53 PM

Hi guys,I have a 2.0 raceline 160bhp zetec black top in my westfield (with heater)

ok on the motorways temp running at 80 deg with no problems,but on country lanes having a play temp starts to rise and the expansion tank ends up 3/4 full.I also notice a hiss from the rad cap situated on the side of the head and a little dribble of coolant.

I have changed the rad cap but no difference.

the car is fitted with a thermostatic controlled fan which does not kick in until around 90 plus deg.

anybody had a similar problem?

cheers Ross

[Edited on 14/7/12 by ross05]

blakep82 - 14/7/12 at 10:25 PM

isn't that just what they're supposed to do?

ross05 - 15/7/12 at 05:21 AM

could be worried about nothing just seems a bit excessive.When the engine cools the level in the expansion tank drops.Just thought I would ask,new car so you do get a bit paranoid.

cheers

jeffw - 15/7/12 at 06:28 AM

Zetecs should run in the 90 deg C area, my thermostat doesn't open till high 80s. My fan comes on at 93 and goes off at 90.

It sounds like you need a thermostat in your system if it is sitting at 80.

ross05 - 15/7/12 at 08:39 AM

it does have a thermostat fitted just did not like the little dribble out of the rad cap and the hiss ..engine sounds fine.

If this is normal for the zetec thats great.


cheers

jeffw - 15/7/12 at 08:40 AM

Sounds like your expansion cap is faulty.

ross05 - 15/7/12 at 09:02 AM

the cap on the expansion tank is the yellow screw on type,and the rad cap is a raceline normal type 18-22 lbs.(situated at the side of the block)

I think air is getting into the system,could this be the rad cap?I did change it for a 20lbs(all I could find) but still dribbles!!

cheers

britishtrident - 15/7/12 at 09:33 AM

Every time your engine cools the system draws air back in through the vacuum relief valve that is built into the pressure cap. Some of this air remains as air space in the expansion tank and some of it goes into solution in the coolant. When the engine started and warms up the coolant and air expands also the dissolved gasses in the coolant are gradually expelled from the coolant as it approaches workinh temperature. As the pressure rises in the system excess pressure bleeds out through the pressure cap.

ross05 - 15/7/12 at 09:39 AM

so all normal then....

cheers for that.