Over heating

[Urchins]

Everytime i get stuck in traffic my expansion tank starts spewing out coolant and I have to pull over and wait for coolant to cool down and replace the lost coolant in the headtank. I have replaced the pressure cap on the Head tank, tested the water pump and the thermostat is new. i have bled the system but the problem is still occurring when in traffic. the temp gauge never goes up when on the move and air flowing into rad but i have never noticed the rad fan kick in but don't think this can be the problem. As soon as the temp gauge goes up to 1/4 i pull over and wait for traffic to clear and top up if necessary.

Does anyone have any ideas as to what else could cause boiling coolant? On the whole the engine runs well and was fine on long 150 mile round trip this weekend apart from a slight spluttering once or twice when shifting from 3rd to 4th gear.

[Ian Hulley]

Sounds like you need to bleed the system properly, you may have a leak you're not seeing.

Ian.

[tinman]

If it was me I'd check the fan is operating correctly, It could be a head gasket but if you done 150 miles without a problem its sound doubtful

[Ian Hulley]

Which engine is this ?

Ian

[Urchins]

Hi yes i don't think it's a Head Gasket ( i hope so) as at the end of May drove back from Snowdonia to Hornchurch (eesex) without any probs - and took her up to Suffolk on the weekend.
it's a 2.1 fuel injection rekon before i purchased only 500 miles before. I think the leak is the most likely - but i have only ever noticed a leak below expansion tank. i am not entirely sure but could there be a leak in seperating coolant on return to engine heads when cooled in rad? excuse ignorance. is there a plug or valve to separate coolant?

[Ian Hulley]

Sounds like a cracked header tank and/or failed dalek cap (both common issues and reasonably cheaply available from Brickwerks) it'll need bleeding properly.

Ian.

[Urchins]

Thanks for replies. is the dalek cap the blue cap on header tank? if so i replaced but need to bleed again by the sounds of things.

[Ian Hulley]

Yep

[xpress]

check the coolant level and take her out for a spin then leave overnight and check the level again the morning after. that will tell you if you are losing coolant.

[Urchins]

Ok, will follow brickwerks and bleed and then see what happens overnight. I can never be entirely sure of lthe source of loss of coolant as it does spew out on move in traffic, much to the suprise and amusement of surrounding cars - in traffic on the M25 a lady got quite concerned and came up alongside thinking i was about to explode

i do check underneath regularly and only seen leakage patches after use underneath the expansion and given that this can happen after relatively short journeys i will bleed again and see what happens.

[xpress]

i am really sorry, but lots of air and spewing out like a jet washer in traffic sounds like head gasket, allowing too much air into system .. shouldn't have that much air in there.

:S

[mrhutch]

^^ WHS


sorry

[xpress]

get a compression tester stick it in one of the plug sockets and test. or a sniff tester on the expansion tank, you're wanting to check for the existence of emissions to confirm head gasket.

[mrhutch]

my old JX (1.6 TD) had a failed head gasket and I drove it for about 300 miles before it finally got really bad..

easy test for head gasket (but not foolproof!)

make sure main coolant tank is FULL

take for a spin, get up to temperature and come home

let cool down!

slowly and carefully undo main coolant bottle cap, if you hear a release of air then something has pressurised the coolant system.. the most likely candidate is the head gasket blowing combustion gases into the coolant.

[Urchins]

Thanks for the above. Haven't had time to take for spin but will be checking next weekend with mechanic who did recon. Engine is one year recon so should is covered by warranty i hope.