Burst the radiator

[jdm]

I have a 1992 2.4TD Auto had a stevo head fitted by Tony about 5 years ago cos original cracked. a few months ago noticed fan kicking in after short journeys and needing to top up coolant via cap. (level in expansion tank seemed ok) after a month or so everything back to normal fan not kicking in even on long trips coolant levels all ok. I never found a leak. on fathers day went to collect father in law about a 12 mile trip with a 1 hour stop at shops on way again no probs with cooling. temp gauge where it should be fan not kicking in. I had checked level few days before only a cup full or less top up. just left father in laws house gone about 400yds up a hill turned onto another road a top of hill going about 20mph or less and heard a loud Pop and lots of steam billowing at front of bonnet. stopped immediately checking temp gauge as i did not reading high though by the time I switched engine off (5 seconds at most) getting close to the red. opened bonnet clouds of steam and coolant all over to find a 2" split along top of radiator AA took me to the mechanic I use. I got a rad and toyota coolant from Roughtrax and back on the road by friday. been checking coolant level via cap and yesterday needed topping up but noticed expansion tank level still high temp gauge behaving normally but fan kicked in after a short trip in hot weather on Sunday. now wondering what could be wrong and could the reason the rad went still be there.I originally assumed the age of the rad (probally original) was the reason it failed any ideas please all help appreciated
Thanks

[fatfires]

My first reaction would be to test the water for combustion gasses

[Tallyman]

Did your mechanic burp the cooling system after fitting the new rad? Could be it's just getting rid of dissolved air and will settle down after a while. Also, did you change the rad cap at the same time as the radiator, as that could be why the expansion tank is full, not allowing water back in. Also, when did you check the expansion tank level, as checking it with the engine hot would likely show it full as the engine needs to cool back to air temp before you check the level again?

[jdm]

My first reaction would be to test the water for combustion gasses

thanks for your fast response
What is the method for testing for gasses is it something that can be done myself or is it better to take it somewhere

[jdm]

Did your mechanic burp the cooling system after fitting the new rad? Could be it's just getting rid of dissolved air and will settle down after a while. Also, did you change the rad cap at the same time as the radiator, as that could be why the expansion tank is full, not allowing water back in. Also, when did you check the expansion tank level, as checking it with the engine hot would likely show it full as the engine needs to cool back to air temp before you check the level again?

Thank you for the quick reply
he didn't burp the system I can't find instructions after searching. yotasurf seems to have gone and on the aussie site the links don't work any ideas where I can get info.
gonna get a new rad cap today. the engine was cold when I checked I ran the engine for about 30 mins after I topped up via the rad cap there was coolant coming out via the overflow but the gauge did not go up to halfway and the fan did not kick in. let it cool down overnight rechecked levels put a small amount in via rad cap. expansion tank was still full

[stormforce]

have both heaters set to hot and on full blast.
Take the rad cap off and have the engine running
While the engine is running keep topping up the coolant until you can't get anymore in.
refit the rad cap and take for a good drive.
Allow to cool and then check the levels again and top up in neccessary as above

[Vagrant No2]

Also check the hose from rad to expansion bottle is not blocked or split as this will stop coolant from expansion bottle to top up rad when cooling down.

[TonyN]

Hi, long time!

Check stuff as others said, make sure the cap is sealing properly and there is no rust under the rubbers, Most original rads are pretty weak on any 2.4 by now, especially if they've had a head go in the past as the coolant mixed withv exhaust gas is very corrosive.

If its overflowing the expansion tank then it must be pressurised or cap problems.

Change the stat and cap, make sure heaters are blowing hot and see how it goes.

Have a look behind/lower than the back of the stat housing on the head, there should be a temp sticker divided into 4 parts, normally the first 2 should be black, the 3rd maybe grey but top on should be clear, if its completely black then it has got worringly hot.

If it still plays up then you need to get it tested to see if its done something bad to itself when it blew the rad and got hot.

Good luck. If you are in the area drop in and I'll have peek.

[jdm]

well thanks for all the usefull advice. I bought a new cap and I spent some time doing as stormforce said I also syphoned some coolant out of the expansion tank down to max level as it was near full took old cap off and run engine topping up as needed noticed lots of air bubbles and the heaters blew cold for a long while before warming up the rear one didn't though. after an hour + bubbles pretty much stopped I put new cap on and went for a drive. lots of white smoke the front heaters got hot but the rear one not. after 2- 3 miles the smoke stopped I parked up for 10 - 15 mins exhaust smelt wrong! when I drove on no white smoke by the time I got home exhaust smelt normal.temp gauge behaved as it should checked this forum read the new replys checked the hose from neck of rad cap to expansion tank seems ok coolant running into tank which was high again (still hot) but no overflowing gonna let everything cool down also do an oil + filter change now and have a look at the temp sticker. fingers crossed and monitor what happens. to change the thermostat do I need to drain the coolant. also noticed while searching the forums the bleed T-piece to put in heater hose will be worth doing that I reckon. would like to drop in Tony but not sure about a long trip yet get this sorted and maybe book in for some work. thank you all again

[stormforce]

if the rear heater isn't getting hot then the pipes that run under thetruck to the rear matrix will be blocked.Either strip them down and clean out or blank the rear heater off completely

[jdm]

been checking coolant everyday and been adding some small amounts daily via the rad cap the expansion tank level has been ok and temp gauge behaving normally. went for a 50 mile trip yesterday. temp gauge fine. when I parked and switched off heard a gurgling noise and saw that there was a fair amount of coolant on the ground seems like it came out of the overflow on expansion tank after a couple of hours I topped up via the rad cap about a litre. the expansion tank level was ok. drove home temp gauge fine. when I parked again coolant on the ground out of the overflow. checked coolant this morning less than half a cup full to top up via rad cap and expansion tank level ok. going to have another trip out maybe 30/40 miles see what happens. do you think the system is just settling down or is something not right.