bizzare coolant pressure

[skyhooked]

hi guys

a week ago, i had the thermostat, rad cap, and coolant flush on my 2.4 surf

after this, the temp sender never went over halfway, the heaters worked great and the electric fan only came on after a long hill climb

i had a few over heating probs prior to this - going into the red - may have caused some major damage there i dont know

the truck runs fine, starts well (sometimes lumpy on starting if left to cool after a long run). can see a bit of smoke in car headlights at night, nothing in the day

last night, after a 200mile plus run i was reverse parking when i noticed the temp sender move into the red. i switched off, got out, popped the bonnet and noticed a leak (it was dark so not certain) coming from a small pipe that looked to come from the thermo housing

fair amount of coolant on the road, and this morning, it took a litre or so of water to top back up

now i notice the top hose pressure is less than it used to be - before it got pressure pretty quick. have tried getting any airlocks out by removing rad cap, opening heaters and running till warm. the water level in the rad cap housing was jiggling about, and dripping into the expansion tank

couldnt see any bubbles in the exp. tank - and heaters werent as warm as they used to be

this morning, when i started the truck after last nights drama, it fired up isntantly and ran great

any ideas what is going on here? if it was the head, i wish it would just pack up and die quickly so i would know what to do

any help much appreciated

dom

[TonyN]

The only way you'll know for sure is to get it tested, make sure its done with the coolant solution test for combustion gases, just putting a pressure tester on the rad cap hole doesn't often show up small cracks.

Running out of water may have shifted gunk from the block into the heater matrix and blocked it, but make sure water is getting to the matrix by gently pulling the hose off the heater valve and making sure water pumps out while its idling. then you can check its coming out the matrix by doing the same on the out hose from the bulkhead.

[Sancho]

I am no expert on these things , but when my head went it fired water out rather than anything jiggling or dripping. The cap blew off the expansion bottle and knocked into a load of stuff in the engine bay. I got lots of lovely white smoke at the end of a run and you could feel a noticeable dip in power just before the temperature flew up.

It sounds to me (see comments on not being an expert) like you had an airlock when you flushed the coolant last week and its only just become apparent. You probably sorted it last night.

[Toyney]

airlock it may be, but it also sounds exactly what my surf was like when its head went.

it always started first time, no problems, didnt see any smoke, there was no major things going pop or poof under the bonnet. but the head was indeed cracked. ( i only found this out for definite when TonyN had a look at it) I drove mine for months with this minor problem until one day in france on an uphill bit of motorway it spat its dummy out and red lined on the temp gauge ( lack of water being the problem)
filled it up with water again and within a few seconds of driving it did exactly the same. thermostat was stuck closed and after some percussive maintenance of the stat ( I couldnt remove it at the time so i jammed it open using a hammer and screwdriver) we were rolling again. Sturdy machines these surfs even when they have a problem.

basically if the cars ever been into the red, for whatever reason, get it checked out. mine only went into the red once (while ive had it) and that was after the head was already cracked.

[SURFVIRGIN]

checked my coolant for any air locks today as i changed it 2 weeks ago and mine did the same as it got up to temprature i.e jiggled about a bit but thought this 2 be normal. level goes down about an inch when revving and levels off. think its the vibration from low revs that makes it jiggle. did notice tho that the rear heater didnt get very warm at all, could this be a blocked matrix and can i just leave as is? dont need heat in the rear anyway.

[skyhooked]

thanks as always for the replies guys

i think maybe was an airlock - both front and rear heaters are both ok. level of coolant today was fine, and have had a few long runs since with no worries

i was confused as to why the system seems to pressurise slower than before - maybe i am imagining this

i will get the head properly checked in a week or so - i have to make sure the money is there incase i get the bad news, then it wont be so bad after all - there is a garage right at the bottom of my street that says he can turn the job around in two days

that said, it drives perfect apart from these odd quirks. i;ve had heads go on other cars and it was very obvious, seems to me that the surf is almost a little to tough for its own good at times...

still having great fun with this truck, mates love it and the missus had her first drive of it today at our kiting terrain park. so now, you've guessed it, she wants one too