thermostat
 

Right my car is making my water vanish so ive just got the thermostat out and shoved it in a bowl of boiling water it dose open but not much.Im just wondering how much should it open?

cheers
baz

Think u will find you have a headgasket problem there mate

Cant see how my headgasket could of gone engine had only done 1000 miles before i had it and all gasket were done (and not with cheap crap).

symptoms are

water going somwhere

top hose has a lot of pressure

checked oil thats fine no steam from exhaust, going to replace bottom hose today with samco one re fit thermo and try again.I hope it nothing serious cant cope with another rebuild:brickwall

i had a water loss in two of my classics.

1st, ****e jubliee clip that was expanding when booted on bottom rad hose
2nd, A heater hose had a split were i over tightened again was only leaking when hot

yes had the same, mostly a fine leak on the top or bottom radiator hoses.
If not then its might be rebuild time!!

It should open "quite a bit" - a handfull of mm between fully open and closed. And it should do it quite quickly i.e. you can watch it move, easily enough.

Perhaps its reluctance to open fully, has caused transient overheating, and caused an HG to fail, hence the water loss???

the thermostat would not cause water loss regardless of opening or closing , unless as joz said , due to not opening properly it has caused overheating and caused something else to fail.

i had the same problem but turned out to be my water pump was buggered. Think it was creating an air lock n it was forcing the coolant out the overflow. The thermostat should open atleast bout 6mm and it will only open at about 99dergrees c. Its maybe worth doin a sniff check i got 1 from sealey £70 which is a little pricey but a handy piece of kit to hand.

Cheers for the replys.
The water pump is working ok as i can see it circulating back into the header bottle.Did check the thermo and seemed to be working ok but i am going to change it just to eliminate that.Then it can only be the HG.:razz:

Thermo won’t be the problem. If the engine has been out in the last 1000 miles, you may at best hope it's a leak, early cars are prone to this. Head gaskets nearly always show sighs of failing on heavy load, ie the water temp will rise, or water will spill via over flow.

well i had the same problem as u , my car was fine off boost but as soon as i put me foot down and put abit of boost through the engine the temp gauge went up and it dumped water out the overflow. took me heads off and there was clear signs were headgasket had gone also scored my bore on number 3 (maybe my own fault for using my car with a fooked headgasket). This is when i decided to do my forged build 18 month ago £15000 later and im just ready get mapped now;)

good luck with it anyway mate.

Cheers matey the car is off the road now will start this next week on stripping it down going to give it a complete re vamp engine and spray job.
Will update when i know the damage.:thumb:

it's worth trying everything else before looking at the head gaskets: thermostat (I know you've checked it in hot water, but if it wasn't replaced last time replace it anyway).

Radiator/filler cap - I had one fail a couple of weeks ago and it was overheating and pissing water out through the overflow. It even built up a lot of pressure at one point.

Water pump - again this really should have been replaced last time the HGs were done but if not try replacing it.

leaking radiator? depending on where the leak is (if there is one) you might not see any signs of the water loss.

I agree with arumdevil ^^^... As I attempted all those listed 'fixes' on my previous 1993 WRX.

But in my case, the HG had failed anyway (an SMR/MDKL engine :Whatever_). :(

yep, same with me, but it's still worth it as you never know it might be something simlpe/small in which case you'll still have to do that after doing the HGs anyway.

Totally. And if OP does manage to fix it without having to change HG/s, then serious moollah/car down-time saved! ;)

lol we've all had the same problems here and have all turned out to be the headgasket!! ID SAY IT WAS UR HEADGASKET MATE!!! DONT FOOK YA BLOCK LIKE I DID,,:(
its winter bud take ya car off the road and do all the things you've been wanting to do to it , thats what ive done takes abit off time and money but ull get ur car how u want it and its well worth it if you like ur car. Good luck mate and keep us all posted.

check the radiator end tanks, its common for the classics to split them, it only becomes apparent when driving. A telltale sign is white calcification type marks on them, also the top hose and also the coolant filler tank, the early classics take of pipes from this turn to mush over time and fail. Also as mentioned the water pump mine went on my classic (funnily after the end tanks of the radiator went!) it was fine on idle in not losing anything, however under any kind of load it just flooded out


The thermostat doesnt open at 99 as someone said iirc its about 87 degrees (fans kick in at about 92 or 94 I cant remember which)

Cheers for the replys ppl its either my HG or a cracked head as whilst tinkering with today its totally gone there are bubbles galore coming into my header tank now.Atleast i now know my problem so i think i will do as 350bhptype~R said and keep it off the road till i have got it where i want i..

Thanks for all the help will update when engine is out
:thumb:

That happened to me aswell!

But a new rad's end tanks tend to last 10+ years before going brittle.

Yep. OEM stat opens at 87C and fans kick in at 91C.

yeah me to , my endtanks cracked but only released water when under preasure , did my head in for 2 days could figure out where the water was coming from! lol:cry: solved that problem for good n got an alloy rad.:luxhello:

Yeah, is a bugger to suss. Luckily you could just see mine trickling out, then as it got hotter and pressure increased, it peed out like the "Boy from Brussels" statuette lol.

lol