Club 80-90 Forums

hi everyone,hope you are all well and ready for tatton park on sunday.this may sound like a stupid question,but,is it possible to put the thermostat in upside down?i have noticed that my pipes to rad get warm straight away and then when the engine gets hot they go cold!could this be the reason i have been having problems?i drove to vdubbinit & back (200 miles) last weekend with no problems,first thing monday morning started overheating again.i am assuming that if i had put it in upside down then all would be well while travelling at speed as the coolant would be cooled by rad,however,when driving around town,i.e. slowly,the coolant would heat up and close the thermostat and stopping it being carried to the radiator to be cooled,therefore overheating! am i going mad as a munchkin or just clutching at straws?! your thoughts please guys and gals?

I have the plastic housing stat and I cannot see anyway that you could invert it and get the top back on.

just clutching at straws then!! should the pipes leading to the rad be hot before the thermostat opens tho?

no, they shouldn't

cheers fellas.so any ideas why they are? thermostat failure?always open? god this is doin my 'ed in now

Some thermostats have a small hole drilled in the top that allows coolant to circulate in the event that the thermostat fails to open or in cooling systems that have no relief for the water pump. As far as I am aware, the T25 VAG stat doesn't feature this hole. The pump circulates the water around the engine block/heater circuit untill the temeperature is correct and coolant is then pumped through the rad via the open stat. Check your stat. Some one else may have an opinion on this. I have a Corrado VW stat and this has the circulation hole in the top.

cheers fella,i will check it in the morning.am proper worried now as i'm supposed to be going to volksfest wales next weekend!

Still doesn't explain why your pipes to the stat are cold with a hot engine unless your engine isn't as hot as you think.

airlock!

bleed it.........properly

Mocki wrote:airlock!

bleed it.........properly

Have to agree... is only thing I can think of as well.

Mocki wrote:airlock!

bleed it.........properly

fully agree with this ^^^^^

i have bled it.....properly x10! if it was an airlock why would it drive fine for 1 week and cover over 260 miles without rearing its ugly head?is this normal? i had the front up in the air yesterday undid spare wheel and squeezed every pipe until no air was in them.it was running for over 40 minutes(bleeding & squeezing) fan came on and off as it should.i then went out for a drive and within 15 mins it was overheating and pipes to the rad were cold again!aaarrrggghhh!!!

then, in that case, after considering the updated information you may well have a cracked head or simular, for it sounds like combustion gases are entering the coolant system.

when you bled it, did you get lots of air out?
then it was ok ticking over, everything got hot, the fan worked, the heater was hot?
then you drove it, put the system under proper load and it developed another airlock, rad cold, heater getting hot then cold, then hot?

you need to be doing a pressure test on the coolant system, and checking the coolant for combustion gases.

cheers mocki.all of the symptons you have described,EXACTLY as you have described!i will get it to garage asap for testing gases in the coolant.cheers again bud

just rang jeff and he said bring it in now for testing, he is mega busy(being saturday morning) but knows i need it for work so will squeeze me in!wot a sorted chap! HOLDEN MOTORS ROCHDALE 01706 354992 he's a proper old skool mech head who loves dizzies,carbs,points,condensors+drum brakes. will let you know how i go later today