Cooling problem

[madsb]

Hi guys.

Just fitted a new thermostat on my 8v and all the coolant was drained here. Put it all back together (why does it have to be so complicated to change a thermostat, VW?) and filled water in coolant bottle to flush system. Put heater control on max heat and turned on the engine. watched the temp rise to almost a 100 before turning off engine. Waited for coolant to cool and then took of the hose connected to the thermostat - but nothing came out. Also the air blowing from the fans was cold....

Being the complete noob I am, what can I do? Does this mean I have loads of air trapped in my coolant system or what? Or is the thermostat not working. Assuming the tstat is working (really don't wanna take it out again), what can I do? Would appreciate any pictures to go along, seeing as I'm a newbie

Cheers.

[tweed]

Yes it does or you got damaged stat.

Should only get to 90, never above.

I massage top and bottom hose. Try to pump the water around the system.

Some people do get air locks but mine have always been fine.

Did you have this problem before the new stat?
Why did you replace it?
I'm thinking maybe the problem is a blockage in your heater matrix, but need more info

[xionsolaris]

Was the cooling fan cutting in mk3 engine barely holds in any trapped air its a fully vented system no bleed screws as far as i am aware what u need to do these checks start engine let it get warm then place your hand on the thermostat outlet hose if this is cold when temp is at 90 or more either you have fitted thermostat wrong eg round the wrong way or it is faulty now if your thermostat pipe is hot and your top rad hose that goes to the flange is cold u could have  air traped in the rad  or your rad internal structure has colapsed which is not allowing the flow of coolant also if all your pipes are hot including the heater matrix pipes check to see if your cooling fan is cuttin also u need to check if your water pump is working aswell if all pipes are cold it can indicate a knackerd water pump if your pump is not pumping all your pipes will be cold aswell so if you have put a new thermostat in and done it correctly this can also be a case of a faulty water pump try the above first to eliminate certain factors

Also to eliminate the new thermostat take it out get a bucket out boil water in the kettle pour it into the bucket place new thetmostat in if u can see through the top of the thermostat its opening if you done all the above pipes are cold thermostat is working as you checked its opening the water pump is not working

[Gavv8]

The trick with this job is to have the heater on full and fill very slowly while squeezing the hoses, i got the missus to pour coolant in nice and slow while i kept squeezing and i've had no problems.

[madsb]

I changed it as the oil would cool down from 90 to around 70 when driving and not just idling. The fan does not kick in now at any point. The only hose that seems to be cold is the one going to the tstat

[GOLF-MK3-GTI]

I changed it as the oil would cool down from 90 to around 70 when driving and not just idling. The fan does not kick in now at any point. The only hose that seems to be cold is the one going to the tstat

Knackered thermostat. At 90 that thermostat pipe should be warm, as the thermostat should open. If it's cold, it's fooked. Where did you buy it from?

[xionsolaris]

Tht dosent make much sense if thermostat pipe is cold all other should be cold as the thermostat is litterally near the water pump if that pipe is cold then youve got alot of air which i cant work out as i have changed my thermostat and i had no problems with air and i changed my cooling fan 3 days ago and didnt have any air blockage or youve got a faulty thermostat or a water pump but your previous symptons dont suggest water pump

[Jasikasisback]

take coolant reservoir cap off...run the car...turn heater on full blast on hot...massage the hoses...you should get some air out if air is trapped...see if the bottom hose gets warm at 90...(try not to get it past 100) if not warm then thermostat is not opening for various reasons..fans should kick in at some point...

.anyways the water will start bubbling in the reservoir tank if your water pump is working.if not you might be very sad as water pumps don't last long when they are pumping air......which is a good reason to turn off the ignition...leave cap off of reservoir overnight and then check level in the morning...top up if needed..put reservoir cap on and then heat up car...if heater is blowing well and hot..then success! if not you may still have an air pocket..if heater is blowing poorly then maybe air pocket..maybe something else...

vw made the thermostat change very very difficult...(hence some people are scared to do it..like me...

by the way there is a valve in the coolant reservoir that is a one way valve that will let out fluid if needed...it is hidden under the plastic black thing on the side that says G11 (at least mine does) just open the cap when it is hot and quickly close it and you will see that fluid is coming out of somewhere.and will find it under the black thing...-not recommending that you do this..but they do have a fail safe to make sure the pressure does escape if it is excessive..

maybe you just put the thermostat in backwards???-I've learned to take pictures of everything if I am doing it the first time (or have pictures on hand of other guides which look exactly like mine..

Good luck!

Why don't you get someone to make a short video of your problem and put it up for people to see..

links FYI

http://faculty.ccp.edu/faculty/dreed/Campingart/jettatech/coolingmaint/index.htm

I like the picture of the thermostat...shows which way it should be put in...

may not need this,but for completeness..

http://forums.vwvortex.com/.php?5691585-Power-Steering-pump-removal-please-help&highlight=power+steering+pump+removal

[madsb]

Thermostat is definitely fitted the right way. Which hose exactly is the top radiator hose? Will maybe make a vid today

[xionsolaris]

You cant miss it it goes to the big plastic housing into the head were the coolant temp sensor is