Cold Renault

[kettle]

just been out in my laguna (1.8rt, 8 valve, n reg petrol) and heater doesnt work very well. with the fan on the '1' setting it blows just about hot but if i turn the fan up any more it goes cold. i have just spent 45 mins with the engine ticking over and the temp gauge didnt move off the second large mark (about 1/4 of the way up, the fan never cut in)

there is water in the expansion tank.
there also seems to be a lot of condensation in the car lately. dont know if thats relevant or not

could it be the thermostat? and is it hidden behind 20 other components or is it easy to get at?

any suggestions gratefully received?

cheers
Chris

 

[yes2mud]

If you idled it for 45 mins after being driven on the road,then it sounds like the 'stat is stuck wide open.Not being a Renault man I can't just tell you where it is.Usually found in the upper water pipe connection on the cylinder head.The higher speed on the fan is just reducing the temp. even more.Some modern cars, need to be bled of air during refilling after any cooling system work.I would buy or borrow a manual to check on this.Any air pockets left can cause engine damage through local overheating.
The condensation will not be helped because the car is just not warm enough,and at present the air is very wet.Air can hold most water at around 4 degs C,which is what we have this week.

 

[munk]

thermostat is located on the engine side of the radiator return pipe, usually held in by a couple of bolts, it then just pops out.

 

[joe-90]

An open thermostat won't stop the heater from heating up, it will just take longer and not get quite as hot, but it won't run cold.

 

[yes2mud]

Joe- 90,I am not one to criticise other peoples attempts to be helpful on here,but you are absolutely wrong.Thermostat is just that,thermostatic.It reacts to the amount of work the engine is doing,the heat produced is in direct proportion to the work done.It does not sit either closed or open,it modulates to control the speed of coolant flow so the temperature stays about the same.It does stay closed with a stone cold engine,then you may see the temp gauge overshoot a bit while it starts it's initial opening and gets things under control.If the 'stat fails stuck open,you get full cooling all the time,hence the gauge stays cool,as does the heater.Ice cold ambient air we have just now,makes it worse.

 

[chapmanbilly]

Joe- 90,I am not one to criticise other peoples attempts to be helpful on here,but you are absolutely wrong.Thermostat is just that,thermostatic.It reacts to the amount of work the engine is doing,the heat produced is in direct proportion to the work done.It does not sit either closed or open,it modulates to control the speed of coolant flow so the temperature stays about the same.It does stay closed with a stone cold engine,then you may see the temp gauge overshoot a bit while it starts it's initial opening and gets things under control.If the 'stat fails stuck open,you get full cooling all the time,hence the gauge stays cool,as does the heater.Ice cold ambient air we have just now,makes it worse.

Absolutely correct.

 

[kettle]

cheers for your replies. changed the stat, all better now

 

[yes2mud]

Glad to hear that.The kettles on the boil again.Warm feet!!!!

 

[joe-90]

Joe- 90,I am not one to criticise other peoples attempts to be helpful on here,but you are absolutely wrong.Thermostat is just that,thermostatic.It reacts to the amount of work the engine is doing,the heat produced is in direct proportion to the work done.It does not sit either closed or open,it modulates to control the speed of coolant flow so the temperature stays about the same.It does stay closed with a stone cold engine,then you may see the temp gauge overshoot a bit while it starts it's initial opening and gets things under control.If the 'stat fails stuck open,you get full cooling all the time,hence the gauge stays cool,as does the heater.Ice cold ambient air we have just now,makes it worse.

Not right. I've run a car without any thermostat but it didn't run cold. Try it and feel the radiator.

 

[yes2mud]

Joe-90,I will grace your post with one reply only.I have run a car without the thermostat,this was to get it to somerset when the head gasket failed on route.It ran cool enough to survive the trip,but was still pushing water out the overflow.The car you are on about was prob overheating too,and having no stat just allowed it to keep going.When an engine is at proper working temperature,the coolant exiting the engine is at 82-95 degrees.I doubt you could hold onto a rad that hot.Read kettles post,the thermostat was open!!!!!!!
It's obvious to me that you are a well meaning chap,but an amateur,with little real experience.