Heating

[bethany]

Need some thoughts on why the cabin of the lotus will not heat up adequately. Recently changed the head gasket replacing the coolant with fresh water/anti freeze mix and had to replace the heater control valve as it had corroded through. whilst doing so i flushed the heater matrix through and there was a good flow through it. But when i run the car it just does not warm up adequately. I know these are a warm car normally as i found when viewing the 2 or 3 cars prior to the one i purchased. Incidentally the water temp guage i belief is faulty as it appears to max out at quarter scale. Any information/rsolutions welcome.

Regards Mark K

[Marcus_uk]

Have you bled the the coolant system since you refilled it?

The guage sits at 1/4 during normal diving conditions, it only goes above this if you are sat in traffic. It goes upto 3/4 before the fans kick in and bring it back down.

[Fetnas]

Has the vacuum line been fitted to the new valve? If so, try to tie the valve open with some wire or string and see if the heater now works. If so, you probably have a vacuum issue somwhere between the valve, heater control panel and the vacuum take off on the back of the intake manifold.

Good luck.

[bethany]

Thank

Need some thoughts on why the cabin of the lotus will not heat up adequately. Recently changed the head gasket replacing the coolant with fresh water/anti freeze mix and had to replace the heater control valve as it had corroded through. whilst doing so i flushed the heater matrix through and there was a good flow through it. But when i run the car it just does not warm up adequately. I know these are a warm car normally as i found when viewing the 2 or 3 cars prior to the one i purchased. Incidentally the water temp guage i belief is faulty as it appears to max out at quarter scale. Any information/rsolutions welcome.

Regards Mark K

s for the reponse will try and confirm the vacumn side of the system is working properly, will be back for any further assistance if that does not work

[M100 TWO]

have you checked the stat has not stuck open as this is a common trait with these stats
john

[Nickydee]

have you checked the stat has not stuck open as this is a common trait with these stats
john

John thats a good shout. When my stat stuck open my temp gauge would not go above a 1/4 even when standing in traffic in the summer- would also be at zero at Motorway speeds. If left to idle for long enough would eventually get up to 3/4 mark and fans cut in. Heater worked but the air was not very warm.

Stat cheap and easy to replace so worth ago.


Regards

Nick

[shakadad]

My heater and ac vents only seem to work in the footwells. I couldn't get the dash or defrost vents to work, and my windshield fogged up like crazy yesterday. Any ideas?

[tomac1975]

Hi,

Mine is the same, the temp gauge doesn't go above 1/4. Excuse my ignorance but what it the stat and where can i find it so i can check?


Regards,

Tom

[RayD]

Tom,

It's normal for it not to go over the quarter mark.

See Here

...

Tom.jpg

Ray

[tomac1975]

Hi thanks i was being a "div" of course the stat is the thermostat!! thanks for the pic. is the housing the same on a N/A car? if so i can check and see if its stuck this weekend.

Cheers,

Tom

[RayD]

Yes Tom it will be the same on the N/A.

You don't need to strip anything down to check if it's stuck open.

If it's working properly the top hose will remain cold as the engine warms up. The temperature will rapidly change as the thermostat opens.

For one or two reasons there may be an amount of hot water making its way past the stat from the start but you should be able to feel a distinct difference as it opens.

When someone tries it it will be interesting to know how long it takes at tickover speed.

Ray

[tomac1975]

Well it seems to working ok! cabin still doesn't warm up too much any other ideas? thanks for the tip though i was a ready to take it apart

[CJ101KT]

The thermostat could be faulty? I'm not sure if the thermostat will fail open when it is faulty or not but you can get a new one cheap which is always worth a try.

[tomac1975]

Thanks for the replies.

New stat in and thats been a big improvement, now nice and warm on the drive to work.

[nicowalker1]

The thermostat could be faulty? I'm not sure if the thermostat will fail open when it is faulty or not but you can get a new one cheap which is always worth a try.

i didnt think they did. But i found mine had so i guess it is possible.

[GeoffSmith]

They can stick open or closed or even go sticky and not open and close properly. Could well be related to not keeping the antifreeze (incl. anti-corrosion) topped up.