Heater

[Merc808]

With the recent cold spell I have realised my car takes a long time to warm up. No problems running but the temp gauge only goes just above 40 and with the heater on full in the cabin and the aux heater on, the interior doesn’t get that warm. Especially on short journeys. Once the car has stood a few minutes it really warms up to about 80 but drops quickly once moving again.

Does anyone else have this or should it be a lot warmer. I don’t particularly like the cabin that warm when I’m driving, but if I did ever need to really warm it up I would struggle. I have though of blocking half the radiator off, but I think that a car of this calibre should be able to handle the recent cold spells without basic modifications.

If mediators feel this is in the wrong section, please feel free to move .

 

[Brian WH]

Most CDI's will take 5+ miles to warm up. Using the heater on full will slow the process down, but shouldn't be much. Will be at 80 by 10 miles and heat should be as per setting.

DONT block the radiator.

 

[nickmann]

Blocking off half of the rad won't really affect warm-up times very much. Until the water temp nears its operating temp the thermostat is closed and of course that is already blocking off the entire rad for you.

It is very easy to check the operation fo the thermostat, and they are very cheap to replace.

 

[Shude]

doesn't the heater core/matrix handle the interior temp independently of the engine?

 

[nickmann]

Yes it does, but the water temp will need to be greater than the required cabin temp for the heater to be noticeable, and then after that point the greater the temperature difference between water temp and required cabin temp then the toastier the heater will feel and the quicker the cabin will heat up.

 

[BTB 500]

I agree with Nick, sounds like a failed thermostat. Simple & cheap job (unless you are very unfortunate and shear off one of the studs retaining the thermostat cover )

 

[Merc808]

I agree with Nick, sounds like a failed thermostat. Simple & cheap job (unless you are very unfortunate and shear off one of the studs retaining the thermostat cover )

I have ordered a new thermostat from stealership, it should be here tomorrow. Question where is the thermostat located, special tools ? do I need a new gasket for it etc ? advice most welcome, duration of change ?

Thanks in anticipation Merc 808

 

[PJH]

.... Question where is the thermostat located, special tools ? do I need a new gasket for it etc ? advice most welcome, duration of change ?

Thanks in anticipation Merc 808

The thermostat will be at the engine end of the top water hose, usually a shiny doom thing. Best to change the gasket as well while you can.

 

[Merc808]

Thanks for all your help. I changed the thermostat (£27 + vat) and what a difference. It included a new gasket in the box. It was a little fiddly and took about half and hour but the car heats up quickly and appears to run a lot better.


Have a great Christmas and seasonal greetings to everyone, and don’t forget leave the car at home if your celebrating.


Merc808.

 

[nigel cross]

Great nothing better than a simplish job that makes a great deal of difference.
Merry xmas to all at Beverly, my great grandfather was from there a Thomas Jefferson Simpson. :bannana: :bannana:

 

[gordonjohnson]

I have a rear mounted radiator in my '31 roadster and have had mixed results cooling my engine. In fact, I've ended up having to mount a small second radiator (from a Mazda truck) in the normal front position in order to keep the system in the 190 degree range where I like to see it. For what they are worth, here are a couple of my observations.

1) The rear mount will GREATLY reduce air flow through the core no matter how you try to tuck it up into the chassis. Also, depending on it's position, you can pick up a LOT of very hot air coming off your engine, trans and exhaust system which will reduce cooling efficiency.

2) I can't be absolutely sure of this but I believe one of the largest problems with rear mounted radiators is the plumbing. In order to route the cooling to the proper locations you need a large number of angles and bends in the plumbing to get your coolant from point A to point B. Each one of these bends creates a major reduction in overall coolant flow. Add them all together and you get very inefficient system flow. I installed a new high flow water pump but I feel it is still under-powered for all the corners I have push coolant around.

3) Pay attention to the air flow EXITING the radiator. I found that heated air exiting my core was getting trapped under the car and then forced around the sides of the radiator only to be sucked right back through the core. Very inefficient. I ended up adding a shroud as well as some sheet metal air dams on the "exit" side to remedy to situation, but it's still far from perfect.

 

[Dieselman]

Thanks for that gordon.

I'm not sure how it relates to Mercedes with front mounted radiators though.