W124 cooling system query

[sweeney todd]

Wonder if anyone can help with this one?

W124 E280 1994 model. Just returned from a continental tour and the car was an absolute peach for the whole journey. Ploughed back up the M25 car park and back up the M1 on Sunday - no worrries despite heavy traffic.

Yesterday in dense traffic & warm weather the temp gauge flirted with 120 degrees (the max before the red zone) and stayed there (although not actually in the red) until the traffic cleared and I got moving again.

The car was hot again on my return so I flipped the bonnet to look at the fan. The big central fan behind the radiator was going around apparently at engine speed ie with no urgency (despite high engine temp). Now I'm no mechanical wizz but shouldn't the cooling system click into 'overdrive' controlled by a thermostat and bring the temp down?

Any answers greatfully received folks.

 

[Satch]

Electric fans, yes. Viscous coupled no, as they are driven off the engine.

 

[guydewdney]

try the carrot test for a bust viscous fan....

use a carrot to try to stop the fan,if you can, then the fan is dead, if you have carrot puree then its working fine...

ask normanB as the inventor iirc of this system...
guy

 

[DrNick]

Do you have any electric fans (usually on/near the front of the rad). These may have failed, or at least the switch that controls them.

 

[sweeney todd]

No other fans other than the one behind the rad.

Carrots eh? Will give that a try tomos?!?!?

Just in case has anyone else had a similar problem or am I in the midst of new owner ignorance induced paranoia (NOIIP)?

 

[NormanB]

No other fans other than the one behind the rad.

Carrots eh? Will give that a try tomos?!?!?

Just in case has anyone else had a similar problem or am I in the midst of new owner ignorance induced paranoia (NOIIP)?

Read this thread : Not sure if your car is the same as mine but you will soon tell if you follow this routine.

Guy has labelled me as the inventor of the carrot test and as much as I would like to be famous for something useful I announce here and now that I read of the carrot test on this or a similar forum

 

[sweeney todd]

Thxs m8.

Will have a butchers now.

 

[pluggers]

Read this thread : Not sure if your car is the same as mine but you will soon tell if you follow this routine.

Guy has labelled me as the inventor of the carrot test and as much as I would like to be famous for something useful I announce here and now that I read of the carrot test on this or a similar forum

I think it was Andy K who came up with that one.Still funny tho carrot test

 

[NormanB]

Thxs m8.

Will have a butchers now.

Theres keen for you!

 

[sweeney todd]

nice one guys.

I've deffo got a similar problem I've just got to explain to my neighbours why I've been shoving root veggies into my car................

Oh by the way I lasted 20 minutes before HP switched on the snooze button

 

[andy_k]

much as I'd like to claim the carrot test as mine, I learned it off a very good friend of mine who is a superb "old school" mechanic - I was just hanging around his garage one day when he started poking a carrot into the fan - well, you just have to ask don't you

Terrific cheap test though and great fun if the fan is working properly

Andy