Engine running too cool - V Meldrew
Just wondering if anyone out there can shed any light on a problem I had many years ago with a Ford truck. (I worked at main dealer then). Driver complained that the cab heater wasn't getting warm. Temp gauge was reading low even after a long run. Both thermostats were changed and radiator was checked against specs for that model. There was no improvement so the driver put cardboard agains bottom of radiator and went away happy. 2 weeks later the engine overheated causing severe damage. Any ideas what the original problem may have been?
Engine running too cool - jc2
BOTH thermostats??? Not a 7V fitted with a V8??
Engine running too cool - mss1tw
Cooling system needed bleeding?
Engine running too cool - V Meldrew
That would cause overheating NOT running too cool
Engine running too cool - V Meldrew
7V's never had thermostats as far as I recall. I get the feeling you are not a youngster LOL.
Engine running too cool - V Meldrew
The truck was a D1000 turbo. They were fitted with 2 stats side by side in the head All 7v's had the V8 engine. Those were the days Ha! Ha!
Engine running too cool - bell boy
the heater matrix was furred up
mk3/4/5 cortinas were also bad for this,you would spend all day bleeding /using bleach/etc but the only solution ever was a new matrix (not cheap in them days)
Engine running too cool - V Meldrew
Not the heater matrix. The cylinder block was cool to touch
Engine running too cool - jc2
V8 thermostats fitted in the hose connection on the outlet from the head-held in place by the hose-heater connection was at bottom of the outlet stub.
Engine running too cool - Lud
Anything is possible with motor vehicles.

Theory: it was cool weather. The first thermostats were stuck open. The replacements also immediately stuck open. The cardboard worked as long as the weather remained cool and the truck kept moving. One day it got warmer or the truck had to sit in a traffic jam, so it overheated at last.

A rogue batch of thermostats. They're pretty cheap and random components usually.
Engine running too cool - Lud
Either that or for some reason they were fitting the wrong thermostats. That can happen too.
Engine running too cool - green oval
Ah the joys of a stuck-open thermostat, last year I think it was I had been to see a friend in Worthing travelling in my much abused WORKING Land Rover Defender Diesel, a petrol tanker had gone over on the M25, of course had to find a different way round, stuck in traffic in cool weather with a cold-running engine. Brilliant. The heater output was so pathetic I decided the engine needed the heat more than I did so switched it off..Glad to get home (North Essex) I can tell you! One new thermostat later it was back to its usual performance, not as bad as some people will lead you to believe!!

John Deere tractor engines also sometimes have two thermostats.

In my experience wax type thermostats stick open, am I right in thinking the old bellows type often did the opposite?

James.
 

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