[Martin]

I remember reading about your Fairlane and its overheating problems which you blamed on Ford for supplying you a wrong thermostat?(Single acting?)

Well today I went and picked up a genuine Ford Thermostat for my ED and the guy at the counter said "This may look a little different than the one thats in the car, it wont have an extra bottom bit, its because Ford changed them to solve the continuous up/down movment of the temperature(guage) that the 6cyl Falcons have"

Ive noticed my ED's temp guage does go up and down quite often during just normal driving so I knew what he was talking about.

But my old EA never had this problem, and it had an 'aftermarket' dual acting thermostat which I installed.


So should I take back this single acting thermostat(its not installed yet) and get my money back and instead install a proper dual acting one? Perhaps the same brand as my what my EA had?


Thanks in advance for any advice you may have, or anyone else!

 

[Aussiblue]

I can't believe they are still selling them at the Small Claims Tribunal I went to the Ford rep said they had returned to the dual acting ones. The risk is if you live in a area of high altitude or cold climes and run a 50% or so glycol mix. The water in the radiator will get more viscous on cold mornings and thereflow there will be less resistance through the bypass system (with the heater tap fully open) than through the radiator and one cold morning you'll blow a head gasket. ....before that a few heater hoses will also fail from overheating.


See http://www.vtr.org/maintain/stag-cooling.html and http://www.cruzers.com/~twakeman/TR/index.html for more info on dual acting thermostats.

Ask any taxi driver with a Ford about the problems they had as well; at least in WA most Ford taxi drivers have heard about the problems using a single acting one causes. The reason Ford decided to try the single acting thermostats was apparently so the gas powered cars got hot enough. So unless you're running on gas stay with the dual acting one.

 

[XR_Strider_GuY]

I remember reading about your Fairlane and its overheating problems which you blamed on Ford for supplying you a wrong thermostat?(Single acting?)

Well today I went and picked up a genuine Ford Thermostat for my ED and the guy at the counter said "This may look a little different than the one thats in the car, it wont have an extra bottom bit, its because Ford changed them to solve the continuous up/down movment of the temperature(guage) that the 6cyl Falcons have"

Ive noticed my ED's temp guage does go up and down quite often during just normal driving so I knew what he was talking about.

But my old EA never had this problem, and it had an 'aftermarket' dual acting thermostat which I installed.


So should I take back this single acting thermostat(its not installed yet) and get my money back and instead install a proper dual acting one? Perhaps the same brand as my what my EA had?
Thanks in advance for any advice you may have, or anyone else!

SO how do i know if mines got the upgraded dual acting thermo as opposed to single?

 

[Kieron]

Re: Re: AussieBlue Re - Thermostats?

SO how do i know if mines got the upgraded dual acting thermo as opposed to single?

A dual acting thermo has a metal disk on the bottom of it, check the links that AussieBlue posted.

Out of interest, I have an EA with the bouncing temp gauge problem, AB helped me with it, but I have done everything to the bloody thing now and still have the problem, here's the things I did -

motor running cool but no needle bounce, so I replaced the single acting thermo with an aftermarket dual acting - temp came up to a decent level but bouncing started.

Replaced the aftermarket dual acting thermo with a genuine Ford dual acting - motor ran slightly warmer again but still have needle bounce.

Replaced heater tap and a few heater hoses, still needle bounce.

Water pump was replaced prior to all this too.

Reasonably new upper radiator hose split/replaced, at this point I had the system pressure/leakdown tested with engine going thru the warm up phase (where the needle bounce appears) and no problems here.

Replaced radiator cap, still needle bounce.

Engine is about 65,000k's old, cooling system virtually brand new and to this day I still get the needle bounce.

The exact symptoms are, cold morning start, drive a few k's, and the needle rises almost into the red then plunges back down rapidly to the start of the NORMAL range, then gradually rises about halfway in NORMAL, bounces a little then settles.

Its bloody frustrating as know one can detect a problem and worst of all as AB has previously mentioned, that rapid cooling isn't good for the head and will lead to gasket failure.

I can't believe 2 dual acting termos could be at fault, so my next step is to throw in a single acting for a day or so to see what happens.

Kieron

 

[Aussiblue]

Kieron; I assume you bled the air from the system per Ford instructions? Something like:fill at thermostat housing with heater tap open, replace thermostat and upper housing, fill balance of system, run with cap loosely (one turn) attached until normal temp (and water overflows) allow to cool, top up screw cap on properly. I also find it helps to use put the final litre or so inthrough the bleed hose that runs from the thermostat housing to the overflow tank. And is the cap OK.

 

[Kieron]

Kieron; I assume you bled the air from the system per Ford instructions? Something like:fill at thermostat housing with heater tap open, replace thermostat and upper housing, fill balance of system, run with cap loosely (one turn) attached until normal temp (and water overflows) allow to cool, top up screw cap on properly. I also find it helps to use put the final litre or so inthrough the bleed hose that runs from the thermostat housing to the overflow tank. And is the cap OK.

Thanks Aussie, yes I did bleed it correctly, and on top of this, I had a reputable workshop completely flush/refill the system and do the leakdown test for me, I put a new radiator cap on too and still no difference.

I'm not sure if its a low water situation, if these OHC engines are very low on water, the temp sender will sit in the blue regardless of actual engine temp as the sender sits in the lower thermo housing away from the head which means of course it doesn't even receive radiated heat from the head, if there was an engine that needed a low water sensor light, then this one is it.

Out of interest, the problem is worse on cold mornings, the recent hot weather in Perth has masked the problem to a degree but I know its still there - bloody cars

Kieron

 

[Aussiblue]

Rereading your 1st post the symptoms sound exactly like what my car was doing with the single acting rather than dual acting thermostat fitted. But if you have a good dual acting thermostat ......I'm puzzled. I'd try the aftermarket dual acting one. The only other thing I've seen cause a similar problem was in aneighbours EA when he fitted a "crud filter" in his radiator hose increasing flow resistance. Have you done anything similar?

 

[Aussiblue]

PS How olds the radiator? They seem to last about 3 years or 60,000 km however well looked after.

 

[Jase_ELXR8]

Kieron,

Your needle is going up and down because the water in head is heating up and then opening the thermostat and filling up with cold water making the needle go back down. Is the thermostat and all hoses installed correctly????? Yes there is a right and a wrong way to fit them and i dont mean what side you have out as thats just common sense. If you look into the thermostat the valve has a little notch in it, this has to be pointing up. Does it have a bypass??? Get one with a bypass or drill a hole in the one you have now. This will allow water to circulate out of the head and will help your needle bounce problem.

 

[Kieron]

Thanks AussieBlue and Jase,

The radiator was recored/1 new tank about 35,000k's ago, engine was rebuilt about 65,000k's ago and a crud filter was initially added but was removed on the first service.

During the engine rebuild, a single acting thermo was installed, all new hoses/clips, heater tap.

It replaced the single acting thermo during winter as it was stuffed an not allowing the engine to reach a decent operating temp, initially I purchased an aftermarket dual acting Tridon brand (made in USA iirc), then my troubles started, I replaced the heater tap again as it was looking a little dicey, lower and upper thermo housing was replaced, still no joy, so I went to Nuford and got a genuine Ford boxed dual acting thermo (made in the UK) and still the same problems, the disk at the bottom of the thermo mates with a hole at the bottom of the lower thermo housing which looks perfect.

Just had a thought, the lower thermo housing may not be a genuine Ford item so might not necessarily have the correct distance between the thermo mounting and the hole which would essentially give me a single acting thermo again - clutching at straw I know, but its worth a look I guess

When the engine has reached operating temp, it sits there pretty much all day regardless of ambient temp, just slight wavering as you would expect in stop go traffic, so the cooling system has to be in good condition, god knows how many times the bloody thing has been flushed lately
:s6:

Thank you again for your input guys.

Kieron

 

[Aussiblue]

Worth a shot but most aftermarket housings I've seen (Kilkenny as I recall) had the correct dimensions although I've seen some others cheapo ones (not for a Ford ) with castings dags left in that might both stop the poppet valve working and the thermostat opening.

 

[Aussiblue]

Also check the bimetallic spring in the fan clutch. Can be distorted by overheating.

 

[Aussiblue]

Here's a pic of the two types ofb thermostats. The one on the right is the dual acting one; the popett valve on the bottom closes of the bypass when the thermostat opens.

 

[Aussiblue]

I wonder if the dual acting t-stat was a bad idea stolen from a chevy.

see http://www.oldchevytrucks.com/Tips/261_six.htm

and the comment "In pure big truck form the 261 has a larger thermostat housing holding a double acting thermostat. This is designed to circulate water through the block and head before the thermostat opens to allow hot water into the radiator. Thus, no internal steam hot spots during warm ups, especially in winter. This is particularly important with very cold coolant. Vital engine spots can become very hot before the total coolant becomes hot enough to open a normal thermostat on the front of the block."

 

[Aussiblue]

And Saabs Delorens and Volvo's use them as well seehttp://www.specialtauto.com/engine.shtml

and

http://www.thesaabsite.com/9000/Thermostat.jpg


...........arrrgh!!!


but so do LT1 Corvette's with reverse flow cooling.