Capri thermostat

savagethegoat

I reckon my Capri has had the thermostat removed (because I can see water surging across the top of the radiator at idle when cold)

Why would someone do this and should I reinstate it?

Of course, it could be faulty 'stat I suppose...

dooroy

What engine ?
How long have you had the car ?
What kind of output from heater ?
Tstat could be removed as car was overheating with it in place.
Best thing is to remove housing and see if stat is missing - it could have failed in the open position.
If it is you could fit a new one and see how it goes .
Make sure to bleed system to get rid of airlocks .

ianobrien

OP, Burton Power is your one stop shop for classic Ford mechanical parts, but as Dooroy said, you would want to investigate why it was removed/failed.

savagethegoat

yes I realise that, but if it's working as it is, is there a necessity to do anything? I dislike opening cans of worms, but I want to be informed of any dangers of not doing so, if you understand.

1,6 Pinto auto btw, heater fine, not overheating. Drove 100km yesterday with no issues

ianobrien

In that case OP, I'd try my local old style autofactor first (you know the type that doesn't rely on a computer for everything). They may have one on the shelf as Ford had a habit of sharing parts like that.

dooroy

If you did a 100 Km drive without problems and heater output OK etc then leave well enough alone.
If there was no thermostat then your heater output would be practically non existent , and if your engine has an autochoke then choke would most likely stay on and fuel consumption would be excessive ;
How does temp gauge read ?

savagethegoat

I can't get my head round that one. When an engine heats up, the thermostat opens to admit hot water to the radiator to be cooled. With no thermostat, surely the water is being admitted to the rad all the time, meaning the engine doesn't reach optimum temperature as quick but surely the heater would work as normal anyway if a little later.

hi5

It depends on the efficiency of your radiator, if the radiator is working too well the engine might never reach optimum running temperature as the radiator keeps it too cool.
Your heater will work to whatever temperature your engine is.

dooroy

If tstat in place and working as it should coolant will only circulate through cylinder block and heater matrix at first . No circulation through radiator .
When coolant reaches a preset temp (stamped on stat) tstat will begin to open and allow coolant to circulate through radiator .
If tstat doesn't open then engine overheats.
If coolant is circulating freely (due to absence of tstat for example ) then it will take many miles for the engine to warm up properly - if it ever does ; if you are on the open road with a good airflow through rad then you will see how long it takes to reach 'normal' temp.
Many moons ago I drove cars with these engines and no stat meant a cold car - not nice on a frosty night with fogged up windows etc.:(
Theory and practice don't always match up I'm afraid .

gavman1

the pinto engine is without a doubt the most user serviceable engine ever made.dont be afraid to investigate the issue.if your engine isnt reaching optimal temp then neither is your oil and thats not good.afaicr the stat is behind a elbow that has the fat coolant pipe on the front of the head.i think its just 2 12mm or 13mm screws that hold it on.when ye have the elbow of the stat (if there is one fitted) will be sitting there looking at you.i would bet its stuck open.if its not there i would check the viscous fan is working properly as they were never up to much.if it hasnt been done in a while i would flush the entire cooling system anyway as the engine is getting on in years and god knows what additives and crap have been added to it over the years.best bet is get yourself a haynes manual.they really are great cars to work on.best of look.

btw if your removing the stat be sure to replace the paper gasket between the elbow and the cylinder head

savagethegoat

not actually the answer to my query but thanks anyway

dooroy

savagethegoat wrote: »

I can't get my head round that one. When an engine heats up, the thermostat opens to admit hot water to the radiator to be cooled. With no thermostat, surely the water is being admitted to the rad all the time, meaning the engine doesn't reach optimum temperature as quick but surely the heater would work as normal anyway if a little later.

The cooling system was originally designed to be able to keep the coolant from boiling in high ambient temps and an engine under load .
The tstat helps to restrict coolant flow until water in block and matrix has heated up . It then opens but still offers some restriction to coolant flow - and if temp begins to drop off stat will partially close and help to get temp up again ;
If there is no stat then the coolant flow has no restriction from the start or at any time.
Depending on ambient temp , air flow through radiator (ram effect ) and load on engine the coolant may just barely warm up ; if radiator is extracting almost as much heat from coolant as combustion process is generating then coolant will barely get warm.
If car stops moving for a bit (no ram effect ) - temp begins to rise ;
If load on engine increases ( climbing a long hill) - temp begins to rise :
Also I think the 1600 had a fan mounted on the water pump and thus running continuously - overcooling the engine at times ; the viscous coupling or electric fan improved this situation .
May make some sense - or not

gavman1

savagethegoat wrote: »

not actually the answer to my query but thanks anyway

your question was is there any point in changing anything if it is working ok as it is.i think i have thoroughly answered that question.if ye want to hear theres no point in doing anything then theres no point in doing anything.its your engine my man

savagethegoat

no, what I hoped to hear is something like "if it isn't a faulty stat, your engine may have been overheating because the timing is wrong (or whatever) and if you don't replace it , it will have (x) effect on your engine"

Heater is working , so I'm assuming the engine is reaching a suitable temperature.
I'm concerned at mention that the choke may not be working properly, seems to be OK though as far as you can tell with an auto.
I have already flushed the sytsem and filled with new antifreeze for the winter
I already have a Haynes manual.

ianobrien

OP, it just dawned on me that some thermostats have a small hole to leave air pass (when bleeding) so if the surging isn't too much, it could be that.

Also, the fan on them is viscous and on all the time. I've a crossflow in the Escort and after starting it heats up after the usual time. The gauge however stops at about 1/3 rather than half but if I'm stopped in town, giving it holly, etc it'll rise to the half. I was worried until I borrowed an IR thermometer off a mechanic friend so that I could take temperature readings off the stat housing, block, head, rad etc without touching them. I found the difference between the 1/3 and half on the gauge was only 2 or 3 degrees so I stopped worrying. I didn't bother with an electric fan but there are simple electric fan kits out there.

As an aside, as its a 1.6 pinto auto, I hope it has the Weber DGAV, rather than the horrid VV carb. The auto choke routinely fails on in the DGAV though so watch that. You can convert to a manual choke.

savagethegoat

it's a VV and it has a fixed fan....poverty style. You could be right about the hole....it's not much of a surge ,just you can see movement when cold.

I never rely on an old Ford temp gauge to work properly...or at all :-)

dooroy

The hole in the rim of the thermostat is quite small and had has a little pin (jiggle pin) in it to prevent it blocking up . Meant to help when bleeding the system - little or no effect on coolant flow .
If heater output is satisfactory , temp is reaching normal and autochoke should be working OK also .