Thermostat.....is It Really There

[DoctorDee]

After my "battery" adventure.......I found a small leak at a t piece just forward of the thermostat housing, the hose from which goes to the outlet from the rad

 

Tightened the circlip and replenished the system.

 

Fired up the engine, did the usual feely feely thing around the hoses. It took almost ten minutes on tickover to reach 40deg on the temp guage....

 

The only way to check if the said thermothingie is absent is to remove the housing.....On the basis that it's not there, should I be fitting a std Zetec thermostat or a beefed up version like the one Burton Engineering sell....think it bursts in to life at 92 degrees.

[Longboarder]

Most zetec thermostat housings are two piece. Three long bolts hold the housing one the back of the cylinder head and three small bolts on the side of the thermostat housing hold a cover which enclosed the thermostat itself and is the main water outlet to the top of the rad.

But you can tell easier than that. Just run the engine from cold and every few seconds grab the hose to the top of the rad. It should stay cold till the stat opens where-as one of the smaller hoses that goes from the thermostat housing to either your heater or the bottom rad hose (called bypass hoses cos they bypass the thermostat) will get warm quickly.

 

Nigel

[DoctorDee]

Having had my first real inspection of the cooling system.....Leaving aside the possible thermostat issue ...I have to reset the height of the tank against the radiator.... I had to remove the mounting brackets when I changed out the battery...

 

I am literally starting again with all of this stuff because I am unsure of the validity of bits of the original build......also I don't know what the previous two owners post builder have done...............I am NOT criticising the original builder in any way,....but I am learning as I go and some of the things do not make sense.

 

Any help will be greatly appreciated

[Guest 2b cruising]

You are taking the correct outlook and action as far as the build is concerned.

If you watch out for your local members meetings, it is a worthwhile idea to go along to them.

If your local members don't have a meeting, find the nearest group that have one.

You will find out just how good the members are and how informative and helpful they really are.

[DoctorDee]

New thermostat...still taking yonks to warm up....

 

Back to basics....I would be grateful if you gentlemen could run your eyes over the plan

 

Disconnect the heater....cap off the relevant outlets on the thermostat housing

 

Install uprated rad.....move fan from blow on front to suck on back.

 

Drop overflow bottle and go to spit and suck system.

 

New hose from rad outlet to water pump

 

New hose from Thermostat Housing to Rad inlet.

 

Bleed valve on outlet on top of thermostat housing

 

I would be extremely grateful for any advice/ comments

 

Ta Muchly

[Guest Gargoil]

Could it be that it just takes that amount of time?

Engines these days are put in tin tops that have engine bays crammed, partially sealed and insulated. This all stops the heat from escaping when cold and gives a quicker warm up. In a kit car, heat is lost through the firewall, bonnet and the big empty space at the bottom of the engine bay.

Try feeling the hose for pressure not heat next time. You will find the hose leading to the radiator get quite firm when the stat opens. If it all gets up to operating temperature and stays there, don't be too worried about how long it's taken.

Also, this cold weather isn't going to make it any quicker.

Edited November 16, 2016 by Gargoil

[kevin the chicken]

It takes a long time for my car to warm up when it is just sitting in the shed idling. Don't forget that even if you sit there revving it that there is no load on the engine. If I go out it probably takes a quarter of the time or even less. I can see the stat open on the temperature gauge as the needle peaks and then drops to normal operating temperature.

[fry61]

A contact-less thermometer will be able to measure all spot temperatures through-out the cooling system --- this second take on the system function may say there is no fault.

[Longboarder]

Simple enough to remove the three small bolts on the passenger side of the thermostat housing. The biggest hose going to the top of the rad comes off with the thermostat cover and you can pick out the stat and test it in a pan of boiling water on the kitchen stove.

Principles. The stat needs to be in a flow of water to work. No flow/low flow = no/slow change in temperature of the stat and slow opening. So the thermostat housing has two other smaller outlets to ensure flow during warm-up. The one on the passenger side is the warm-up bypass and is Teed into the lower rad outlet hose and is closed by the stat when the engine is up to temperature. The one on the driverside of the stat housing is to the heater and then Teed into the lower rad outlet hose and is always open unless you fit some sort of valve in it.

On my car I have a heater, use the latter hose as heater feed and warm-up bypass and don't bother with the intended warm-up bypass. I don't bother with the little bleed hose either. It all works fine. Diagram below and it doesn't show the warm up bypass. Spit and suck off the rad top works fine and doesn't matter at what height it is fitted.

 

Nigel

[DoctorDee]

Thank you to you all for the comments and suggestions.

The builder of this car lived on a farm......some of the hoses must have come off a combine.To say they are substantial is the understatement of the century, you couldn't compress them with a g clamp.

Thanks for the schematic and the descriptor Nigel.Big help.

Phil

[DoctorDee]

Sorry. Help.Away from home and want to order hoses etc.Forgotten to write down internal diameter of hose that couples to thermostat housing exit on drivers side of 2 ltr Zetec.Sony help would be appreciated.

[nelmo]

I bought 32mm but I can't remember if that is OD or ID...

[kevin the chicken]

If you bought 32mm hose that would be the inside diameter of the hose and the outside of the metal fixing. At least that is the general rule I have found. Must be an easy way to remember, ie if it's hard measure it outside where nobody can see You!

[DoctorDee]

Pretty sure that's the ID of the rad return or top hose. The hose ID I am short of is the outlet from the drivers side of thermostat housing to heater input. I think it maybe 16mm ID.....don't want to get it wrong as that's an expensive cock up

[nelmo]

Pretty sure that's the ID of the rad return or top hose. The hose ID I am short of is the outlet from the drivers side of thermostat housing to heater input. I think it maybe 16mm ID.....don't want to get it wrong as that's an expensive cock up

 

Sorry, you're right - missed your description of 'driver's side'. I'm not using a heater so that outlet is just blocked off for me...I'll try remember to go out tonight and measure it if you haven't already got your answer?

Edited December 6, 2016 by nelmo