What does it do? Thermostat housing spring thing.

[Lukeydookeydoo]

At the bottom of the thermostat housing are two pipes. They lead to the spring bottom of the thermostat. In the pipe where the two join is a spring with a plastic bit that can be pressed down. When the thermostat is fully open I imagine the disc at the bottom of the thermostat covers it.

In my old housing the plastic bit had dropped so the spring wasn't holding it and it was stuck in the spring halfway down. At worst it would be blocking the pipes when orientated downwards.

Could this e causing my overheating?

[Burn2]

Hello, i would say that yes of course,
if you got problem with the housing of the termostat you could have problem.
I am not really sure, but i think i have read somewhere that when thermostat is fully open, it should close the "by pass" route of coolant (when thermostat is closed the coolant by pass the radiator and only go on the engine).

I am not totally sure about that, you should follow the pipe to confirm that, but i remember i have read that somewhere. So if it's true, if you got wrong thermostat, or thermostat housing problem, it could explain why the the heat does not really go to the radiator and why the cooled coolant does not go enough to the engine.
But not sure that it's on all the 2.4 or only on the Euro V version or it's on the 2.2.


Here is the plan of the coolant system:
https://www.catcar.info/ford/?lang=en&l ... RU5IOTA%3D

and
https://www.catcar.info/ford/?lang=en&l ... 49PUVOSDkw


I am searching where i have read that but i am pretty sure i am read something like that.
But even without that, it's pretty sure that if something is wrong with your thermostat housing, it could restrict the flow to the radiator.

[tranmx2]

Could this e causing my overheating? Unlikely.
Over heating likely blown head gasket, system blocked, little coolant, and other reasons.
Better if the type of van and year, engine etc is shown. They are not all the same!
Seems you are describing somethink like as below.

Cab htr shtr system dwg (2).png

Closed main closed bypass (2).png

If the bypass is blocked likely the cab htr could heat up quickly.

[metalworker0]

its a 2.4 rwd i think - note he's already gone down the viscous fan diagnostic route

NOTE - sorry if you start a new thread on this, you must say all the things you're investigated or tried to help responders here

Here's my guide for testing for head gasket failure ..not sure if ive posted it on one of your threads.

Rather than go into detail over and over, with every which and what or if, wrote this a while back ..
hope it helps - note water escaping from somewhere will possibly cause air in the system, which will bleed out.
Note head gaskets are funny things when they go ..they can start off slowly and go on for a year or more or fail strait away spectacularly ..the slow ones can be tricky to diagnose and keep you guessing for months as to what it is.

main pointers are
water in the oil.. turns it mucky brown colour on old oil ..mustard colour on new oil
oil in the header tank - can also be caused by oil cooler failure
lots of what looks like mayonnaise when you take the oil filler cap off .
hissing and gurgling sounds


well you need few tools to check it properly

but first bypass the EGR cooler by connecting together the coolers inlet and outlet hoses, cant remember if you've already done that.



Tool 1
A coolant system pressure tester,

If when pumped up with a the coolant system pressure tester, if it then t looses pressure ..meaning with test started at 15 psi and goes to zero within say one min ..then there is an internal leak somewhere ..that's if if you cannot see external ones.

Possible places for hidden leaks are
1. Head gasket --- can go strait into combustion chamber and out the exhaust or into engine oil , engine oil will take on a different colour from milky white to dark mustard brown... and there will be cream mayonnaise in the rocker cover oil filler area.
2. EGR cooler
3. Oil cooler - usually leaks oil into the coolant though, but pipes to it may leak.
4. Heater core - right inside the dash ..will be noticed by wet carpets ..steamed up windows or sweet smell of antifreeze inside car.
5. Water pump weep hole
6. Coreplug rotted, hidden behind the bell housing - my last car had this ..note i don't know if a transit has such a core plug hidden away. (just checked it does not ..but check other core plugs)

if the cooling system pressure tester does not loose pressure..then there is no leak...on the static test ..and the vans own pressure cap should be checked.

if that's ok ..move onto engine running pressure test with cold engine.

other notes ..a slow weep of coolant can often be seen as a build of crusty salts at the leak point, often the same colour as the antifreeze.


Tool 2. - a compression tester

This compression tester has many diagnostic uses:

Diagnose a faulty head gasket blowing between cylinders

Tool 3 a sniff tester

or buy one of those coolant combustion gasses tester kits

INSTRUCTIONS from description


100ml Bottle ( 50ml for Tests + 50ml Free for Flushing )

- easy, fast and inexpensive way of detecting combustion leaks in cars and motorbikes.

- works with PETROL/DIESEL/LPG engines (blue fluid for PETROL, red fluid for DIESEL)

- compatible with radiators and expansion tanks

- rubber bung (bottom diameter: 31mm , 45mm - top diameter)

HOW DOES IT WORK?

When combustion leak is present, a small amount of combustion gas goes into the cooling system which can be easily detected by this simple device. In presence of these gases, the test fluid will change colour to yellow.

TEST RESULT:

If the test fluid changes the colour to:

- YELLOW, the combustion leak is present.

- STAYS BLUE, combustion leak IS NOT PRESENT during the test.

- GREEN , unclear, combustion leak could be present (50/50)

HOW TO PERFORM THE TEST:

(Before each use, flush the tester with fresh fluid )

1. Unscrew the coolant cap to release the pressure but leave it on. To avoid splashes and burns during the task, make sure the engine is cold!

2. Start the engine and leave it on for a few minutes to warm it up. (the coolant must be warm and circulating)

3. Fill the tester with supplied test fluid (2ml per test)

4. Insert the tester into the radiator's or expansion's tank inlet and observe bubbles in the chambers. You can increase the number of bubbles by accelerating the engine. Be aware that the tester is without a filter; accelerating could induce coolant droplets or fog into the device and falsify the test result. In this case, the test fluid will stay blue.

5. Don't perform the test for longer than 5 minutes. Heat is harmful to test fluid and can change the colour to green.

NOTE: Dispose of the used test fluid (even if not changed the colour), never mix it with a fresh one as it could affect the sensitivity of the whole batch.

There are other things you can spend money on ..or just wait until, one day it will fail "good style" that failure date may be days , months or years away, but if it has it in the oil ..Head gasket must be changed, if you have the faulty block, then that must be changed.

Note the above test can also be done quickly at an mot test station or garage with the emissions tester probe .

There is also a very rough test that costs nothing

Tool 4 . The glove test
Put a rubber glove in the header tank instead of pressure cap ..if it inflates in seconds on a cold engine its the head gasket.


all the best.mark

[Lukeydookeydoo]

Thanks all - I'm keeping in mind it may be a head gasket issue. I have done a sniff test and it showed no exhaust gases and none of the classic symptoms are present (aside from overheating). With the changes I've made (new thermostat housing, new stat, new water pump, new radiator, new cap, new coolant and flush, new viscous fan now permanently enabled, oil and filter change), it seems to be keeping the temperatures down to an extent where - if I wasn't logging the temperature - I wouldn't notice any problems on hills locally (the overheating is just on a hill).

Getting a lower temp stat has been fruitless - I have one more option coming before I give up on it.

With my stat collection, I have now drilled the thermostat with a few small holes to open the stat earlier. I'll only use it in the summer so a slightly longer warmup won't be a problem. Also the van seems to be running 10 degrees higher than Burn's across the spectrum and this will help to account for this to give the cooling system a 'headstart' when it hits a hill and heads to 120 degrees CHT. The most it's got to so far after the changes is 120 CHT and 105 ECT but I ran out of hill at that point. Before the changes, it would have overheated. I think it's been getting to the point where the heat generated hasn't got enough time to be cooled when the stat opens, so the changes should help this.

It may still turn out to be the headgasket still, but there isn't enough evidence of it yet.

Also, I found the Robust branded water pump doesn't fit well with the vacuum pump so I now have a leak there too, just to add insult to injury!

[tranmx2]

I have done a sniff test and it showed no exhaust gases - better done shortly after the temp rise.
I have now drilled the thermostat with a few small holes to open the stat earlier. The thermostat shall open later.
Has the engine and compartment been cleaned recently?
Is the radiator air flow restricted, is the air flow through the engine compartment restricted?
What ambient temp is the vehicle used in?
The dwg of the thermost coolant system is not for your vehicle as the vehicle the dwg refers to does not have a CHT sensor.

[Lukeydookeydoo]

I'll give the sniff test a go straight after a hill.

The theory for the stat is that the holes mean there is unregulated coolant being cooled as if it is partially open all of the time. The coolant from the engine should also run through the holes to heat the rad side of the thermostat to bring it open slightly earlier - at least that is what I read. The thermostat will open later, but that should be because cooling is happening earlier due to the holes - giving more 'head room' for cooling on hills.

The engine compartment doesn't seem overly messy - it's an old minibus I bought so there lots of 'fixes' I've seen on the engine like cut pipes which have been joined with joiners. I haven't checked their sizes so, on thinking about it, they could be undersized. They're all of the smaller pipes from the thermostat housing, if that makes a difference.

Ambient is 10 - 25 degrees. Typical UK summer.

dwg? I changed the CHT sensor too.

Edit: I might just try looping some of the lines that are to the EGR and to the heater matrix to ensure they aren't causing anything. Is the super helpful diagram of the cooling system provided the same for the 2.4? It looks like it is.

[tranmx2]

The coolant from the engine should also run through the holes to heat the rad side of the thermostat to bring it open slightly earlier. - To have the thermo open earlier the coolant needs to be above the opening temp of the thermo. The aplication of heat and expansion occurs within the thermo housing. The wax if they still use it, is in the stem of the thermo which is not on the rad side of the unit.
Having more or bigger holes in the rad valve plate is likely to cause more heat to go out to the rad and be lost but the whole system is then warmed up. There's less of a cold area to dump exess heat. All depends on how the system operates. Years ago in the winter cardboard was placed across the rad to block the passing air and so cause heat to be not lost too quickly.

Types of pipe do collapse internally. Yes a series of smaller IDs (joins) can affect the flow and = higher temp'. The cab heater has an affect on the engine coolant system.
dwg drawing.

Is the super helpful diagram of the cooling system provided the same for the 2.4? It looks like it is. The drawing likely applies to Transits made 26th Sept 2011 to 2014. It might apply to Transits made 2006 to 2014.
It is made up from info' gleaned and from what I have seen on the 2012 van.

Better you show info' relative to the vehicle year etc. The info' can be put in the signature which is shown at the bottom of a post.

There's lots of posts re' head gasket leaks.
As an old van used in the UK it is likely something that has been done ( has happened) to the system. Could be gunged up due to accumulation over the years.