Hi, I'm new here. I've just got my hands on a 2005 focus MK2. I have a few questions.

My coolant temperature rarely make to middle middle. only seems to if I've been in a lot of traffic.I have done some research and it sounds like I need a new thermostat. I am unsure of its location or how to get to it. Guides and videos I have seen do not match my engine.

My second question is my coolant overflow tank has two outputs, one is capped off, is this normal?

My Engine

Coolant

Would this be the replacement part?

http://www.eurocarparts.com/ecp/c/Ford_Focus_1.6_2005/p/car-parts/car-cooling-parts-and-car-heating/cooling/car-thermostat/?209590191&1&5459c809bd6950cbb09bd6aaa5215a02f5899d7f&000325

Thanks in advance

its a ti vct its normal for the gauge to show just under midway however if you did the dash test youll find the engine is up to temp it doesnt need a thermostat its quite common on the ti vct so ignore the you need a thermostst rubbish unless its barely moving at all you dont the gauge also is a coolant temp gauge not an engine temp gauge i had mine in at ford and they ran it on the road connected to the laptop and it is how its meant to be 4 others were checked and do the same and yes its supposed to be capped off

Your engine looks like 1.6 vct-ti.

The thermostat is located left hand side. You need to remove or move the alternator and the aux belt to get at it I believe. The cap on the reservoir is spec.

I had this problem to. Replacing the thermostat and the coolant bypass valve (right hand side on you photo; follow the pipe for on the tank and you'll see it) solved mine. I additionally had a fault code related to the solenoid I replaced. Just added that for reference.

That thermostat you linked to looks right but don't rely on me saying that solely!

1.6 ti vct the water pump is on the left hand side (looking at the car) the thermostat is located on the right near the coil pack as is the temp sender its nowhere near the alternator or the aux belt theres also a second thermostat the bottom coolant hose and the bottom expansion hose lead to a plastic y piece with a small thermostat inside if the temp is just under halfway and its not overheating let the car idle on the drive for a bit if the top hose and bottoms hot leave it alone youll waste time money and a headache for nothing

Listen to that bloke Arthur. He knows what he's talking about.

I read the procedure to change the thermostat on another website. Thought it was on about the 1.6 ti. I was very wrong so ignore!

My thermostat needed replacing though as it never rose off 60c unless in heavy traffic on a summers day. I found that bypass valve/secondary thermostat that helps throw heat into the cabin more quickly for pennies at a scrap yard and my additional fault code went away.

Thanks for you help. This is my gauge after a 8.5mile trip in medium traffic. I will do the test to see if the pipes are hot or cold. I must admit the fuel economy seems poor - another sign pointing towards the thermostat. This morning I did the same trip in no traffic and it didn't move at all.

So there is two thermostats? any way to know what one is faulty? If I do the engine temp check what should it be running at?

OK so I did a test on my lunch break. Idled the car for about 20 mins. I touched the coolant pipes and they are warm. The car seems to warm up ok when idling its when driving the needle doesn't move. Ill repeat the test on my drive home.

7 minutes.

15 Minutes

20 Minutes

is this still pointing to a thermostat issue? I think the dash test I did was the engine temp. was the only one with oC. as I said ill complete the test on my way home.

Any more help would be great!

the coolant temp is 40 degrees lower than the engine temp so 98 engine temp which is the thermostat opening is 58 coolant temp

the 102 engine is 62 coolant temp and 111 is 71 coolant temp so youre engine is up to temp its simply the coolant temp

again this is not an engine temp gauge but a coolant temp gauge and coolant never sits at the same temp as the engine is cold the coolsnt gauge should hit just under halfway it will go down as the thermostat opens and the coolant circulates however the aircon fan on the car runs constantly so to prevent over cooling it will reroute and bypass the radiator to maintain engine temp

people find it hard to understand that the gauge doesnt check engine temp only the coolant temp so it can be as simple as its cold outside the car isnt driving any distance 8 miles is a short journey did you do the above test with the interior fan and aircon off if not all you did was vent the heat from the coolant so the needle wont get anywhere

it has to be off or the heat is used to warm the cabin...i personally dont think you have an issue if you understand the system and how it works

on cold the coolant does not go through the radiator so the thermostat remains closed instead it bypasses the main thermostat and goes through the bypass hose the water pump sucks coolant from the expansion tank via the lower hose through the engine and back round the system till the engine warms up then the main thermostat opens and the coolant flows through the rad however since the aircon fan is running if its cold outside the temp drops too quickly and the car overcools so the thermostat closes and the coolant goes around the engine again you may find that if you give it a longer run it will sit just below halfway and stay there its likely due to the short journey and sitting in traffic with the heater etc on all that does is draw the hot air away from the engine till the engine gets some heat from driving

Thanks for you reply. I was done with the air con on. I didn't notice till the end of the test. I will drive home with the aircon/fans off and see if there is a difference. I did do a 50 miles trip on Saturday and 50 miles back and the temp was on the quarter mark, but I cant remember if the air con was on or off. I remember it hitting near the 50% mark then dropping back down a few miles later.

I do know the gauge is for coolant temp not the engine temp. ill let you know my results.

Thanks again.

OK so i repeated the test making sure the ac was off while on my tip home. The engine peeked at 123oc. I made a quick stop to collected my daughter then continued on for about a mile

Engine temp when i got out the car was 112. engine and coolant temp appear to rise and fall together. i'm guess there isn't a fault here. when the car engine was at 123oc the gauge was a mm off the half way.

was i being paranoid? never had a car that does this that all.

Yeah you're just being paranoid mpg will be in the lo 30s ive seen people replace thermostats and sensors wasting money to have the same issue if it ain't overheating and its running okay I wouldn't be concerned

I must admit, that is odd. The stat should open at 83c (123c on dash test) which it seems to, but should then close again if the coolant cools significantly to keep the coolant roughly at 83c for best efficiency, which it doesn't appear to be doing here. Fair enough if that's normal for this engine/stat, but I've never seen any other stat do that.

it did open at 123 degrees 83 but as he said as he drove and the air cooled the coolant the stat would shut and cycle round the head instead so the temp will drop but then go back up again if the test was done after switching the car off you dont get a proper reading

the thermostat is ecu map controlled and opens at 98 degrees so 138 engine temp so it hasnt even opened yet this was done to get better fuel economy via higher operating temps

Thanks for all your help. I'll go spend my money on something else.............umm possibility's .

Hi There,

I know it's an old topic, but I'm gonna try maybe someone will reply. The thing is that I have a ti-vct 1.6 Ford Focus 2005. Honestly never checked before, but the coolant temperature hardly moves from the 60c mark, when the engine is in hard use (like accelerating up a hill etc...) the coolant temp rising a bit to 65c-68c, and that's it.Even if I put the car in neutral and just rolling down from a hill the temperature gauge goes back to the start position. I was also trying to run the car at idle, in that case the temperature is rising to 100c. (and probably above... I stopped the car when hit the 100c) . Checked it via mobile phone + bluetooth obd II reader). In the hidden service menu I was able to check the engine temperature as well, that was approximately 103c when I stopped the car (after 30min drive) . I know it's winter time now, but is this normal? I should have checked if the cooling fan cuts in. When should that happen anyway? It didn't cut in at 100c... Cheers for the help. 

in the top post in the picture there is a bypass valve on the right hand side for the coolant, what is this exactly for?

As i have seen one where the pipes have been cut and the car is still running looks like its somehow been bodged to run without it.

anyone got a diagram of where the pipes are supposed to go?

I have had a similar fault. Recently I noticed that the temp gauge hardly moved off its stop, indicating just over 60 degrees. I assumed there was a fault with the sender but the garage put it on their PC, revved the engine with the car stood still and the temp went up, as did the reading on the gauge. I`m sure the temp needle used to stay in the middle of the gauge !

What I don`t understand is that on a long run the other day the car still did about 45mpg, so there can`t be that much wrong with the engines efficiency, also the heater seems to come on as quickly as ever, or slowly as ever, my wife`s Yaris heater gets warm quicker and always has !

 

Can you just swap the just thermostat and not the housing too cheaply and easily ? You used to be able to buy cheap easily fitted universal ones from any car spares shop (such is progress....).

Well the thermostat was faulty. It cost £120 to replace. When I nearly fainted at that the chap at the garage showed me the part he`d fitted. It wasn`t just a £5 thermostat fitted in minutes or less (as they used to be) it was a housing which comprised the stat and an electronic actuator (or something). Furthermore he told me that to fit it they had to remove the alternator and to remove that they had to remove the headlight.

Question, what exactly is that all that electronics built into the stat, and is it really necessary ?

I can`t help thinking that if Ford, or any other manufacturer, came up with a gizmo which would improve a car`s MPG by, say, a couple of %, but required a garage to fit it, cost 20X more than the conventional part, and possibly made the car more unreliable, most people wouldn`t want it.....

 

The old wax thermostats aren't particularly quick, lose efficiency over time and can only operate through direct heat against them.  Using an electronic thermostat controlled by the ECU means it can open or close much more quickly, whenever the ECU decides and should last longer as well...    

I don't think the driver has any say in emissions systems...people don't 'want' DPFs or EGR's either lol.

2 hours ago, TomsFocus said:

The old wax thermostats aren't particularly quick, lose efficiency over time and can only operate through direct heat against them.  Using an electronic thermostat controlled by the ECU means it can open or close much more quickly, whenever the ECU decides and should last longer as well...    

I don't think the driver has any say in emissions systems...people don't 'want' DPFs or EGR's either lol.

Sorry I don`t want to imply I`m in favour of polluting cars, though I have to say the best way to reduce pollution in cities is make public transport cheaper and better....

What I don`t understand is why a thermostat which only acts "through direct heat" should be inefficient. I thought the thermostat was simply to keep the engine at a particular temperature by diverting all, some, or indeed none, of the coolant to the radiator. Hasn`t an engine got an optimal working temperature and why should that change appreciably ? I still don`t see why the ECU has to be involved at all ? ! ? 

The stat just isn't very quick or accurate as standard.  It takes time to open and can only open once it's felt the heat, then it'll usually open too far and start over cooling before closing slightly again etc, it also can't cope well with sudden changes such as a loss of heat through switching heaters to max or sudden cooling from a blast of acceleration onto the motorway in cold ambient temps after sitting in traffic with a hot engine.  With the ECU deciding it's opening temperature and flow amount, and an immediate electronic actuator, it can keep the engine at it's optimum temperature for a larger amount of time. 

Not sure if this is the case on the Focus but I know with some German cars they can also use external influences such as air, fuel & oil temp to alter the optimum coolant temp.  It's one of the ways they keep fuel efficiency high.