On some Focus mk 2.5 1.6 petrol cars, they have an electrically heated engine coolant thermostat.

The idea is run the engine on the hot side of things for emissions and efficiency,  and when engine ECU detects hard acceleration etc. it turns the heater element on to get the stat to open quickly.  These stats cost a fortune and are horrid to replace.  The heater element dies around the 9 year mark leaving the cooling fan coming on all the time trying to try and stop it over heating.  You get away with it OK in winter, but it doesn't work out so clever in the summer.

Without fixing the fault eventually something in the oil pump gets hot and bothered and it means all the oil drops out the top of the head and the oil filter system each time you turn off the car.  Thus the oil light doesn't like to go out for 30 seconds after start up.

Having stripped down the oil pump it shows little signs of wear and tear and in my mind has nothing unusual that will cause the issue.  But after fitting a new one the oil light goes out instantly as it always did till the stat played up.  I haven't fully investigated but there's one "drilling in the oil pump" that looks to be superfluous.  I can imagine a brass bung (or more cleverly a plastic one that melts) in there keeps pressure in the right place but with an overheating engine this bung falls out and you get low pressure.

All in all I believe these are two designed to kill the car features purely to help new car sales.  Having owned BM and Merc these guys are at the fore front of stealing your money and fit LOTS of designed to fail features.  Any thoughts on these two ford oddities?

Mercs are just designed to die from the very beginning. With their crap quality steel and lack of protection. 

That and Renault derived engines in some.. enough said lol.

Mines is 10 years old and still runs as it should, coolant doesn't drop and I hardly hear the fan as temp stay normal. I have hammered the he'll out of it cos it's not fast enough the only issue it's had was it's original battery died so I would call that build quality.

2 hours ago, stef123 said:

 

That and Renault derived engines in some.. enough said lol.

That's the same 1.5 Tdci that ford uses is it not? Nissan and Mercedes use it too

The 1.4, 1.5, 1.6 and 2.0 TDCI Ford engines are build in conjunction with PSA (Peugeot/Citroen) and have nothing to do with Renault.

wot about the subject

iffy stat and dodgy oil pump?

Dunno about the 1.6 petrol but my MK2 Focus 1.8 TDCi is on 145K miles and the largest bill so far was a reconditioned alternator at £150, although I've replaced some wear and tear items I've not found anything so far that appeared to be designed to fail "early".

Not sure about the default design/s @Botus but l would agree they certainly do the odd things to make you want to replace with newer, take our MK1 focus the 1.8/20 petrol both share a common fault sudden high revving and wanting to cut out ( which isn't good for powersteering pumps !! ) Unless you know of it you'd probably scrap after looking and finding no reason why but 99% of the time it's the emmisions pipe as it goes from the back round the side ( along the engine ) due to heat it collapses or splits but then you can get an improved version from ford at £75 it has heat resistant material wrapped around it, yeah bugger that £20 n a bit of DIY sorted ours nearly a year ago now

thanks for the replies.

interesting so few here have had an issue with either component.  I would expect all the rattly variators and engine flushes are really related to the oil pressure issues

 

On 3/11/2018 at 9:35 AM, Botus said:

On some Focus mk 2.5 1.6 petrol cars, they have an electrically heated engine coolant thermostat.

 

Is that right?

I have never heard of an electrically heated engine coolant thermostat.

Happy to be further educated.

ScaniaPBman.

3 hours ago, ScaniaPBman said:

Is that right?

I have never heard of an electrically heated engine coolant thermostat.

Happy to be further educated.

ScaniaPBman.

The 1.6L Duratec-16V Ti-VCT engine is equipped with an electronic thermostat. The electronic thermostat will manually open if the coolant temperature has reached 98°C and there is no current flowing to the thermostat electrical element. When the engine is under load the electrical thermostat will receive a current from the PCM. The electrical current will heat the element inside the thermostat to allow the engine coolant to flow through the radiator when the coolant temperature has reached 60°C.

they discontinued this type of thermostat oct 2007 and reverted to normal stat. 

Well I now have expanded my knowledge of engine cooling systems.

In my thrashing round the internet since my last post here I found this article on the same subject.

http://www.counterman.com/electrically-assisted-thermostat-smarter-way-greater-engine-efficiency/

ScaniaPBman.

ive never had to replace one on the focus 1.6 vcti 

I have

Fault code "P0599 thermostat control circuit high"    makes the fan cut in almost permanently, which if you search the internet is dead common on focus'