Hello and thank you for allowing me to join your group. I have decided to join as I’ve scoured the internet and not found the answer I’m looking for .

I have a Focus Mk3 Zetec S (pre face lift if that matters) 1.6 TDCI with a coolant/heater issue. It’s of 45k miles. 
 

The issue I’m experiencing is this. 
The temperature gauge goes up and down, it never sits in the middle, the heater blows hot when the temp gauge shows low and when it rises to the middle the heater will blow cold. 
 

The coolant level goes under minimum after each drive and then once it’s cooled down, I remove the cap to top it up and it bubbles back up to the correct level indicating there is air locked in the system. The coolant hoses also feel very hard. 
 

To try and fix this problem I have already done the following.

 

Replaced the thermostat.

Drained the coolant, aadded a cleaner treatment, flushed it through until it was running clear and then refilled it. After which I then bled the system by running it up to temp until the thermostat opened and slowly added more coolant whilst squeezing all the hoses I could get at as I watched it burp out loads of air from the expansion tank and then finally replacing the cap. This didn’t help! 

 

Took it for a good drive with the hot blower on topping up the coolant before it reached the minimum level. Replaced the cap after I was done. 
 

Connected the OBD and no DTC are showing. Engine oil temp and coolant temp seem to go up at roughly the same level.

 

I’m just wondering if anyone else can shed some light on this issue? Thanks 

 

 

There are a few people who have or had similar problems to yours. There seems to be no one answer to fix the problem. It does sound like an air lock but why you can't clear it I don't know.

Many of the big garages now have vacuum filling systems to ensure the coolant system is fully filled with no air locks . Perhaps worth taking it to a garage and getting them to drain and refill

1 hour ago, unofix said:

There are a few people who have or had similar problems to yours. There seems to be no one answer to fix the problem. It does sound like an air lock but why you can't clear it I don't know.

Many of the big garages now have vacuum filling systems to ensure the coolant system is fully filled with no air locks . Perhaps worth taking it to a garage and getting them to drain and refill

I have seen this mentioned elsewhere online and I have thought about it. Makes me wonder why that would even occur in the first place.
 

Hopefully someone who has resolved the problem can shed some light.

 

Thanks for your reply, it’s appreciated. 

It’s going into Ford on Friday so I’ll update the group with the outcome in case someone faces this issue in the future.

Have had the same problem, changed stat, not Ford but not a cheap one vacuum filled really easy if you have a compressor, but now with this cold weather will drop from just under half way to about a quarter if sitting in traffic. Will probably try a ford stat when it’s warmed up a bit. The other thing I’m not sure of is the front shutters weather they modulate on coolant temperature or not, but not got round to investigating that yet.

No compressor or I’d do it myself. Must be an air lock. I’m just hoping the cooling system isn’t being filled with air from the cylinders or something really bad. My van runs slight under half in this weather too. 

Like you say hopefully just an air lock, although my gauge fluctuates with driving conditions and ambient temperature I don’t loose any coolant, level has remained constant since I replaced the stat 6 months ago. Let us know how you get on.

Is there a valve in the expansion tank cap?

1 hour ago, VFR800 said:

Is there a valve in the expansion tank cap?

Yes. It's very similar to the old style pressure relief valve on a traditional radiator cap.

yes but the magic design means when it lets go it spills on the floor leaking out at the bottom of the tank dribbling on to the engine mount - so you never know this is what's letting go

Car is in Ford, they can’t even diagnose it until the 30th! They think it needs a new engine and mentioned it could be the bottom end. Personally think the mechanic is talking out of his butt. We will see.

9 hours ago, Botus said:

yes but the magic design means when it lets go it spills on the floor leaking out at the bottom of the tank dribbling on to the engine mount - so you never know this is what's letting go

Not quite sure what you mean.

We all need one of these...https://www.amazon.co.uk/Universal-Radiator-Pressure-Tester-Cooling/dp/B078RJT13X/ref=sr_1_5?keywords=Coolant+Pressure+Tester+Kit&qid=1671346939&sr=8-5

I hear you can get 'OTHER' attachments for it, of the personal nature!!! 😉 Just a thought!

Welcome I had the same problem exactly a month ago can you help or give me some advice thank you 

44 minutes ago, eyad0090 said:

can you help or give me some advice thank you

You do realise that all of those posts above in 'December' were made in 2022 ??

Why not start a brand new thread and tell us exactly what problems you're having ?

On 12/12/2022 at 4:56 PM, fordfocusmk3 said:

The issue I’m experiencing is this. 
The temperature gauge goes up and down, it never sits in the middle, the heater blows hot when the temp gauge shows low and when it rises to the middle the heater will blow cold. 
 

The coolant level goes under minimum after each drive and then once it’s cooled down, I remove the cap to top it up and it bubbles back up to the correct level indicating there is air locked in the system. The coolant hoses also feel very hard. 
 

To try and fix this problem I have already done the following.

 

Replaced the thermostat.

Drained the coolant, aadded a cleaner treatment, flushed it through until it was running clear and then refilled it. After which I then bled the system by running it up to temp until the thermostat opened and slowly added more coolant whilst squeezing all the hoses I could get at as I watched it burp out loads of air from the expansion tank and then finally replacing the cap. This didn’t help! 

 

Took it for a good drive with the hot blower on topping up the coolant before it reached the minimum level. Replaced the cap after I was done

 

Do you have a European, UK, or some other version ? Is it LHD or RHD ? Petrol, Diesel or Pixie Dust ?

I've never come across a Ford model "z"

Ford Focus  1.6 TDCi ECOneticFord 2014