A couple of things I would suggest.

Check coolant level is correct.

As per previous advice clear the codes.

P0299 does trigger limp mode. A regular culprit causing that code is the infamous vacuum pump diaphragm. Can be easily inspected for deterioration (often torn/split) or sometimes the valve cap comes loose.

Easy removal from the pump with a torx screwdriver or male torx socket.

https://youtu.be/yr0EHRTmN5g?si=gvH0RaQ4SrJXVdt1

 

On 12/11/2023 at 6:18 PM, RayC333 said:

A couple of things I would suggest.

Check coolant level is correct.

As per previous advice clear the codes.

P0299 does trigger limp mode. A regular culprit causing that code is the infamous vacuum pump diaphragm. Can be easily inspected for deterioration (often torn/split) or sometimes the valve cap comes loose.

Easy removal from the pump with a torx screwdriver or male torx socket.

 

Thanks for this. I'm going to check that tomorrow and see what I can see. Should be a cheap, easy fix if so. If it's not the vacuum pump diaphragm, or leaky hoses as unofix suggested, then I'm not sure what to do to be honest. Do you think it's safe to drive if I reset the codes and just see what happens?

I'll let you know how I get on with the vacuum pump and hoses anyway.

Update: It is the vacuum pump diaphragm. It had completely disintegrated… but I now have another problem. When removing the hose the plastic nipple on the diaphragm snapped and is lodged tight inside the hose. Like really tight - I can’t get it out. So, I’m going to need a new hose as well. Does anyone know where I can get one? Is there a specific part number for that particular hose or will any hose of the same gauge do? For that matter what is the gauge of the hose? Or how can I find out? I’ll attach a couple of pictures to this post so you know which hose I’m talking about. Also where can I get one of those clamps that go around the hose (clearly visible in the pictures)? Or will they come with a new hose?

Sorry if these are blatant n00b questions but I’ve never undertaken any work on a car before besides changing the odd tyre so I’m a little unsure. I can do the work easy enough but want to make sure I get the right parts. I need to keep this car running into the new year if possible before I look to sell it.

Cheers.

You're making good progress so hang in there!

Before considering replacing the hose I would look to remove the snapped piece of plastic. When undisturbed for a long time, rubber hoses do get a good grip on what they're attached too. The trick to enabling their release is to twist the hose such that the bond is then broken. Of course, a lot more difficult in your case given there's nothing to hold on to the stuck plastic part with but see what tools - real or makeshift - you have to hand that might allow you to get that plastic part turning. Dipping the hose in boiling water (for a good few minutes - really let the heat really sink in and not just warm the surface up) ought to help soften it up which might be particularly helpful at this time of year. Twisting before pulling out is the key here I think, and if you can get it turning you are just one step away from getting it out.

An alternative/backup approach might be to cut off just a few mm of hose around the plastic part with a stanley knife so as to give you something to grab with pliers. One step at a time though - try and remove it without doing this first. Disconnect the other end if you can to make it easier to do off the car / indoors.

Edit: Just thought of a near-perfect method - screw a suitably-sized screw in to the plastic part and pull the thing out with pliers! I've got boxes of them but if you haven't then look to 'borrow' one from somewhere in your house: door handle, hinge etc.

5 minutes ago, MJNewton said:

You're making good progress so hang in there!

Before considering replacing the hose I would look to remove the snapped piece of plastic. When undisturbed for a long time, rubber hoses do get a good grip on what they're attached too. The trick to enabling their release is to twist the hose such that the bond is then broken. Of course, a lot more difficult in your case given there's nothing to hold on to the stuck plastic part with but see what tools - real or makeshift - you have to hand that might allow you to get that plastic part turning. Dipping the hose in boiling water (for a good few minutes - really let the heat really sink in and not just warm the surface up) ought to help soften it up which might be particularly helpful at this time of year. Twisting before pulling out is the key here I think, and if you can get it turning you are just one step away from getting it out.

An alternative/backup approach might be to cut off just a few mm of hose around the plastic part with a stanley knife so as to give you something to grab with pliers. One step at a time though - try and remove it without doing this first. Disconnect the other end if you can to make it easier to do off the car / indoors.

That’s good advice. I’ll give it a try and see what I can do. Thanks.

I’d still like some advice on replacing the hose though so I know what my next step is if I can’t prize the plastic out of the existing one. I’ll let you know how I get on with that though.

4 minutes ago, MJNewton said:

Edit: Just thought of a near-perfect method - screw a suitably-sized screw in to the plastic part and pull the thing out with pliers! I've got boxes of them but if you haven't then look to 'borrow' one from somewhere in your house: door handle, hinge etc.

Ah even better. Hadn’t thought of that. I’ve got a million and one screws lying around (I may be crap at car repairs but I’m quite handy around the house lol). 

2 minutes ago, DoTheDonkeyKonga said:

I’d still like some advice on replacing the hose though so I know what my next step is if I can’t prize the plastic out of the existing one.

No need - you will get it out.

(If only to satisfy your curiosity though, you'd need to buy an original replacement as it needs to be formed into the right shape. A 'generic' pipe won't do.)

Sorry for all the questions but I’ve got two more:

Firstly, can anyone recommend a specific seller or brand for a replacement diaphragm? There are so many on eBay and Amazon with varying prices. I don’t want to order something that isn’t going to do the job. The link to the one used in the YouTube video posted above is dead. I’m not really sure how much I should be paying versus how much I should be expecting.

 

Secondly, is this vacuum pump solely for the turbo, or is it the same vacuum pump that also operates the brakes? Because obviously if the latter then I really want to get this right!!!

A few answers:

If you still can't remove the broken nipple from the vacuum pipe using previous suggestions, try squirting a little WD40 into it. If you have a long enough Phillips type screwdriver/knitting needle or other suitable implement about your home, try pushing it out. 

The short piece of hose in question is not separately available from Ford, but if the worst comes to the worst it will be possible to get a something suitable to replace it so don't worry. It won't be the nice shape of the original though 😀

Why not use the same hose clip?  It shouldn't need a new one unless it has been damaged. Again, if necessary, a suitable replacement can be sourced on ebay.

The diaphragm in question is only used for the Turbo. There is another one in the the vacuum pump which assists the brakes.

Unsure about the replacement valve assembly. I have seen reports where it's said the cheapest ones fail again or the housing parts come apart releasing the diaphragm. Buy one that has some sort of guarantee/refund policy.

Well, she's back on the road!

I couldn't get that plastic piece out of the hose though. I tried everything I could think of - including all the helpful suggestions given here - but it wouldn't budge at all. In the end I decided there was enough play in the hose to just cut it below the end of the stuck plastic. Replaced the diaphragm and wrestled the hose back on and all seems well. No more limp mode - at least not yet anyway. I've done around 100 miles or so on varied roads since and it seems to be holding up well.

Thank you all for your help with this. Without you lot I'd have either scrapped the car or ended up paying anywhere between £3000 and £7000 to get it back on the road! I really, really do appreciate all the help.

All the best for the holiday season and new year!!