Turbo issue - some mechanical opinions/solutions please!

[Harry5]

Hi guys,

Just a question regarding the Turbo of a ford fiesta mk7.5 140PS, (black/red edition specifically). I have this car for 6 years now and the last 1 and a half year approximately, on occasion while I rev up the 2nd or 3rd gear  around 3.5k-4K RPM(usually when I want to accelerate to go faster or take over a slower vehicle), sometimes the turbo seems to shuts down its function and a message appears on the dash saying 'check engine'. The thing is that the car was freshly serviced and made any repairs necessary, and even check on OBD scanner (serviced on time and oil change is done every 5K kilometres). I mentioned it at the Ford department where i bought it and take it every time for its service and checked the program too. 2 years ago they told me that there was an update from the factory so they 'updated' the car's software program. Another thing is that when I bought it at the very beginning, for the first year up to the point I took it for its service, while driving in the highway or changing gears from first to second, third  etc I could hear the turbo whistling (oh the joy of turbo sound!) and was perfectly fine. After its first service, the turbo sound significantly reduced and thought that ok, they may have done some changes until the engine gets used to daily driving and components get their initial wear and get used to friction and function.

Now the turbo giving out, this has been done 4 times already and the only thing they told me to do is to go to the side of the road and switch off the engine. Restart it and would be fine again. And that's what i do. After I turn on the ignition, seems fine and drives normally as it should but I avoid to rev up higher than 3K RPM each gear. I'm suspecting that some stupid mistake has been made from back then when I took it for service and this has affected its performance drastically or when serviced they may squeezed tightly some bolt or something and it gets overheated very easily and that's why it shuts down to prevent further damage. Or it simply needs to be changed because of gunk and tear from 6 years of driving around. Usually i know turbos lifespan is up to 200K kms. Mine now has 70k kms and this makes me think that something is not normal. I mean wtf could be happening and they can't find it in Ford those mechanics?  It really gets me mad! Any help provided with some solid solution could be appreciated guys! 

Thanks!

[RayC333]

Personally I would suspect the turbo vacuum system for a leak (pipework) or a deteriorating diaphragm in the vacuum pump (a common problem) and turbo valve actuator.

I checked my daughters engine with a cheap and cheerful vacuum test kit off eBay and found the tiny silicone diaphragm in the pump outlet was covered in oil and split.

As the problem is not consistent, the use of an OBD scanner would tell you if boost pressure is being lost when the issue next occurs on the road. That might help to narrow things down. I use a simple ELM327 scanner bought off eBay.

Unlikely that routine servicing at a garage would check for such problems.

 

[Harry5]

Hi RayC333. Thank you for providing some insight from your experience with this problem I am having here. is it something that I can change myself or do I have to take it to the ford dealership. I mean, I'm not a mechanic but I do understand enough things more than 'average Joe'. I do have an OBD forscan scanner so I would give it a try. One last thing, any suggestions how to proceed checking it step by step so I won't cause any harm by accident? or a diagram indicating this silicone diaphragm? Not absolutely sure what you meant there like I've visually know what that is or saw it and didn't catch my eye...

[Harry5]

So, here's an update. Took it to the dealership and checked if there was a turbo malfunction or if there was any leak/vacuum issue but everything seems fine. There was an error code which appeared and now the electrician needs to have a look as well, maybe it's something with its circuit. Still waiting and need to be kept in garage. Something seems odd and I don't like it, trying to keep calm and my patience. FML! FFS!

[RayC333]

Sorry I didn't reply earlier; I've been on a few days holiday. 

If the dealership has checked the vacuum system I guess there is not much more you can do yourself apart from looking at the actual vacuum/boost readings when the car is displaying the problem you described. Checking it when everything is working fine is unlikely to pinpoint the problem.

I check vacuum/boost on the go by using an OBD scanner connected by bluetooth to a free app on my smartphone called Torque Light.

During the driving cycle the vacuum/boost reading in the induction system is constantly changing. In a normally aspirated engine the reading would always be in the vacuum -range. In a Turbocharged engine like yours, once the vacuum pump creates enough suction to operate the turbo valve, the pressure in the induction system will increase above atmospheric pressure into the positive +range.

My idea would be to get some readings when everything is working ok and then see what you get in comparison when the problem occurs.

I suppose it could be an electrical/software problem, incorrectly operating the turbo blow off valve or turbo pressure solenoid valve but I've not heard of or experienced that.

 

[Harry5]

Hey RayC333, no worries. So the update is that after I took it to the dealership, they initially couldn't locate the problem but they could identify on the system the error code upon scanning the car. Later, like you said, they took it for a test drive and live scanned while driving it and found what was the issue and it is indeed a valve misbehaving and occasionally does this when driving it above 3K rpm. All in all, I got my car back as it's still able to drive around with it in this situation without stressing it much while waiting to let me know when to take it in and change this valve once they have it in their garage. Hopefully this will be solved and enjoy many more miles driving it around as I really like its sport character and find it an ideal vehicle to drive around city as well as going for some trips in general. In case anything else comes up, I will post it here and have a little discussion about it. I hope not so fingers crossed! Wish me good luck!

[Harry5]

update here: ..... and the same story goes on! Supposed to be a programming fault but still doing the same thing. If it's not the overboost valve, nor any fuse (as they say), nor the updated software, wtf could be? seriously got really annoyed and have second thoughts about buying ford again or car with similar technology!!