My 2016 Mondeo Titanium X 2.0TDCi 150BHP has a “Turbo Under Boost” problem. Under hard acceleration the power will drop significantly and it remains down in power until I turn it off and restart. Not an issue during gentle driving. The error code is P0299. No other fault code present. I checked all the hoses and intercooler for a leak but I couldn’t find any.  I checked the turbo actuator and it holds the vacuum fine. The vanes are moving freely. I checked it in real time using Forscan and the wastegate needle is all over the place but the vane position is matching the acceleration There is a  turbo control valve but I am not sure if this is the issue.

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On 5/15/2020 at 10:47 PM, Jim McA said:

My 2016 Mondeo Titanium X 2.0TDCi 150BHP has a “Turbo Under Boost” problem. Under hard acceleration the power will drop significantly and it remains down in power until I turn it off and restart. Not an issue during gentle driving. The error code is P0299. No other fault code present. I checked all the hoses and intercooler for a leak but I couldn’t find any.  I checked the turbo actuator and it holds the vacuum fine. The vanes are moving freely. I checked it in real time using Forscan and the wastegate needle is all over the place but the vane position is matching the acceleration There is a  turbo control valve but I am not sure if this is the issue.

Hi Jim,

I just bought a Mondeo Mk5 Estate 150 BHP TDCI and have the very same problem. Until I use the car in the city (Budapest Hungary) no matter how I drive it there is no problem. However, on the highway I get the wrench on the display and computer says "See manual". The motor control goes to service mode, no further acceleration just very slightly. Problem disappears when restart. Computer showed oil pressure problem that my serviceman thought it was an oil pressure sensor problem. Replaced the sensor but the problem remain. Did you manage to solve your problem? If so, I'd be glad to hear from you, it would be helpful for me. Preferably by email on [email protected].

Thanks!!! Gabor P.

Hello

I had this problem on a 2L diesel, The garage fitted a snake pipe, which increased the intake pressure in line with a racing engine, I also had the louvers module changed which allowed high revving. 

 

Out of interest, what's a snake pipe as I've never heard of that one, and how do the louvres effect your rev range? Wondered about retrofitting them and not heard about this.

I have the same problem man. My mechanic doesn’t know what the problem is and I can’t find it on the internet. However, when I changed the oil filter the problem disappeared, unfortunately not for too long because it came back.. I don’t know what to do, let me know if you found the problem please.. [email protected]

On 3/11/2021 at 10:35 PM, Mark M said:

Out of interest, what's a snake pipe as I've never heard of that one, and how do the louvres effect your rev range? Wondered about retrofitting them and not heard about this.

Snake pipes are used in the racing side of Mondeo cars, they are a a silicon pipe with a steel outer spring which prevents movement and pipe expansion making sure you have more pressure at the turbo. If the louvers are not opening correctly on the turbo it can lead to your problem and the turbo blows eventually, rather than fit a new unit or turbo, individuals wire them shut which allows the car to run OK, but above 4000 rpm you hit trouble, A new turbo from Darlington costs about £125 on the return of your old one.  

On 3/11/2021 at 10:35 PM, Mark M said:

Out of interest, what's a snake pipe as I've never heard of that one, and how do the louvres effect your rev range? Wondered about retrofitting them and not heard about this.

For further information see Viper Performance pipes