Mk3 Mondeo Tdci Problem
Posted 29 January 2013 - 10:12 PM
just brought a mk3 tdci euro 4 engine 55 plate mondeo
the problem is really wierd
if u drive it hard after 3000rpm it will go into limp mode ... but if driven sensibly it will go all the way round the rev range ????
when i brought it the guy said it has had a second hand turbo actuator on it . as the old 1 failed .. . and he was told sometimes they need recoding ??? is this true ?? or not ???
also today i unplugged the MAF Sensor ( airflow meter ) and the car didnt run no different ..... but im sure it should of ran lumpy and smokey with out that connected ?????but the engine management light did come on ??? but went off when reconnected MAF Sensor .
it starts first time in a morning . no smoke from cold when started . and no smoke when driving .... engine is a little knocky but put that down to a diesel knock
the things i have tried is
Clean EGR Valve
Unplug MAF Sensor ( Changed MAF Sensor as it brought code p0100 up )
Changed Boost Pipe As it was split
Changed Airfilter As it was black ....
checked for a power feed to MAF - All Workin Fine
What else could it be ????
its got 148k on clock ....
Im still getting 40mpg combined ....which i think is good ???? and around 35mpg round town .....
Posted 29 January 2013 - 11:34 PM
I wonder if the turbo vanes are sticking when you just bang the revs up to the top? Thing is a 2nd hand one might not be much better than the one it replaced. 'fraid I can't really help much, beyond saying that I get almost 50mpg just moochin about, and almost 60mpg on a motorway run.
Do you have a code reader? Force it into limp mode and check for stored DTCs.
Also, did you clean the MAF or just look at it then put it back? Clean the metal wires (very carefully) with a cotton bud dipped in carb cleaner, also clean inside the little tube bit as well. If it's caked up in filth it won't be working properly.
When you cleaned the EGR valve did you have a go at the inlet manifold too? Because that can get just as bad.
Posted 30 January 2013 - 06:56 AM
Posted 30 January 2013 - 11:07 PM
Posted 31 January 2013 - 02:03 PM
Posted 31 January 2013 - 11:20 PM
Posted 01 February 2013 - 11:00 AM
Good idea to blank the EGR, some Mondeo owners are on their 4th valve, a Mondeo TDDI runs better with a blanked valve than a "perfect"ly working one - solid,(no holes to let gasses through) stainless steel ones ate best
As you have a Euro 4 the EML is liable to come on with the blanked EGR (but limp home mode should not be triggered)
Worth cleaning out your inlet manifold as well
There must be a reason the car goes into "limp home" mode when you drive hard and not when driven "sensibly"
One possibility is the variable vanes in the turbine are coked up / not moving to their fullest extent, the vanes control the boost pressure via the control rod and actuator, if these items are not attenuating boost enough it may cause exessive boost triggering limp home mode when driven hard and when driven "sensibly" not enough energy in the system is created to generate enough boost to trigger "limp home" mode
the vanes sticking can cause actuator failure, as the SWR on the motor goes up, that may be why the actuator was changed
Other things can cause this eg, fuel delivery / injector problems (sufficient flow/ preesure for moderate driving, not enough for hard driving etc)
Not everyone achieves 60mpg, it can depend on road conditions, driving style, outside temprature, duration/ length of each run, tyre size/ type/ make/ pressure, weight in the car etc etc, 35mpg round town and 40mpg isnt too bad and results an ST220 driver could only dream about
The engine is quite low revving, peak power may only be at 3 to 3.5k (euro4 Mondeos tend to develop peak power at lower revs than euro3s, in my experience ) and peak torque much lower (typically 2.2k, depends on exact model)
so changing up at 3k may make the car accelerate faster anyway - if you are "mooching about(cruising?)" you probably want to change up earlier, 2 to 2-1/2k car will probably pull better/ return a better MPG
No point in "booting" it round town/ in 1st/ 2nd, these cars are rubbish 0-60 / through gears anyway, once your in the higher gears/ in the midrange its a different story, if you use the available torque, again you will make better progress, and get a better MPG
Posted 01 February 2013 - 11:07 PM
Posted 03 February 2013 - 07:07 PM
Posted 03 February 2013 - 07:33 PM
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