FORD S-MAX
Bogging down
Q My friend has a 2010 Ford S-MAX 2.0 diesel bought a couple of years ago. When he first got the vehicle, it had a loud turbo whistle which I quickly Identified as a bad intercooler (it had a hole in it). Now fixed.
Now on occasions it seems to bog down when under hard acceleration and then when he changes down a big puff of black smoke is emitted, then off it goes again all fine. Once whilst on holiday it left him stranded as wouldn’t gain any power, wouldn’t even rev properly at standstill.
I have looked at the entire intake system from filter to turbo then to intercooler and inlet manifold, etc., the only fault I found was where the air pipe attaches to the turbo the two bolts were NOT tight and there was a little oil around the area. However, it did improve the problem for a while.
My question is – is the turbo seal perished and would that cause this issue. It’s a nightmare to do as one bolt is hidden and getting a tool on it is a pain but if I need to do it I will.
Karl Funnell
A The black smoke is normally an indication of a mixture imbalance, and this could be due to a number of factors. The lack of power or bogging down at the same time does sound as though they are connected to the problem. The two main areas that should be checked are the MAF sensor and the EGR valve.
Starting with the MAF sensor this may have become contaminated from the earlier
