Hi everyone, I have an very peculiar issue, or group of issues with a 1.6D that has my local mechanic, volvo specialist and the dealership all completely stumped.

For context, the car just went through it's MOT with only minor issues. The car was absolutely fine but since the MOT it has been an absolute pig. I'm not sure whether this is one issue causing a cascade effect, a freak coincidence of multiple things breaking at once or whether the MOT centre has done something they shouldn't have.

Here's the list of issues:

- Car will not start on the clutch alone, for some reason now wants the brake pedal too and isn't happy about starting up at all when it does start turning over (I discovered the brake pedal start by accident) - Car knows the clutch is depressed as it won't start without the clutch pedal down so not a sensor.
- Idle feels a little rough, though only a little.
- There is a strange delay from the throttle where it lags when you put your foot down but then keeps going when you lift off (only for a half second or so) - but only when it is in gear and seems WAY more pronounced in first, second and third compared to fourth, fifth and sixth. Cannot reproduce this in neutral. When not in gear the throttle is sharp as a tack.
- Dashbord gear shift up/down indicator seems to turn up only when it can be bothered to, which is new.
- Engine feels angrier than usual, trying to get up through the revs a lot quicker than usual with less pressure on the throttle.
- First feels really, really sluggish (much more so than usual) - revs are there but transmission feels vague.
- Noticed recently i'm getting some resistance from the gearbox when I want to change gears quickly in first, second and third. If the clutch pedal hasn't been depressed for half a second or more, the gearbox actively fights me.

So, with all that in mind, here's the exploratory list so far:

1. Not a clutch pedal sensor.
2. Exhaust manifold is fine.
3. EGR valve seems to be in good order.
4. Not an ECU issue so far as anyone can tell (the ECU is not throwing any ECU related error codes)
5. Not the throttle cable or throttle body, will behave normally in neutral.
6. Ever so slight blow from the back box, but not enough to cause performance issues on this scale.
7. Transmission and transmission fluid seem to be ok, nobody has spotted anything obvious and there are no error codes to that effect.
8. Gearbox is ok, some scoring from some ropey gear changes, but otherwise fine. No issues with plate.
9. Flywheel is in good order.
10. Head gasket is fully in tact. Cylinders, valves and piston heads are fine.
11. There is no engine management light with this at all, so far as the car itself is aware, it's reporting everything is fine internally.

Things I have not checked:

1. Cam shaft.
2. Piston rods.
3. Vacuum lines.
4. Boost pipes.

There is a slight bit of play on the clutch bedal, which would imply some air in the system, so I will bleed it, but I don't think that is repsonsible for all of this.

I am open to suggestions at this point, can anyone help?

 

with all this much information. have you tried and replaced the Spark Plugs and or Coils?

 

what year? Dunno about the manual gear box - but on auto's the brake pedal position sensor is part of the start up protection - ie you can't start without the brake pedal pressed. I wonder if there's something going on with the pedal position sensor? Seems to make sense that the clutch/shifter position is in play as well so as to not allow you to start with the car in gear and the clutch petal out.