Hi folks,

Me again with another diesel question! lol

Pulled out across 4 lanes of a dual carriageway way this afternoon and thought it would be best to accelerate as fast as possible to avoid any potential hazard. However, when changing from 2nd to 3rd, the car shook fairly violently for a few seconds and there was also a noticeable hesistation after applying gas, again, only a second or so.

It happened once before in the same situation and have not noticed it during daily driving. The acceleration was very quick, as to were the gear changes.

The other thing; is it me or is 2nd gear on the car a very poor ratio, 2nd produces very little acceleration compared to 3rd?

Cheers folks :)

If you're used to a petrol, maybe you're holding the gear too long before changing up? The torque in a diesel is low down, that's where you'll feel the pull, around 2000rpm.

As for the shaking, not sure what that's about. You will get a bit of a hesitation due to turbo lag btw. Was the shaking after slotting into 3rd or between changing with the clutch down?

Thanks again for replying Tom. The shaking came after slotting into 3rd and the clutch was up. Only for a few seconds but was a tad worrying at the time!

For a diesel, at what RPM would you recommend changing?

Hi,

Tbh I'm not sure what that is then, I know you can feel the DMF 'wobble' between gearchanges after a high rpm, but if it's with the clutch up it may be a minor sensor or fuel fault somewhere. Can't really diagnose that any further over the internet myself. Someone else may know of a common issue with that particular engine though.

As for when to change up, there isn't really a set RPM as it depends on so many factors. But you should feel the power dropping off as you get higher up the rev range, somewhere around 3700rpm roughly, you want to change up just before the power starts to drop ideally. Though it is counter-intuitive compared to a petrol where the more you rev the more power you get! You should get a noticeable 'shove' of torque around 1900rpm so theres no point changing up so late that you miss that!.

Thanks again. The 'wobble' would be consistent with what I'm feeling and hearing.

Having tested the car, it would seem there is no real need to be going over 3500-4000rpm anyway.

Don't think I've ever hit 4k in mine lol.

Funnily enough though, after this thread I took note of when I change up... I do only have the 1.6 so the 1.8 may be different, but I found even accelerating onto the motorway I didn't pass 3.25k lol!

Shudder can be the fuel if you use supermarket fuel sisters diesel does this either use injector cleaner or quality diesel and see if that cures it

Thanks both for the responses. Currently on Texaco fuel but will try Shell next. Funnily enough, put some injector cleaner in this morning.

Will test this again tomorrow lol