Not sure what turbo lag feels like but I have been experiencing a kind

of lumpy drive when cruising from 65 mph in fifth gear. it almost feels

like a misfire, can some explain what turbo lag is.:confused:

Turbo lag is this:

When you put your foot down it takes a little time for the turbo to spin up and send pressurised air into the engine, this is due to the fact the turbo is driven by exhaust gases. Initially you get nothing, then you get that familiar boot in the backside when the turbo is working at full capacity.

If you are in top gear and the engine is at around 1500rpm you will experience turbo lag, if you are in 3rd and the engine is running at 3000rpm you will get virtually no lag.

Turbo lag isn't jerky either.

More here: http://en.wikipedia.org/wiki/Turbo_lag

You shouldn't be getting lag in 5th at 65 mph as your revs will be in the turbo range. Sounds like a fault.

Cheers lads, Thats turbo lag ruled out. and now I know what it is.

Sorry about the lack of knowledge but this is my first diesel.

P.S. The lumpy drive only seams to happen in fifth gear. Will have to

speak to stealer anyway as my cruise/c stopped working on the M8

today but has since begun to work again.

Will have to

speak to stealer anyway as my cruise/c stopped working on the M8

today but has since begun to work again.

Had same problem with CC last week, haven't been to the dealer yet but the guys on here confirmed it is a known fault and is cured by a stalk replacement.

Never had any trouble with lumpness in my PD100 in 5th... yes there is a slight lag sometimes but it depends what speed in doing in 5th... usually just pull straight away with turbo if in 5th on motorway.

Generally for the 1.9TDI unit, boost builds between 1200rpm - 1800rpm, at which point you are more or less on full boost. If you cruise at 1800rpm and put your foot down, you'll get the most lag. If you're already accelerating slowly, the turbo is likely to be spinning up so the lag is reduced. As you move around the rev range, the lag reduces further still.

The key is if you are accelerating, keep it above 1800rpm if you want any sort of power. Certainly around where I live where it's very hilly, I made the mistake of changing too early when I first got my diesel. It's quite alarming when you drop off boost and loose nearly all your power on a steep hill!!