Keeping a diesel fit

[alogbe]

I have a 2000 Audi A4 1.9 TDI which has done 125,000 miles without giving any engine trouble. It's been serviced according to the book and in addition it's had the oil and filter changed in between the scheduled services - i.e. twice as often as Audi recommends. So it's been treated well and it runs well.

I find that even though I drive fairly briskly, I hardly ever take the engine speed much over about 3,000 rpm - there doesn't seem to be any gain.

A couple of friends, both engineers (which I'm not), have told me - independently - that once in a while I should put the car into a low gear, take it up to the engine limit, and keep it there for maybe 10 seconds. Not just the red section on the rev counter (which begins at about 4,500 rpm), but right up to the point when the limiter stops it going any further. The idea, they say, is to burn off or clean off deposits around the injectors which have probably resulted from my driving style.

Is this an old wives' tale, or is there some merit in it? It goes against my instincts to stress any machine unnecessarily.

[chrisvrscrx]

They are right. These deposits build up especially on your turbo VNT mechanism, this causes it to stick open or closed. Ive always been told diesels need ragging every once in a while because of the way they burn fuel, they are much dirtier than a petrol engine.

[Col]

Totally agree.

You need to excercise the turbo and ensure the VNT mechanism operates throughout its entire range.

[devonutopia]

Mine's kept fit by being run every day (usually) and during one journey I will try to use max boost to clean it all out a bit, especially if I've been pootling. This is only done once the engine is warm though. My car's been ultra reliable, even though I'm running 100% stock power.

[Singlespeed]

Relying on the limiter to control the engine at maximum revs is a bit dangerous in my opinion.

It would be much safer to use all the revs up to the red line, once every now and again, rather than trying to blow away the cobwebs with a quick fix.

A brisk run before MOT time is a good idea, or your engine may well have some spoty youf testing your limiter to clear the exhaust system, to pass the emisions test. Ive heard of some places doing this stationary, ie - not under load

Don't rev the engine to the red line or limiter without a load on it. Infact don't rev it without a load, full stop...

But hey, it's your engine

[Loofer]

Relying on the limiter to control the engine at maximum revs is a bit dangerous in my opinion.

It would be much safer to use all the revs up to the red line, once every now and again, rather than trying to blow away the cobwebs with a quick fix.

A brisk run before MOT time is a good idea, or your engine may well have some spoty youf testing your limiter to clear the exhaust system, to pass the emisions test. Ive heard of some places doing this stationary, ie - not under load

Don't rev the engine to the red line or limiter without a load on it. Infact don't rev it without a load, full stop...

But hey, it's your engine

I'm going to be a bit thick here... but what do you mean by 'load'? When is it with/out a load?

I guess I need to give a bit of a pelt as I rarely go over over 2000rpm!!

Having said that, I couldn't convince myself to go past the redline!

[bora(ing) nick]

I'm going to be a bit thick here... but what do you mean by 'load'? When is it with/out a load?

I guess I need to give a bit of a pelt as I rarely go over over 2000rpm!!

Having said that, I couldn't convince myself to go past the redline!

No load is when the car is not in gear.... or is in gear but wheels allowed to turn freely (ie if it were on axle stands)

With load is normal driving....

I do a regular trip from Manchester to Anglesey and back again weekly, pushing the engine quite hard most of the way.... The A55 is a brilliant road, just too many Volvos with cameras.

My engine gets blasted most of the time and has just done 23K miles in between services on the long life regime.

Nick

[Eshrules]

under or without load is another way of saying 'at standstill' if you rev the backside off a car whilst stationary, it doesnt do it any good.

id disagree with not revving it to limiter though... no harm will be done 'as such' as the rev limiter is there for that very reason. once warm, take the car for a good blast down the motorway, i usually do it when i'm moving from a freshly joined motorway, leave it in 3/4 gear dependant on your box and carry it to 70/80, by which time your limiter will more than likely have kicked in.

you'll notice the difference once you've done this, the car will respond and run a bit better.

id say you ought to do this at least once a month IMHO Col & Chris know their stuff and it isnt the first time i've heard this mentioned about Tdi's.

[Eshrules]

The A55 is a brilliant road, just too many Volvos with cameras.

this much i can vouch for, on both counts.... when it's quiet (around 12am/1am) it is a brilliant road to be on.

i stayed at a travel lodge just off the A55 for valentines and we went for a midnight mooch, i must say it was jolly good fun!

[cbrpaul]

i think it is good to have a " blow out " now and then also ,


I drive steady most of the time but every now and then when shes fully warmed up and usually when im on my own , i keep my right down for abit longer , vrooooooooooooom

its quite surprising the performance to behonest , and you can feel the engine wanting to go for it too !!!