engine noise

[bcm]

hi, recently bought an a4 xreg 01 no service history.
possible problem is that 4 about 2 0r 3 secs after i start the engine it sounds like a diesle engine ,
was advised to change oil and filter asap,and done so but the noise is still there.
i have noticed just inside oil filler cap i can see residue clung to the inside of the engine
question . could i just need an engine flush?.
or anyone got any other ideas
cheers
ps bit of a novice with ltd funds [yer i no ,dont buy an audi then]

[rojam]

The problem is symptomatic with this engine, it's just the hydraulic tappets that are noisy until the oil has got up to the correct pressure.
I've heard many engines in Audi's and VW's that are like this all the time and run perfectly well.
The only way you'll get rid of it is to replace all the tappets, as long as they quieten down after a few seconds I wouldn't worry too much.

[Buenchico]

Starting a car takes a lot out of the battery. The alternator quickly recharges it but there's a short period, immediately after starting, when the battery isn't able to give of its best. If you've got an HT lead which has built up excessively high resistance (as they do over time), the battery won't be able to provide enough current (for that short period after starting) to fire the cylinder which it serves. Consequently, the car will be running on just 3 cylinders for a short while, which makes it sound like a diesel engine.

Get your HT leads checked. (It simply involves checking the resistance with a multimeter). A new shouldn't cost a great deal.

Chris

[NORMANTHEDOG]

Chris is talking a load of rubbish,it will not be anything to do with your HT lead,as rojan suggests audi and vw engines are very noisy on their tappets on starting up the car,it would be advisable to give the engine a good flush out and put in a high quality oil,which should help a lot.

[rdv]

The hydraulic tappets in these engines do not normally behave like this until the engine has done 80/100,000 miles. They only cost �55 a set so if it bothers you change them. Its risky buying an Audi of this age without history but it can be obtained from the reg. no.

[bcm]

cheers all for the answers,
if i decided to change the tappets is that a relitivly simple job

[rdv]

yes, takes about 1 hour, get the tappets from German and Swedish not Audi.

[Donquixote]

Rojam's right....it's the hydraulic lifters. It's common on most German engines, for some reason, especially BMW's.

[rojam]

You could also try Eurocarparts if there's a branch near you, there pretty reasonable for all German car parts.