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The 'Sludge' thing

Discussion in 'A4/S4 forum(B5 Chassis)' started by NineNails, Jul 19, 2010.

  1. NineNails
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    NineNails Proud sponsor of the snack food industry

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    [Jul 19, 2010]
    Hiya
    I've had years of Audi ownership but just got a 1.8t (AJL engine) I'm a proper green newbie when it comes to this engine and it's my first turbo car so I certainly know stuff all.
    I've read a bit on the sludge problem and am now paranoid as hell my engine is about to die a horrible death.
    It's got full service history but the oils not been changed at 5k all the time and I think it's also been on a 'Long Life' service schedule (whatever the hell that is...)
    Is there a way to tell of any impending doom on the horizon? The inside of the filler cap has some hard black (what looks like) carbon built up on it...Should I be worrying??
    Si.
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  3. phoenixv6quattro
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    phoenixv6quattro staylowmovefast

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    [Jul 20, 2010]
    Drain half the oil and refill with diesel fuel. Start engine. Get up to temp. Increase revs to 2k at 1 min intervals. Do this 3 times. Drain the mixture straight away. Watch the sh1t pour out. Do this every 15-20k for a sludge free engine. Change the oil every 5k using 5w-40 fully synthetic. If you stay on top of it you will not have a sludge problem.
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  4. Matt82
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    Matt82 Active Member

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    [Jul 20, 2010]
    if youre feeling brave id be tempted to get the sump down and clean up the oil pump pick up
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  5. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jul 20, 2010]
    Step 1 is an oil pressure guage imo, the stock warning light is next to useless.

    Step 2 depends on the oil pressure.

    If the pressure is normal, then i'd just change the oil, if you want you can always do a minor flush (drain out half a litre of oil, and put half a litre of diesel or kerosine in instead, run for 10 mins at 1500-2000rpm, then shut off and drain) then refill with 5w40 synth perhaps a little bit of ATF in there for good measure and then change it after 1k to get rid of any remaining *****., then just do normal oil changes after that every 5k, or earlier if the oil starts to turn black.

    If the pressure is bad, you have a couple of options, you can try a diesel flush (as per the minor flush, but with a higher concentration of diesel), to see if that will help, however if the engines particularly clagged up, flushing all the gunk into the sump could make things worse. You could pull the sump off and clean the pickup and sump out, THEN do a diesel flush, or go the whole hog and replace the oil pump while your in there.

    I would imagne that seen as your doing something about it before the lights come on, then you will hopefully find the pressure is fine, and it just needs a minor flush and regular changes to keep it all in good condition.
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  6. phoenixv6quattro
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    phoenixv6quattro staylowmovefast

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    [Jul 20, 2010]
    Prevention is better than cure. If the pressure is ok then just stick to 5k changes. A 50/50 flush as a pre-emptive measure will not harm the engine in ANY way shape or form, even if it dosnt need it. For the sake of 4 quid of derv, its a no brainer! Mines done 140k now and 40k ago when I got her the engine wasn't running as smoothly as I had hoped. a few flushes later and it was excellent.
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  7. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jul 20, 2010]
    Ye exactly.

    When i got the TQS i chucked a bottle of engine flush in (i got it free so i figured i may as well use it up, its just kerosine anyway) along with 2 litres of flushing oil (its thin oil with lots of detergents in it, again had it sat on the shelf so may as well use it up), and a bit of the normal 5w40 to get the level up to the dipstick min mark, then ran it for 10mins at 1500-2000rpm, before draining and refilling with good oil.

    I didnt suspect anything wrong with it, i just did it for peace of mind.

    If i hadnt had the stuff laying around then i'd have used the diesel approach instead.
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  8. NineNails
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    NineNails Proud sponsor of the snack food industry

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    [Jul 20, 2010]
    That's all top advice, thanks alot lads. I had thought of flushing but was in fear of dislodging a load of **** in there and blocking up the strainer quicker but it seems some of you have done it with no problems.
    I'm not sure what oil this engine has had in but I 'think' it was on a long life service so should have been fully synth? Will it be ok to change to fully synth if it was only on semi before?
    On a positive note it does seem to have an over size oil filter on it just now.
    Time to get the hands dirty if it ever stops raining!
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  9. NineNails
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    [Jul 20, 2010]
    Oh forgot...Someones told me I should think about changing the feeder hoses to the turbo too...Thoughts??
    Si.
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  10. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jul 20, 2010]
    If its on longlife then it should be on fully synth oil. Theres no issue switching between them anyway, as long as the appropriate service intervals are held to.
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