I bought a cheap high mileage audi diesel the other week, drives ok, a bit under powered with the immense 90bhp it originally had...

Engine runs clean, no real smoke, but when I drive up the hill to my house, theres a slight dip in power, and a nice black cloud chasing me. I'm suspecting EGR valve could do with a clean? It leaves a big sooty patch on the road if you rev the engine up while stood still too. The air pipe into the egr is all grimey too. Oily and stuff.
I know I'm best taking it off to clean it out, but it doesnt really clean the rest of the intake, so I'd have to take that off too, and in the words of Sweet Brown, ain't nobody got time for that.
Wynns egr cleaner, you spray into the intake, but misses the egr valve really.
Or maybe a fuel additive? Will it eventually work on both intake and egr valve, or is its effects detroyed once burned
Whats the most convenient option, not best! Convenient.

Would like to blank it off, but that might just cause more trouble.

The car was cheap, I like it because I don't care about, but I want to try and improve it as much as I can, as cheap as I can. This is locost builders after all...


Anyone has any other cheap tips on improving this engine or car, I'm all ears (or eyes? )

EGR and manifold clean on a Mondeo, used carb cleaner then thinners
It's the filthiest job I have ever done on a car, and that stuff gets everywhere
Fuel filter makes a difference and it doesn't hurt to throw in some injector cleaner here and there

Might be worth looking for a boost leak. I had one on my 306 XUD where the intercooler connects to the inlet manifold, a rubber 'D' seal. The turbo was making boost but as the full amount of air wasn't making it into the cylinders the ratio of fuel to air went out the window, resulting in excessive black smoke on boost.

If it's the 1.9 AAZ IDI engine then here is a good forum to read through. I looked into using that engine in a project not long ago

[Edited on 29-4-2013 by Benzine]

so taking it all off and apart is really the only proper way to do it snapper? I'll look at it again tomorrow, with a view to taking it all apart if the manifolds easy enough to remove (i've got a feeling its not easy to get at all the bolts due to exhaust and turbo pipes and stuff.

Ben, there could very well be a leak. if i was feeling flush, i'd replace all the pipes to be sure, but no money for that right now. not sure how i'd find any leaks though? can't hear any hissing, but then i can't feel the pipes stiffen up with air pressure either.
its an AHU engine
turbo is one side of the engine, pipes go right round the front of the car to the intercooler, then all the way back. a good few metres of piping to fill with air!
thats one for later. i suspect the EGR is the bigger problem just now. car just needs a good going over for now.

here's the beast

Description

not bad for 800 quid i guess...

no way to get a reasonable result without taking it all apart then?

[Edited on 29/4/13 by blakep82]

AHU engine you can just disconnect the EGR valve - it won't throw up any errors or faults. Literally just unplug the vacuum hose to the EGR valve.

I disconnected mine on the Passat because I thought it was responsible for some rough running (turned out to be IP timing in fact).


If it still does it disconnected, check IP timing (easy with Vag-COM)

You can also probably pick up signs of boost leaks with Vag-com.

[Edited on 29/4/13 by PSpirine]

If you're getting bursts of soot, it's also worth giving it a "good ragging" (technical term) every now and then to clear it out. You need a big hill and a hot engine, then simply floor it up the hill all the way to the limiter. Once you get to the limiter, lift and floor it again... repeat untill you get no soot. Normal running won't do it as it needs to be on full boost. It feels wrong but you have to be cruel to be kind.

My check list would be.


Check air filter,
check oil level ( too much ?)
tank of decent BP Derv in
bottle of Injection clener
get it nice and warm and give it a real ragging !

ATb Agriv8

Cheers for the suggestions!
Adi, I tried that on my way home, I live up a hill, barely made 3000rpm up the hill lol, the engine really doesnt have much power :-)
However, this time on full boost, no soot! I'll disconnect the egr valve (thank you for the u2us pavel!) And pour some injector cleaner in. Hopefully all the crap in the intake will work its way out eventually too, though I will eventually clean it out, maybe next week.

Agriv8, havent looked at the air filter yet, but of course it will need to be checked! The oil is completely black, so I suspect the air filter will be pretty rank too.
I changed the oil and filter the other week. New oil in, ran the engine to check pressure. The oil is still just as black as before... its at the top of the dipstick marks, but not over. There is or was a slight drip of oil, so I'm happy where it is. Will get some injector cleaner tomoorow I think

THank you all for the advice!

MMm,

Long shot but thinking your Air / MAF sensor may be shot that went on my 90 bhp Passot TDI never had the black smoke but the not wanting to rev. have a read up on the internet !!

ATB agriv8

While you're at it I now replace the fuel filter every year on our 1.9 and 2.0 PD engines. It's surprising how dirty they get and the difference a (very locost) new one can make. I don't think the normal service schedule sees them change frequently enough.

Example on our 1.9PD (2001 with 127k) it had a real flat spot above 2k and struggling to rev any higher. Fresh filter has transformed it, now pulls clean to 4k with good power delivery. £6 for the filter and 10 mins work.

The smoke issue may well be solved with a good ragging...either that or it'll blow up

funny how these things happen The EGR valve on my 57 plate A6 TDI (96k) just been dignosed as troublesome by RAC man after only giving me 2.5k RPM limit. going to whip it off and take a look.

RAC man recons it goosed and needs to be replaces but prepared to clean it and give it a go before shelling out Circa 200 notes for a new onw.

Picking up gasget at dinner time and taking a look hopefully photo's will follow.

Regards

Agriv8

quote:

---

Originally posted by Agriv8
funny how these things happen The EGR valve on my 57 plate A6 TDI (96k) just been dignosed as troublesome by RAC man after only giving me 2.5k RPM limit. going to whip it off and take a look.

RAC man recons it goosed and needs to be replaces but prepared to clean it and give it a go before shelling out Circa 200 notes for a new onw.

Picking up gasget at dinner time and taking a look hopefully photo's will follow.

Regards

Agriv8

---

Ooh photos would be good if possible!
Haven't had much chance to do mine yet. Weather, work, busy weekend etc, but I have managed to get it on vcds, got a charge pressure control deviation intermittant error, which hopefully explains the crap power. Struggled to make 60 on a very slight motorway hill the other day. So far though, nothing particularly expensive to fix yet though.
I suspect the turbo isnt working right, but shouldnt be hard to find the reasons. 20 quid for a control valve, or 1.50 for some vacuum hose hopefully

these are the instructions I am following ( seems silly to repeat ) I dont think you have to be ameber to view. If you do let me know and I will PDF and email them to you (U2u your email address )

http://www.vwaudiforum.co.uk/forum/showthread.php?134701-A6-EGR-location-amp-removal-quot-how-to-quot/page2

Post from JimC64 about 2/3rds down the Page

but I will try and Post ( my blocked - and fingers crossed unblocked ) one this eve depending what time I get finished at work

ATB Agriv8

Well rac man was correct yet dead due to A 50P GEAR


a6egr

Best get a new one ordered. Bu66er
Agriv8

So found a new own one from ebay for 160 inc delivery and gaskets. Better than 300 that Audi were after.

The valve itself was not too carbonated up the flap operated freely just the gear that had worn out.

Here is a photo anyway


egrdirty

Regards agriv8

Interesting thread. I have intermittent problems with my Citroen C3 - the engine managment light comes on (usually during the first couple of miles of a trip) and all power disappears. I think it is the ECU turning off the turbo / going into 'limp home mode'. Turning the ignition off and on again sorts it - but the warning light usually stays on for a couple more 'on/off' cycles. The code reader at the garage showed the EML was for a EGR fault. So i'm assuming the valve itself gets gummed up and sticks sometimes? It's an 05 / 94k and never had the EGR cleaned or replaced to my knowledge...

I'd agree with Benzine and look for a boost leak first, we had similar problem with one of the Combo vans. Ran system cleaner through it no difference, took injectors for service and clean no difference, changed air mass no difference, blanked egr no difference, in the end it was the simplest thing a fine split in a the boost pipe.
Egr seems to be the first thing the web points to with Diesel problems and can lead you astray from the easiest and most obvious fix.
Cheers,
Bob

[Edited on 9/5/13 by splitrivet]

well you learn something new every day.

Fitted new EGR valve and cleared faults and the thing would still only rev to 2.5 K. slip of paper with new unit said it needed coding with VCDS but could fine no instructions regarding this on the vcds web site so MMmmmm. resigned myself to the fact that I was going to have to take it to local independent audi specialist in Skipton. I took it to the off-licence to buy some beer to drown my sorrows and it revs as sweat as a nut all the way to the red line. So a lot of modern diesels don't rev all the way to the red live unless you are moving ( Why did I not know this !!) but after a 2 second search of goggle.

So now celebrating with can of Beer

( PS will still check with independent tomorrow to see if it does need coding )

ATB Agriv8