MIs Fire problem.

[Steve B]

Help!!!!

I have a major problem with my 1.8t A4. I has the oil pump fail on me, and the engine made some strange noises. I had it recovered to a local Skoda garage, who replaced the pump, oil pick up pipes and checked the top end. after a lot of time amd money I got the car back and it seem to run ok. then I noticed it had a oil leak, when back to the Skoda garage who said it was the main oil seal between the engine and gear box, so I had it replaced and at the same time had a new clutch fitted. All good, had the car back all weekend drove really well no problems, then about 5 days later the car started mis-firering, went back to Skoda, had it for two days couln't find the fault, they advised me to take it to Portsmouth Audi, which I did, they checked it for a day, said it could be a sticking valve, they flushed the engine with something and cleaned the throttle body, but no joy, so their answer was to replace the head. S..t nearly 4k. I took the car to a local well known garage who quoted me £900 to fit a new head. they have now done this, but are saying their is still a mis-fire on cylinder 2 and 3. What the hell can still be wrong with this car, looks like I have spent £900+ for nothing and the garage has now run out of ideas. what else could be causing this fault, Skoda / Audi and now another garage have come to the end. Have you guys got any pointers I could give the garage to sort this ****** car out. I have just about run out of money and fed up ring the garage to be told, sorry you will have to walk to work again !! and that 10 miles !!!!!

 

[ScottyP45]

I take it the obvious coil packs were tried? It is a very common misfire problem and they can fail in ones, twos, even threes for one guy on here, I have had one go in the first 6 months of owning the car. They are £40 each from VW Audi dealership here in scotland, ive heard cheaper ones are on the net but couldnt wait till it got shipped so I pitched up to a VW dealer and bought a passat 1.8T coilpack, and it worked a treat.

That sounds like a terrible saga - and drastic to get advised to change the head for a misfire!!!

I would change the coilpacks and the plugs too if need be, next would have been the injectors or harness between cyls 2 nd 3 - misfires are usually coilpacks, plugs, injectors, then lastly, sticking valves. You could have problems with sludge in the hydraulic lifters, but a flush at 2k rpm for 5 mins should have cleared that when the oil was done after the pump died.

 

[J7USS]

This is why Im going for a Tdi for my next Project . The Oil sludge saga just keeps popping up more frquently!

Sounds like the Damage wasnt diagnosed properly to me. I just went the whole stretch and bought a Recon Engine! I never want that ball ache again..
Know the feeling mate but sounds like you've already spent the best part.

Try what Evil says as the last resort, failing that....well I dont know what else to say. Cut your loss and buy another Engine and just sell yours for what you can get for it as it is!

 

[aragorn]

or maybe dont jump the gun like everyone else seems to have done?

Ignition amplifier and coil packs first in my book.

OR A leakdown test on the cylinders to see if there IS actually a bent valve before replacing the entire cylinder head....

I'd throw another ignition amp at it first, and swap the coils between 23 and 14 to see if the fault moves.

 

[J7USS]

Give me the Gun to Jump over the Frigging headache any day!

 

[aragorn]

well the point is if it IS the ignition amp then 3 grand rebuilding the engine or a complete working engine from a breakers still wont fix it...

Its not part of the engine, its an external component, and wouldnt be changed with an engine swap/rebuild.

I'm saying check the basics before jumping in at the deep end, the engine ran fine for 5 days, if there had been damage present from the oil pump, it wouldnt have taken 5 days to appear...

If the missfire had appeared without the oilpump/crank seal issues, coilpacks and ignition amp would have been the first stop, to get from those to a mechanical problem takes quite a big leap, without some evidence like a leakdown test showing a badly sealing valve, and seen as audi just said that it might be a sticking valve it says to me there was no such evidence.

 

[Steve B]

Hi Guys,
Thanks for the comments,
I have repaced 4 coil packs and had new plugs fitted by Audi during the time it was there, still no joy. they said they had checked everything and could only say it was due to a valve sticking. this I said was rubbish as the car drove finr for 5 days, without fault, but they said this is all it could be. So the head was replaced and yet the same fault is still their, Audi did a compression test and oil pressur test and all came back good, yet they still advised the head to be changed. So I will be contacting them in the morning to discusss their advise. How much is an ingnition amp, and how easy is it to fit. trouble is nowI have spent nearly £2.5k on the car and it still runing like a bag of nails. I'll also check the wireing so see if there is signs of wear, but you would have hoped that one of the garages would have check all of what has been mentioned.

Cheers
Steve.

 

[J7USS]

aragorn - Maybe you should look at it for him incase everyone else as missed something then!!
Im sure steve wouldnt mind sorting you out...

Good Luck Steve, Hope you get to the bottom of it mate as like you say you have already thrown 2.5k at it and its still not right - that itself would tip me over the edge.


These ****** 1.8ts are proving to be more unreliable.

 

[ScottyP45]

have they checked the MAF??

The recorded misfire on 2 and 3 may be coincidental and happened to occur when those cyls were on firing stroke hence were recorded in the ecu memory.

The car could have been hooked up to a simple SUN engine analyser and the plug firing and injector pulses trace-recorded for missing pulses, if none are missing but misfires still occur, that would prove the ignition and fuel signals were not the fault I guess, try disconnecting the MAF plug and driving it, see if that clears it, if so, change the MAF.

 

[aragorn]

If the engine runs wasted spark, 2 and 3 will be on the same channel of the ignition amp.

I dont know if it DOES run wasted spark though, as it does have 4 individual coils. However when the amps go, they tend to drop 2 or 3 first for some reason.

An Amp is about £100, probably pick one up from euro car parts or GSF. It sits on top of the airbox on a B5.

Just look at the basics, if you have fuel, spark and compression you should get ignition. I'd REALLY hope audi checked the injectors before changing the head (and it should be obvious because the non-firing plugs will be wet), and they've told you that you have compression, which means its not a sticking valve (infact advising a head swap with a perfect compression test seems incompetent to me and you might have some form of legal claim there). Which leaves the spark itself. You've changed the coils and that didnt help, next step in the chain is the amp.

If you know someone around with a 1.8T, get a loan of their amp and try it out if you dont want to spend the money first.

Perhaps someone on the forum who lives local would be willing to lend a hand/amp? I'd be happy to, but living in scotland i'm about 400miles away!

 

[Steve B]

Gents,
Thanks again for your help and comments,

I am going to buy a ignition amp, and give that ago, £100 again is painful, but a drop to what I have already paid out. is this a stright forward DIY fit job,if so has anyone goy any photo's of the actual part that I need to buy and then fit. my is a 2004 1.8t (163BHP)
To top it all, I have today recieved a parking ticket when my car was sopossed to be in the garage. IS SOMEONE HAVING A LAUGH OR WHAT !!!!!

many thanks again lads.

Steve.

 

[aragorn]

http://home.earthlink.net/~andrewaranda/audi/N122.gif

That pics stolen from audiworld forums. Thats its position on a B5, i'd imagine its the same on yours. Two plugs and a couple screws holding it on. Easy job to swap.

http://forums.audiworld.com/a4/msgs/1594531.phtml

 

[ScottyP45]

I havent got anything like that mate on my B6. Theres nothing on top of the airbox lid at all cos I removed mine and run a cone filter now, I would have noticed and wouldve had to relocate it if there was so the OP's will likely be the same as mine.

I'll have a look today when im topping up the water and see if I can see one like the pic anywhere.

Theres a large silver module at the front passenger side bolted to the underside of the slam panel that has fins (heatsink) just above the electric rad fan, dont know if thats the amp on a B6 tho sorry.

 

[aragorn]

hmm, looking at vagcat, it seems that while they are used on the B6, it seems they're only used on the "AVJ" engine code.

I'd have to dig out elsawin and pull off the wiring diagram to see how they run the coil wiring on the other engines, It might be that the power stages are built into the ECU or something similar.

A method of testing would be to get a test lamp or similar hooked up to the feed to the coils that arent firing and see if theres any voltage there. I think they are earth switched, with the 12v being supplied to the coils all the time, but i cant be sure without checking over the diagram. Or even easier, pull the coil out, leaving it connected to the loom, and shove a spark plug in the end and lay the whole assembly on the rocker cover and fire the motor up. If the coil is firing you'll see the sparks.

 

[ScottyP45]

mines a 163 and its the BFB code so if yours is the same Steve then maybe Aragorn can look up that one to get the info.

Obviously what he says is spot on (guess your a mechanic Aragorn mate) and you need to systematically eliminate all the parts involved in the problem, and whatever you are left with, must be the fault, but we arent saying to buy anything else until you know what is wrong.

Each bit is quite easy to test, and if you make a list of the possibles, then mark what works one by one, you will get to the bottom of it without spending more cash till you know what you really need.

A quick story, I had an idle misfire on a Golf GTi and it also misfired during light throttle, turned out to be a camshaft / engine speed sensor, on the Golf it was part of the distributor body, but the audi one is somewhere up top I think - near the cam rear end? Anyhoo, it could probably have caused a misfire or a complete non start if it was truly ********, but the ecu should have shown something like "camshaft sensor implausible signal" or some such, so I guess that may not be useful info.