Misfiring, Fouled spark plugs, and Excessive oil Consumption

[xbnipx]

Car was misfiring on way back from work. VCDS it and came up with misfires in cylinders 3 and 4.

I recently did:

-Oil Change (86482miles)
-Spark plugs

About 2 weeks ago.

Also The oil level needed a quart again (87364miles)
When pulling the plugs they all looked black.

I tried using different coil packs however they still misfired.

Any suggestions?

[new2s5]

Time for carbon cleaning.

[pierreb]

has the car had its pistons replaced? chain tensioner?

[xbnipx]

The timing chain and tensioner was updated by Audi as preventative maintenance

[A4x]

The timing chain and tensioner was updated by Audi as preventative maintenance

Try taking it back to Audi as they should warranty the work that was performed.

[pierreb]

Should be warrantied for 12 mos 12k miles

[Crucible35]

What year is the car? If it isn't the timing chain, it's likely the pistons and rings that will need to be replaced....has this car had the 2 stage fix for oil consumption? You're outside of warranty, so this may be an expensive remedy......

[zbloot]

Just to chime in as I'm recently dealing with exactly this issue, although it is only occurring on one cylinder.

I recently tried to start up my car and noticed the idle was really rough. Sure enough I ended up getting a CEL. I checked the codes and it just looked to be a mis-fire in my first cylinder. I had recently had my spark plugs replaced by the dealership, so I really didn't think that the issue was with them. To see if I could fix the issue I threw new coils in (I did this on all cylinders just to be safe). After this not fixing the problem I brought it into the shop and the promptly let me know that my plug in my first cylinder was really fouled. So, the replaced the plug and sure enough everything looked good.

This continued for roughly 2 weeks until the issue arose again. So, I checked the plug in the cylinder and sure enough it was fouled up again, which indicated to me that something bigger was going on. Since I had the dealership replace the plug and tell me everything was good I decided to bring it back in to them. They let me know that the issue actually looked to be due to a leaking injector. Thankfully the injectors for my car were under extended warranty so they went ahead and replaced the injector. But, I got a call from them the next business day letting me know that the issue was not in fact resolved by the injector replacement and they found that my cylinder wall had been scored by the excessive fuel present, and the only solution was to drop a new engine in the car. Thankfully, though, they said that the end result was caused by the injector and due to it being under extended warranty I would likely be covered.

Naturally the problem didn't end there haha.. I had performed a stage I tune on the vehicle with a APR chip, effectively voiding any warranty or extended warranty on the vehicle. Because of this they blamed the leaking injector on the APR tune and told me they would not be covering the engine or any of the work done when replacing the injector. I had major problems with this because I towed the car in immediately after the CEL came on and trusted that the dealership would correctly solve the issue. But by only applying a band-aid fix to the problem I continued to drive for two weeks on a bad injector which absolutely could have been what pushed the cylinder over the edge. I personally wouldn't have a major problem with this if the issue only resulted in an issue taking $200-300 to fix. But an engine replacement is not that :/

So now I am fighting really hard with AoA and the dealership to get some level of partial warranty coverage, unless they can prove to me that the tune caused the issue. Obviously I'm certain that the tune did not cause a leaking injector, and also less inclined to believe so when Audi released an extended warranty on the part for the same exact problem.

To wrap all of that up I would push them as hard as possible to find the true root of the problem ASAP, to avoid being $10k+ in the hole.

[Crucible35]

^^^^not sure what MY you have but did your car get the dual stage oil consumption fix? If it did, the scoring could have been caused by the replacement of the pistons and rings. I had both stages on my '09 A4 done and it was never the same....turned out they scored cylinder #3 so badly that coolant was leaking into the cylinder from the water jacket. Of course, now they have indicated that your tune is the cause and a new engine is required without fully diagnosing the issue. "Scored by the excessive fuel present"....never heard that before.

[xbnipx]

Dealer says I have a burnt exhaust valve. They said its a 20+ hour job. And after tax it's around $3994.

What do you guys think. Should I take my car somewhere else. $4k for a valve is excessive. Also my car is 87k miles so is it even worth it at this point?


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[The Infiltrator]

Dealer says I have a burnt exhaust valve. They said its a 20+ hour job. And after tax it's around $3994.

What do you guys think. Should I take my car somewhere else. $4k for a valve is excessive. Also my car is 87k miles so is it even worth it at this point?


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Why the hell are you going to the dealer in the first place!!!!!? They will destroy your bank account.

I would find a good shop that's worked on Audis before and get a price from them. There might be some threads on changing it out on here or another site, maybe change it yourself and save more. You can get the part numbers from the dealer and look around at prices too.

[xbnipx]

Yeah I will look around when I have a chance. The dealer did a timing chain update to the car a month ago. However they know I have an apr tune on the car. They claim that the tune did it. However I never heard of apr tune burning valves


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[The Infiltrator]

Yeah I will look around when I have a chance. The dealer did a timing chain update to the car a month ago. However they know I have an apr tune on the car. They claim that the tune did it. However I never heard of apr tune burning valves


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Eh, the dealers always use that excuse. I would just find a good shop and look at reviews if possible. The dealer is shafting you hard with that crazy price man.

[xbnipx]

Can a timing chain jump cause the valves to not seat properly. That's the only major job done by them that i can think of, that would cause an issue like this.


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[The Infiltrator]

Can a timing chain jump cause the valves to not seat properly. That's the only major job done by them that i can think of, that would cause an issue like this.


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It's possible, the timing is very important and can jack a lot of stuff up if it's not spot on. I read some stuff on carbon build up and a few people showing burnt valves too.

[pierreb]

I'd start shopping for a used engine

[A4x]

Yeah I will look around when I have a chance. The dealer did a timing chain update to the car a month ago. However they know I have an apr tune on the car. They claim that the tune did it. However I never heard of apr tune burning valves


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Can a timing chain jump cause the valves to not seat properly. That's the only major job done by them that i can think of, that would cause an issue like this.


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Hold on. What exact work did the dealer do one month ago to the timing?

If you are having a valve issue now, which is most likely a timing issue, the dealer should cover everything and make this right. If they were in there messing around a month ago, sure as shit this problem was caused by them! Make them believe it!

Good luck brother.

[Militant-Grunt]

Time for carbon cleaning.

Incorrect. Carbon build up causes misfires on cold start, not on warm operation while driving.

When you have a bad oil consumption problem, your plugs start to foul pretty quickly, the plug anode and electrode starts getting covered in burned oil. Clean your plug and it'll go away, though you probably need some pistons and rings pretty badly.




Feel free to PM me if you have any questions.

[pierreb]

It's not been my experience that the specific oil consumption issue fixed in so many cars results in plugs fouling up and misfires. None of those things happened in either of my 2 affected cars. The occasional misfire I did experience was essentially due to a bad cyl head, damaged by carbon buildup (valve guide possible preventing the valve from spinning) or by a bad (but not fully failed) tensioner.

[Militant-Grunt]

It's not been my experience that the specific oil consumption issue fixed in so many cars results in plugs fouling up and misfires. None of those things happened in either of my 2 affected cars. The occasional misfire I did experience was essentially due to a bad cyl head, damaged by carbon buildup (valve guide possible preventing the valve from spinning) or by a bad (but not fully failed) tensioner.

OP mentioned he just changed plugs. Theres not much that'll foul the plugs in 2k miles. Burning a quart of oil per 1000 miles will..

[pierreb]

I put 120k on one car and 110k on the other with that oil burning rate. Plugs were never an issue. I'd have to read the oil consumption thread in detail to see if anyone else reported the problem. On the other hand, misfires due to timing problems would mess up the plugs, no?

This one sounds unique to me and points more at cyl head damage. Just my impression I guess. He said the plugs were 'black'. I didn't immediately conclude it was because of oil burning.

[jfo]

If there is a burnt valve you can either source a rebuilt head and have it swapped, or have a shop pull the head and replace the bad valve. No need to replace the engine, etc. Over the years I've had 2 situations with burnt exhaust valves, both on high mileage cars. It's not a difficult job for a shop, but it is quite a bit of labour. I did them myself and chose to swap the heads with rebuilt units.

[pierreb]

If there is a burnt valve you can either source a rebuilt head and have it swapped, or have a shop pull the head and replace the bad valve. No need to replace the engine, etc. Over the years I've had 2 situations with burnt exhaust valves, both on high mileage cars. It's not a difficult job for a shop, but it is quite a bit of labour. I did them myself and chose to swap the heads with rebuilt units.

I agree on the head, but since he hasn't had the piston swap done, he might as well just shop for a fixed used engine.

[jfo]

I agree on the head, but since he hasn't had the piston swap done, he might as well just shop for a fixed used engine.

I skimmed over the oil consumption issue. It does make it a more complicated choice and you're right about looking at a used engine that has had the pistons done. That might be hard to determine though? I guess the dealer could check the VIN on a potential engine.

[pierreb]

I skimmed over the oil consumption issue. It does make it a more complicated choice and you're right about looking at a used engine that has had the pistons done. That might be hard to determine though? I guess the dealer could check the VIN on a potential engine.

You can actually put a used B8.5 engine in there. Guaranteed fixed pistons and tensioner.

[xbnipx]

So do you guys think my apr stage 2 tune caused the burnt valve?


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[Militant-Grunt]

I put 120k on one car and 110k on the other with that oil burning rate. Plugs were never an issue. I'd have to read the oil consumption thread in detail to see if anyone else reported the problem. On the other hand, misfires due to timing problems would mess up the plugs, no?

This one sounds unique to me and points more at cyl head damage. Just my impression I guess. He said the plugs were 'black'. I didn't immediately conclude it was because of oil burning.

My sample size of seeing what these cars do while burning oil is much larger than yours... I have seen this happen on multiple occasions, and put pistons in cars due this problem. Fortunately for those customers we were doing pistons on just about any CAEB that rolled in through the shop.

If he had a timing problem, chain off by even one tooth, he would have a timing correlation fault set.

OP get the car properly diagnosed before jumping to conclusions such as a burned valve. Very low likelihood of that being the problem. I'm putting my money on you just needing to take care of pistons, seeing that you're at 86k miles means that you're outside of the permissible warranty replacement.

[pierreb]

I bow to your more extensive experience but I would still recommend he try to get the pistons done via audi warranty anyway. I know my dealer has done cars past 100k and they do 5-6 of these a week.

[Militant-Grunt]

I bow to your more extensive experience but I would still recommend he try to get the pistons done via audi warranty anyway. I know my dealer has done cars past 100k and they do 5-6 of these a week.

Its totally possible, if they have a large good will budget. Though if he walks into a dealer and has 0 service history with them, it'll be cash all the way.
Also depends on if he ever received the crank breather and crank seal / software update. If he has, or the previous owner has, and never completed a part 2, its GG.

Good luck OP.