# Problem after oil change - Misfire codes



## vetaldj (Dec 28, 2011)

Hi All,

Recently I did change an oil in my 2006 A3 2.0T FSI, car was running OK before but after that it starts to shake, vibrate, RPM jumps like a crazy, can rev up by itself etc. Got a misfire codes for 3 of 4 cylinders.

I check dipstick and it looks like I little overfill it . Went underneath and tried to take some out by using that oil filter housing orange nipple but when I push it in no oil came out at all. IS that normal? Looks like oil is not coming into oil filter housing.
Prior to oil change I did remove vacuum pump and replace O-Ring but it started as before so it's definitely started after oil change...

I definitely screwed up somewhere but where? I bet oil should be in filter housing, is that because vacuum pump or filter? Looks like I need to redo all again...

Please help!


----------



## TBomb (Sep 23, 2009)

I don't want to sound like a dick, but if you can't do a simple oil change without running into problems, maybe you should take your car to a professional and have them figure out where things went wrong. Maybe it is something simple, maybe not, but it's hard to diagnose an issue like that via the internet.


----------



## vetaldj (Dec 28, 2011)

Any respond counts so no worries. I was doing my oil changes for years (as well many others DIY projects) and this is not mine first.


----------



## BeeAlk (Jun 3, 2013)

You didnt get any codes for low oil pressure, did you?

There should definitely be oil coming out of the orange nipple. Sounds to me like the oil is not flowing into the filter.

Did you spill any oil on the valve cover when you were refilling?


----------



## TBomb (Sep 23, 2009)

vetaldj said:


> Any respond counts so no worries. I was doing my oil changes for years (as well many others DIY projects) and this is not mine first.


Ok, no worries...like I said, didn't mean to sound like a dick even though it probably did. Have you had your A3 with the FSI engine for a while? I typically pour some oil into the filter housing after replacing the filter so that there is some oil in there to get sucked up when the engine first starts up. I highly doubt that overfilling the engine could have caused some kind of catastrophic failure, unless you overfilled it so much that the pistons literally had nowhere to go (I'm not even sure this is possible as you'd likely blow the oil out somewhere else).

You could possibly have a vacuum leak that cause it to run really rough (depending on how bad it is) and possibly cause some misfires. I know you said you did some work on the vacuum pump at the same time, so I would check that first.


----------



## vetaldj (Dec 28, 2011)

BeeAlk said:


> You didnt get any codes for low oil pressure, did you?
> 
> There should definitely be oil coming out of the orange nipple. Sounds to me like the oil is not flowing into the filter.
> 
> Did you spill any oil on the valve cover when you were refilling?


Nope, I did not get any codes for that. I have just codes P0300 type for misfire, then 3 more like that for cylinders 2,3,4.
Also no spilling anywhere.

I did not add oil into oil housing, that's maybe the case.


----------



## vetaldj (Dec 28, 2011)

TBomb said:


> Ok, no worries...like I said, didn't mean to sound like a dick even though it probably did. Have you had your A3 with the FSI engine for a while? I typically pour some oil into the filter housing after replacing the filter so that there is some oil in there to get sucked up when the engine first starts up. I highly doubt that overfilling the engine could have caused some kind of catastrophic failure, unless you overfilled it so much that the pistons literally had nowhere to go (I'm not even sure this is possible as you'd likely blow the oil out somewhere else).
> 
> You could possibly have a vacuum leak that cause it to run really rough (depending on how bad it is) and possibly cause some misfires. I know you said you did some work on the vacuum pump at the same time, so I would check that first.


I was checking into that and only place I found was those hard plastic hoses that come from vacuum pump to the valve (brake booster related), I did replace them though.


----------



## 2006_A3_2.0T (Jan 11, 2013)

we (with my mechanic) never add oil in the filter housing but... last oil change, when I first cranked the engine to start up, the engine did a sqeaking rare sound like something was running badly without oil. I dunno what caused it but next oil change we will add oil in the housing just for peace of mind. hoping is nothing serious g/l


----------



## Audi_Mechanic (Mar 24, 2012)

How much oil did you put back in after you drained it? 4, 5, or 6 quarts/liters? When you say you overfilled it a little, what's a little? 1/10th of a quart, 1/2, full quart? If no more than a quart then you probably didn't hydrolock it.

How far are you pushing into the oil filter drain nipple? You have to **** it over a decent amount to get it to drain. If you're moving the nipple a similar amount to when you drained the filter housing initially, then I can see why it's a problem. Try removing the oil filter cap again and see if something came apart and is blocking oil flow. 

After you filled the engine with oil, how long did you let it idle before shutting it back off? 

While the engine idles, does it sound kinda bad like a lot of loud metallic rattling as if it has no oil? Or does it sound normal aside from the misfiring noises? While the engine idles, can you remove the oil fill cap from valve cover? If you can't, then the crankcase breather valve that's mounted onto the side of valve cover might be faulty.


----------



## TBomb (Sep 23, 2009)

2006_A3_2.0T said:


> we (with my mechanic) never add oil in the filter housing but... last oil change, when I first cranked the engine to start up, the engine did a sqeaking rare sound like something was running badly without oil. I dunno what caused it but next oil change we will add oil in the housing just for peace of mind. hoping is nothing serious g/l


Has it done it again since? I have an occasional squeak right when the engine first cranks up. I first noticed it after I had my timing belt service done and thought it was related to that, but evidently it could possibly be traced back to the starter motor (or so I've read), as it is only on the initial crank of the engine.


----------



## 2006_A3_2.0T (Jan 11, 2013)

TBomb said:


> Has it done it again since? I have an occasional squeak right when the engine first cranks up. I first noticed it after I had my timing belt service done and thought it was related to that, but evidently it could possibly be traced back to the starter motor (or so I've read), as it is only on the initial crank of the engine.


never, only heard it that only time. my starter does a squeek everytime but way different on what I heard that start after the oil change.


----------



## vetaldj (Dec 28, 2011)

Audi_Mechanic said:


> How much oil did you put back in after you drained it? 4, 5, or 6 quarts/liters? When you say you overfilled it a little, what's a little? 1/10th of a quart, 1/2, full quart? If no more than a quart then you probably didn't hydrolock it.
> 
> How far are you pushing into the oil filter drain nipple? You have to **** it over a decent amount to get it to drain. If you're moving the nipple a similar amount to when you drained the filter housing initially, then I can see why it's a problem. Try removing the oil filter cap again and see if something came apart and is blocking oil flow.
> 
> ...


Yea, that was the case - I did no push very hard, just hard  After more muscle power it went bit more up and oil came out. 

I did put 5qt, whole jar. It was on MAX level so not that huge over, I drained a bit so it little bellow average.

I did it idle until it almost died from misfires (3 of 4 cylinders). Got new plugs and coils as they are look original, will see tomorrow after I replace them.

Only one spot that makes me worry - oil cup was broken and I see old spill to 3 of 4 cylinders (from left to right). Had new cup coming.
Also, that plastic set of hoses for brake buster that comes out of the vacuum pump, can that be counted as vacuum leak? I have it temp fix for now while I waiting new hoses.

Thanks!


----------



## Audi_Mechanic (Mar 24, 2012)

vetaldj said:


> I did put 5qt, whole jar. It was on MAX level so not that huge over, I drained a bit so it little below average.
> 
> Only one spot that makes me worry - oil cup was broken and I see old spill to 3 of 4 cylinders (from left to right). Had new cup coming.
> 
> ...


Okay, so you didn't overfill it enough to matter.

You mean oil fill cap on valve cover? One of the signs that the crankcase breather valve is faulty is that oil will be pushed out of oil fill cap when the engine is under boost; the breather valve's internal diaphragm fails and allows boost pressure to reach the crankcase. Misfires and lean codes are other signs of breather valve failure.

The vacuum pipes off the vacuum pump shouldn't affect how the engine runs, they're a separate system. That pump provides the brake booster a continuous supply of vacuum so that you have power brakes while the engine is under boost.


----------



## vetaldj (Dec 28, 2011)

I came from BMW and it's first place to look as well.

OK, looks like I will go and study breath valve locations and parts. Is that thing are you talking about?


----------



## Audi_Mechanic (Mar 24, 2012)

Yup, that's the valve. Again, easiest way to check is by trying to remove the oil fill cap from valve cover while engine is idling. If it's very difficult to remove the cap, the breather valve is likely faulty. There is an extended warranty on the valve, something like 10yrs/120k miles maybe, don't remember how long. If it seems like your breather is bad, it might be worth calling your local dealer with your VIN in hand so they can check if your car qualifies for the extended warranty.


----------



## vetaldj (Dec 28, 2011)

Audi_Mechanic said:


> Yup, that's the valve. Again, easiest way to check is by trying to remove the oil fill cap from valve cover while engine is idling. If it's very difficult to remove the cap, the breather valve is likely faulty. There is an extended warranty on the valve, something like 10yrs/120k miles maybe, don't remember how long. If it seems like your breather is bad, it might be worth calling your local dealer with your VIN in hand so they can check if your car qualifies for the extended warranty.


Well, that will be hard to perform as cap is broken - top part separated from bottom, it's hard to open it even without engine running. Will try it though anyway. Thanks for info about warranty, will try it out. It will be 10 years next month  so just in time.


----------



## vetaldj (Dec 28, 2011)

Ok, was able to try that cup test. I can take it off no problem with pressure coming out of the engine and since it was already rough it was hard to tell if if something changed. It looks like it almost die after I took that cup off.
That doesn't sound like and PCV issue based on what I've read so far.

On another note it sounds like it struggling to turn itself and have some burning rubber smell. Only thing I touched was vacuum oil pump before it started, so looks like I need to look that way again.


----------



## vetaldj (Dec 28, 2011)

While waiting for some other parts I did check my spark plugs and they are all in fluffy black soot. I did replace them but nothing changed. So plugs and coils are off the list, they are changed.

From what I've read online black soft soot is rich conditions - too much fuel not that much of air. Funny thing that I just finished recently fighting with lean condition on my other car, now this. 
No any other codes except general misfire and misfires for cyl 2,3,4.
Engine has signs of spilled oil around left 3 cylinders, when I remove oil cup it has some air coming out. I've read that this is right conditions but I still going to check PCV, not that hard to take it off. 

Vacuum pump leaking badly again so I ordered another one as O-ring did not help. Since everything started after I did that "fix" I hope that it will fix it. Will see, pump in the mail, latest revision. Also decided to replace cam follower as this is cheap and easy fix.

More stuff to do this week  Any other ideas what to check?


----------



## ImSpecialerThanU (Sep 25, 2007)

Looked at the coil pack harness its self? If you swapped coils around and did spark plugs with misfire staying on 3&4 I would check it.


----------



## vetaldj (Dec 28, 2011)

Good point on harness... Since of that bad oil leak from vacuum pump pretty much all cables are in oil, I was looking into that but hope it not bad.

Looks like I need to see if those harnesses actually bring voltage to coils itself. Even more work for the weekend 

Thanks!


----------



## vetaldj (Dec 28, 2011)

Alright, problem solved.

It turned out that I had bad oil vacuum pump. Today I replaced it with upgraded version H (I had E revision) and engine smooth like a butter now!

Will finish few more minor items and here we go, time to remember how to drive stick.

Thanks everybody for help!


----------

