Turtle Power

Hi

I have had trouble with a misfire and think i have isolated the problem to a bad coil. I have replaced it and although the car idles better its still bad.
Although above about 2000 revs it runs pretty smooth.

When replacing the coil i found a large split in the crankcase breather tube - do you think this may be cause rough idling?

Found this DIY to test for boost leaks and right in the last picture is the exact same breather hose problem - except his is small fry compared to mine the hose has pretty much disintegrated on mine!

http://www.a4mods.com/index.php?page...tml&category=5

New one on order just wanted some opinion

If when refitted this doesnt cure it do think it might be the ICM? Not sure where this might be

2002 A4 Avant 1.8T Sport Quattro

PS i have a VAG Com Cable en route so hopefully i will be able to provide some data if this doesn't repair i.

Thanks in advance

Et Cetera

You should definitley replace that hose and go from there, checking for other breather/vacuum leaks as well.

You do not have an ICM.

Also, does the check engine light flash when running?

Turtle Power

Et cetera have changed the pipe and 2 coils, although engine still running rough.

The cel is flashing and when given revs it is pretty smooth with the odd misfire.

when idling it will be butter smooth then will go rough as you like and cycle between the two.

Moved the car about 10 metres earlier and under load it felt pretty rough.

I did think it could be too easy just to replace that and it would be fixed!!!

Turtle Power

I took 2 readings

basically i read the memory and cleared the codes, ran the engine and checked the fault codes again. This is what i got

Friday, 18 September 2009, 17:23:46

VAG-COM Version: Release 409.1-US



Control Module Part Number: 8E0 909 518

Component and/or Version: 1.8L R4/5VT 0001

Software Coding: 0011701

Work Shop Code: WSC 63351

6 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected

P0300 - 001 - Upper Limit Exceeded

16686 - Shareware Version. To Decode all DTCs

P0302 - 001 - Please Register/Activate

16688 - Shareware Version. To Decode all DTCs

P0304 - 001 - Please Register/Activate

16685 - Cylinder 1 Misfire Detected

P0301 - 001 - Upper Limit Exceeded

16687 - Shareware Version. To Decode all DTCs

P0303 - 001 - Please Register/Activate

16486 - Shareware Version. To Decode all DTCs

P0102 - 002 - Please Register/Activate - Intermittent

---------------------------------------------------------------------------





Friday, 18 September 2009, 17:31:47

VAG-COM Version: Release 409.1-US



Control Module Part Number: 8E0 909 518

Component and/or Version: 1.8L R4/5VT 0001

Software Coding: 0011701

Work Shop Code: WSC 63351

2 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected

P0300 - 001 - Upper Limit Exceeded

16685 - Shareware Version. To Decode all DTCs

P0301 - 001 - Please Register/Activate

---------------------------------------------------------------------------

All i believe are either random misfires or specific misfires - i think i got one for each cylinder!

What do you think is the best approach? I have 2 brand new coils fitted today and a set of new plugs. but still getting these problems. (the problem started whilst i was sitting in a layby on the phone - one minute ok, next minute like a tractor!)

Obviously found the breather hose problem - thats on now. The breather hose, plugs and 2 x coils have helped, from how it was initially, but it is still basically undrivable.

Any help with ideas on diagnosis without having to buy any more parts 1st would be a great help!?!

Et Cetera

All the P030X codes are misfires, P0300 is multiple cylinders and P0301 is cyl. 1, etc.

P0102 is a mass air low input fault.

I'm not at work now so I can't be real specific with the codes, but I will say this:
Start the car and let it idle, and note how it's running.
1. Unplug the Mass airflow sensor and see if it gets better.
2. Try to remove your oil filler cap while it's running. See if it is under a vacuum. If it is you need a PCV valve.
3. Try erasing the faults and see if the P0102 fault returns. If it returns without even starting the engine it's probably a mass air or connector issue. If it returns only after starting the engine, it could be the mass air air or any loose/torn hose in the intake tract. If it doesn't return, ignore it for now.

Those coils are junk, btw. If you have Audi coils, check the last letter in the part # and let us know what it is.

Turtle Power

As indicated all sorted out now.

Ok, recap, I had replaced 2 coils plugs and found a breather hose that was severly damaged replaced them and car was still rough as you like. Got the VAG Com working and cleared all the faults that were logged and displayed in the previous post. Then ran the car again - got random misfire and cylinder 1 misfire. Repeated this again and got the same result.

Moved the cylinder 1 coil to cylinder 2 and the misfire followed it then moved it again to be sure and it moved again.

I tried the coils that i thought were bad in replacement of the indicated dodgy coil and none of them were any better - ie i was right that they were knackered!

Decided to replace the bad coil and the one remaining original coil for good measure - now runs like a treat.

Thanks Et Cetera for your help - although i do have a couple of further questions for you

No idea why 3 coils went bad at once i would bet the failed breather hose may have helped - maybe greater strains on the engine trying to compensate?

I checked the vacuum in the oil filler cap and none was present - it was puffing out at me.

Also thinking about the codes i posted i think the P0102 probably related to me doing as you suggested disconnecting the MAF - which produced no change at the time. This i forgot to mention - sorry .

If you still would like the coil code i can have a look as i have kept them for the time being.

Those questions

Could you tell me what the PCV valve is?

And can you identify this part:-

The braided hose goes into the silver thing (technical term!) but you can feel that as it enters, the hose under the braid is broken or has become pulled out. Is it important? Do i need to fix urgently?

And just before i sign off thanks again everyone who posted here or on the double post i made (accidently)!

Et Cetera

Sorry, I was on vacation for a couple of days.

Coils are notorious, happens all the time.

That's how the oil cap should behave. If it takes great effort to pull it off while running then the PCV (Positive crankcase ventilation) valve is stuck. It is located under the intake manifold in a rather hard to get to location, connected to a breather hose that routes behind the engine and connects to that 3-way rubber hose you replaced. It also connects to 2 other hoses. I would not worry about it until it goes bad, but some of those breather hoses and vacuum hoses are common problems as well.

That part is a braided vacuum hose that goes to your secondary air combination valve (silver thing). It will not cause a problem until it breaks off and set a code for secondary air flow. Even if it does, it's definitley not urgent.

And you're welcome, glad you got it figured out.

Turtle Power

Thanks again

i tried serching PCV valve but all it came up with was mentions of PCV without saying what it was!

Also thanks for the explanation of the braided hose i will see if i can reconnect it or change it in the coming weeks.

All the best

Turtle Power

Et cetera and anyone with similar problems to this might be interested to know that i had the following code thrown up(retrived by VAG Com)and solid check engine light

1 Fault Found:

16795 - Secondary Air Injection System: Incorrect Flow Detected

P0411 - 002 - Lower Limit Exceeded
which according to the ross tech code wiki idicates the following

16795/P0411/001041 - Secondary Air Injection System: Incorrect Flow Detected
Possible Symptoms

* Malfunction Indicator Light (MIL) ON

Possible Causes

* Fuel Pump Relay (J17) faulty
* Hoses/Pipes to/between Components faulty/clogged
* Secondary Air Injection Pump (V101) faulty
* Secondary Air Injection Pump Relay (J299) faulty
* Secondary Air Injection Solenoid Valve (N112) faulty

Possible Solutions

* Check Fuel Pump Relay (J17)
* Check Hoses/Pipes to/between Components
o Check Secondary Air Injection Hoses/Pipes for Carbonization
* Check Secondary Air Injection Pump (V101)
* Check Secondary Air Injection Pump Relay (J299)
* Check Secondary Air Injection Solenoid Valve (N112)

This may be caused by the braided hose that is coming loose (pictures above) that et cetera identified as attaching to the secondary air combination valve.

I will repair/replace and see if it throws this code again.

i will repost in a few weeks with the results.

michaelpalbicki21

Hey guys im having the same problem any fix?