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audi a4 99 2.8 quatro slight shaky idle throwing random mis and misfire codes
have a 99 a4 2.8 quattro i just bought car has 71000 miles ..i replaced spark plugs with bosch super with copper core, replaced ignition coils whole peace cost $160 from autozone..found oil level was high so i drained it down to where it should be, found broken pvc hoses replaced with same size rubber hoses, replaced almost all the little vaccuum lines from what i can see, my next step is pull tb and clean it...im kinda stumped on this..im getting random misfire and misfire in cyl. 123..p0300,p0301,p0303,p0302 i clear codes and hold idle up codes dont come back until about 5 min after i let idle below 1000.. idle acts funny ill hit the gas and it will drop real low after i let off the gass pedal almost stalling then comes back up to about 800 850 rpm and i get a slight shake...im stumped any ideas on what i could check next?
throttle body was kinda dirty took it all apart cleaned the gunk out of it and started to reinstall it and kinda broke the pvc breather hose below the throttle body so now i gotta replace that before i continue installing...will post again when all put back together with results..i did some research i found out the new ignition coils made in china are junk so might be replacing those again hope this fixes my misfire at idle
no it didnt sorry it drove me nuts for a week now ive tryed swappin wires from one side to the other codes didnt change i pulled fuel rail and injectors cleaned and swapped them around nothing changed..i swapped 02 sensor pluggs around to see if codes would change from one side to the other had no luck ..i noticed alot of carbon build up inside the engine so i changed the oil and filter and when i drove it i floored the pedal and then it got worsee with a loud tapp and now when it idles it has a slight tap i think the engine is toast in mine
what misfire code you getting? ..if you can maybe do cylinder pressure test also on that cylinder i did cylinder pressure tests on mine and the number came back all weird 150 on 123 and 105 115 and 90 on 45 and 6 then when i drove it and floored the pedal lol i brought it back and got a big 0 compression on 2 and 3 :/ lol..um yea i screwed somthin up ..try swappin wires around and replace the plugs check for vaccum leaks to see iff the plug is fouling
Hey I sont know if this will help you or not, we have mirror image issues, yours are 1,2,3 mine are 4,5,6. I am pretty sure mine is a leaking valve cover gasket. When you pulled your spark plugs were they oily? I wasn't able to diagnose mine until I put in 0W-40. That was light enough that it started to leak through the valve covers
i meen yea and no the plugs didnt have any oil on them ok maybe just a little but i think i was having problems with the valves getting stuck open not closing corectly i lost compression in 2 and 3 and now i got some tapping so i think i might of jus possibly bent maybe the exaust valves ..im gonna pull the heads maybe in a day or 2 and check them out might go to a junk yard and see if i cant find a nice set of heads to throw on it..umm im tryna figure out if atq heads work on the aha motor so i kno what im getting into im not sure on that thanks tho.
i did have alot of carbon built up in this engine breather hoses were broken and cracked clogged up i pretty much replaced all of it who ever had the car before i got it really poorly maintained it from what im seeing its crazy cause the car only has 70,000 miles on it
02-23-2015, 08:24 PM
audi a4 99 2.8 quatro slight shaky idle throwing random mis and misfire codes
