Usual rough start and occasional good start
#1
Usual rough start and occasional good start
My 2003 A4 1.8T is giving me a CEL.
car starts fine maybe 1 out of 6 times usually first time only. I can test drive it around town if it runs smooth, but must not kill engine otherwise car starting will be rough. When it does start/runs well, then it will drive fine, but with an occasional misfire usually during deliberate acceleration. If i kill engine and restart car, then it idles and drives rough as if the coils were not working...
Had codes checked at AutoZone only to confirm the engine was getting occasional misfires. no other codes... Trying to determine what is causing coils to foul... I have replaced the coils several times in last two years. Got into habit of carrying spare coils in car. First time coils went was at about 65,000 miles.
Recently I was driving home and engine began running rough. I replaced the #2 coil and the car drove fine for another 30 minutes, then engine began misfiring and began running rough, coils went out... have not determined what is causes the coils to foul...
the car...
has 70,000+ miles, new Audi coils; I have checked coil harness and measure approx. 12+ volts at each coil connector. the engine coolant was recently flushed, engine oil was flushed. I use Castrol syntec with changes at recommended intervals, I have replaced the oil sender and fuel filter and new platinum plugs. MAF sensor has been cleaned and I have confirmed it is working. I have checked my vacuum lines, check valves and have replaced the hose clamps. no apparent leaks to the larger lines. the smaller softer lines located below the intake were holding a vacuum when lines were disconnected. trying to get the car running to see dealer about recall on timing belt/tensioner.
What has not been checked:
O2 sensors, catalytic converter, ECU, temp sensors...
i do not have a VAG-Com. Currently living in small town and practically all mechanics in town work asian and domestic cars...
Open to your suggestions...
feel free to PM me.
Chito
chitoinaustin@gmail.com
car starts fine maybe 1 out of 6 times usually first time only. I can test drive it around town if it runs smooth, but must not kill engine otherwise car starting will be rough. When it does start/runs well, then it will drive fine, but with an occasional misfire usually during deliberate acceleration. If i kill engine and restart car, then it idles and drives rough as if the coils were not working...
Had codes checked at AutoZone only to confirm the engine was getting occasional misfires. no other codes... Trying to determine what is causing coils to foul... I have replaced the coils several times in last two years. Got into habit of carrying spare coils in car. First time coils went was at about 65,000 miles.
Recently I was driving home and engine began running rough. I replaced the #2 coil and the car drove fine for another 30 minutes, then engine began misfiring and began running rough, coils went out... have not determined what is causes the coils to foul...
the car...
has 70,000+ miles, new Audi coils; I have checked coil harness and measure approx. 12+ volts at each coil connector. the engine coolant was recently flushed, engine oil was flushed. I use Castrol syntec with changes at recommended intervals, I have replaced the oil sender and fuel filter and new platinum plugs. MAF sensor has been cleaned and I have confirmed it is working. I have checked my vacuum lines, check valves and have replaced the hose clamps. no apparent leaks to the larger lines. the smaller softer lines located below the intake were holding a vacuum when lines were disconnected. trying to get the car running to see dealer about recall on timing belt/tensioner.
What has not been checked:
O2 sensors, catalytic converter, ECU, temp sensors...
i do not have a VAG-Com. Currently living in small town and practically all mechanics in town work asian and domestic cars...
Open to your suggestions...
feel free to PM me.
Chito
chitoinaustin@gmail.com
#3
you indicate that heat has become a problem for coils. I'm wondering why heat would be an issue now rather than for the first 65,000 miles?
For me I've gone through several sets of coils since...
I'm running new audi/vw coils (same part number) purchased from the Corpus Christi VW dealer... The coils have less that 30 miles and were installed when i changed the fuel filter. Car ran great for about 25 miles...
I haven't been driving the car because i've got a persistent CEL.
I'll probably take the car by trailer to my dealer in Austin for the coil recall, and drive belt/tensioner recall...
I'm thinking that coil failure is a symptom rather than the initial problem...
For me I've gone through several sets of coils since...
I'm running new audi/vw coils (same part number) purchased from the Corpus Christi VW dealer... The coils have less that 30 miles and were installed when i changed the fuel filter. Car ran great for about 25 miles...
I haven't been driving the car because i've got a persistent CEL.
I'll probably take the car by trailer to my dealer in Austin for the coil recall, and drive belt/tensioner recall...
I'm thinking that coil failure is a symptom rather than the initial problem...
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brit.mike13
Audi A4
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10-17-2010 08:26 PM