Telsdon

1999 A4 1.8T Quattro

I started my car up today and the 'check engine' light came on and the engine was shaking like I've never felt before. I immediately turned it off.

Has anyone experienced this and is it just a matter of checking the spark plugs?

4Driver4

Call me crazy, but I'd probably pull some codes and try to diagnose it.

Telsdon

I unfortunately don't have a scan tool. I will most likely have to take it in to get it checked out.

Any other suggestions before I do?

AudiMick

Scanners are cheap now, less than $60. Amazon has one on sale for less than $23 (black friday sale). Not sure about Canada.

http://www.amazon.com/Autel-MaxiScan...=pd_sim_auto_3

Never change parts before pulling codes. Possibly a coil pack, but pull the codes and check which one.

Many part stores will pull codes for free.

Telsdon

Wow, that's really inexpensive. Thanks for the link! I came across a scanner that links to your iPhone via WiFi... wouldn't that be handy!

I might take your suggestion and and get someone to pull the code for me. But I did read that I shouldn't drive the car when it's in this condition. What do ya'll think?

AudiMick

If the CEL is flashing, it's potentially dangerous to drive. So don't drive it. You risk damaging the catalytic converter and if it's a bad misfire the raw fuel pouring into the exhaust can catch the car on fire.

If the light is just on (not flashing) drive it to the nearest place with a code reader.

pilot5.0

Need to check codes. Most likely a coil, ICM(ignition control module), or plug. In that order. Wouldn't drive if CEL is flashing. If codes are for intermittent misfire on one cylinder, move coil packs to different cylinder and reset CEl. Recheck to see if misfire moves with coil pack. If not, ICM.

I have lost ICM at 49k and 108k. Buy ICM on line, not at stealership.

Telsdon

I wanted to give ya'll an update on what happened;

Took the advice and didn't drive the car anywhere. My father-in-law helped me run a few tests to try to get it running. That wasn't successful, so called in the tow truck.

Brought it into the shop and they pulled the codes. Turned out it was the ignition control module along with some fried/exposed wires. (you were spot-on, pilot5.0.)

Replaced that for $450. Also got an oil change (oil light will not go off for some reason though - any ideas?) and a few other things that popped up ($$$).

I will have my precious Audrey back tomorrow evening. I miss her!

Thank you for your help, 4Driver4, AudiMick & pilot5.0. You've all been great resources!

All things considered, she's done pretty well for her age! I'm so happy with my car! LOTS of LOVE for Audi.

eliastfk

did ur car shake at a specific rpm or all together, mine shakes ONLY at 1700 rpm it runs fine before and fine after that rpm.

BoostLad

Regarding the ICM (ignition control module) vs coilpack diagnosis, its typically the ICM on the earlier cars (97-99) and typically coilpack on later cars (99.5 up). Its very rare for them to fail in opposite fashion- newer cars almost never fail ICM's, and older A4s coilpacks are virtually bulletproof.

Shaking engine with flashing CEL is a misfire, caused by above. Typically not plugs (unless one suddenly failed altogether; that prob wont be caused by intermittent misses from fouled plugs).

Shaking at a certain RPM sounds more like a motor mount issue; probably nothing to do w/ ignition.