Hi, I just bought an '99.5 A4 1.8TQM with 86k miles a couple weeks ago, and it died yesterday. I have changed oil, filter, sent the car for timing belt job last week.

The car starts jerking low RPMs, usually 1st and 2nd gear, it some times just dies. It sounds like missfiring. But sometimes it's perfectly normal, I notice it missfires mostly when the temperature is high, it doesn't happen as much in the morning or at night.

When it idles, the RPM will drop to 500 and then jump up to 2k and drop back down, does it a couple times and it's normal again at around 800.

I searched and found out it could be dirty MAF, ICM, or coilpacks? I took out the MAF yesterday and bought some MAF cleaner, but the MAF looks very clean (like new) to me, wondering if the previous owner has changed it. (Please see the attached pics, is this MAF?)

Should I replace the ICM next? It still runs but it missfires sometimes and dies, on highway it runs good.

Within the last few weeks this happened and the cruise control stopped working. I thought my old DSM (Eclipse) was bad The fun has just begun!! Thanks for any input.

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Welcome to the wonderful world of Audi kidding

I am having the same symptoms to the tee, total loss of power sometimes, misfires, "jumpy" idlenot accelerating very well most the time(even on highway)

You have the right idea for your basic steps ICM, MAF, coilpacks. . . check spark plugs etc.

Also you may want to look for the thread that is a few pages now about this same problem, serach "rough idle"

 

is ur car burnin rich..it could also be a cheap part (about 40$) i dont kno the name exactly but its the temp sending unit for hte coolant and that could be why it happens with the car is warm

 

do you have any CEL's?

have you read it for codes?

 

That part that your looking for is the CTS or Coolant Temp Sensor. I had mine go bad in my car and I had a rough idle, coolant leaks, wouldn't start and a few other things. Changed it out and bam fixed them all. Also brought my MPG up a little! Try that first and see what happens.

Josh

 

whats up josh, how much was your CTS and is it easy to DIY

any way to tell if thats the problem or kind of a guess and check type thing?

 

my CTS was like 45-50$ installed, thats dealer cost and my buddy being the certified audi mechanic

 

Cleaning Maf was a good idea.
Really, the very next thing you should do is get the codes read, and post them here.

This sounds like symptoms of a bad vacuum/air leak. Check your hoses to/from the smic, to the TB intake. Look for any other loose or split vacuum hoses/connections. Look at the airbox as well, make sure all connections are good.
You can also try - cleaning the TB out good, and also a TB alignment. For this just turn key to on position and wait 60 seconds.

You may wan to ask who ever did the t-belt to take a look, play it off like its been doing this ever since you got it back from them. Or maybe they will at least read the codes for you for free.

Oh yeah, and the Coolant temp sensor could likely be the cause, I would do that as well. Although if you find a hose off, and everything goes back to normal, then probably dont need the CTS.

Good luck.

 

I got my CTS from the dealer and it was $30 or something close to that. As for how hard it is.. it's really easy IF you do it right. LOL When I did mine the o-ring had been put on the wrong side of the sensor (It was not me who put the o-ring on the sensor. It was on when I got it so I figured it was in the right spot) Anyways I ended up pumping ALL, yes my coolant tank was bone dry, out onto the road when I took it for a test drive. Once I figured out what had happened I fixed it and filled it back up and now all is well!

A-Fizzle, we should get together sometime and try and figure out whats going on with your car! I have a friend (18Audi18 on inlandeuros) his neighbor has a rack and everything so we can get up underneath the car if we have to.

Josh

 

yeah that sounds good man, and photo shoot before you take off

it will be in the shop most of next week so maybe next wknd . . . ?