Rough Idle on 99.5 Golf IV

Hello,

The last two days I have been having a really rough idle on my Golf. Yesterday afternoon, when I started the car and got to my first traffic light, it felt like it was going to stall. So I gave it a bit of gas and it was OK (note the AC was not on at this point if that matters at all). It did this until I got on the highway, and by the time I got home it seemed OK when at a stand still.

Today, it was fine early on, but once I got to work it was idling really roughtly. I had the AC on while on the highway, but turned it off for local streets about 10 mins before I got to work and parked. So once I parked I just let it go to see if it would stall, but it never did. After idling for a few minutes it seemed to be less rough.

I have always had a light knocking from the front of the car (engine?) when idling in park (about 4-6 per sec - with or without AC on). But as I let it idle longer today, the knocking just got faster and faster until it sounded like a constant noise. It may have always done that but I never let it idle in park so I dunno.

Any suggestions? I have had a MAF replaced within the last 6 months, and I just had a new battery put in within the last month. Oil is good (5w30 sythetic) and I use 89 octane gas. Oh, and yesterday I hit 60,000 miles. As usual I am hoping for something simple that my mechanic can do since I try to avoid the dealer like the plague.

Thanks for helping my poor little Golf. ;)

-Pete

Reply to
lynchman666
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Some additional (probably useless) info:

I have the 2.0 Engine. No 'Check Engine' light is on. I have used Chevron Techron fuel injector cleaner within the last 2000 miles (about a month ago). The behavior sounds very simular to this problem:

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Thanks again,

-Pete

Reply to
Pete Foley

I just went outside and started the Golf since it has been sitting for two hours and popped the hood to see if anything visible was wrong. The only thing I notice is that the engine gives a good shake every second or so. Also, it seems that once it is about to stall, it revs up real quick and then stabilizes for a second. It seemed to stop the almost stalling after being on for a few minutes.

Maybe that helps some.

Thanks,

-Pete

Reply to
Pete Foley

I got a quick chance to look at this over the weekend. I think I figured out how to get to the air intake tube - but I forgot my tools so I could not take the airbox out to get to it. But the air filter needs to be replaced so I will be putting that in next weekend. I will check the screen out at that point also.

After shaking off the air filter and cleaning out the box a bit, the car seems a bit better. We will see after next weekend what happens.

Thanks,

-Pete

Reply to
Pete Foley

So I finally got around to taking out the intake tube yesterday. By then the car was getting really bad - I stalled out several times.

So when I took out the intake tube the screen had already been cut out (maybe at the dealer once or by the previous owner). I took out the whole air box and cleaned it all out and popped in a new air filter. The old filter had been in there for about 20,000 miles and was pretty skanky.

The ride to work today seemed to be better. The RPM's aren't really dropping much when stopped at a light. Now I would say it bounces between

750 and 800, but before it would bounce between 550 and 900 when it was at its worst.

Could it just have been the crap (dead bugs, small leaves) in the air box and the dirty filter? I suspect it could also be the MAF Sensor, but I have no CEL on right now...

It is usually the ride home in traffic when it gets bad, so I will see what happens tonight....

Thanks,

-Pete

Reply to
Pete Foley

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