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Discussion Starter #1
Hey everyone, just curious if I could get some good opinions on this...

Whenever I stop at a light or stop-sign the engine idles really rough. I can fix it by shifting into neutral while at the light, and it runs smoother again. But it runs rough as all heck when I have it in drive and am stationary.

It seems to have started once the weather got colder (here in Arizona). But also at the same time I was given advice by a guy at Wal-Mart and Autozone (I know... terrific sources) that I should put a heavier weight in with the colder weather.

So my question is... could the heavier weight oil be making it idle rougher? And is there a good chance it just needs a tune-up? Its at 75k miles, an 03, and I just bought it about 6 months ago, so I dunno when its last tune-up was.

Any and all help/advice is welcomed and appreciated. Thanks guys! [8D]
 

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Check the PCV hose that runs into the intake manifold.

They're known to get soft next to the manifold and collapse or even get a hole in them.
 

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5w30 oil! y would u put heavier weight oil in the cold when oil gets cold it gets thick and dosent flow right. walmart people are stupid and autozone they just sell stuff they dont know nothing just what parts u need and sometimes they dont even get that right
 

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Discussion Starter #4
Yeah, I thought that sounded kind of strange... I guess I'll just eat that money and go buy the 5w30. As he was telling me about putting the heavier weight in, I sat there thinking I probably shouldn't follow their advice as they were telling it to me... but I know so little about this stuff it sounded believable at the time. No more of their nonsense for me.

How about a tune up? Sound like a good idea to fix the rough idling?

And I have no idea how to find the PCV hose by the intake manifold.
 

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ive never played with that hose knock on wood but some1 that comes along later will be happy to tell you how to find it. plugs couldent hurt. now i doubt the thicker oil is the problem but your car will be happier. and youll get better gas mileage. if u just changed it dont bother with a new oil filter just take it off and dump the oil out just to save u a few bucks. i use 5w30 syn oil and change every 5k.
 

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By all means go back to the thinner oil......5-20 year-round is fine, and recommended by the factory.

But that probably isn't your idle problem. These cars have a computer-controlled idle speed. The usual problem point is the idle speed valve. It's called an IAC valve, but goes by other names.

Check it after the engine is warmed up......let the car idle in park or neutral, then turn on the lights, and step on the brake, and turn on the rear window defroster. The idle speed should stay the same, maybe go up slightly. If it drops way down.....your IAC circuit has a problem.
 
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