2002 chev 6.0

[ratmn218]

when cold idles rough and then revs to about 3000 rpms . replaced fuel filter and fuel pressure regulater?on fuel rail, with vacume hose attatched to it.still same problem what do i try next? no engine light service soon lights are on.

[PierBridge]

Many possiblitys.

I would get it on a scanner first off and check air intake and coolant temp variances they should be within 10 degrees.

Possible vacume leak?

Hopefully some of the smarter guys will chime in!

[ratmn218]

checked pcv valve, looks to be empty. no rattler? i thought to test them they should rattle? can see right through it?after warm up seems to run great.

[Jeremy airjer W]

The PCV valve should be on the drivers side on the back of the valve cover.

As far as the high idle I'm not sure. Typically a vacuum leak (plenum gaskets) will flag a check engine light with codes for both banks lean. Usually there will also be a ruff idle symptom when cold.

[UMDSportsman]

my mom's truck does the same thing on the cold days. I don't know exactly how high it idles, but it does it for a little while then it stops. she has a 2000 silverado, with a V8, pretty sure the 5.3. They are trying to find out what is wrong, but nothing yet.