Engine trying to shake itself out of truck for 60 sec after start-- no CEL
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Engine trying to shake itself out of truck for 60 sec after start-- no CEL
'03 XLT 4X4, 170K, 5.4L, not a moment's trouble with it. Has run like a top since I bought it at 105K.
Started it this AM and "rough idle" does not describe it-- like unbalanced washing machine on spin cycle. Whole truck was loping. After 1 min or so it went away and behaved fine all day. No weird noises from engine, no check engine light, it was not dying/struggling to run at the time, RPMs seemed normal. I spoke to a mechanic who said these trucks can run rough when IAC is going out, but that it would have been idling high-- the event does not sound to him like IAC.
I know pretty much all I can do is see how it runs in the morning (its not cold-- central TX), but I am awful curious what can make a truck shake like that for a minute after start-up.
Before shaking had died down completely I put it in drive and crept forward 30 or 40 feet and it was still shakin'.
Ideas?
Started it this AM and "rough idle" does not describe it-- like unbalanced washing machine on spin cycle. Whole truck was loping. After 1 min or so it went away and behaved fine all day. No weird noises from engine, no check engine light, it was not dying/struggling to run at the time, RPMs seemed normal. I spoke to a mechanic who said these trucks can run rough when IAC is going out, but that it would have been idling high-- the event does not sound to him like IAC.
I know pretty much all I can do is see how it runs in the morning (its not cold-- central TX), but I am awful curious what can make a truck shake like that for a minute after start-up.
Before shaking had died down completely I put it in drive and crept forward 30 or 40 feet and it was still shakin'.
Ideas?
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
So your not in a cold climate ? You know, they also do that when the EVR is supplying to much vacuum to the EGR valve.
No DTC's no help.
For that matter it could be fuel related. The FP could be going south.
Hard to say, you have to look for hints. Without a DTC to provide one, - could be any of those mentioned.
If there's nothing to go on, you either have to go thru everything or take it in for diagnostics.
Even it you don't have a CEL, - scan it anyway. There could be something in memory as long as you haven't disconnected the battery lately. If you have, you've erased all clues.
No DTC's no help.
For that matter it could be fuel related. The FP could be going south.
Hard to say, you have to look for hints. Without a DTC to provide one, - could be any of those mentioned.
If there's nothing to go on, you either have to go thru everything or take it in for diagnostics.
Even it you don't have a CEL, - scan it anyway. There could be something in memory as long as you haven't disconnected the battery lately. If you have, you've erased all clues.
