I know this is not a lot to go on, but I would love some input and ideas. No codes, had 1884 and 1170 but they cleared themselves, no tick, running great, but at warm idle, there is a very minor shudder about every 5 seconds, like a little shake. I just fixed my tick, some members think it was because oil wasnt getting somewhere in the engine, sure this could be the cause, any idea how I could trouble shoot this or this or possible fixes / upgrades that could solve this problem? Thank you for your speculation.

 

What are the RPM's doing when it shutters. Do they drop and come back up? Does it happen with the transmission engaged at idle or nuetral at idle or both?

 

No changes to rpm, happens in park and drive, seems to take about 10 seconds of sitting at a light to start, and then it's a cyclical very minor vibration every 10 seconds or so

 

Start with the mileage, when was the last tune up along with plug wires, have you cleaned the t/body and what octane gas are you using?

 

Mike - I have the same issue. 83K, new plugs ~7K ago, premium gas...How do you clean the Throttle Body?

Thanks,
Dave

 

How long ago, and how many miles ago did those codes clear? Some times if I have a bad O2 censor I feel a little roughness in the truck.

 

I am starting to think that the crank sensor needs to be changed at every tune up.

 

Food for thought, I have replaced a torque converter for a similar vibration.

 

Phil, check out the pm I sent you.

 

DiscoRover007: Codes cleared around 40 miles and about 5 trips later, the 1170 as I understand it is a downstream 02 sensor, could that still cause the rough idle?

Mike: Don't know if you recall, I was who called you while I was doing the plugs and wires and you gave me the great advice regarding the ATF flush. You could eat off the throttle body, in fact, every time I pull the intake hose it is clean, seems to never get dirty. Always 93 Octane, seafoam every few tanks.

As aside, what technically qualifies as a "Tune Up"?

I am thinking I am going to do the O2 sensors as they are bound to go bad anyway and not something that doing is going to mess with the fragile equilibrium of the truck
(ie. headgaskets before they mess up). Also the crankshaft position sensor seems to be a part that can leave you high and dry if it goes...