tyler2569

Hello, So my truck has had this higher than normal idle for awhile now and its bugging me. It idles at 1000-12000 all the time.. regardless of operating temperature. It starts fine in cold weather, hot weather.. runs great, but hold that high idle. I know the truck should be fully warm after a 45 minutes drive, Once the truck is warm if i turn the truck off and than restart it, the idle drops to the normal 750-800..and maybe if im lucky once i a while sitting at a stop light it will drop to normal rpms.

At 135,000 miles truck overheated, had bad head gasket.. I had the whole top end replaced and rebuilt, never changed temp sending unit, and i don't believe i changed thermostat. I cleaned MAF, throttle body, IAC.. new 02 sensor.. Ive recently noticed now that when i drive the truck hard and high rpms the temp drops.. so im thinking i have a thermostat issue, which i plan on replacing soon and a new temp sending unit. Does anyone think these are my main issues to the high idle or maybe something else? I've triple checked all vac lines, new fuel filter, I am running a pair of doug thorley headers with a flowmaster, but i doubt thats a contributing factor to the idle.. Like i said though, trucks runs great.. But i did notice what i believe to be a larger than normal amount of carbon on my spark plugs.. Maybe truck's reading not warmed up so its running rich which could be the higher idle?.. pointing me back to the temp unit and thermostat?

Your contributions are appreciated

Thanks

tyler2569

Ok, need a little help now.. I managed to snap off the coolant temp sensor in the housing. I've been searching for a replacement housing with no luck.. Anyone know where I can find one? 4cyl 2.7

BLRobertson

You might check your throttle body for side play. Open the throttle wide open and pull the shaft from side to side where the cable hooks into. Mine runs the same way, after a complete overhaul and everything new and clean I couldn't get a stable idle. Try warming up the engine, I'm guessing it will be as you describe a high idle and push on the throttle shaft, mine would then drop down to normal. Just a thought kinda sounded like how mine is acting.

Swede

The "SEARCH' feature works wonders! https://www.yotatech.com/forums/f2/m...-cured-258318/

tyler2569

I figured it out.. It was the thermostat and coolant temp sensor which solved my problem, Thanks BLRobertson for the suggestion, i did check that as well but my TB has no play.. but its good to check on that as i never thought of it as a possibility. Now the truck warms up a bit quicker, does not drop temp when i drive it hard, and the idle rpms drop to a normal 750-800 after warm up. Another thing it use to do was when ever i put in the clutch, or came to a stop light, the rpm was trying to drop to a normal 750rpm but the tach would bounce off 750 and quickly rise to 1000.. all the time.. i figured that was not a normal function to have the tach gauge bounce up always. now it does not do that either.

And yes Swede i did use the search function.. nothing specific to my description, just more of the same old.. Check vac lines, clean IAC, check TPS, clean TB.. ect, which i've done all of.

Anyways its solved finally and hopefully it helps out a few others as well... Just be careful wrenching in that new coolant sensor, don't over tighten as i did... or it will snap, luckely the local mechanic was able to get it out for me.. as i could not find a replacement coolant sensor housing to save my live.

Swede

Glad to hear you got it figured out.