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I just bought a 04 Expedition 5.4 with 122,000. One of the issues that I am having is I have a rough idle while sitting in gear after the motor has come up to temp. The RPM gauge does not bounce up and down. If I shift into neutral or park the idles improves greatly. The check engine light is not on either. Where should I start?
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Check your transmission oil level first. Low transmission level cause hard shifting and noisy idle transmission. Too hight transmission oil cause noisy motor at cold start but not good shifting when the motor is hot. The oil expend and create more pressure.
Then you might have dirty upper cylinder injector that cause a lack in lubrication. Personally I use Lucas upper cylinder lubricant that I had in my gas tank. After that check you air filter is It’s dirty or nor. Dirty one cause shifting problem and a noisy motor all the time and performance problem.
If you still have the problem after that is out of my knowledge.So far I have used a propane tank with a hose to check for vacuum leaks and have been unable to find any. I poured in a bottle of Lucas fuel injector cleaner today. I will update as I complete more of the things in Eric’s videos. I plan to change the PCV, fuel filter, and plugs. Air filter looks new. I filled up my tank and have driven 80 miles and I am sitting on half a tank. I know I am not going to get the best gas mileage with a 5.4 V8 but come on…. :blink:
It is a well known problem, not enough oil pressure to the timing chain tensioner. Usually caused by bad oil pump or physical wear in the engine, or partly plugged oil passages, and sometimes bad tensioner. will probably get a code for the cam sensor eventually. Last customer i had with that problem didn’t like what i said so he took it to another shop and i was right, they are replacing his engine now.
There are other possable reasons but that’s the big one.Not having any motor noise just rough idle. I had lacking oil pressure on my Durango and it ticked on cold start which is why I got rid of it and got the Expedition.
Yup, that’s what they do. It just drops the pressure enough to mess with the variable cam timing used on the 5.4 from 2004 to 2008
sorry to be the bearer of possably bad news, still could be something simple, just saying what i know as common, i have done a bunch of them. If you check it out and it is then DO NOT get a wrecker engine, proper rebuild for sure.
Did you check the idle valve for cleaning. Some time this valve redistrict the amount of oxygen at idle and can shut the engine down. For oil pressure issue, you might need to use normal engine oil instead synthetic, synthetic oil have some time smaller molecules and cause a drop oil pressure. If you have normal oil engine try to use oil whit Lucas stop leak.
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HOW OIL PRESSURE WORK :[/size]
[video]http://www.youtube.com/watch?v=8f2fcbTh5yw[/video]Some interesting theories on this one. I think worth looking into personally. That said I’d also do the power balance test just to be sure the problem wasn’t due to an issue with just one cylinder. If the power balance test doesn’t find a problem cylinder I’d look into the timing chain issue or if it’s an oil pressure issue. You can easily check oil pressure. Even if you bought a tool I don’t think it would set you back more than $30. I’d say it’s worth checking out. Better safe than sorry.
Thanks all for the info. I got an extended warranty on the power train today from ASC. 6 month, 6,000 miles. I am going to take it to my mechanic and let him take a look at it. I am getting terrible gas mileage right now. I filled up last night, drove 60 miles today and it is on 3/4 of a tank. Thanks for all the videos too Eric. I really enjoy watching them.
Here is the update on the Expedition. The molded hose that runs into the heater core has a small leak under pressure and coolant was filling up the spark plug holes. The leak was small enough that no coolant ever hit the ground. The coolant ate the coil pack boots and caused spark issues. My mechanic replaced the hose, 8 coil pack boots and 8 spark plugs and the idle is a lot better. Thanks for the advise on here and I hope that this takes care of it.
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