Nichole Marie

I have a 2001 F150 4x4 XLT with ~ 154,000 miles. About 2 months ago I started experiencing a rough idle when I was stopped (nothing noticeable while driving). When I say rough idle I mean it seemed to shake/shudder sporadically. I put a fuel system cleaner in the tank to see if that would help but it didn't and then one morning I saw the RPMs rev up and down and it almost seemed like the truck was going to stall.

Brought it into the local garage and here is what they said:

1. The Intake Manifold Gasket is leaking on the left side causing the fuel trim to be at +19 because the vehicle is breathing more air than supposed to through the leak on the manifold and causes the left side fuel trim to add more fuel to compensate for excessive air.

2. The spark plugs have worn out electrodes and to add to this issue the valve cover gasket is leaking oil into the spark plug hole contaminating the spark plug boots which insulate the spark from the coil to the plug. This causes the rubber boot to swell and not keep the spark within the rubber boot causing arching against the engine block.

The following repairs are recommended:
1. Replace Intake Manifold Gasket
2. Install new Valve Cover Gasket
3. Install new Spark Plug and Coil Boots
4. Fuel Filter suggested on preventive maintenance

So...I took it to another shop for a second opinion. They said they agreed with the suggested repairs and quoted me a few hundred bucks lower than the other place. I had all the repairs done, got the truck back and it is still shaking/shuddering when I am stopped. I brought it back in for them to look at while I was on vacation and they said it seemed to be running fine. I've been driving it for almost 2 weeks now and I know something still isn't right. It's shaking/shuddering too much which was not normal prior to these issues. I'm going to bring it back in on Monday and take a drive with the mechanic to point out exactly what I am feeling.

Any suggestions? Do you think the new Intake Manifold Gasket didn't seal up completely? Could there be a vaccuum leak? Some other problem entirely? I'm not sure if it's worth it to keep putting money into this truck. Help!

Almighty

I would think either a Vacuum leak or IAC valve.

Dholla

Mine does the same thing after I replaced the iac, spark plugs, got a new fuel filter, cleaned the maf, cleaned the throttle body. Ive been told the coils could be bad or a vacuum leak... I just stopped caring for now haha but it def shudders and the rpms still drop as well

plingpling

Mine does the same thing. 4 shops, including the dealership...no one can figure it out. Replaced IAC, EGR, fuel filter,plugs,coils, BG fuel system cleaning, tested fuel pressure, PCV valve........ummmmm...... Any body have a thought on this???

bustamoveben

for:Nichole Marie
they make a "fix" intake gasket seal from fel pro just for sealing problem areas... you can get both a regular MS928361 and the special thicker one with permatex built in MS98008T3 .... maybe find out which on he put in.
ask your mechanic if his scanner does mode $06 or if he knows about it for trouble shooting LIGHT missfires in fords.... if not goto another mechanic.

This kindof sounds like the couple weeks of hell i just went thru... first i will describe the problem with my truck.

i went for a drive after a heater core job, I was doing about 110km or 70mph roughly on the highway then all of sudden it had a hiccup, just a little shutter here and there nothing major... well as you guys all know it has to missfire something like 17000 times before it sets a check engine light. so i was told to keep driving it until it sets(i did order a mode 6 scanner so i can count the missfires per cyl, but its on back order unfortunately).it slowly got worse over a couple of weeks, to one rainy night it was so bad it idled rough shook the truck... it was like driving over train track or a gravel road wash board constantly.

what I found while trying to track this down.. so finally i got a P0302 which is missfire cyl 2. thank god it was easy to get too... so 9-10 times its a COP going on these 5.4 i hear. so to confirm this i switched COP with cyl 1. still missfire on cyl2... maybe it was an injector... switched it still miss fire on cyl 2.....

**now mind you to add to this i now had a BLINKING engine light.... i checked codes after and i had a P0302 and a P0171(what ever the bank 1 lean code is), So i did some reading when the check engine blinks, its REALLY not good.. its harming your cats cuz they can't handle the unburnt fuel your sending to them from the miss fire... so the computer will cut the fuel to the injector to save the cats...... then its like hey the engine is running lean no fuel from a cylinder.... its like it has different departments in there that don't talk to each other ANYWAYS...

so how i fixed my problem was there was oil in the bottom of cyl number 2..... how it got there still a mystery(will keep an eye on it) valve cover gaskets look good why i don't think its the valve cover gaskets is for one its at the top... usually oil pools at the bottom, its not really under pressure if anything its under vacuum so not release oil fumes into the air...... so i cleaned it up really well brake clean then a solid 5 min with compressed air... i also cleaned around the hole well to watch for where the oil is coming from.... some say its from spilling oil then it slowly seeps into that plug... what i did which i do not know will work or not was got some 500F proof grease and put it around the top little seal there.

sorry for running on here.... what i also found with the coils on these trucks is they need to be REALLY REALLY..... one more time, REALLY clean...i took my time pulled the cyl 2 cop apart(which was cop cyl1) let the spring soak in brake clean... cleaned corrosion on the coil end... cleaned boot... pipe cleaner used on inside of the spring. and it runs like a DREAM... also to note that when i did my spark plugs the first time a while back i had a minor missfire in cyl 5.... same thing i just cleaned the tip of the coil wire really well and good to go again.

also check from cracks that you can see thru too... mine have minor cracking at the bottom but nothing deep yet..

Czuber

Check the 90 degree rubber boot right behind your oil cap. It's the other end of IAC valve mine was really loose causing similar issues.

Pity7700

like these guys stated. check that 90 degree boot and clean or replace your IAC. also check all of the other rubber hoses. i just had a rubber hose on my truck break that came from the intake plenum and went to bank #1. replaced it and cleaned my IAC, problem solved. you might try seafoaming as well.

simple way to find a leaking hose, just prop the hood and start the truck. start shaking all your vacuum lines. thats how i found mine. i had 4 different codes. misfire cylinder 4, cylinder 3, too lean bank #1 and misfire detected at start up.

my buddy has a 97 f150 that had a horrible idle, turned out to be that 90 degree elbow, he chased the problem for a weeks or so.

Frank_Ford

The fuel filter and PCV replace, is a good idea and it is very low cost and most likely should be done anyway. Oil leaking into your spark plug sockets also caused the problems as described but I would first try snugging down the valve cover and cleaning out the COP and spark plug sockets before you tackle the bigger expense of changing the gasket, replacing plugs, coils, IAC and EGR. You can remove the EGR and clean it so you don't necessarily need to buy a new one.

If you can drive the truck, first go to autozone and run the codes as this will give you more information. If you are getting misfire messages, this will tell you to focus on the plug sockets and leaking oil.

Nichole Marie

So, after all that...they came back and told me about a Technical Service Bulletin that's out there for Fords and basically said that's why it's idling rough. It wasn't idling rough before all of these issues popped up so I still think it's BS but what can I do?

Then, in April I one of the spark plugs blew. I took it to a new shop close to work and they said they would only have used a certain type of spark plug that apparently the other shop didn't and, to fix everything correctly, it would be about $800. So I called the old shop asking if they would cover repairs and they ended up towing my truck to their shop. Had to replace the spark plug and coil. And, guess what? They again pointed me to the internets explaining that the Ford 5.4L engines have a "known issue" with spark plugs blowing out. Again, this had never before happened with this truck, which now has about 160K miles on it. So I think it's BS. They probably didn't put the spark plugs in right when they replaced in January but, what can I do? Just hoping it will hold on a little longer.

Tackle

Nichole,

Sorry this has been dragging on so long for you.

Yes, the spark plugs blowing out does happen and is a known flaw. The best preventative measure is to change the spark plugs yourself, or find a mechanic that will tighten them past what Ford recommends. (28ft pounds instead of 13 foot pounds). It can happen at any time or even not at all.

As you've found out, fixing a blown out plug is expensive.

As for the Service Bulletin stating a reason for it to have a rough idle, I'm curious as to what they showed you. Do you have any other details on it?

As far as I can tell from your posts, the rough idle is not causing you any issues except an annoyance. I too have a shake at idle that I cannot find a reasoning for. I live with it and do not consider it a reason to get rid of the truck.