Hi I would like some advise or at least some comfort. 
My wife and I have a 2000 Ford Explorer XLT with 170,000 miles. It’s the 4.0l 6 cyclinder and it’s been a great car. I just took it in, to a new shop for us, to have an oil change and a tune-up. Well now it has a terrible hesitation/jerking/misfire-type thing that is does when you try to accelerate from 45-60mph. It drivers smooth from a stop til about 40. Then you have to really baby the gas or it starts jerking.
The shop who did the tune up looked at it for us and told us it was probably a valve problem. We drove it over a weekend, and it was so bad we had to take it back in. The Check Engine light wasn’t on before the tune-up but it came on after. We gave it back to the shop and they tested it more and just gave us their final word. They think it has a misfiring cylinder due to a stuck valve. They tried to fix it by doing a “Top End cleaner” or something but couldn’t fix it. Their only advice is to take the valve to a valve shop which will probably run $1800-2000.
Obviously with a truck of this vintage, we are not interested in putting that much money into it. But since I don’t have a real relationship with this auto shop, I don’t 100% trust their assessment. Does anyone here have any advise as to what may be causing the misfires?
Also, is a valve job our only option? Is there something we can do that will run under $500 and possibly give us another year or so out of the truck?
Our next plan of action is to pick it up from the shop, and call our local Ford dealer and ask their advice and see what it will cost to have them give us a second opinion on what’s going on.
We JUST bought a new car last week to replace an older small pickup truck so we’d love it if we could get another year or so out of our Explorer. But we know we can’t with it having this bad jerking at 45mph.
Thanks for your help and input!
Im not going to be much help for you but im thinking this shop did something wrong on the tune up. Dont give up on her yet. Does the engine make any noises (when it runs smooth)that it didnt make before you took it in?
Not really. It doesn’t idle super smooth but it has kind of been that way for a while.
If you just drive it around town on surface roads, going under 45 it drives pretty well. But going 65 on the highway and trying to go up a hill will make it jerk.
Yea I can’t help but suspect the shop a little. We told them that it wasn’t doing the skipping/jerking thing before we took it in. The manager says he felt it skipping when he moved it in the parking lot so he’s trying to say he thinks it was already like that.
I’d love for them to fix it but they have now looked at it for a total of 3 full days and have said they’ve tried a bunch of tests like fuel line, compression and they think it need valve work.
I don’t know if asking the Ford dealer here will be any better but I’m hoping they can diagnose it cheaply and maybe it’s a something common to an Explorer that isn’t too expensive to fix.
Find out what the actual error codes were that showed along with the check engine light. These are in the format: P1234. The shop should be able to tell you or many auto parts stores read them for free.
How long was it since the “tune up?” Specify - exactly - what was involved in the tune up. (“Tune up” doesn’t have a specific meaning.) What did the shop do when your brought it back in?
It would be very odd (though possible) for this to be a coincidence. Though “tune up” is vague these days it almost always involves new spark plugs. My first guess would be that a) the wrong type of spark plugs were installed; b) the plugs are fine but weren’t gapped properly (if applicable) and/or c) the spark plug wires were damaged while removing & replacing on the plugs, or if new, are defective.
Perhaps you need to drop by a whole different shop and get another opinion. The valve thing sounds pretty outlandish to me.
Never go to a new place with a good running car and tell them to give you a tune up. Cars haven’t needed tuneups since they got rid of points and distributors.
Try to find a recommendation from friends or Car Talks mechanics files for a local independent garage. Right now you don’t know what the first garage did wrong, if anything, but you need to find out what is wrong with your car.
After it is fixed, just do the maintenance items from your owners manual and if the car starts acting badly, just ask them to find out whats wrong. If they tell you that they will do a tuneup first - find another shop.
Just out of curiosity…i was told if you replace the plugs ALWAYS replace the wires…???
Im with take it to a different shop
There’s no real answer to that. Standard plug wires are fairly inexpensive so not a large investment. But wires of decent quality will often outlast several sets of plugs depending on the change interval for the plugs. So no - its not necessary to replace wires every time you replace plugs. A careful check of the wires is always in order, however.
You may be in luck. I gave some advice yesterday that included a possible bad, burnt or bent valve and the problem seems to have been solved by pouring Seafoam into the gas tank. There may have been a fuel injector that was clogged until it freed itself in three minutes of driving after Seafoam was “installed”.
Your Explorer is a goner now but there’s always later to consider. The good news is that if it is a goner, you are free to experiment on it.
This kind of thing is not guesswork and it’s unlikely the problem is due to a stuck valve. If that were the case you should hear a valve lash adjuster rattling away.
Often what will happen is that someone will disconnect (yank in many cases) the plug wires or COPs as the case may be when changing the spark plugs. This can damage the wires or COPS.
You refer to compression and a stuck valve. Does this mean they checked the compression on all cylinders? If so, they should have provided you with readings on all of those cylinders.
There’s a number of things that could be causing this problem but without knowing compression readings, any codes that may be present, etc. it’s very difficult to make much of a guess. Odds are this problem is not nearly as serious as portrayed.
Thanks for all the tips and comments guys! I’m going to go and pick it up from the shop this morning and I’ll ask all the questions you guys put in. I’m ready to give up on this current shop though.
Would you all recommend a independent shop over the Ford dealer?
Just out of curiosity…i was told if you replace the plugs ALWAYS replace the wires…???
Who ever told you that is WRONG…If you keep plug wires clean they can last the life of t he vehicle…I’ve kept OEM plugs on vehicles well past 250k miles. All I ever did was replace the plugs…and the vehicles ran PERFECTLY. The trick is keeping the clean…About twice a year you should wipe them down with a damp cloth. This will keep them lasting for-ever.
I wonder if the shop that did the “tune up” knocked a vacuum hose off. This culd casue the symptoms you describe. My dad had this happen some years back. The car was a Buick and after it came back from a tune up, it ran worse than before. The service department at the dealer retarded the timing and “adjusted” the carburetor. It still didn’t run much better, I took a look at it and found a vacuum hose off to damper that brought hot air in off the manifold when the car was cold. With the vacuum hose disconnected, it brought in hot air all the time. After reconnecting the hose, the car ran much better, but the timing was retarded to far. My dad took the car back and the dealer reset the timing and adjusted the carburetor, but tried to charge him. I intervened and made them eliminate the charge. Needless to say, this Buick dealer didn’t last very long.
Just a 2nd opinion and go from there. You have nothing to loose. I would not mention any of the diagnosis at this point.
I have the car back now and have some more info, though not a whole lot.
The shop told me the codes are P0300 and P0302 and it’s misfiring on cylinder #2. They performed Top End cleaner for valves twice and could get it unstuck (and CEL off) while it was in the shop but once they took the car on the highway, the check engine light would come back on when they drove over 45 mph. They said that exhaust is being sucked in from the bad valve in cylinder 2. They couldn’t do a leakdown test because it requires a special tool that they don’t have. I’m not sure what a leakdown test is though.
They told me that they checked the connection at the coil and swapped the spark plug wires and the problem stayed with cylinder #2.
We talked to our local Ford dealer and they won’t be able to look at it for 2 weeks.
There is a shop near us that a friend of mine recommended called Mid-Tenn Ford that is supposed to be good with Fords. We talked to them and they said we can bring it by Monday. Their shop rate is $90 per hour and they said they’d charge for the diagnosis. We don’t mind paying but I don’t know how long it should take. Anyone have a guess? Do you think they should be able to diagnose it in under 2 hours?
Is it common for shops to put the cost of diagnosis towards the repair? Or is it more normal to just pay for both separate. Thankfully the original shop did not charge us for their tests so right now we have only paid for the $180 tune-up, which I believe was just new spark plugs)
I’m starting to suspect maybe a fuel pressure problem. The shop said they though it was fuel related first but that it checked out, but somehow I doubt that they drove it over 40mph with a pressure gauge attached. These are the days where I wish I could work on cars. I’ve been reading about other Explorer owners who had fuel pressure problems related to either a bad fuel pump or a dirty gas tank that has clogged the fuel line.
A bad valve will cause problems through the entire RPM rang and be noticeable at idle. A clogged fuel injector will give issues at higher RPM due to inability to keep up with increased fuel requests. This may translate to a lean mis-fire, and the other fuel injectors may squirt more fuel to compensate, preventing a lean fuel code from popping up.
This engine uses a distributor based ignition system. I wonder if they crossed up a couple of the sparkplug wires.
If you can stop by a psrt store and pick up a Haynes manual you can check this yourself. Teh manual will give you the correct order.
“The manager says he felt it skipping when he moved it in the parking lot …”
If it only acts that way for you above 45 MPH, why did it do the same dance for him at 10 MPH? Am I missing something, or is this a lame excuse from the garage?
I would suspect a fuel pressure problem myself. It might be worth the cost of the gauge to test it yourself.
That was some money saving info. Thanks