help new heads now engine runs like crap

[393mach1]

i'll try to sum this up so you don't have to read a book.

2000 explorer 4.0 OHV 5r55e automatic 4x4 120K

when i bought the explorer, it had antifreeze in the oil, so i pulled the heads and found one had a crack, so i ordered a set of rebuilt heads and installed them according to the ford electronic manual. everything went together smoothly, so i expected no problems, but when i started it up, it was missing really bad, especially when it is in drive or reverse. when driving, it has very little power, and when i floor it and the engine gets reved up, it makes a poof/pop sound every once in a while. everything has good spark, and before the teardown, the engine ran really well, so i think everything i reused is in good shape. it feels like the timing is really off, but i did not touch anything that would have affected the timing. the only thing i can think of is if a pushrod came off and an intake or exhaust valve is not opening. is that even a possibility? any other ideas?

 

[reserved50]

compression test then check the codes

 

[Tbars4]

also warped heads that were not ground or intake manifold leakage?

 

[JDraper]

Check all your valvetrain components, check the spark plugs and wires to make sure the plugs are tight and the wires are going to the right plugs, and make sure you have all the sensors plugged in.

Are you seeing a Check Engine light?

BTW, welcome to the site!! I'm only about 25 miles down the road from you.

 

[393mach1]

thanks for the quick replies

first of all, it has not thrown the check engine light. i had it running for only about 5 minutes total because i did not screw anything up.

the heads were milled, so i am sure they were fine. the intake could be leaking, but i doubt it because i used felpro gaskets, and i sprayed the gaskets with aerosol gasket maker to ensure a good seal.

i have checked the plugs and wires, they are all fine, and the wires are all in the right order. i have also checked all the sensors and everything seems to be plugged in to the right spots. checking the valvetrain seems to be the next step, i just don't really feel like ripping everything back apart, so i'm trying to make sure it's nothing else first. any other ideas?

 

[Bigg_billy]

Sounds like the valves aren't adjusted right to me.........

 

[393mach1]

Sounds like the valves aren't adjusted right to me.........

how do i adjust the valves? i was under the impression that the lifters were hydraulic making them self-adjusting???

 

[dynamite196]

did you use new sparkplugs?

 

[393mach1]

yep, new plugs

i just pulled the driver side valve cover and everything looks ok. i had a friend crank the engine over and everything seems to be working properly.

if it was just one cylinder missing, the car should still have decent power, but it definitely feels like it is just more than just one cylinder missing. it feels like the timing is off for all cylinders, but i did not touch anything that would have affected the timing.

 

[ezrider440]

i will admit i don't know too much about the ford 4.0L but when you took the head off did you set the first cylinder at top dead center? one cylinder misfire will throw a check light, also you'd not lose too much power, more than one cylinder misfire would cause the motor to rock back and forth, my first check before starting over will be to take the valve covers off just to make sure all your rockers are turning. second let it run for a bit, and look at the condition of each spark plug from each cylinder, a wet plug would mean your valves aren't closing tight a overly dry plug would say that your intake isn't opening soon or long enough, next i would check compression, although a warped head would be noticable and the gasket would close the gap most of time, check to see the condition of the gasket when the heads are off, otherwise it could be a bent valve you were stuck with form the rebuilder, easy way to check, is to close the valve, pour alchol or kerosene into the chamber and measure it's level.

Good luck

 

[reserved50]

at this rate I think the entire engine will be torn down before compression is checked

 

[393mach1]

i will admit i don't know too much about the ford 4.0L but when you took the head off did you set the first cylinder at top dead center? one cylinder misfire will throw a check light, also you'd not lose too much power, more than one cylinder misfire would cause the motor to rock back and forth, my first check before starting over will be to take the valve covers off just to make sure all your rockers are turning. second let it run for a bit, and look at the condition of each spark plug from each cylinder, a wet plug would mean your valves aren't closing tight a overly dry plug would say that your intake isn't opening soon or long enough, next i would check compression, although a warped head would be noticable and the gasket would close the gap most of time, check to see the condition of the gasket when the heads are off, otherwise it could be a bent valve you were stuck with form the rebuilder, easy way to check, is to close the valve, pour alchol or kerosene into the chamber and measure it's level.

Good luck

i didn't bother setting #1 to TDC because i did not touch anything that had to do with the timing. i'm a little confused about why the check endine light has not turned on, there has certainly been more than one misfire. the motor does shake pretty bad when it has any strain on it (sitting in reverse or drive), but in neutral/park it does not shake too bad, but you can see a little more than normal. also, if you rev it up, you can feel it missing pretty bad. i pulled one valve cover today, and everything looks like it is working properly. i will check the spark plugs as you ddescribed once i throw it back togather.

unfortunately, i do not have a compression tester, but i did pull the plugs and crank the engine and i was getting a good poof of air from each hole.

as far as the heads being warped, i doubt it, they were just milled. i really don't want to pull the heads back off to check the valves, but i guess if it comes to that i may have too.

 

[gto78]

I havent seen this mentioned yet but, did you double check your ignition leads to the correct cylinders? Possibly it's got one or two leads on the wrong cylinders. One other suggestion, check all the spark plugs to make sure the electrodes didnt get bumped or a blob of grease on one of them. My third suggestion is to make sure there isn't some vacuum hose thats unhooked, you know listen for some loud hissing noises etc.

 

[Bigg_billy]

How did you go about adjusting the valves after you torqued the heads back on? As I said before if you haven't touched anything else, it sounds like the valves are adjusted too tight and are not closing properly. As mentioned a compression check will identify this.

Bill

 

[393mach1]

I havent seen this mentioned yet but, did you double check your ignition leads to the correct cylinders? Possibly it's got one or two leads on the wrong cylinders. One other suggestion, check all the spark plugs to make sure the electrodes didnt get bumped or a blob of grease on one of them. My third suggestion is to make sure there isn't some vacuum hose thats unhooked, you know listen for some loud hissing noises etc.

i rechecked the plug wires and i thought they were correct, however, i disconnected all three wires on the drivers side from the coil and the engine actually ran a lot smoother only running in the three passenger side cylinders. i hooked the wires up so that the number printed on the coil pack went to its corresponding cylinder number. i looked at this site for the cylinder numbers:

http://www.therangerstation.com/tech_library/FiringOrder.html

i must be missing something here, did i do this correctly?

 

[Bigg_billy]

How did you go about adjusting the valves after you torqued the heads back on? As I said before if you haven't touched anything else, it sounds like the valves are adjusted too tight and are not closing properly.

Bill

 

[393mach1]

How did you go about adjusting the valves after you torqued the heads back on? As I said before if you haven't touched anything else, it sounds like the valves are adjusted too tight and are not closing properly.

Bill

i did not adjust the valves. i was under the impression that the lifters were hydraulic making them self adjusting. when i had the valve cover off, i tried to spin the pushrods by hand to make sure there was no pressure on them. the ones that were not in the process of opening or closing a valve could be spun by hand, indicating that there was little or no pressure on them, which was far as i can tell, means that the valves should be fully seated.

do the valves need top be adjusted? what is the proper way to do that?

 

[393mach1]

since the engine runs smoothly on the three passenger side cylinders alone, i am assuming everything on that side is working properly. i plugged the three wires back in for the drivers side cylinders and started the engine. it was obviously still missing, so i started to unplug the drivers side plug wires one at a time. when i removed the #4 and #5 wires, there was a noticeable change in the way the engine ran, but when i unplugged the #6, the was only a minor change. after doing this a couple times, the engine started to run smoothly and seemed to stop missing, so i took it for a drive. it is definitely better than it was, but when i get on it, it starts to miss pretty bad. now it seems like a bad coil, and if it is, i'm sorry i wasted everyones time, but i don't understand why it ran so much worse before. initially, it felt like it was running on 2 cylinders. now, when it misses, it still feels worse than just one cylinder, but at least it doesn't feel like its gonna blow up. how do i test the coil to see if that is the problem?

 

[dynamite196]

I think you still have the wrong firing order, I'm not sure where you found that site but i think that's where your problem is.

This is the correct firing order (from the haynes manual), I used it when i did an engine swap in my ex:

 

[JDraper]

I'd tend to agree with the possibility of the firing order being wrong. It's an easy mistake to make since the one side follows the coil order, and the other side swaps things around.