Rough Idle / Bad Fuel Economy

[Exproblems]

Hi All,

I'm new to this site, so please bear with me. I have a 2005 Ford Explorer with a 4.0l v6 with approx 84, 200 miles on it. I am currently experiencing a rough idle either while the vehicle is in park or in gear, sitting idling at a red light, but the vehicle has never stalled. The rough idle tends to fluctuate at times, sometimes unoticable after first start up, but gets seemingly worse after the vehicle warms up or when the outside air temp is warmer, say 60 degrees or more. I am also getting poor fuel economy, 10-12mpg depending on city driving or highway driving, it's killing me $$$$ on fuel costs. The CEL has not come on as of yet and no error codes are showing up according to Auto Zone scan. I have already replaced the spark plugs, wires and fuel filter and have even had a fuel injection cleaning done at a Ford dealership. The rough idle is still there, so is the poor fuel economy. I took the vehicle to a repair shop (first time to this place), they claim they did a bunch of tests on the engine components, MAF > (claimed to have installed a temporary new one as a check), EGR, vacuum leaks, Intake Manifold gasket leak test, not the fog test etc., but can't locate the problem. I am not 100% sure this repair shop actually did what they claimed on my vehicle as far as all these tests, so can anyone in here possibly direct to me the source of this rough idle problem I am experiencing? I was told by another member here that I may have an out of balance Harmonic Balancer, but I can’t see a problem with it as of right now, found no dry rot or loose play in it and it appears to be tracking correctly as it spins, no wobble. Any help would be greatly appreciated, thanks!

 

[Exproblems]

UpDate on Rough Idle/ Bad Fuel Economy

Hi all,

This is an update on a rough idle/bad fuel economy problem I had with my 2005 Ford Explorer 4.0l that I posted about approx 2 weeks ago. After taking my truck in to 2 different repair shops to have engine diagnostics done on any component that could cause this sort of problem, they both have concluded that the rough idle is most likely caused by an "out of balance" problem.
The first shop I took it to suspected it may have been an out of balance Harmonic Balancer issue, but they never checked it, just mentioned it to me. They also found no problems in the engine components. So I took my vehicle to a different repair shop and had them specifically check the Harmonic Balancer out as well as the engine components, and he found nothing wrong in my engine or Harmonic balancer. No vaccum leaks or loss, fuel pressure problems etc. What he did state is that he feels I have an out of balance Torque Converter or Flywheel. This would explain why no "Check Engine Light" has ever come in since I started to feel this rough idle a few months ago. He told me that this out of balance problem in the flywheel or torque converter will not harm my vehicle by driving it. I now have good reason to believe that this out of balance problem was intentionally done to my vehicle due to a problem I had a few months ago with a transmission shop owner that installed a rebuilt transmission in my truck. I believe he tampered with the counter balance weights on either the flywheel or torque converter or left out a bolt or two on my torque converter to throw off the balance and cause this type of problem. He knows I have no way of checking it myself. I'm not sure what I am going to do about it right now (any suggestions out there?), since he denied he could have caused this sort of rough idle issue after I asked him about it right after I picked up my vehicle and started noticing this problem. It's a long story on what happened with the tranny shop owner, but it makes perfect sense to me now that 2 seperate repair shops have ruled out a engine or fuel problem. One good thing happened though, my fuel economy has gone up to 14mpg, from 10-11 mpg. The second repair shop I took it to, took apart my Mass Air Flow Sensor and cleaned it. I stopped back at this repair shop and spoke to the mechanic and told him about my increased fuel economy and I asked him if he cleaned anything on the engine, thats when he said he cleaned the MAFS. I asked him if it was clogged up and he said no, just that he cleaned it up. What ever he did, it worked! I'm getting 3-4 miles per gallon more right now. Hope this info helps anyone with bad fuel economy and no check engine lights coming on.

 

[guilateen]

what kind of spark plugs did u install i heard of people using aftermarket brands and having similar results. some say motorcraft only i believd autolite makes them. other plugs will cause same issues including no cel. also check gapping. wouldn't an offer balance torque converter show defect at speed not just at idle. hope i helped

 

[Exproblems]

>>>>>>>>>>what kind of spark plugs did u install i heard of people using aftermarket brands and having similar results. some say motorcraft only i believd autolite makes them. other plugs will cause same issues including no cel. also check gapping.>>>>>>>>>>>>>>>

I first installed Bosch Platinum Plus 4 spark plugs and a set of Autolite Professional Series wires back in February. At the first repair shop I took my vehicle to after installing these plugs and wires in regards to this rough idle issue I have, he told me that I had the wrong spark plugs installed for my vehicle. He said he only uses an OE brand like Motorcraft or Autolite. He said the Bosch plugs are just not the right type of plug to use with this engine. He went and changed them and installed a single platinum Autolite plug and my gas mileage dropped a little from the Bosch plug. Reving of the engine sounded different too. But since this second repair shop cleaned up my MAF sensor even though it wasn't that dirty, my gas mileage went from 10.2 to 11.6 mpg, to 13.2 to 14.0 mpg, quite a difference. The rough idle I have is not from any plugs, wires, or engine component issues, it's been checked out by 2 different shops, because for the 2 1/2 weeks I drove this vehicle after purchasing it with the orginal plugs and wires in it, there was no shake or rough idle, just a transmission problem. It was only after I picked up my vehicle from the transmission shop that installed a rebuilt tranny, did I start to notice this rough idle problem in my vehicle. The tranny shop owner claims he couldn't have caused this problem, which isn't true, since an out of balance torque converter or flywheel will cause a similar feeling as a rough idle like an issue with a engine component does, but not set off any error codes or check engine lights. The tranny shop was the only place that had access to the torque converter or the flywheel since they removed the original transmission that came with my truck. I didn't want to make any accusations about this tranny shop owner till I had ruled out that it wasn't a engine idle problem, which I now know it isn't. It was a circus event in dealing with this tranny shop owner and the dealership. The two of them do business together on a regular basis.

>>>>>>>>wouldn't an offer balance torque converter show defect at speed not just at idle. hope i helped>>>>>>>>>>>>>>

Not sure what you mean here, but when I rev the engine up in park after the vehicle has been warmed up fully, I can still feel a little shake in the engine area, but you feel it worst at idle, either in park or stopped at a light. You don't really feel it driving down the road or at Highway speeds. Funny thing is, I would expect to feel this shake all the time if it is truly coming from a torque converter or flywheel inbalance problem which I suspect, but there are times when I don't feel it as bad. It's usually more noticeable after the vehicle has fully warmed up or been driven for a while or on a hot day. The shake kind of fluctuates at times from light to rougher, but the RPM's usually stay the same, between 600-800 rpm's at idle.
Thanks for the advice and comments.

 

[04 EDGE]

Those bosch plugs damaged your engine! you need to do a compression test to find out what cylinder(s) is damaged.

 

[Exproblems]

?>>>>>>>>>>>Those bosch plugs damaged your engine! you need to do a compression test >>>>>>>>>>to find out what cylinder(s) is damaged.

04 Edge,

The rough idle or better yet, balance issue, didn't start until I drove out of the transmission shop after they installed the rebuilt tranny. I drove this vehicle for nearly 3 weeks prior to going into the tranny shop and there was no rough shake in this vehicle. I changed my spark plugs to Bosch, after I got the truck back from the tranny shop, the balancing shake was there by then. The vehicle had Motorcraft plugs in it during and after the tranny install. I changed the plugs just to rule out a plug related problem to this new shake. I did plug wires as well and a fuel injection cleaning.
The Bosch plugs didn't damage the engine and the gaps were fine, they were the correct plug for that vehicle in terms of the correct part from the auto parts store. One repair shop guy stated he only uses OE plugs in the vehicles he works on and the other shop said he only uses Bosch or NGK plugs that match OE equivalent or better. I guess it's preference issue with them. As far as a compression issue, I mentioned that to both repair shops to check out and they both ruled that out because a compression loss on this vehicle would set off and error code and check engine light. Have never gotten either so far. Thanks for the suggestion though.