Ok it''''s kind of long but please read and help if you can. 2001 sable with e85 3.0, car has a slight miss at idle, took to a shop and paid for diagnostics, they said it needed a tune up. So we did plugs and wires, drove home and was fine. next day missed again. took back and they charged me for diagnostics. said it needed a belt, belt tensioner,front brakes and a Coil pack. So i did ALL of that. seemed to be good, next day missing again. took back and they tried to charge me diagnostics,again so i kind of lost my cool and was told to leave the shop. went home and they had put the cheapest plugs possible in, so i replaced with iridiums, the car ran absolutely perfect for 3-4 days and now is back to normal. runs very bad on 87octane,with a loud ping/knock. its throwing no codes, the trannsmission checked out good at 2 different shops. the miss seems most noticeable when in Overdrive, and very low RPMs . Please i cannot afford to keep replacing random parts,if you have any idea please help. ive also put a new air intake and checked for vacuum leaks,aswell as new fuel filter and the seafoam direct induction cleaning twice

Edited by: AndrewMack

 

I think I''''d be calling the Better Business Bureau on this shop..


I''''m just going to take a stab here, but it almost sounds like your engine is running lean..Especially with the pinging and such.. Sounds like you have covered alot of the diagnostic on that, especially the vac leaks part.... To truely verify a lean condition you would need access to a scan tool that will allow you to see all the sensor data.. How many miles does your car have?? I''''m pretty sure the e85 3.0 isthe overhead valve 3.0 and not the dual overhead cam or "Duratec" engine.. Am I correct?


Some of the things that could cause it to run lean that that haven;t been checked coudl be low fuel pressure (a bad regulator or pump since you covered the filter)You could even have plugged or partially plugged injector/s


Oxygen senors can cause some issue as well.. Generally failed o2 sensors cause a slight rich condition and poor fuel economy but once in a while they can do strange things..


When you replaced the air intake had you looked at the EGR valve at all?? It could be sticking open a tad, possibly dirty..


THe Mass air flow sensor could be contaminated and cause a bad reading.. The "hot wire" in these will get coated with crud causing the computer to see less air going into the engine than what really is.. Since the computer sees less air, it puts less fuel in..This problem may or may not set a check engine light.. A faulty MAF can cause both rough running, and pinging


Alot of people have had good results with cleaning these with brake cleaner, or there is a regular MAF cleaner on the market..I think I would start withthat and see what happens.. Sometimes cleaning the MAF won;tcompletely (or at all)fix it but it''''scheapto try... And if it improves the situation that''ll give you some direction.


Something else, you had mentioned they used cheap spark plugs, what about the plug wires?? Do they seem to be of decent quality?? An easy check of those would be to have the car warmed up and take a look under the hood in the dark and see if you can see any arcing.. especially when snapping the throttle open...


Edited by: maxfax3

 

a shop cleaned the MAF,same thing, it is just the regular OHV 3.0, the plug wires are the regular set from autozone, now that im back to running 93octane the ping has stopped but its still very boggy sounding when you first give it gas and you can kind of here a noise when you lift the hood, the dealership said it was injector chatter........

 

THe thing that really makes me think it''s a MAF problem (aside that it sounds like it is running lean and you''ve covered alot of conditions that cause lean running) is the fact that the car would run okay for a day after it had been at the shop.. Chances are they cleared the fuel trimand suchdoing the diag.. Did this problem come on all at once or has it been gradually getting worse??


Have any friends with the same car that would let you borrow their MAF??? Actually the MAF is generally the same on all Ford/Merc products rougly from 1999 - 2003, some newer..F-150 to an escort if it plugs in it should work.. There are a few exclusions in there, but they are mostly the more performance oriented vehicles with larger injectors... If you look up a new MAF on Kragen.com for your car there is a link that will list the other vehicles that it fits..


The noise you are hearing, sort of a slight ticking??? The injectors do make some audible noise... If it weren;t for access issues you could try a power balance test with the injectors.. disconnect and connect them one by one with the engine idleing.. See if any one injector changes how it runs less than any other.. (THe one that has the least change is the cylinder with the problem) However I don;t think you can access the back 3 due to the intake...


EGR valve sticking open can cause some of the sypmtoms although the pinging is generally not one of them.. And Fords generaly kick the CEL on if the egr so much as sticks open for a milisecond longer than they think it should...


How many miles does you car have?? Ever run over something on the highway?? Say something that could have stuck and damaged a cat converter??

 

I do run some Highway but i dont think i have hit anything, i think im just going to buy a new MAF but i did find a dealership who only charges 75 for diagnostics and they think they can figure it out.

 

The dealer *should* be able to plug in the scan tool and look at the values for the fuel trim and the MAF if that is for sure the problem.. Let us know how you make out.