Originally Posted by drof2001
2001 Taurus 3.0L 4V 6 CYL Duratec with 48,000 miles. Has been a good car so far, other than usual repairs. A couple of months ago, following problems developed:
1. started to idle rough in morning for a few minutes; 2. between 35 and 40 mi. with slow acceleration, started to hesitate, almost like a misfire in one of the cylinders; and 3. around 35-37 mi. if you kicked the accelerator just a little harder, there was a mechanical “thunk” (almost like a lose motor mount) and car would shudder a little (did not shift to higher gear). And the check engine light was on.
Thinking it could possibly be a tranny issue, took it to a (well known) transmission place. They did all kind of diagnostics, but told me it was definitely not the transmission, motor mounts were fine, but needed a complete tune up. This is my daughter’s car, so wanting to make sure everything possible was taken care of, I told them to do the works: changed transmission fluid, new filters, etc. in other words, serviced the tranny (and no metal parts detected or attached to the magnet), new plugs, new wires, new fuel filter, cleaned injectors, plus whatever. Only cost about $700!!!
After a few days, all the same problems were still there. The transmission guys gave my daughter the usual BS – runs rough because the fuel injector cleaning dislodged particles that are still in the system and to get some higher grade gas and run through couple of refills. Well, that did no good, took the car back, they fiddled with it, still same problems. They said to bring it back (and they were willing to try and fix it, but…) they had to let it sit overnight so they could see how it started when cold. Well, after another visit, they decided that it was the EGR valve, said codes showed misfire on cylinder 3 (they replaced the plug again and checked the wire) and told me the EGR valve is “connected” with cylinder 3, so that could be the problem. They did not charge me for the labor, but of course, I was out $90 for the valve. Yep, the same problem persists. At this point, I’m not sure the transmission guys know what they are doing and trial and error just does not cut it. I assume they checked the coil, PCV valve, etc. Could it be a “bad” injector and what does that mean? Guess I could go to a dealer and start from scratch. But would really appreciate any comments or suggestions on this. I need to solve this within a few days. Thanks for any help.
I had the exact same problem on my car (2001 Taurus SEL 3.0L Duratec). But, the spark plugs and wires fixed it. I had the problem since I got the car. The former owners had brought thew car to a disreputable shop, and they said the car never ran right since. I thought it was a trans. problem, so I changed the fluid because it wasn't too clean. No change. So I just let it go for a little bit. 6 months later it was getting worse. Intermitently on hard acceleration I'd get the banging. So one day, I just matted the gas hard. The banging or popping got so worse, the Check Engine light was flashing. Bingo!!! It was a misfire. So that week, I pulled the three front plugs to check them. To make a long story short, (TOO LATE!!!) all three front plugs were worn out. The plugs had a 0.080" gap, with a spec new of around 0.052". So I got a fresh set of Motorcraft plugs (from AutoZone) replaced the front set. When I got to the back set, they were not worn out!!! This is where the disreputable shop maybe comes in. They threw in 3 bad plugs to get the former owners to pay more money for stuff they didn't need. So I put the new ones in the back too, and here's where things improve but not completely. The plug wires had very light carbon tracking, so I cleaned them and put them back in. BIG MISTAKE. The original issue was gone, but I had a intermintent skip sitting at a stoplight. So a week later, I threw in a Motorcraft set of plug wires, all gone. The injectors for the back three cylinders (Where #3 is) are under the upper intake. Before you go ripping the Intake off, I have a suggestion. Just a week ago, someone had a misfire issue with an 02 Taurus 3.0L Duratec. What they eventually found was the coil pack had a crack on it. After replacing it, their problem was solved. Also, my uncle has had a Misfire on his 1999 Sable LS Premium 3.0L Duratec. He had it looked at, and it too had a cracked coil pack. Get a spray bottle, fill it with water, then while the enigne is running, spary the coil pack. If the engine gets really rough, and or you see a electrical light show on the coil pack, you have a bad coil. Try this first and see what you get.