Is it TC shutter? I'm confused...

[MeeSHO]

As some of you might have read, I was going to get my transmission rebuilt under the assumption that the shake/shudder I have been feeling is the TC. The car shakes when accelerating mildly but steadily at a light in traffic from about 30-50 mph, on hills while trying to maintain a speed of 50-60 and again while on the power at 90-100. I have already done the pan drop and added some Dr. Tranny.
I had a few minutes today, so I took it to an automatic transmission shop today for a diagnosis. I let the tech drive it and it acted as it normally does which I guess was good. However, he said that his first instinct is that it is not the TC. He says that it would be a different shake and if I have been driving it for a month that way, it would have failed by now. He suggested that maybe it is a slight misfire under load. He said not to rule out a bad valve or other problem with the tranny, just the shutter didn't seem to be the TC. He said that I was welcome to leave it there for further investigation at no charge, since we only had taken it out for a short trip. I was unable to do that today, so I figured I would take some time and research a possible bad coil. When I get the opportunity sometime next week I will probably drop it off for a more indepth test if I need to.
I have done a lot of reading on both transmission and coil pack probems and I am not really sure what to think. I still feel it is the transmission as the car idles fine with no backfire. I have not had the codes read, but the SES light has never come on either. So, is it even possible that this would be a bad coil pack? Or is this def. the transmission? Maybe something else entirely... MAF? I was sort of looking forward to having the trans done, but I sure could use the money I would save if I didn't have to do it at this point. Either way something is wrong with my SHO and I just want it to be right again... Please help.

 

[SHO#7]

Sounds like you found an honest shop. That is great. Now you know where they are. I also agree with your description that you may have a coil heading south. The only thing I know to do in a situation like this is go to Ford and have them run a cylinder balance test. They should charge about one hour of labor. Be sure to let them know that, that is all you want done. They have special equipment that will tell what cylinder has a weak coil. Your SES light does not have to be on for them to run this test.

Good Luck.

Mike

 

[whitneyd]

What happens when you floor it? I would think this would put enough strain on your coils to make the bad one miss. Please keep us informed and good luck.

 

[ES96SHO]

I've got to agree with Mike. Though impossible to completly diagnose over the internet, your symptoms don't sound anything like the TC failures that I've experienced. While I'm sure TC failure can manifest itself in different ways, typically the shudder is felt when trying to engage, not across the range of speeds and load that you've mentioned.

Conversely, while never feeling a coil miss myself, your symptoms sound very similar to those who have reported such. I agree that a load balance test will be money well spent. You could follow the tests on the links below, but just getting to the back bank will take enough time that you'll wish you had paid for the conclusive dealer test*

http://www.v8sho.com/SHO/MissfiresandCoilTests.htm
http://www.v8sho.com/SHO/CoilOnPlugTest.htm


George

* - Probably the only time you'll hear me advocate going to a dealer...

 

[Mr. SHO]

Sure sounds like a coil...

If a rear bank coil is shot, you really should just bite the bullet and replace all 4. By the time one coil has succumbed to the heat, you can bet that there is another one or two or three back there that aren't far behind. Cough up the $300 for 4 new coils, install new double plat plugs, and you are good to go for another 50K before you need to dig into that area again.

 

[MeeSHO]

When I floor it, it just lifts and goes like normal, no hesitation I can feel. Something I noticed on the way to work today was that when I would pull around someone on the highway to pass, giving just a little more throttle to go, it would shake hard. As soon as I back off the throttle the shake stops.
When I got home last night from work, with the car being good and hot, I pulled in the driveway with all the accessories off, minus head lights, with the windows up. This was something I have never really done to this point, never really having a reason. Going from moving in D to stopped and putting it in P, the idle would go to where I normally see it, probably 700rpm or so. However, I sat there and tried blipping the throttle. When I would blip the throttle, the tach would of course jump then fall, as I left off, but would drop very low, probably 300-400rpm and the motor would hesitate a little, enough to dim the headlights before leveling off around 600rpm. I am not really sure if that means anything, but it doesn't sound too normal to me.
I appreciate all the feedback and tips from you guys. I am going out of town this weekend so the SHO will have to wait, but I will schedule an appointment to have the load balance test done. However, now for the hard part... is there such a thing as a "good Ford dealership"? I still have images of when I was looking for a place to weld my cams and I stopped in at the Ford dealer down the road to ask for tips. "SHO? Now what kind of car is that?" So, I will have to make a few phone calls before I am comfortable, but I NEED my SHO back! At least when I want my transmission done I already have the place picked out though
I will keep you guys posted on the outcome, it just might have to wait a week or two...

 

[MeeSHO]

Well, I bought 4 new coils and 8 new spark plugs today. I also bought a new fuel filter while I was thinking about it. I plan on tearing into it on Saturday. I have my Chiltons warmed up and ready to go. See you on the other side...

 

[MeeSHO]

Well I did the plug and coil thing today. Everything went really well and it wasn't hard. I put in 8 new Motorcraft plugs, and 4 new coils in the rear. I put it all back together, test drove it, and it was still acting up. Under steady acceleration at certain speeds the car just starts to shake until I let off the gas. So, I thought, well if it IS a coil problem and I am still getting it that one of the FRONT plugs had to be bad, so I took all the old coils from the rear and moved them to the front. Well, that didn't work either. However, the car seems to be more powerful and on the test drive the second time I had my wife with me and really got on it. She looked at me and said, "Wow, I didn't realize your car was that fast." That made me feel good, but I do still have the shutter/hesitation/shake problem. I didn't have a chance to clean the MAF yet and I have plans to put in a new fuel filter too, but I am pretty sure that they are not the culprits... Who really knows at this point? Back to square one... Any ideas???

 

[naval-avi8or]

Mybee you just move a bad coil from the front to the rear.

 

[Funmart6]

I am having the exact same problem. I too had my car looked at and driven by a trans shop and the mechanic thought my shudder was caused by a misfire. I do have a slight misfire when idling and plan on changing coils and plugs when I can find the time to do it, but, like you, I doubt that this solves the problem. (Any useful tips on changing the back coils and plugs will be appreciated.)

 

[MeeSHO]

I would check out this link on the V8sho website... V8SHO. It was very easy to do. I took my time, tested the coils, cleaned things up a little and had it back together in 3 hours. Once you take the plastic engine cover off, it is pretty much self-exlainitory on what needs to come off. I did a lot of reading before I started though, and the provided link will help a lot.

As far as my SHO is concerned, I cleaned the MAF, replaced the TPS and put in a new fuel filter this weekend. However, it is still acting up. I am not really sure what else I can do at this point, before I have to take it to a shop to look at it. However, I am still up for any advice.