Classic coil issue. No code. Should I just replace all?

Jtown

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Location
Franklin TN
Car: 03 ls 3.9l 55.6k miles

Issue: Once car warmed up, surging and engine or tranny shake over 40 mph. In neutral / park, will not rev above 3k rpm. Will achieve 60+mph but can feel sputter or surging.

Recent maintenance: (1) Just did a tranny pan drop replacing the filter and 6 its of fluid. First drive after that work. Was okay until she warmed up. (2)New plugs 50 miles ago. (3) New fuel filter. (4) New serpentine belt. Plus lots of other stuff pretty much unrelated to motor but no sign of an issue after 2 thru 4 were done.

Coils: #7 replaced 41,635 mi on 10/15. #8 replaced 42,742 mi on 10/16. #2 & #5 replaced 51345 mi on 1/18

There is no check engine light on. Can codes be thrown without a warning light on these cars? I guess I need to run this by a shop to scan for codes.

If it's another coil, should I just replace all coils to start a fresh base line using FoMo DG529?

Car is new to me so I don't know what a bad coil feels like. I do have the maintenance records from new.
 
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This doesn't really sound like a coil issue.
Note that there is a rev limiter when in park or neutral. That's normal.
6 pints sounds low even for just a pan drop. Did you warm it to normal temperature and check the level immediately after shifting through all the gears?
Are the coils recent vintage Motorcraft? If not, then they probably should be replaced anyway. If you do, then the spark plugs should be replace too (even though you just did).
Yes, there can be pending codes without a light on. Good scan tools can also get to the misfire counts for each cylinder. That can help with diagnosis.
I wonder if your catalytic converters might be clogged?
 
It does shutter like a torque converter but I'm no expert. FoMo Mercon 5 fluid. Parts guy said I'd use 5qts. with a pan drop. Shop said it used 6. I gave them the overflow attachment also and even told the guy to make sure to follow the procedure I took from here and gave them. Sounds like I need them to re-check the tranny fluid first. I'll have to go back and double check how to do that and look for codes. A drive along scan performance check might be in order too.

All coils are original FoMo even the replacements. Replace the plugs again if it's a coil? Even if it's one coil bad and I just replace all (so 7 are assumed good)? I understand the bad one or two.

All parts are FoMoCo stuff ie. plugs , filters, fluids, suspension...

Don't even scare me with a plugged cat!... I just see $! HA!
 
Sorry... our posts crossed.

All I can tell you is that every 60,000 miles when I do a fluid and filter change... my LS takes 8-8.5 QUARTS on refilling. And that's without draining the torque converter, (since mine doesn't have a drain plug). It will take more if I blow out the tranny cooler and lines.
 
I don't think I would take my LS back to that shop... and I don't think I would drive it anywhere until the fluid is topped off.

Strong suggestion......

Call your local dealer and set up an appointment for a "fluid level check" , (don't tell them ANYTHING else) ... and just face the fact that it's gonna cost you up to $150. :(

In the mean time... take another vehicle to get 2 quarts of Merc V from somewhere... and a hand pump that will screw onto the quart bottles.

Then pump in 1.5 quarts yourself... and see how it checks out at the dealer.

With the milage on your LS ... you shouldn't be having any issues... and I really don't think you want to be replacing a transmission any time soon.
 
I did have them put in a new tranny filter and pan gasket. The Lincoln dealer did say he would do a flush with his BG unit but after reading all the ya's and nay's here, I opted to just drop the pan and refill. I did that at a local shop that works on lots of high dollar exotics. Again, I even took them the instructions from a post here on how to refill. The shop is about 4 miles away. Can I drive it there doing under 40mph?

The only way I can get under her is with ramps on the front (or rear). It's a mother to lift the other end (making it level) and put it on jack stands (for me anyway). Always fear bending something. I did drive it around a bit when things started acting up trying to self diagnose her. Please say I didn't break it...ugh.

Sounds like your saying get the front end up and just add fluid. Them go to the shop, put it on a lift (level), run through the gears, and check the level. Using the drain adapter, do I check the level in park and running or off?

I could get it flatbeded over to the shop if I have too. Cheap insurance (so to speak).

Then if the level checks out okay, I'll put it on a scope to look for coil issues.
 
Check with the engine running, always. I couldn't say if any damage would be or has been done driving a short ways. I do agree that a little overfilled would be safer than a lot under filled, for a short distance.
 
Sounds like your saying get the front end up and just add fluid.

Yup... get a quart and a half more in it and see how it acts.

As far as any damage... that depends on how long you have driven with the issue. You may get lucky.

If it acts ok... then driving it to the shop would be the same as running it through the gears.

If it doesn't dribble out the fill hole when level at the shop... then it needs more fluid. I usually put the plug back in while its still trickling out a little.
 
So I got the front up on ramps and lifted the rear but it was not perfectly level (low in the front). I added a quart of Mercon V. Let it warm up, ran through the gears several times, left it running, opened the center top runoff plug and it poured out! I put the plug back in loosing about an eight of the Mercon qt. bottle. I dropped it down and took it for a mile run not exceeding 45mph. Began to act the same with surging or pulsating. Stoping and sitting while in gear I could feel some sputtering through my seat. I did not see or feel any movement in the shift lever or steering wheel. Brought her home and put her back in the garage.

I have an appointment for Wednesday at the shop to scope it. I will check the tranny fluid level on the rack again to be sure. I can's say how they drained the tranny. I did see the pan off and they didn't see any sediment. Maybe they didn't drain the torque converter (is that possible)and that's why it used 6qts only.

A slight concern: when some of the Mercon drained out the overflow pipe, I did see some metal flecks in the catch pan. I can't say for sure if it was from the LS or residual in the pan. But I have a bad feeling. Maybe I'll drain the tranny again but be there to watch. I can have the pan dropped and torque converter drained and reuse the filter. I need the peace of mind.

Hopefully it's a coil and the tranny is okay. Jez, it only got 55K mi. on the tranny and taken care of.
 
It would be 12 quarts if they drained the torque converter and cooling lines.
 
A slight concern: when some of the Mercon drained out the overflow pipe, I did see some metal flecks in the catch pan. I can't say for sure if it was from the LS or residual in the pan

That's why you always start with a clean pan.

. I added a quart of Mercon V. Let it warm up, ran through the gears several times, left it running, opened the center top runoff plug and it poured out! I

And you probably should have let it run out... until it slowed to a dribble... then put the plug in.

Then poured the excess tranny fluid into quart bottles and checked how much excess came out. Since you only put a quart in... it should have only been a quart. If more than a quart in the bottles... then somehow it got over filled .
 
Shop run a scan for codes. No hard codes but showed recent multiple misfires in cylinder 3. That is one of the original coils (4 original to the car and 4 replaced w/ FoMoCo coils).

Question? Do I need to replace the entire eight coils as a set or just as required (read replace at once but want to ck here). Obviously the dealer only replaced as needed as evident by the four replacements they did within the last 13k miles.

Maybe replace the four originals remaining (from mile 0). The coil giving me an issue (misfire cal 3) is an original. Guess I order 4 or 8 coils based on what you guys recommend.
 
You can do it whichever way you want. Normally, we say to replace them all at once because the experience here is that once one fails enough to notice, all the others are already degraded and soon to fail. Of course, that isn't valid if all the others aren't the same brand and same age.
What you really, really do need to do is to replace the spark plug at the same time as the coil, even if that plug is only one month old. Bad coils damage plugs, damaged plugs damage coils, repeat, ...
Personally, I'd at least replace the four "original" ones (and their respective spark plugs).
It's important to check/set the plug gaps all to 1.0mm. Yes, they will say they are correctly pre-gap'd correctly, but in every set of eight that I have purchased, at least of couple have been wrong.
 
Thanks Joegr. Will order the set of eight. Bitch is I just did new plugs... Guess it was good practice.

Thanks for the clarification on replacing new plugs at the same time. I would have skipped that part.
 

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