Community Forums

superk · 03-24-2015, 07:01 PM

THE SHORT OF IT:

COACH VIBRATES WHEN ACCELERATING SOFTLY IN THIRD GEAR (30-50mph), FINE EVERYWHERE ELSE
COACH SEEMS TO SLIP, OR SPLIT-SECOND POWER-LOSS

THE FINER DETAILS (may or may not be necessary)

The coach has incredible power, like when I first got it. Idles well, and runs in OD great, purrs like a kitten. Accelerating is somewhat rough.

When accelerating, the coach revs high as most v10s do im told. around 3000 rpm it starts to feel like you are hitting patches of ice, in the sense that you momentarily (for a quarter/half second) feel as if you lose traction. Difference is, on ice, when you slip the rpm go up. Here, the rpm still increase, but much slower. Once in overdrive, the problem disappears and the coach rides smooth. I should add that this occurs during hard acceleration.

During soft acceleration, in 1st or second it doesnt do this, drives just fine. In third, during soft acceleration the coach shakes. BADLY. Feels like its coming more from the rear end. It did this when we bought it, but it was very gentle and the coach quickly got over it so I thought it was just the old tires or a small gap in gear ratios. Since then, I have had all 6 tires replaced with brand spanking new ones. The vibration is now immensely worse after coming out of storage.

ALREADY CHECKED/REPLACED:

Fuel filter
air filter
new fuel
injector cleaner ran through full tank of gas
replaced all tires
transfluid/filter replaced 800miles ago, 5 months roughly.

will be checking the shaft and ujoint this weekend.

tderonne · 03-24-2015, 07:21 PM

I'll be the first to say....coils. Search this site, you'll find some similar stories.

GREGORYJ · 03-24-2015, 07:28 PM

I had a similar problem on our 2002 Class C with Ford V10. The engine run great except under a light load, usually going up hill, even slight, and in a higher gear.
To me it seemed like the engine was shuttering or slightly missing. One on level ground, highway speeds, etc. it ran normally. I searched this forum for a solution:
Ford Truck Enthusiasts Forums - Ford truck and SUV owners and enthusiasts Community And Information Source.
From searching here it appeared the problem was likely a bad coil over plug (COP).
Some suggested if one was weak, others could follow and go weak. Ford wants a bit over $100/each. Most suggest buying them else where. Someone suggested a
seller on Ebay selling sets of 10 for $140 complete with boots,etc.& free shipping.
I got them, replaced all 10 and the engine ran fine after that . This was 3 to 4 years ago. Some also listed other suppliers & part numbers but check first :
Motorcraft DG508 & DG491
Ford F7TU 12A366 CD; F7TU 12A366 AA; 1L2Z 12029 AA; 1L2U 12A366 AA; 3W7Z-12029 AA
Delco F523
Standard/Hygrade FD503 & FD493
Tru-Tech FD503T
SMP/Bluestreak SPP39
Wells C1139
AIRTEX 5C1127 & 5C1412
BORG WARNER E213 & E262
Here's an example from Ebay currently:
http://www.ebay.ca/itm/FORD-4-6L-5-4...a7b233&vxp=mtr

89sandman · 03-24-2015, 07:57 PM

Let me be the third, plugs and coils. Have your computer scanned you will probably find code 300 which is a random misfire code or 301-310 which will indicate exactly which cylinder/cylinders are misfiring.

superk · 03-25-2015, 06:05 PM

Quote:

Originally Posted by GREGORYJ

I had a similar problem on our 2002 Class C with Ford V10. The engine run great except under a light load, usually going up hill, even slight, and in a higher gear.
To me it seemed like the engine was shuttering or slightly missing. One on level ground, highway speeds, etc. it ran normally. I searched this forum for a solution:
Ford Truck Enthusiasts Forums - Ford truck and SUV owners and enthusiasts Community And Information Source.
From searching here it appeared the problem was likely a bad coil over plug (COP).
Some suggested if one was weak, others could follow and go weak. Ford wants a bit over $100/each. Most suggest buying them else where. Someone suggested a
seller on Ebay selling sets of 10 for $140 complete with boots,etc.& free shipping.
I got them, replaced all 10 and the engine ran fine after that . This was 3 to 4 years ago. Some also listed other suppliers & part numbers but check first :
Motorcraft DG508 & DG491
Ford F7TU 12A366 CD; F7TU 12A366 AA; 1L2Z 12029 AA; 1L2U 12A366 AA; 3W7Z-12029 AA
Delco F523
Standard/Hygrade FD503 & FD493
Tru-Tech FD503T
SMP/Bluestreak SPP39
Wells C1139
AIRTEX 5C1127 & 5C1412
BORG WARNER E213 & E262
Here's an example from Ebay currently:
Ford 4 6L 5 4L 6 8L V8 V10 Heavy Duty Quality Ignition Coil DG 508 SET OF 10 | eBay

Ok I can take a hint lol.

I just ordered this

Ford 10 Ignition Coil DG508 10 Motorcraft Spark Plug SP479 B267 10 IC170 New | eBay

Figured, might as well change the plugs while I am at it. I have no idea when/if they have been changed since stock. The coach now has 91000 miles on its odometer, so might as well change them, judging by the terrible maintenance on this unit from its previous owner, these more than likely have not been changed.

keymastr · 03-25-2015, 06:16 PM

Run a couple cans of Seafoam through it, ( youtube videos show safe vacuum ports to let it get sucked in without messing up the sensors). That will get rid of the carbon that sticks in the threads of those plugs which have been known to break off in the heads.

superk · 03-25-2015, 06:51 PM

Quote:

Originally Posted by keymastr

Run a couple cans of Seafoam through it, ( youtube videos show safe vacuum ports to let it get sucked in without messing up the sensors). That will get rid of the carbon that sticks in the threads of those plugs which have been known to break off in the heads.

I went to look at Seafoams website, they have 2 products that could do the job. One is labelled sea foam motor treatment, and the other is seafoam spray. Any particular one I should use?

superk · 03-25-2015, 08:21 PM

Here is my change out plan.. please chime in if something is wrong or inaccurate?

I plan to run some seafoam through a vacuum intake to help break up the carbon on the inside of the engine. Then, after removing all 10 coils, I will blow out the holes with 120psi air. Penetrating oil will be allowed to work its magic overnight and in the morning I will attempt to loosen each plug gently. After about 2 turns, i will blow more 120psi air to prevent debris from entering the cylinder. I will lightly coat the threads of the plugs with anti-seize and gently thread them in until they snug up. I will torque them to 13ft lbs. I will then coat the plug in dielectric grease and install the COPs.

Miss aything?

I read that you may or may not need to loosen a fuel rail? Is this applicable for the f53 since we can just remove the doghouse and have full overhead engine access?

spyderRV · 03-26-2015, 02:43 AM

superk, I had a similar issue as you described. I had no ecm codes so I threw about $50 worth of 44k in the tank. No change. It was a bad coil. The fuel trim was +20 because the computer saw the oxygen from the dead cylinder and assumed the mixture was lean.

http://www.irv2.com/forums/f23/help-...00-225228.html

GREGORYJ · 03-26-2015, 09:01 AM

superk, that sound like a good plan, basically what I did. Lots of talk on the Ford Trucks forum on what torque to use, but when using anti seize it seems 13 -14 ft/lbs is what one should use. Also they talk about using a spark plugs compatible with aluminum heads, that is so the threads won't corrode. I forget what I used. As I mentioned on the other forum site, this job isn't that difficult in an RV compared to a truck.

superk · 03-27-2015, 01:54 AM

Quote:

Originally Posted by GREGORYJ

superk, that sound like a good plan, basically what I did. Lots of talk on the Ford Trucks forum on what torque to use, but when using anti seize it seems 13 -14 ft/lbs is what one should use. Also they talk about using a spark plugs compatible with aluminum heads, that is so the threads won't corrode. I forget what I used. As I mentioned on the other forum site, this job isn't that difficult in an RV compared to a truck.

Great, I was hoping to hear that.

I wonder however, if its worth just bringing it to my ford dealer, stripping the coils off right there in the parking lot, and then having them come out and remove and replace the spark plugs? Its not that I am incompetant and cannot do so myself, the concern is actually that if *somone* over torques or under torques these plugs and one ends up ejecting itself from the motor, it would be awesome if *someone* fixed it for free too lol.

Obviously I would ask for a master tech and give him the instructions per ford specs as a reminder, and this way, if it happened, ive got my butt covered.

It should really only be a 1 hour job *MAX* to R&R 10 plugs?

Ill gladly pay the 90 bucks for the piece of mind....

GREGORYJ · 03-27-2015, 11:10 PM

It wouldn't hurt to check with a Ford service center - get an estimate. I was concerned getting all 10 lose to removing but it went well, not too hard at all.
I used a 3/8 socket set with an in/lb torque wrench(168in/lbs.) to install.
I see there are several spark plug thread repair kits and service available so it would seem heads can easily be repaired if spark plug head threads became damaged.
After reading about some problems that could occur, I was a little concerned about
doing it myself , but it wasn't that hard in the end, took my time , 2 to 3 hours & the COP"s & plugs where done.

LouieL · 04-04-2015, 08:10 PM

If you know some one with a engine scan reader they can check the engine for "Misfire counts" It will tell you which cylinder is acting up. Those scanners are very cheap now. having one for a gas RV and you cars at home comes in very handy.

I know I sound like a broken record, but your local auto parts store can check the codes for you. Just be ready to point out the OBD2 port for them.

superk · 04-04-2015, 08:30 PM

unfortunately,

Its OBD1 :(

As such, it wont report misfires, but i can hear it at the exhaust, it sounds like sputtering for a moment, then clears up for a few seconds.

Plugs and coils should be hereby the end of the week. They are at the CA/US border atm. I just ordered my torquewrench too. Going to change all coils and plugs. Its due.