Solved: Vibration while accelerating issue

[SuperD]

1999 Ford e450 v-10, 63k miles.
On a recent trip I noticed a vibration in the engine area and steering wheel when accelerating under load (like uphill) at highway speed. With no load there was no vibration (flat or downhill areas). New tires, alignment ok, no other issues except I found it was about 3 quarts low on trans fluid. Oops! I heard it could be a misfire, but had no check engine light, so wasn't sure.

After much research and deliberation I decided to start 'small' and go with a basic tune up, just changing the spark plugs to see if it was an ignition or misfire issue. Sure enough, that solved the problem. Apparently, the thermostat gasket was leaking onto the number 6 and 7 plugs and making problems. All the plugs were pretty bad, too, must've been originals. New plugs made a big difference in performance, too! Cost around $500 for everything, happy to invest that money into fixing the problem.

Just passing this along because there were lots of other posts with similar issues. BTW - thankfully there were no issues changing the plugs, broken plugs, etc.

Safe travels!

[ron_dittmer]

Just FYI on spark plugs.

My brother replaced the spark plugs on his 1998 E350-V10 motor home. Apparently the original plugs are no longer available. He told me the replacements are Ford AGSF22WM.

[SuperD]

Krusty wrote:
Keep an eye on the coolant too. I have never seen a thermostat gasket leak. It is usually the intake manifold

Oddly enough, when they changed my spark plugs earlier this year, the thermostat gasket was leaking coolant onto one of the plugs. They fixed it of course, but it was a burnt gooey mess on that plug!

[Krusty]

Keep an eye on the coolant too. I have never seen a thermostat gasket leak. It is usually the intake manifold

[SuperD]

Update: the vibration came back harder than ever and tripped the check engine light on a recent trip. If I gave it any serious throttle, like up hills, it would shake and shudder. It ran 'ok' with very light throttle.

Turns out it was an iginition coil (COP). When we got home, I ordered a set of 10 online (~$100) and installed them myself, took around 2.5 hours, not too bad of a job for DIY, fairly straightfoward (and Youtube helps!).

I HIGHLY recommend replacing your coils if you have these symptoms, or if your rig is getting up in miles. It's just a matter of time before a coil fails and you'll be stressing all the way home (or to a repair shop).

I also changed out the fuel filter just in case. It was pretty easy, too, with the quick release tool (~$8), filter was ~$10. Took 15 minutes.

[travisc]

I replaced an ignition coil this last summer in a rush went to the dealer $300 and I can buy 10 lemon from amazon for $250 only 60k on my 10 year old rig

[T18skyguy]

I have a V10 in a box van that had 50,000 miles on it. I changed the plugs and was amazed how far out of spec they we're; just a huge gap. Runs so much better.

[Home_Skillet]

I was a Ford technician for 25 years, so I've seen this many times.

My RV had a misfire on acceleration. It wasn't severe enough to set a code.
I just changed all the coils and spark plugs. Eventually some of the other coils will fail.

[SuperD]

The scanner showed a misfire but the coils were still ok. I took it to an auto parts to get the free scan, but they wouldn't even scan it because there was no check engine light. I really didn't know if it was a big problem and wasn't too excited to go down the rabbit hole of fixing this and that until something worked. Plugs and coils seem to be a pretty common fix for the v-10.

[Cobra21]

I would think the code reader should have picked up on a miss fire?

[klutchdust]

zigzagrv wrote:
Had the identical problem on my V10 in the motorhome. Checked U-joints, center bearing, etc. Turned out to be a bad coil pack on #8 cylinder. Swore it was a drive train problem.

Wish I had seen your earlier post, I could have helped. Good job!

A friend who had (totaled in a wreck) a truck with the V-10 and close to 300K miles told me the

only parts he replaced were the water pump and ignition coils. I now carry a few spares in my rig

along with a code scanner.

[Lwiddis]

“All the plugs were pretty bad, too, must've been originals”

After 21 years of service I do believe the plugs needed changing.

[ron_dittmer]

Thank you SuperD for that great report.

[zigzagrv]

Had the identical problem on my V10 in the motorhome. Checked U-joints, center bearing, etc. Turned out to be a bad coil pack on #8 cylinder. Swore it was a drive train problem.

Wish I had seen your earlier post, I could have helped. Good job!

[MDKMDK]

Thanks for the closure, Super D.:)