Common Class C Break Downs & Maintenance Ideas

Sam Spade wrote:


I thought there also was a problem for several years with insufficient threads in the heads, causing it to be easy to strip the plug mounts.....which required removing the heads to fix.

Then maybe I'm getting that mixed up with another model ??

'97-'99 V10 had less threads. That on its own didn't cause spark plugs to pop out, it just made it more likely to happen from over-torquing plugs during a change. The real cause was a machining fixture error which allowed threads to be cut off-axis from the bore, making them weak. That wasn't corrected until 2003. The bad news is, if one plug blows the remaining in that bank probably will go at some point. The good news is that by now, if a motor hasn't had a plug blow yet, it probably never will.

Thanks everyone for great information.

This page discusses maintenance issues including the spark plug ones.

Spark plugs are a whole different animal on this engine. They decided to place each of these sensitive coils upon a specialized spark plug that tends to break when removed. Due to the design of the combustion cylinder, essentially these engines are semi-hemispherical, the plugs needed to protrude down through the head to the combustion chamber. The situation is slightly ironic since earlier 2 valve 5.4L (97-03) tended to blow spark plugs out of the head but later 3 valve 5.4L (04-07) tended to break off in the head.

These plugs generally last around 100k miles but they are a bear to remove when you do go to replace them. They have extended sleeves that reside down inside the head that tend to break off because of possible carbon/rust build up. This issue was fixed by a redesign of the spark plug in the 2008+ years. More details are available in another article I wrote which include step by step instructions on Replacing the spark plugs on the 5.4L Triton at home.

5.4 L Triton 3 valve engine


I have already identified a mechanic who is familiar with the problems and has tools to deal with broken plugs. He says wait until the 100k miles before changing plugs.

Another thing to look out for are broken exhaust manifold bolts. This is apparently a chronic problem with the V10 motors. Long cast iron manifolds attached to aluminum heads. Differential heating and cooling can pull on and break the bolts.

Pull your doghouse out and check the bolts. My 2010 E450 Class C had 6 broken bolts with only 28000 on the clock. Calling around to RV repair shops I was quoted around $1500-2000 to make the repair. Lots of labor involved. Very little room to work in the van cut-away chassis.

So to make things short, I cut my losses and took the RV to Banks in SoCal and had them install their cat forward header system for $2000. They have all the equipment to make the installation and as part of the install, they replace all the manifold bolts. Problem solved.

Mike

Harvey51 wrote:
This page discusses maintenance issues including the spark plug ones.

Spark plugs are a whole different animal on this engine. They decided to place each of these sensitive coils upon a specialized spark plug that tends to break when removed. Due to the design of the combustion cylinder, essentially these engines are semi-hemispherical, the plugs needed to protrude down through the head to the combustion chamber. The situation is slightly ironic since earlier 2 valve 5.4L (97-03) tended to blow spark plugs out of the head but later 3 valve 5.4L (04-07) tended to break off in the head.

These plugs generally last around 100k miles but they are a bear to remove when you do go to replace them. They have extended sleeves that reside down inside the head that tend to break off because of possible carbon/rust build up. This issue was fixed by a redesign of the spark plug in the 2008+ years. More details are available in another article I wrote which include step by step instructions on Replacing the spark plugs on the 5.4L Triton at home.

http://www.expertswrite.net/ford-5-4l-triton-3valve/common-problems.html

I have already identified a mechanic who is familiar with the problems and has tools to deal with broken plugs. He says wait until the 100k miles before changing plugs.

Yes, this is the 3 valve engines only, which they never used in the
E series.

not really mechanical but annoying and age related. i have a 2002 e450 chassis with about 121,000 miles
last summer i lost my dash AC, it started blowing out of the defrost vents only. this is a default for Fords so if you lose HVAC you still get defrost capability.

there is a short rubber hose after the vacuum chamber powered by the exhaust manifold UNDER the ac system. 20 hour repair by the book, draw down ac, pull battery, battery tray and ac system. this hose dry rots and eventually breaks. i rerouted the PVC vacuum line and put in a different vacuum chamber under the passenger side dash. tied that into the existing system after the failed vacuum chamber. all good now.

also noticed getting intermittent failures on the master window and lock switches. i have pulled and cleaned them once but may need to r&r this year.

One side note, and this is not related to the chassis:

Your generator's carb is probably shot. It may be old enough to be rebuildable, but most likely it will need to be replaced. Change the oil as well, because it is likely sludge. Heck, I would probably use an oil evac pump down the dipstick hole just to suck up the old oil, add oil to the fill line, try to run it, then change the oil again just to get out all the chunkies due to it sitting for so long.

I'd also replace "consumable" items like house and chassis batteries as well.

Harvey51 wrote:
He says wait until the 100k miles before changing plugs.

That might be good advice IF you do NOT intend to keep it long enough to log 100K miles.....and pass the potential problem off to the next owner.

It seems rather strange advice, however, if you intend to keep it well PAST 100K.....because that would give it another 50K and maybe 5 years for them to rust and corrode in place, versus changing them at 50K when they still are relatively fresh.

It sure looks like you have it right, Krusty. Good news for all motorhome owners!

There is a fair bit of chatter about E350 spark plug problems on forums. This post has the Ford TSB on the thread problem and it lists the E series, 1997 to 2008. Can't quote; it is a picture in a PDF file. Revbase.com

Curious, other sources say the thread problem was fixed for 2004.
I have seen other TSB posts that do not list E350.