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Powertrain Q & A: Jun 2003

Originally Published in MotorHome Magazine

Q.  We own a 1986 Journey motorhome with a 454-cid Chevrolet
engine in it, purchased in March 1992. I was a full-timer for about
three years, but due to health reasons I was forced to give it up. I
made only short trips until November 1999, when I parked the coach in a
campground. I have gasoline in my rear tank, so I am able to run my genset from time
to time, but I have not run the engine since November 1999.

My question is: What do I need to do to my engine before trying to start it again?

–Lyle Spencer, Calvert City, Kentucky

A.  That’s a long time for gasoline to last. I’m surprised the AC generator will still start on it. But that’s a good sign.

In many areas there are mobile mechanics or local shops that will
make a “road call.” I recommend that you have the oil and filter changed
on site, before you try starting the engine. Have the batteries charged
and tested. Carefully inspect the tires on both sides for sidewall
cracking and deterioration (plus set pressures). Also have them check
all fluid levels and carefully inspect the engine compartment and
running gear for any problems that may have occurred during storage.

Often, rodents will get into the engine compartment and build
nests. Sometimes they also hide seeds or nuts, etc., in places like the
top of the intake manifold, or inside the air cleaner. They also like to
chew on wires and hoses. This can lead to short circuits and/or fuel
leaks, which can result in a fire.

If the front tank is empty, I’d put some gasoline in it and start
the engine on the fresh gas. The carburetor may need to be primed. Have
the mechanic on hand at startup, and also keep a fire extinguisher
nearby. Leave the engine cover off, and watch for leaks or other
problems while it warms up. After a test drive, check everything again
and look for any leaks, etc. Then I’d have a full maintenance service
done, including a tune up, all fluids and filters, coolant and
brake-fluid flushes, and a chassis lube.

If the genset runs fine on the gas in the rear tank, I’d use it up
that way rather than risk gumming up the engine’s carburetor or
incurring the expense of having the tank drained.

Q.  We have a 1999 Fleetwood Tioga on a 1998 Ford E-350
chassis with a V-10 engine. It was bought new in January 2000. It has a
slight washboard effect that you can feel at 20 mph, then at 40 mph and
again at 65 mph. You don’t feel it in the steering wheel, but you can
feel it in the driver and passenger seats, and also in the coach seats.

I’ve had two sets of tires; the first set was balanced three times
and the front end was aligned twice. Then, at 11,000 miles, we replaced
the original Firestone tires with Michelins. That was not done to cure
vibration, but due to tire separation.

We have put 19,000 miles on the second set of tires, and they have
been balanced three times. Finally I had the drivetrain alignment
checked, and it was out of line by 2 inches. We had them correct that
problem, but I still have a slight tomoderate problem. Also, rough roads
seem to

amplify the situation.

I need to know if anyone has the solution to it. My motorhome is
still under warranty, and the dealer wants to help in finding the
problem and is willing to fix it.

–Greg Rozman, St. Louis, Missouri

A.  The type of vibration you describe, which is not felt in
the steering, but can be felt through the seats (and often the
dashboard), is usually caused by a driveshaft problem. Faulty U-joints
would likely have given out by now, but an out-of-phase or improperly
balanced shaft would cause it.

Take the coach to a driveline specialist and have the angles,
joints, ride height and balance checked. It could be as simple as a
balancing weight that fell off. Try to find a shop that has a vibration
analyzer (many GM dealers have them).

Q.  Referencing Mr. Fitzgerald’s letter (“Cantankerous Cat”)
in the January issue, I too have similar problems getting my
Caterpillar 3126 diesel started, and have since it was new. My Cat is in
a 1998 Newmar coach. The problem is related to the ambient outside
temperature. It seems that when the temperature is right around 60 F,
the engine computer will not turn on the intake-air heater grid. (The
WAIT light on the instrument panel lights only briefly or not at all.)
Yet, the engine itself is still cool enough that it has a difficult time
combusting the cold fuel-air mixture it is being fed.

It will usually try to start several times with much belching of
gray and black smoke and will finally gather itself up and run properly.
I’ve had some success just letting it rest for several minutes after
trying to start it a couple times.

I have also turned the ignition switch off and on several times,
watching the WAIT light on the instrument panel. It appears that cycling
of the

ignition switch might be allowing the grid heater to come on at
least momentarily, putting some heat into the manifold. Once, I even
turned on

the engine-block heater for about 20 minutes, which seemed to help.

I’ve never used ether, and the engine has never failed to
eventually start. However, the cloud of smoke certainly is not a
pleasant side effect

when it finally does start, and I hate to use the starter that
much. It has always started just fine at other temperatures, even down
to minus 9 F one morning, without the engine-block heater being plugged

–Mike Welsh, Marriottsville, Maryland

A.  We typically get fewer letters about problems with
diesel coaches than about gasoline chassis. However, this letter seems
to have unleashed a landslide.

Q.  I was experiencing the same starting problem with a
Caterpillar 3216B diesel as Tim Fitzgerald. I have that same engine in
my 1999 Damon Ultrasport; however, it would eventually start after
repeated tries with lapses between attempts. Sometimes pumping the
primer would help. Finally the engine stopped while I was en route, and I
could no longer start it and keep it running to proceed.

It was towed to Freightliner in Calgary, Alberta. At first, it
started for the mechanic and he couldn’t find anything wrong, even using
the diagnostic computer. He took it for a test drive and it stalled,
but he got it running and returned. He worked on it for two days, using
diagnostic equipment and taking test drives, and it wouldn’t fail when
the test equipment was connected – until finally it did.

The faulty part was the fuel-metering valve (Cat part no. 1225053),
which is one of several components the fuel passes through on the way
from the tank to the combustion chamber in Cat’s hydraulic electronic
unit injection (HEUI) fuel delivery system. This metering valve is about
the size of a spark plug and is actuated by hydraulic pressure from the
engine’s crankcase-oil pump to compress the fuel to a very high
pressure (20,000 psi) in preparation for delivery to the fuel injectors.

Freightliner replaced the valve, Caterpillar picked up all the
costs, and the engine has run well for the last 10,000 miles with no

–Cliff Demetrick, Calgary, Alberta

A.  Thanks for the letter, Cliff, and I’m glad you got it
fixed free. This valve is vital to the operation of the engine. The HEUI
system is used by Caterpillar and Navistar, and also in the Ford Power
Stroke diesels built by Navistar. They run cleaner and better than the
old systems, but are considerably more complex and expensive to repair
when things go wrong. They’re more finicky than the older engines, so
it’s especially important to use clean diesel fuel and the
factory-recommended oil grade and do regular maintenance, including
filter changes, to help avoid problems.

Q.  You can title this: “A Day Late and $2,602 Short!” I would like to pass on our little tale to maybe help other Tracker owners.

We had been pulling a Tracker for about four years without incident until our trip to Florida last year.

I took my latest copy of MotorHome with us, but hadn’t found time
to read it the first week we were out. Upon leaving Ft. Meyers, we
hooked up as usual and headed for the expressway, and I noticed that the
dinghy was towing funny and the tires were chirping at stoplights.
Since I had just installed U.S. Gear’s Unified Tow Brake, I figured the
gain was too high, so I lowered it and headed for the on-ramp.

As I got up to cruising speed, 65 mph, I looked in my mirror to
change lanes and saw a very scary sight. There was nothing but smoke and
mayhem going on behind my coach and rubber streaks all over the
highway. I thought my car was on fire, but reality set in as soon as I
stopped and got back to look at the problem. Oil, antifreeze, tire smoke
– you name it, what a mess!

As soon as I got in back of the wheel, I saw what I’d forgotten to
do. The transfer case was in gear and, per the owner’s manual, the
transmission was in second gear. You can guess the result of 65 in
second gear. Although the engine had started right up, there were two 2 x
4-inch holes in the block.

We found a Chevy dealer and, after spending $1,400 for a junkyard
motor and $1,202 for labor and miscellaneous parts, we had our

Tracker back two days later.

Had I read your answer in the June 2002 issue about putting the
transmission in fifth gear(instead of second), I’d be a little bit
richer. Oh, well, live and learn. Keep up the good work. Your column is
very helpful even if it’s read after the fact.

–Gary Roberts, Shelby Township, Michigan

A.  I won’t say, “I told you so,” because it doesn’t apply
in this case, but I would like to remind our readers of the serious
consequences of improper towing, even if accidentally. The cost to
repair many late-model highline vehicles could be a lot more than
$2,600, too. So double-check everything each time you tow.

Q.  In the August 2002 issue of MotorHome (“Third
Brakelight”), you replied to Sandy Seyfried concerning an add-on third
center mounted brakelight blinking when the turn signals are used. Your
answer is correct to avoid the blinking, but there is an easier way.
J.C. Whitney, (800) 529-4486, sells a logic circuit that’s available as
part no. 13XD8974T for $4.99 plus shipping.

I used it on my 1973 GMC motorhome several years ago, and it works fine without running a wire from the brakelight switch.

–Robert L. Sovis, Fenton, Michigan

A.  This is a viable option for people considering the addition of a center brake lamp on older coaches that don’t have them.

Q.  I would like to comment on the “Dodge Distemper” item
about an overheating 1979 Dodge Class C motorhome with the 440-cid
engine in your September 2002 column. I have a 1976 Winnebago with that
engine and had similar problems.

The reason turned out to be that the radiator had both the inlet
and outlet on the same side. It was basically using only about a third
of the core for cooling. The solution was to have a radiator shop move
the inlet to the opposite side. That change solved all my overheating

–Michael Martin, Butner, North Carolina

A.  Thanks for writing, Michael.

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