Thermostat/maiden voyage from hell

[robert m fukumoto]

When my GMC is cruising/loafing the temperature is approx 208 degrees. =
It'll
go up with terrain as well as with traffic jams. In stop'n go traffic of =
a
few hours it is not uncommon to see 225-230 and then the fan clutch =
kicks in
to bring it back down. Same for going up long hills, i.e. the Grapevine =
into
LA or I10 out of LA, etc.

I just returned from my maiden voyage (from hell) of my 76 Palm Beach. =
I put on 2,700 miles from Denver thru Las Vegas, to Yosemite, Monterey =
and back home via Las Vegas. With a new analog water temp gauge, I ran =
mostly between 190 and 200 degrees except when climbing long hills such =
as up to Eisenhower tunnel and Vail Pass on I-70 where I ran 220. On a =
steep grade on I-70 in Utah in the hot sun I ran the hottest: 230. =20

My transmission failed in Yosemite and I had to be towed from the park =
and delayed for 3 days. I had to return to the transmission shop to =
have the transmission chain replaced and lost another day and was $1600 =
lighter in the wallet. My Wife wasn't crazy about the coach to begin =
with and she says sell the coach. We'll see. (Also, like mentioned by =
someone else before, my Wife does not like sitting in the co-pilot's =
seat and I can understand why. Anyone figure out how to block some of =
the view out of the front windows?)

FWIW going westbound thru the mountains, I was able to go 35-40mph up to =
Eisenhower Tunnel and Vail Pass. The grades are steeper coming =
eastbound where I was only able to go 25-30 mph. Is this consistent =
with others experiences? Going eastbound on I-15 from Barstow to Baker, =
this is the longest grade that I have ever seen. But, it wasn't as =
steep as the mountains and I was able to do 40-45mph. I have the =
original final drive - has anyone traveled these grades with some of =
the aftermarket units? What speeds were you able to maintain and how =
much did it cost to upgrade? I surely can see that pulling any toad =
with my present configuration is out of the question.

I had put Syntec synthetic oil plus Prolong oil additive in the engine =
prior to the trip. The best news of this trip was that I used no oil =
during the whole 2,700 miles. =20

I ran the generator and the roof air conditioner the whole trip. Going =
thru the desert (it was 98 degrees at midnight in Baker CA) the a/c was =
bearly adequate. During the day in the hot sun, the roof a/c couldn't =
keep up with the heat. Fresno, Las Vegas, Oakhurst CA were all over 100 =
degrees. What are other's experiences? Are the new roof units much =
more effective than my 22 year old unit? My unit seems to throw out =
adequate could air in 85 - 90 heat but just can't handle the higher =
temps. My dash a/c unit is next to useless in this kind of heat.=20

I haven't calculated my mileage yet but it seemed to vary between 4.5 =
mpg and 6.5 mpg, depending on the grades I was climbing. This is with =
the generator running full time and driving 70 - 75mph whenever the =
terrain would allow.. =20

I have a vibration in the coach that I will need to address if I am =
allowed to keep it (I do have a for sale ad in the local paper). From =
the wear on the passenger side bogie tire, I need to have a six wheel =
alignment done. What do I need to look for in an alignment shop to be =
sure they can handle this? How much should this cost?=20

Any other ideas on how to quiet down the noise in the coach (other than =
slowing down). At 55mph the coach is fine; at 70 mph it's pretty noisy =
and vibrates a lot.

Thanks

Bob Fukumoto
76 Palm Beach
(If I get to keep it)

 

[bartz paul]

Bob:

I have several thoughts for you to ponder:

a. Are your side windows (including the sliders and above) and rear
window tinted? If not, you are getting a tremendous heat gain through
them. You should consider installing a dark, REFLECTIVE, I repeat
reflective type , tinting film installed on them to reject the solar
heat gain and lower the workload on your roof A/C unit.
b. Do you have a ball valve in your coolant hoses going to the
heater core? If not, at the ambient air temperatures you talk about,
you'll definitely have some additional heat gain to deal with.
c. Although you don't mention specifically what bothers your wife
while riding in the passenger seat, if it's being blinded by the sun, I
know of one coach owner who has installed a band of tinting film along
the top of the windshield. It has an arc shape to the bottom edge of
the tinting film on each windshield glass corresponding to that traced
by the travel of the top of the wiper blade as it sweeps across the
glass.
d. Perhaps your radiator cooling fins are starting to deteriorate
(rot away), they actually corrode and disintegrate, or the radiator
tubes need to be rodded out. Look at the bottom of the back side of the
radiator to verify if there is deterioration. If so, you should expect
to gradually with time notice the temperature gauge getting hotter and
hotter.
e. Although I didn't see you mention it, was your thermostatic fan
clutch working? Generally, as cooling temperatures rise, the fan clutch
senses that and engages. The engine sounds like it all of a sudden
speeded up in rpm's, however it hasn't. It's just that the radiator
cooling fan instead of freewheeling is engaged directly, which then
results in it temporarily pulling more ambient air through the radiator
until the coolant temperature drops sufficiently. My clutch generally
engages whenever the gauge reads 200 deg F or so.
f. If you don't have a 50/50 mixture of anti-freeze for your
coolant, you're likely to run hotter than normal, also.
g. Of course the obvious concern is if you have the correct type
coolant thermostat.

Paul Bartz

From: Robert M Fukumoto [mailto:fukf19]
Sent: Monday, August 10, 1998 1:38 PM
Subject: GMC: Thermostat/maiden voyage from hell

When my GMC is cruising/loafing the temperature is approx 208 degrees.
It'll go up with terrain as well as with traffic jams. In stop'n go
traffic of a few hours it is not uncommon to see 225-230 and then the
fan clutch kicks in to bring it back down. Same for going up long hills,
i.e. the Grapevine into LA or I10 out of LA, etc.

I just returned from my maiden voyage (from hell) of my 76 Palm Beach.
I put on 2,700 miles from Denver thru Las Vegas, to Yosemite, Monterey
and back home via Las Vegas. With a new analog water temp gauge, I ran
mostly between 190 and 200 degrees except when climbing long hills such
as up to Eisenhower tunnel and Vail Pass on I-70 where I ran 220. On a
steep grade on I-70 in Utah in the hot sun I ran the hottest: 230.
My transmission failed in Yosemite and I had to be towed from the park
and delayed for 3 days. I had to return to the transmission shop to
have the transmission chain replaced and lost another day and was $1600
lighter in the wallet. My Wife wasn't crazy about the coach to begin
with and she says sell the coach. We'll see. (Also, like mentioned by
someone else before, my Wife does not like sitting in the co-pilot's
seat and I can understand why. Anyone figure out how to block some of
the view out of the front windows?)
FWIW going westbound thru the mountains, I was able to go 35-40mph up to
Eisenhower Tunnel and Vail Pass. The grades are steeper coming
eastbound where I was only able to go 25-30 mph. Is this consistent
with others experiences? Going eastbound on I-15 from Barstow to Baker,
this is the longest grade that I have ever seen. But, it wasn't as
steep as the mountains and I was able to do 40-45mph. I have the
original final drive - has anyone traveled these grades with some of
the aftermarket units? What speeds were you able to maintain and how
much did it cost to upgrade? I surely can see that pulling any toad
with my present configuration is out of the question.
I had put Syntec synthetic oil plus Prolong oil additive in the engine
prior to the trip. The best news of this trip was that I used no oil
during the whole 2,700 miles.
I ran the generator and the roof air conditioner the whole trip. Going
thru the desert (it was 98 degrees at midnight in Baker CA) the a/c was
bearly adequate. During the day in the hot sun, the roof a/c couldn't
keep up with the heat. Fresno, Las Vegas, Oakhurst CA were all over 100
degrees. What are other's experiences? Are the new roof units much
more effective than my 22 year old unit? My unit seems to throw out
adequate could air in 85 - 90 heat but just can't handle the higher
temps. My dash a/c unit is next to useless in this kind of heat.
I haven't calculated my mileage yet but it seemed to vary between 4.5
mpg and 6.5 mpg, depending on the grades I was climbing. This is with
the generator running full time and driving 70 - 75mph whenever the
terrain would allow..
I have a vibration in the coach that I will need to address if I am
allowed to keep it (I do have a for sale ad in the local paper). From
the wear on the passenger side bogie tire, I need to have a six wheel
alignment done. What do I need to look for in an alignment shop to be
sure they can handle this? How much should this cost?
Any other ideas on how to quiet down the noise in the coach (other than
slowing down). At 55mph the coach is fine; at 70 mph it's pretty noisy
and vibrates a lot.
Thanks
Bob Fukumoto
76 Palm Beach
(If I get to keep it)

 

[robert m fukumoto]

Bob:

I have several thoughts for you to ponder:

a. Are your side windows (including the sliders and above) and rear
window tinted? Yes, I put the reflective tinting with the highest =
rating on all the side windows. =20
b. Do you have a ball valve in your coolant hoses going to the
heater core? Yes, on both the dash heater core and an added on heater =
placed under the front dinette seat..=09

Although you don't mention specifically what bothers your wife What =
bothers her is the unprotected feeling that one has (that I have) when =
sitting in front of a window that basically goes down to your knees. =20
d. Perhaps your radiator cooling fins are starting to deteriorate
(rot away), they actually corrode and disintegrate, or the radiator
tubes need to be rodded out. Look at the bottom of the back side of the
radiator to verify if there is deterioration. If so, you should expect
to gradually with time notice the temperature gauge getting hotter and
hotter. I actually was very happy with the temperature performance of =
the coolant, expecially compared with what Henry said his coach ran.
e. Although I didn't see you mention it, was your thermostatic fan
clutch working? I think its fne as Winterfeldt put in a new fan clutch

Paul Bartz

 

[thomas g. warner]

Boy I can tell you that the thing that sold my wife on the GMC was the view
from the co-pilots seat. She did insist on installing the seat belts that
someone previously had removed.

Anyone know of a bad accident in a GMC where someone got hurt because of the
windows?

>In a message dated 8/10/98 12:42:11 PM Central Daylight Time, fukf19
>writes:
>
>not like sitting in the co-pilot's seat and I can understand why. Anyone
>figure out how to block some of the view out of the front windows?) >>
>
>Bob, if you have any Grandchildren, enlist their help., Grandmother probably
>couldn't withstand their pleas to keep the motorhome. That's what save me !
>
>