Simple overheating diagnosis

[transit360]

I'm working on an RTS (taking a break from my 2 Bluebirds),
however my question is general and not specific to just one bus.
How can I tell if I'm getting proper flow of coolant through
the radiator? I will be purchasing an infrared non-contact temp gun
(where is the best place to get them?), but for now, I am collecting
advice on radiator dynamics.
I got the old bus to operating temp, but while driving I
notice she gets little hot. I checked the radiator when I got home
and on the outside I put my hand on it and was NOT hot to the touch.
The tanks on either side were super-hot. I shut the bus off and felt
the inside (towards the engine), and the top of the radiator was
warm, not hot, and the bottom was hotter. What does this tell me?
I did find on hot spot on the lower part of the radiator, and
after looking contributed it to being clogged with oil and dirt. The
rest of the fins looked good. What's the best way to clean the fins
in the radiator?
My fan is working great, coolant is good. Any suggestions on
diagnosing a worn water pump? Just looking to get this thing running
as cool as possible. Thanks.

Steve
'79 GMC RTS and 2 '98 Bluebird QBRE's

[ronmarabito2002]

The simplest way is to use an infra-red thermometer. Check the
inlet end of the radiator and then the outlet end. There should be
about a 15 degree swing in temperatures. If not, the radiator needs
to be cleaned out.

R.E. (Ron) Marabito, Dallas, TX 92WB40
Moderator



--- In WanderlodgeForum@yahoogroups.com, "transit360"
wrote:
> I'm working on an RTS (taking a break from my 2 Bluebirds),
> however my question is general and not specific to just one bus.
> How can I tell if I'm getting proper flow of coolant through
> the radiator? I will be purchasing an infrared non-contact temp
gun
> (where is the best place to get them?), but for now, I am
collecting
> advice on radiator dynamics.
> I got the old bus to operating temp, but while driving I
> notice she gets little hot. I checked the radiator when I got home
> and on the outside I put my hand on it and was NOT hot to the
touch.
> The tanks on either side were super-hot. I shut the bus off and
felt
> the inside (towards the engine), and the top of the radiator was
> warm, not hot, and the bottom was hotter. What does this tell me?
> I did find on hot spot on the lower part of the radiator,
and
> after looking contributed it to being clogged with oil and dirt.
The
> rest of the fins looked good. What's the best way to clean the
fins
> in the radiator?
> My fan is working great, coolant is good. Any suggestions on
> diagnosing a worn water pump? Just looking to get this thing
running
> as cool as possible. Thanks.
>
> Steve
> '79 GMC RTS and 2 '98 Bluebird QBRE's

[rrob@...]

Steve I bought my IR temp gun from Radio Shack on sale for $25 but I hear they
are now twice that. I use it every day on the road to check tire temp at rest
stops. I use a tire guage first thing in the morning and IR the rest of the
day.

Quoting transit360 :

>
>
>
>
>      I'm working on an RTS (taking a break from my 2 Bluebirds),
>
> however my question is general and not specific to just one bus.
>
>      How can I tell if I'm getting proper flow of coolant through
>
> the radiator? I will be purchasing an infrared non-contact temp gun
>
> (where is the best place to get them?), but for now, I am collecting
>
> advice on radiator dynamics.
>
>       I got the old bus to operating temp, but while driving I
>
> notice she gets little hot. I checked the radiator when I got home
>
> and on the outside I put my hand on it and was NOT hot to the touch.
>
> The tanks on either side were super-hot. I shut the bus off and felt
>
> the inside (towards the engine), and the top of the radiator was
>
> warm, not hot, and the bottom was hotter. What does this tell me?
>
>       I did find on hot spot on the lower part of the radiator, and
>
> after looking contributed it to being clogged with oil and dirt. The
>
> rest of the fins looked good. What's the best way to clean the fins
>
> in the radiator?
>
>       My fan is working great, coolant is good. Any suggestions on
>
> diagnosing a worn water pump? Just looking to get this thing running
>
> as cool as possible. Thanks.
>
>
>
> Steve
>
> '79 GMC RTS and 2 '98 Bluebird QBRE's
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>
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[mrdonut12]

Based on what you've said, I'd replace the engine thermostat
before I did anything else. That's a "baseline" repair to start.
Until you do that, you're just guessing. They're cheap and
they wear out.

George Witt
81 FC 35
Lincoln, Nebraska


--- In WanderlodgeForum@yahoogroups.com, "transit360"
wrote:
> I'm working on an RTS (taking a break from my 2 Bluebirds),
> however my question is general and not specific to just one bus.
> How can I tell if I'm getting proper flow of coolant through
> the radiator? I will be purchasing an infrared non-contact temp gun
> (where is the best place to get them?), but for now, I am collecting
> advice on radiator dynamics.
> I got the old bus to operating temp, but while driving I
> notice she gets little hot. I checked the radiator when I got home
> and on the outside I put my hand on it and was NOT hot to the touch.
> The tanks on either side were super-hot. I shut the bus off and felt
> the inside (towards the engine), and the top of the radiator was
> warm, not hot, and the bottom was hotter. What does this tell me?
> I did find on hot spot on the lower part of the radiator, and
> after looking contributed it to being clogged with oil and dirt. The
> rest of the fins looked good. What's the best way to clean the fins
> in the radiator?
> My fan is working great, coolant is good. Any suggestions on
> diagnosing a worn water pump? Just looking to get this thing running
> as cool as possible. Thanks.
>
> Steve
> '79 GMC RTS and 2 '98 Bluebird QBRE's

[transit360]

Mainly what I'm trying to diagnose is whether or not I'm
getting proper coolant flow through the radiator. I was a little
surprised to be able to lay my hand on the center of the radiator
and have the tank scalding hot. Is that normal?
The bus mainly gets a little hot when I'm running the A/C, and
it was about 80 degrees yesterday here, and I'm on the interstate
running. It was steadily slowly climbing towards 205. I can park the
bus and it comes down within minutes to a normal operating temp of
around 185.
That's why I'm gonna get a temp gun, to confirm what my gauge
is saying with accurate shots of the engine.
I don't think it's the thermostats, but could be I guess. I'm
thinking more along the lines of some clogged passageways INSIDE the
radiator or worn water pump. So any input on how I could diagnose
those would be great.

Steve
'79 GMC RTS 6V71


--- In WanderlodgeForum@yahoogroups.com, "mrdonut12"
<mrdonut12@y...> wrote:
> Based on what you've said, I'd replace the engine thermostat
> before I did anything else. That's a "baseline" repair to start.
> Until you do that, you're just guessing. They're cheap and
> they wear out.
>
> George Witt
> 81 FC 35
> Lincoln, Nebraska
>
>
> --- In WanderlodgeForum@yahoogroups.com, "transit360"
> wrote:
> > I'm working on an RTS (taking a break from my 2 Bluebirds),
> > however my question is general and not specific to just one bus.
> > How can I tell if I'm getting proper flow of coolant
through
> > the radiator? I will be purchasing an infrared non-contact temp
gun
> > (where is the best place to get them?), but for now, I am
collecting
> > advice on radiator dynamics.
> > I got the old bus to operating temp, but while driving I
> > notice she gets little hot. I checked the radiator when I got
home
> > and on the outside I put my hand on it and was NOT hot to the
touch.
> > The tanks on either side were super-hot. I shut the bus off and
felt
> > the inside (towards the engine), and the top of the radiator was
> > warm, not hot, and the bottom was hotter. What does this tell
me?
> > I did find on hot spot on the lower part of the radiator,
and
> > after looking contributed it to being clogged with oil and dirt.
The
> > rest of the fins looked good. What's the best way to clean the
fins
> > in the radiator?
> > My fan is working great, coolant is good. Any suggestions
on
> > diagnosing a worn water pump? Just looking to get this thing
running
> > as cool as possible. Thanks.
> >
> > Steve
> > '79 GMC RTS and 2 '98 Bluebird QBRE's