Radiator temp in/out and temp gauge readings

[Tom Warner]

You obviously are not listening to all of the advice you were given. If you
have a temperature gauge on your dash then you can very easily tell if your
thermostats are opening at the proper time and working correctly. WATCH the
gauge that is what they put it there for. The temperature will continue to
climb but should hit the thermostat temperature quickly when the engine is
running and you can see as the thermostat opens since the temp will start
to drop. Then the temp will stop going down again and slowly build up until
the thermostat once again opens and this cycle will continue until it
stabalizes. If the temp does not rise rather quickly after running the
engine with the bus moving, then most likely the thermostats are not
closing and are wide open. If the temp keeps climbing with out cycling off
and on then the thermostat is frozen shut.
If the bottom hose on the radiator is always cold, then once again the
thermostat is not opening and coolant is not flowing thru the radiator.
Same thing when you take the radiator cap off and watch the coolant flow
thru the radiator. You can tell when the thermostat opens since you will
immediately see coolant flow past the radiator neck.

For all of these you dont need a toy...you need to understand how the
cooling system works and how to troubleshoot it.

tom
1982 FC35
Vernon Center, NY


At 03:43 PM 7/20/2005 +0000, you wrote:
>George,
>
> 1. First of all, the post you are referring to was about a
>different bus, on my RTS, with a different problem. It turned out
>that deep within the radiator fins there was crud and buildup on
>over half the radiator, thus making cooling difficult. This current
>problem is with a Bluebird.
> 2. It was just over a week ago when I addressed this problem,
>not three, and it's a long term project so I'm in no rush. I'm in
>the process of learning as much as I can about the Bluebird bus
>line, so forgive me if I ask a lot of questions.
> 3. Your advice was to replace the thermostats. I had 3 members
>from this board and 3 others from another board tell me to get the
>infrared gun to help diagnosis, so I did.
> 4. I don't recall argueing with anyone on this board about any
>of their advice. I appreciate everyone's input and gain as much I
>can from what they state. Your's was helpful also and gave me
>something to think about.
> 5. I wanted to get a tool that I could use in the future as well
>as now. I'm sure all the folks that told me to get it don't think of
>it as a "toy", but as a valuable tool to diagnose problems instead
>of just throwing parts at an engine.
> 6. I was just curious if you could diagnose a bad thermostat
>without having to loosen the hoses, lose antifreeze, test and
>replace the part and gasket, bleed the system if needed, and dispose
>of old antifreeze. I'm a big fan of making a quick diagnosis if
>possible. And from what I can tell, this gun will be able to help do
>that. So in the time it would take for me do all that, the toy would
>have paid for itself.
>
> If you wish to offer any advice please do. But I hate screwing
>around as much as anyone would. That's why I followed the majority's
>advice.
> And I'm taking it that there is NO possible way that you think a
>bad thermostat can be diagnosed without taking it out. I won't argue
>with you since you have the experience. Thanks again for your input.
>
>Steve
>2 '98 QBRE Bluebird
>
>
>
>--- In WanderlodgeForum@yahoogroups.com, "mrdonut12"
><mrdonut12@y...> wrote:
> >
> > Steve,
> > Forgive me if I'm a little short with you, but I'm a
>professional
> > mechanic with over 30 years experience, ASE Certified Master
> > Technician, Advanced L-1 Engine Performance Certification,
> > Service Advisor Certification and I own one of the best auto repair
> > shops in the US. In 10 years in business, my shop has fixed over
> > 34,000 cars.
> > I told you 3 weeks ago, the first step in fixing this thing
>is
> > to install new factory thermostats. You have to establish
>baselines
> > of performance in a system in order to fix it. No other part of
>the
> > cooling system can be properly evaluated with malfunctioning
> > thermostats in place.
> > Thermostats get old, they wear out and they break.
> > You asked my advice, I gave it to you, you argued with me and
> > went out and bought a new toy that costs about 7 times what a
> > thermostat would cost and now you want me to answer more questions.
> > My question to you is, do you want to screw around or do you
>want
> > to fix this thing?
> >
> > George Witt
> > 81 FC 35
> > Lincoln, Nebraska
> >
> > --- In WanderlodgeForum@yahoogroups.com, "transit360"
> > wrote:
> > > Tom and George,
> > >
> > > OK, sorry guys. I forgot to mention I also shot a temp
>reading on
> > > the hose going in and out of the water pump, both at around 200
> > > degrees also.
> > > To be honest with you, I'm not sure where my thermostat is.
>I'm
> > > assuming it's in a usual spot near the water pump, but I've
>never
> > > worked on the 8.3 Cummins before, and I've been trying to find a
> > > manual for a month. But it should be a no-brainer.
> > > So I'm gathering that we're suspecting improper coolant
>flow,
> > > which could be caused by a stuck thermostat or possibly a weak
>water
> > > pump? I'm assuming when I locate the thermostat that I should be
> > > able to shoot it at operating temp and the temp should be the
>same
> > > on both sides, otherwise a temp difference would indicate it's
> > > closed, yes? Sounds feasible.
> > > However, this is pretty much how this bus has always run,
> > > around 200 degrees on the highway. Wouldn't it overheat if the
> > > thermostat stayed closed? Could it be partially open or closed?
>That
> > > would restrict flow but maybe not enough to totally overheat the
> > > engine?
> > >
> > > Thanks,
> > > Steve
> > > 2 '98 Bluebird QBRE Partybuses
> > >
> > > --- In WanderlodgeForum@yahoogroups.com, Tom Warner
>
> > > wrote:
> > > > George what he established is that the radiator is not
>exhanging
> > > heat.
> > > > There should be only about a 10-15 degree difference between
>the
> > > temp at
> > > > the top and bottom. If not the coolant is not flowing more
>then
> > > likely
> > > > because the thermostat is not open.
> > > >
> > > > tom
> > > > 1982 FC35
> > > > Vernon Center,Ny
> > > >
> > > > At 02:15 AM 7/20/2005 +0000, you wrote:
> > > > >Steve,
> > > > > You've established that the radiator, at the current flow
> > > > >rate, is capable of exchanging heat.
> > > > > What you haven't established is if there's any water
>flow.
> > > > >With that deep a drop in temperature, does that tell you that
> > > maybe
> > > > >the coolant is flowing too slowly?
> > > > > Use your Raytek infrared temp gun to tell you if the
> > > thermostat
> > > > >is working properly.
> > > > >
> > > > > George Witt
> > > > > 81 FC 35
> > > > > Lincoln, Nebraska
> > > > >
> > > > >
> > > > >--- In WanderlodgeForum@yahoogroups.com, "transit360"
> > > > > wrote:
> > > > > > I just got my new Raytek infrared temp gun and was
>getting
> > > some
> > > > > > shots on my 8.3 Cummins pusher in my '98 QBRE Partybus. I
>shot
> > > the
> > > > > > top of the radiator and it read 200 degrees, which is what
>my
> > > bus
> > > > > > temp gauge said. I shot the lower radiator hose and it
>read 130
> > > > > > degrees.
> > > > > > I made sure to test location and reposition my gun
>several
> > > > > > times, and this is what I got. Should there be such a
>drastic
> > > change
> > > > > > in temp through the radiator? I was expecting about 15-20
> > > degrees
> > > > > > difference. Could this indicate any problems?
> > > > > >
> > > > > > Second question: My temp gauge on the dash has green
>(safe)
> > > > > > markings up to 220 degrees. Past 220, it reads in the red.
>My
> > > bird
> > > > > > typically runs at 200 degrees while riding. Is this
>normal?
> > > Seems a
> > > > > > little on the warm side but this is my first Cummins as I
>have
> > > dealt
> > > > > > primarily with 8.2 and 6V71 Detroits in the past. My other
> > > Bluebird
> > > > > > partybus (same exact bus) runs at about 190, although I
>haven't
> > > > > > confirmed it with the temp gun like the first.
> > > > > >
> > > > > > Thanks,
> > > > > > Steve
> > > > > > 2 '98 Bluebird QBRE Partybuses
> > > > >
> > > > >
> > > > >
> > > > >
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