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Author Topic: 6v92ta no heat ?  (Read 1576 times)
sledhead
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« on: January 27, 2013, 11:02:22 AM »

We just came back to huntsville ont canada .Cold and snow ,had to wash off all the salt $#!% from the drive   Now a problem with heat yes heat ! on the drive from florida I couldnt get temp. over 140-150 f ? I had to jerry-rig my shutters to a switch on the dash and close and open manually to get the temp up to 180f . Outside temp. was as low as 19 f on fri. morning . And to top it off my electronic heat on the bus (red degital read out push botton ) is not working so no heat out of defroster or main heater.( only worked 2 out of 10 times I tried ) , so the floor heat was not as hot as it should have bean and the propane wall heat helped to keep the front warm . Is there a manual heat unit for this bus ? IN the fall I replaced the thermostats for new 170 f ( org were only 2 years old when eng. was rebuilt) Now I installed new ones same as org. t stats could they be in backwards ? Or can they stick open ? Since the eng, was rebuilt eng. has run cold . Frustrated as heck!

      thanks    dave                       
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1990 mci 102c  6v92 ta ht740  kit,living room slide . home base huntsville ontario canada
lostagain
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« Reply #1 on: January 27, 2013, 11:23:04 AM »

Regarding the heat in the coach, I would make sure the valves to the hot water lines are open in the engine compartment. You would think coolant even at 140F would heat the coach...

About the engine heat, you might have to drain the coolant to look at your thermostats to insure they are operating correctly, and to look at the tstat seals too.

I don't think the shutters have a lot to do with it. Once warmed up, the stats should be able to control engine heat by themselves. The shutters are more for a faster warm up from a cold start, and idling all night at 30 below.

JC
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JC
Invermere, BC
1977 MC5C, 6V92/HT740
Lin
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« Reply #2 on: January 27, 2013, 01:02:07 PM »

Was the heat working up until now?  If not, check the gate valves in the plumbing.  Mine has one in each of the supply and return lines plus a ball valve for the drivers heat next to the driver.  These valves may have been closed by the rebuilder when removing the engine.  Is your gauge accurate on the engine temp?

I may be wrong, but I had thought that the shutters did play a part in keeping up engine temp when as cold as 19 degrees.  Our shutters have been removed, but we don't go into that kind of cold weather.
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You don't have to believe everything you think.
sledhead
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« Reply #3 on: January 27, 2013, 02:18:46 PM »

Lin   yes the heat was working . I installed new t ststs because the org. ones did the same thing .some times they work fine 180 f but 1 in 7 runs only .Is it possible they were installed wrong and when i installed the 2nd set the same way    nothing changed ?
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1990 mci 102c  6v92 ta ht740  kit,living room slide . home base huntsville ontario canada
sledhead
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« Reply #4 on: January 27, 2013, 03:04:42 PM »

The driver, main heat is a seperate issue. The electronic control is a degital unit in the dash with red led read out . up buttons and down buttons for temp. settings. Is there a relay that turns on or opens a heat valve ?It does work sometimes but I would like to replace it with something simpler that works!           dave
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1990 mci 102c  6v92 ta ht740  kit,living room slide . home base huntsville ontario canada
lostagain
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« Reply #5 on: January 27, 2013, 03:23:50 PM »

There probably is some kind of solenoid valve that is controlled by your digital unit in the dash. I know there is one like that in the D model that I am familiar with. Do you have a manual for your coach? If not you should.

As for the stats and seals, you need to look it up in the engine service manual. If you don't have one, you can find one on EBay on CD for $15, $20. Look for Detroit Diesel V92 service manual.

JC
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JC
Invermere, BC
1977 MC5C, 6V92/HT740
hargreaves
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« Reply #6 on: January 27, 2013, 04:56:50 PM »

It wolud be pretty hard to install the thermostats upside down, but if the seals are worn out or torn, or maybe not there, it will cause issues. Did you change them when you did the stats?   Cheers Gerry
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hargreaves
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« Reply #7 on: January 27, 2013, 05:09:21 PM »

On some models there is a 24 volt activated worm gear driven body heat/ defrost valve in the first bay on the right hand side of the coach. It is behind a fiberglass cover. It is open when there is no power to it.  It  generally works in conjunction with the coach A/C,  Cheers Gerry
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now as of Feb 2012 series 50 B400  . Sunshine Coast British Columbia
sledhead
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« Reply #8 on: January 28, 2013, 05:30:38 AM »

# 1     

   all new gaskets,seals,2 new 170f t stats. Can they stick or is there something else I could look for?
# 2
  The light on the electronic unit on the dash comes on when heat is called for but I don't think it's telling the valve to open to allow heat !          thanks  dave
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1990 mci 102c  6v92 ta ht740  kit,living room slide . home base huntsville ontario canada
hargreaves
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« Reply #9 on: January 28, 2013, 04:28:58 PM »

Check the area I mentioned and see if there is a valve there. It should have one power wire and a ground that will go to the chassis.  Cheers Gerry
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now as of Feb 2012 series 50 B400  . Sunshine Coast British Columbia
eagle19952
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« Reply #10 on: January 28, 2013, 04:48:40 PM »

WHY WOULD YOU USE 170* TSTATS ?
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Donald PH
1978 Model 05 Eagle w/Torsilastic Suspension,8V71 NA, DDAllison on 24.5's 12kw Kubota.
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buswarrior
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« Reply #11 on: January 28, 2013, 06:51:54 PM »

Well, hold on a minute. Multiple problems and combined diagnosis mixed with frozen bits...

We need to figure out what the problems really are.

For instance, air locked defroster and a broken wire to the heat control valve equals frozen busNUTS.

1) How do you know your temperature gauge is accurate? May be lots of heat, but you can't get it into the coach? What is a Canadian doing running 170 degree thermostats?

2) Check for power at the water valve in the front baggage hold when the dash indicates it is calling for heat. Rig a hot wire to test it.

3) Are you air locked? How did you get all the air out after you swapped thermostats?

4) Check for air in the top of the defroster heat exchanger, there is a bleeder on the top of the unit.

5) As others have pointed out, confirm BOTH big valves are open in the engine room, easy one is inside curb side, side engine access door, the other is above the engine, above the transmission, where the pipes start heading into the utility channel.

Let us know!

happy coaching!
buswarrior

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Frozen North, Greater Toronto Area
sledhead
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« Reply #12 on: January 29, 2013, 05:36:24 AM »

Tstats    When I replaced them I drained out aprox. 8 gal and 8 gal went back in .I will check the bleeder in defroster . I have checked with lazer many times and the dash gage is really close . All valves are open . Other then our trip to and from florida each year I don't drive the bus in winter ( 170 stats ) IT is the tstats that concern me the most .

With the dash unit I was hoping to replace it as this has happened before. Is there a unit that I can replace it with ?                  thanks   dave   
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1990 mci 102c  6v92 ta ht740  kit,living room slide . home base huntsville ontario canada
eagle19952
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« Reply #13 on: January 29, 2013, 08:35:22 AM »

thermostats allow the motor to heat up to the set temp and then open.....a lower number just means that they open sooner....and begin cooling/sending coolant to the radiator.
imo you do a DD more harm running it that cold. alot more.
if you are using 170* stats to cure a overheating problem...you still have a problem.
ps these are questions and thoughts.
« Last Edit: January 29, 2013, 08:37:40 AM by eagle19952 » Logged

Donald PH
1978 Model 05 Eagle w/Torsilastic Suspension,8V71 NA, DDAllison on 24.5's 12kw Kubota.
Wants Paint Smiley
Previously owned by Wee Willie Ent.
sledhead
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« Reply #14 on: January 29, 2013, 03:16:26 PM »

The tstats are not working and I am tring to find out why.In 2010 when the eng. was rebuilt is when the problem started but not very often (would not come up to temp.170 or 180 ) I changed the tstats in the fall and the temp. was up to 175 on the lazer .Thought It was fixed .Since then it has slowly getting worse .On the trip to florida after 4-5 hrs of running to get temp up past 160 f.Is there a reason for the tstats to stick open ?      thanks    dave 
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1990 mci 102c  6v92 ta ht740  kit,living room slide . home base huntsville ontario canada
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