Low temp in winter? Ideas?

[neoneddy]

Took ol Red out to Owatonna,mntonoght to see our local Junior hockey club play an away game.

I thought it might be fun for the family to relax and enjoy the ride and sleep well on the way back.

Anyway I noticed the temp gauge never got much over 140-145. 180 is optimal for complete fuel burn right?  I did notice a little white smoke when I really have it the go juice.

The otr heater is installed and used, got it to a comfy 74 inside by the time we got home.

Nothing else to report.


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[bevans6]

Do you have the shutters and dampers still installed?  MCI used  a "shutterstat" system to activate air powered shutters in front of the radiators and dampers to kill the efficiency of the big fans if the engine was running too cold.  The shutterstat closes at 178 degrees, so MIC obviously wants the engine to run around 180.  Ditto the thermostats open at 170 degrees, fully open at 185 degrees.  This is for a 8v71, might be a little different if you have another engine, but close.

[luvrbus]

You don't want to run the 6v92 that cold 170 is the minimum it causes a washout as it is called in the engine world and you will be rebuilding the 6v92 if you don't get the temp up,we would change the t stats to the fully closing type in cold weather.You can also have the snap on type covers made for each side and adjust those I had a set for my MCI 8 to help keep it warm in Idaho I bought from MCI,get the temp up though are you will have problems JMO     

[neoneddy]

Ok, thanks guys, didn't know it was that dire, everyone always talked about overheating being the big one. We only put 180 miles or so on it in this condition. My next stop will be to DD shop down the road.


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[Geoff]

It could be your temperature gauge.  Buy a laser temperature gun and check.  They are on sale this weekend at Harbor Freight, $17

[neoneddy]

Update: checked my louvers on the raditors and they moved freely. I guess they aren't getting activated for.some reason, I'm 95% sure they were open last night.


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[neoneddy]

It could be your temperature gauge.  Buy a laser temperature gun and check.  They are on sale this weekend at Harbor Freight, $17

Thanks Geoff, I have one but didn't think to use it when I got home. I had to manually shut off the engine, that darn shutoff selonoid keeps sticking.

Anyway, when I'd did that everything felt abnormally cold. When I first bought the bus last year it was in freezing temps and it was much hotter.   

Can thermostats fail open? I suppose that preferable to failing closed.


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[Scott & Heather]

Time to get 180°F Tstats. Problem solved


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[chessie4905]

I wouldn't jump on thermostats. If shutters are staying open, check to see if the air shutoff valve is open. If it is, loosen airline going to shutterstat. If you have airflow, replace shutterstat. They're usually Kysor of Cadillac. They are available on eBay and most likely Luke and others. The temp setting should be stamped on shutterstat.
If you don't have air supply to shutterstat, figure out why. Follow air lines to make sure you are checking the input side. The output goes to the shutter cylinder. If you have air on both sides of shutterstat, then the problem is in cylinder, linkage or shutters.

[neoneddy]

I wouldn't jump on thermostats. If shutters are staying open, check to see if the air shutoff valve is open. If it is, loosen airline going to shutterstat. If you have airflow, replace shutterstat. They're usually Kysor of Cadillac. They are available on eBay and most likely Luke and others. The temp setting should be stamped on shutterstat.
If you don't have air supply to shutterstat, figure out why. Follow air lines to make sure you are checking the input side. The output goes to the shutter cylinder. If you have air on both sides of shutterstat, then the problem is in cylinder, linkage or shutters.

Where is the shutter stat and or what does it look like?


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[Geoff]

I don't think shutters are THE problem.  The thermostats should keep the engine at minimum 175F.  And the thermostats can fail in any position.

[lostagain]

I don't have shutters, and the engine always goes up to 180, 185 no matter how cold outside. I think shutters have a benefit only for idling in winter, or driving around town when you're not running hard enough to make enough heat. Modern coaches don't have shutters, they have coolant heaters like Webasto, that maintain operating temperature in slow going.

JC

[sledhead]

on my mci even after I rebuilt it and bumped the power to 350 hp if the shutters did not close when it is cold I could never get any heat up front unless you were going up a big hill under load . if the temperature is not cold you never have a problem . I always lubed the system and checked the air lines

dave

[neoneddy]

Update : got out one of the handyman's secret weapons and sprayed WD40 and lithium grease on the shutter attach points as well as the air piston.

Next I did find the shutter stat, I saw an adjustment handle and did some once the coach was aired up. At first the adjuster was snug tight. I loosened it some and noticed I could no longer move the shutters by hand, and then they shut on my fingers. No biggie, flexible aluminum.

I took it for a drive and sure enough she came up to temp , but then it kept rising.   I never let it get above 190-195.   Next I adjusted it tight closed again and the temp dropped to 160ish , heading to 145.   So I opened it just a smidge and the shutters popped shut this time.   I made it home with temp 190-195 and Parker it still scratching my head but about new problems.


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[richard5933]

My earlier research on the subject of shutters seemed to indicate that one of the reasons for the shutters is to aid in building heat if the OTR heating system is still in place. Since the OTR heat acts like a secondary radiator shedding heat to inside the coach, the closed shutters help keep the engine radiator from also shedding heat in extreme cold conditions. Apparently running the OTR heat and having the airflow into the engine bay will keep the engine at too low a temp. I'm guessing that it has something to do with reducing air flow across the engine and not just across the radiator, since the thermostat can shut off the flow to the radiator when the engine is too cold. The thermostat cannot, however, cut off air flow across the engine bay. At least on the 4108 the engine fan is always spinning, so the shutters are about the only way to keep cold air from entering the engine bay.

Mine are still not fully functional, but it's on my list of things to accomplish once the spring weather creeps up on us. I'm going to sit this winter out.