Low temp in winter? Ideas?

[eagle19952]

Time to get 180°F Tstats. Problem solved


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in the dead of winter (-20 below or lower) we used 190 degree  T-stats.

the metallurgy involved is like Clifford says: If the motor doesn't expand with heat as designed, you are churning,grinding,piston slapping the motor to a slow early demise.

[chessie4905]

Turboes work best with engine at designed full operating tempearture.

[neoneddy]

With some reflection I'm thinking two things were or are going on.

1) the thermostat is stuck open. It needs to be replaced. I suppose I should thank my lucky stars it did that vs sticking closed on a trip.

2) the shutter stats are maybe working?  It seems this is a manual control for extreme cold. This bus is from a northern MN transit company.  Or should they automatically open and closes as needed?


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[eagle19952]

With some reflection I'm thinking two things were or are going on.

1) the thermostat is stuck open. It needs to be replaced. I suppose I should thank my lucky stars it did that vs sticking closed on a trip.

2) the shutter stats are maybe working?  It seems this is a manual control for extreme cold. This bus is from a northern MN transit company.  Or should they automatically open and closes as needed?


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they should be controlled by a shutterstat. shutterstats seldom go bad perhaps yours did and someone put a shut off there....

[RJ]

Eddy -

My MC-5C still has the original shutters on the radiators, and they've been working fine.  I just lubed them a couple of weeks ago, so they're operating even more freely now (not that they were sticking before.)

Anyway, on the roof of the engine compartment, underneath the blowers and to the right of the RH blower discharge, I have a "goodie" (for want of a better term) that has a valve on it fed with air lines.  By opening or closing this valve, it either turns the shutters on or off.  Default with the shutters "off" puts them in the open position, with the shutters "on" they open and close according to coolant temp, but I haven't found that sensor yet.

Your MC-8 should be very similar to my 5C, so you might try looking for this valve, it's probably in the same general area.

FWIW & HTH. . .

 

[Scott & Heather]

Sorry, have to disagree on the shutters thing. I’ve had them on both my coaches and they were a pain. They also block some of the much needed air flow needed to cool my 500 hp. My tstats work perfectly to keep my Bus at 180 degrees even when it’s below freezing outside. Every single diesel car and truck on the road today uses a thermostat to maintain engine temp....no shutters in front of radiators. To each their own, but I tossed mine and haven’t had any issues in 8 years of fulltiming even up north in -22f temps and 20,000 miles a year on the Bus.


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[richard5933]

Sorry, have to disagree on the shutters thing. I’ve had them on both my coaches and they were a pain. They also block some of the much needed air flow needed to cool my 500 hp. My tstats work perfectly to keep my Bus at 180 degrees even when it’s below freezing outside. Every single diesel car and truck on the road today uses a thermostat to maintain engine temp....no shutters in front of radiators. To each their own, but I tossed mine and haven’t had any issues in 8 years of fulltiming even up north in -22f temps and 20,000 miles a year on the Bus.


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If they don't accomplish anything that the thermostats don't already accomplish, then why are they there? Not like GM or MCI to waste money on unnecessary do-dads.  Around here in SE Wisconsin it's quite common to see entire fleets of school buses with their noses covered with snap-op covers during the coldest of winter. Same with fleets of semis. 

I'm wondering if you have a different scenario running turbo engines than someone running a more stock setup which doesn't produce as much heat?

[chessie4905]

500 hp engines are hot even when not running. These coaches were designed with smaller injectors and could run cool in some conditions. Also needed shutters when idling at depots in cooler temps to have heat for interiors. The efficiency of a diesel engine makes the least amount of heat at idle.Anyway, what you prefer for your own use should be fine. Besides, most of us don't use ours in cold temps much.

[bevans6]

In original charter use a bus might sit in the parking lot of the ski resort for 6 - 8 hours idling with interior heat on.  An idling engine needs a lot of help to keep warm, hence the shutters and dampers would automatically close to help keep things circulating.  In original use, being able to warm up quickly to operating temp while idling in a depot or lot was important, so the first passengers of the day had a warm bus to enter.  Closed shutters and dampers made this a lot more possible.  The bus was designed for very different uses than our typical requirement.  I removed my shutters entirely, and wired my dampers full open.  I also never run in below freezing temps.

Brian

[neoneddy]

Eddy -

Anyway, on the roof of the engine compartment, underneath the blowers and to the right of the RH blower discharge, I have a "goodie" (for want of a better term) that has a valve on it fed with air lines.  By opening or closing this valve, it either turns the shutters on or off.  Default with the shutters "off" puts them in the open position, with the shutters "on" they open and close according to coolant temp, but I haven't found that sensor yet.

Your MC-8 should be very similar to my 5C, so you might try looking for this valve, it's probably in the same general area.

FWIW & HTH. . .

 

Here is my dingus you describe. So far mine never closed, maybe they would if temps went over 200 but I don't want to get there.





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[buswarrior]

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.

That is not an adjustment, it is an air valve. Open or shut.

Follow the other lines off the control device, (edit after seeing the picture: follow both lines attached to the control back, the sensor is inline, opens or closes the air line,) the lines that go to the sensor should end in a screwed into a coolant tube somewhere, the other is the air line to the shutters. The temperature sensing part may need some encouragement to function, nothing to lose, open the air lines and see if penetrating oil will help, otherwise, you now know why the air valve was closed, there's something wrong in the controls.

Cold engine and proper air pressure present, the shutters should close. This is a harder time of year to troubleshoot, because gaining hot engine temps to confirm the shutters open is not always easy...

Lubing the shutter fins contact points is folly. The lube will quickly pick up all the dust and dirt that flies through the cavity, and then they jamb up again. If the shutter fins are actually stuck, meaning there is crud in the pivot points, then by all means, use lube to get stuff moving again, and then plan on a good soapy wash so all that dirt just blows on by.

happy coaching!
buswarrior

[Geoff]

When running in freezing temperatures my engine runs at 175F but the heater lines going to the interior of the bus cool down quite a bit and the outside cold creeps in.  That is when it is time to turn on the Webasto to keep the interior warm. 

[luvrbus]

Shutters are old technology you never see those anymore,they are supposed to close air tight for warm ups in about 1 year you could forget about that.I have a stack of those things from MCI's , FWIW I never saw but 2 Eagle buses with shutters and they didn't work.Now the buses use the diesel fired units on a timer a driver goes out the cabin is nice and comfy and the engine is warm ready to go    

[buswarrior]

The Dodge Ram EcoDiesel and the Chevy Cruise Eco have shutters in 'em?

Aerodynamic purpose and some heat retention.

happy coaching!
buswarrior

[Geoff]

Nobody has mentioned fan clutches.  They are the update to shutters.  Wish I had one but the only one I have seen for my particular bus and engine was in a bus at the First Capital Auction in Vallejo, CA.  I wasn't going to buy a whole bus just for the fan clutch, although I could of bought the whole bus for the less than the price of a new fan clutch.