During the past 5 days of travel, twice the engine has just stopped.
1st. - on I-17 south of Flagstaff going toward toward the north, uphill.
2nd - on US 93 just over Hoover Dam going uphill toward Las Vegas.

Both times, midafternoon in the heat of the day. Both times, the only warning was a brief high pitched noise (alarm?) coming from the dash area.

First time the mobile mechanic thought dirty fuel, so replace the filter. Second time a different mechanic thought dirty air cleaner, replace air filter.

First mechanic thought that the may be something with the engine (CAT 3208, 1989 vintage) that prevents overheating, so it shuts down the engine.

Both times, after waiting about 4 hours, the engine did restart with no problems, just prior to the arrival of the mechanic.

So, should I try to make it back to Mesa, AZ and avoid all of the uphill routes, perhaps go US 95 through CA to I-10 then to Mesa?

What could be the issue? Upon my return to Mesa, we will stay there a week, prior to heading to Indianapolis for the month of June. If possible I would like to do that option and then take the coach to a CAT dealer in Indy that I trust. The engine has 104K miles on it and was service in Port Charlotte FL for the 100K service.

Thom Feit
1990 Regency Widebody, 300hp CAT, Gillig Chassis, no toad.

I would suspect that the engine is going thru a high temp shutdown to protect itself from the operator. It could also be shutting down from a low coolant level. These are engine protection devices. Even if you can see the coolant that doesn't mean that the level is above the probe while pulling a hill.

What temps were you pushing? Could your oil psi have dropped? How long was the buzzing noise on for? Did you check your fuel shutdown solenoid with a test light? Did you loose anything else electrical during this event? What was the voltage like?

brief high pitched noise (alarm?) coming from the dash area.

Sounds (pun)like the "high temp" alarm.

While you are checking the coolant ALSO check to see if the radiator is dirty. Pushers are known for pulling dirt into the rad and if there is any oil around the engine the two like to mix and plug things up. A can of gunk and a GENTLE sprayout often will cure problems with overheating. DO NOT USE A POWER WASHER, ask me how i know this! ;>)

quote:

What temps were you pushing? Could your oil psi have dropped? How long was the buzzing noise on for? Did you check your fuel shutdown solenoid with a test light? Did you loose anything else electrical during this event? What was the voltage like?

Since it is now late in NY, here are my responses - as best I can. As best remembered, the temps were mid range, no warning light for oil temp, etc.

Buzzing was for perhaps 1 to 3 minutes each time. I knew there were problems the second time, so I quickly moved off the highway.

Do not have a test light for solenoid. Lost those items that do not operate when engine is not running and ignation switch is off.

Testing the coolant level - I removed the cap from the overflow and with my finger as the "dip stick" there was about 1" in the container. I could not find any gauge, level indicator, etc. I did put about gallon of coolant in the unit prior to leaving Mesa.

There were no warning lights on the dash that gave any indication - except for the "low air pressure" at the very end as I would pull off the road.

Thom

I would suspect a bad electrical connection either at the cooling level sensor (mine fell off once and gave me a "low coolant" light, but that doesn't shut down the 6.5L TD).

The other would be to check connections at the fuel shutoff solenoid.

I don't recall how the 3208 shutdown system is wired (i.e., whether there's a low oil pressure switch separate from the gauge sender, but it surely sounds like there's a gremlin somewhere in the sensors or the shutoff solenoid.

quote:

Originally posted by thomfeit:
Buzzing was for perhaps 1 to 3 minutes each time.

It sounds like you have a Kysor Engine Shutdown System.

Look at this link and see if any of these items look familiar to you.

I will take exception to his info in that the system operates in a warning mode for temp at 214 and then shutdown at 220 or with a different sensor at 205 warning & 210 shutdown.

Oil psi warning is 9lbs and then shutdown at 5 lbs.

They have some sysytems with a built in 30 second timer too. You would have to look to find out which system you have.

There is a bypass if you have good oil psi and coolant temps. Keep in mind that if you bypass and there is a problem your going to be very upset with yourself.



This is your fuel shutdown solenoid. On a Cat you run a jumper wire from a 12v power source to the wire that doesn't go to ground. In this picture that wire is on the left side. You should hear a clunk. If you don't then the Fuel Shutdown Solenoid is defective. This should lift the plunger off of the stop inside of the fuel injector pump.

Depending upon the type of Kysor (if this is what you got) you have would tell me how to jump it out at the control panel. There is an Ignition terminal and a Load terminal. Some might say Ignition and Solenoid and still another might say Ignition and Fuel.

I enclosed that link because it's correct in most of what's said.

Bill N.Y.

Gary Gruber owner of a 34 foot Regency had exactly the same problem. Here is his email address nuevomex@mac.com.

Interesting link, Bill N Y; BTW, if one clicks on this sub-link a free book can be downloaded. Unfortunately, much of the terminology is incorrect, and many of the conclusions are off-base and/or ill-informed. However, much of what is explained is reasonably useful.

quote:

Originally posted by Rusty:
much of the terminology is incorrect...However, much of what is explained is reasonably useful.

That's what I thought too. You can easly make out what he's talking about but he seems to gloss over or skip the hard facts. I just typed in Kysor shutdown for Google and got this link. Seeing that it was very close I linked it.

There aren't any truck engines being produced now that doesn't already have a shutdown feature built into the ECM. You just change the operating parameters to what you want. But back then, Kysor was king.

The basic design is N.O. and N.C. circuits running thru a control panel that really wasn't more then a glorified relay bank with leads going off of it for power, ground, signal lines and fuel solenoid. The real workings were in the sending units.

Look back at those picture in his post. You'll see the coolant one leaking onto the hose below. We know that coolant will pass electricity. That sending unit should be replaced.

You could have taken the sending units and ran them thru two or three 5 pole relay and did the same thing without a timed shutdown. Get fancy and add in a time delay relay and then you have it.

Bill N.Y.

Well, we made it back to Mesa, where the coach will set while we travel by car to Indy then to Ft. Myers to sell our house in FL prior to returning to Mesa to live.

My real question has become - what will cause the engine to overheat? What preventive measures should be taken? I now believe the engine was protecting itself, and that overheating was the fault, not the indicator.

Thanks for all of the info.

Thom

Uphill both times? Sounds like your engine was lugged down which will raise the temp real quick. Try downshifting sooner. The 2 most important gauges on my bus are the tach and the temp guage. Even though i have an Allison Auto trans i always try to downshift it manually instead of letting it do it on its own.