DTA360 Overheating in '93 Amtran Genesis

bret2094 · 03-01-2021, 12:29 PM

Hello all,

Yesterday we picked up a '93 Amtran Genesis 38ft bus with the DTA360. she's got 230k miles and we were able to limp her from Houston to College Station, TX back to my house. We bought it with the intention of ripping the seats out, using it to move and then converting it into a skoolie, however we are having some issues. The bus gets quite warm while on the highway. it idles all day at 180 degrees, but once you lay into it to get to 55mph it sends the gauge up to 210 and hovers there until you slow down to 35-40 mph. I am mechanically inclined, but do not have any experience with international, or anything industrial outside of the 12v and 24v 5.9 cummins engines. has anyone else had this issue? obviously if I don't flog it, the bus wont overheat, but i'm worried that something is awry, and with summer coming soon, i dont think the cooling system is up to the task. Not entirely sure we can trust the old gauge, but where would yall start? I thought perhaps the fan clutch was suspect, but it didnt seem to match the symptoms. Id prefer to not start firing the parts cannon at the thing

Thanks,

Bret

johnbloem1974 · 03-01-2021, 12:55 PM

Honestly, anything between 190 and 210 is OK. As long as it doesn't get above 220 for an extended time, you are OK as well. With the DT engines (DT 360/466/530), 225 and up is what you want to avoid to prevent any severe damage.

As far as gauges, get either a scanguage II or BlueFire for a more accurate temp reading - the stock temperature gauges on the cluster are pretty crummy

John

Johnny Mullet · 03-01-2021, 01:15 PM

Sometimes a coolant fluid change can do wonders. Also try hosing out the radiator cooling fins from dust and dirt.

cadillackid · 03-01-2021, 02:00 PM

when my DTA360 did that.. i noticed no engine fan roar.. replaced the fan clutch wit ha kit-masters clutch that i set the temp down a notch and now I only ever see 200 is when im in 104 degree texas in the summer..

cadillackid · 03-01-2021, 02:01 PM

Quote:

Originally Posted by johnbloem1974

Honestly, anything between 190 and 210 is OK. As long as it doesn't get above 220 for an extended time, you are OK as well. With the DT engines (DT 360/466/530), 225 and up is what you want to avoid to prevent any severe damage.

As far as gauges, get either a scanguage II or BlueFire for a more accurate temp reading - the stock temperature gauges on the cluster are pretty crummy

John

he is DTA360.. no computer

johnbloem1974 · 03-01-2021, 02:44 PM

Quote:

Originally Posted by cadillackid

he is DTA360.. no computer

Derp! Should've seen that it was a '93!

John

bret2094 · 03-01-2021, 03:21 PM

Quote:

Originally Posted by cadillackid

when my DTA360 did that.. i noticed no engine fan roar.. replaced the fan clutch wit ha kit-masters clutch that i set the temp down a notch and now I only ever see 200 is when im in 104 degree texas in the summer..

I assume you clock the spring in the clutch a couple of notches down? Wheres the preferred vendor for something like that? Any idea how much coolant the system holds or how to get a copy of an operators manual or service manual for this thing? As far as the computer scan gauge goes, i was scratching my head how that would work without a computer lol

Bret

CHEESE_WAGON · 03-01-2021, 05:38 PM

I would suggest checking thermostats. Yes, plural. Some engines have two. If one or the other, or both are not flowing correctly, it can cause overcooling or overheating.

bret2094 · 03-02-2021, 11:27 AM

Last night I tested the fan clutch. Everything operates as it should. Slight resistance when cold. As it heated up to operating temps, the clutch began to lock up and began to spin with considerable noise and force. Any one else with a suggestion? i plan to test the thermostat today after I get off of work. I was able to rinse the fins of the radiator but it doesn't seem to have made much of a difference .

Thanks,

Bret

djdalfaro · 03-02-2021, 01:02 PM

Shoot me an email address in PM and I'll shoot the service and diagnostics manuals if you haven't found them yet.

bret2094 · 03-02-2021, 01:22 PM

Quote:

Originally Posted by djdalfaro

Shoot me an email address in PM and I'll shoot the service and diagnostics manuals if you haven't found them yet.

Thanks,

I sent a PM. LOL took me a bit to navigate and post a message to the right place.

Bret

bret2094 · 03-12-2021, 08:15 AM

Well its been a few days so I thought id give an update:

I did a bit of investigative work with the coolant system and found that the heater loop was left on( I'm assuming the valves work the same as a water hose) and the system was about 2.5 gallons low before opening the system to check out the thermostat. Does anyone happen to know what kind of capacity these busses usually have for the radiator alone? I'm assuming that its probably in the neighborhood of 5 gallons with the rear heater hoses shut off. I still need to get a big enough bucket to catch everything so i can do the thermostat. I'm hoping that this resolves my problem. I missed the level before as I just went off of the site glass by the filler neck, however it did not give an accurate reading and the radiator cap was next to impossible to remove with the small space that's provided at the nose of the bus. This doesn't account for where the coolant went, but we had to go ahead and remove the bus seats and start packing our things into it. I do appreciate the service manuals!

Doktari · 03-17-2021, 03:52 PM

I had a short bus with a 7.3. After I flushed the coolant system, with the rear heater loop valve open, it was running hot on the highway. There was a loud gushing noise from the back so I pulled over and found the rear heater hose loose and coolant on the floor. I reattached the hose, added a little water, and it ran cooler after that. What happened?. Did it have a air lock preventing proper circulation?.
I also had a engine that would blow off radiator hoses with a loud gushing noise. Both the lower and upper hoses blew off in different incidents. I reinstalled them and kept driving (I always carried 5 gallons water fortunately). The engine was known to have faulty intake manifold gaskets so I replaced them. Sure enough the gaskets were rotten. My theory was exhaust gas was getting into the coolant and blowing the the hoses off? Does that make sense? I didn’t have the problem after replacing the intake gaskets. I drove several thousand miles.
Strange things happen with pressure and temperature. I had a cooking pot implode on me one time.

bret2094 · 04-07-2021, 10:48 AM

Hello everyone,

Over the Easter weekend we managed to pack up everything and move into our new house. The bus was less than happy moving everything and it continued to have the same overheating issues. As long as you stay out of the throttle, it cools to 190-200, but when you get above 45 mph and hit some hills, the needle climbs and the overheating light pops back on. Before we moved, i did drain and refill the coolant, and checked the thermostat. Additionally i did hose the rad fins out and make sure the fan clutch is operational. I'm beginning to suspect either the water pump is on the way out or the radiator is plugged. Hopefully it is not something more dreaded such as headgasket. Anyone have a guess where to go from here?

Bret

cadillackid · 04-07-2021, 12:01 PM

"make sure the fan clutch is operational" what procedure did you use? that the fan spins when you look under the hood? when the bus is hot does the fan ever go on high speed.. and you will know.. it will roar like the wind when its on high speed..

bret2094 · 04-07-2021, 01:06 PM

Quote:

Originally Posted by cadillackid

"make sure the fan clutch is operational" what procedure did you use? that the fan spins when you look under the hood? when the bus is hot does the fan ever go on high speed.. and you will know.. it will roar like the wind when its on high speed..

Thats how it was checked. That and when the engine is completely cold you cannot easily spin the fan. The Fan gets deafening when hot.

Bret

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