DT466: how hot is too hot?

Diesel Dan · 08-19-2010, 11:28 AM

I've heard that the DT466 have problems with overheating, and mine is apparently no exception. Does anyone have any knowledge of what typically causes this problem in the DT466 and what is the remedy? Also, how hot is still okay to run the engine for long periods of time? Mine runs at 200F most of the time, and climbs up to 210F when climbing hills. If the ambient temperature is also hot, then it gets even hotter when under load, like 220F. This is getting close to the top end of the temp gauge which is 230F. Any thoughts?

nevrenufhp · 08-20-2010, 06:26 PM

230 is ABSOLUTELY a no-no!
220, and it's time to pull over. Any hotter will mess up the cylinder liner Orings, they get brittle, and start leaking coolant into the oil.

JakeC · 08-21-2010, 09:26 PM

I run at around 175-180*...almost no matter what. I drove it through Arizona last august and it was 105* outside, even had some hills to climb, the hottest it hit was 190*. I would highly recommend flushing your cooling system and making sure it has the proper coolant to start with. Also, do you have an intercooler? If so, do you have the goofy side by side intercooler/radiator deal? I think that was a terrible idea to build them like that. I don't think they provide enough cooling capacity. Mine didn't come with an intercooler, so I am installing an intercooler out of a 6.0 super duty. It fills the space almost perfectly! I would also make sure your fan is functioning properly. You should be able to hear it "come on" once the temp gets hot enough.

Hey neverenufhp! Gonna have to wait a couple weeks to finish my turbo project. I just put the old one back on, cuz I'm goin camping!!

Diesel Dan · 08-23-2010, 01:27 PM

Thanks for that perspective Jake, I'll need to dig in an see what is going on. I've seen the fan spinning at idle, so unless it's only malfunctioning sporatically, I think that is probably not the problem. The coolant is a reddish color, not the green stuff, so I think it's the "good" kind. So I guess that leaves either the thermostat or the radiator itself as the possible culprits. I would think that if the thermostat was bad, it would overheat whether under load or not. As long as it's not under load, it will idle at 180F even at over 100F ambient temp. Perhaps I should take it to a radiator shop and get them to check for blockages. Although, I once had an older Ford F150 pickup that was overheating due to radiator blockage, and it had the opposite problem as my bus: so long as I was moving it would run cooler, but at idle it would heat up. Hmmm....

nevrenufhp · 01-17-2011, 01:26 PM

An IH dealer, or a parts store that deals with HD trucks will have the proper coolant. These engines require different coolant than automotive stuff, and has more additives in it.

bus-bro · 01-20-2011, 08:49 PM

Wet liner engines require coolant with SCA's (supplemental coolant additives). Some sort of nitrite chemical. Otherwise, tiny bubbles form on liner wet side during operation; and when those tiny bubbles collapse, a little bit of the metal goes with it. In short order you get pits through the liner, and need to rebuild.

Chasgoat · 01-18-2015, 09:42 AM

I had a bad viscous fan clutch that caused similar symptoms..some resistance on fan blades with engine shut down but not enough..I put two bolts thru clutch fan ran constantly but I lost 2-3 mpg temperary fix put new clutch on and good cooling that engine need a lot of air it only has 1/2 radiator other half is intercooler.
Charlie

cowlitzcoach · 01-18-2015, 10:03 AM

I have never heard the DT466 described as a hot running engine. Quite the reverse is true.

When it was designed 60 years ago for combines and tractors it was designed to run at 160 degrees. One of the problems IHC is having with it today is to make it run at 200 degrees for emissions purposes.

Unless your bus is 2010 or newer you should be running at temperatures no higher than 190 or 195 after a real hard pull uphill.

The first thing to check is your temperature guage. If it is the OEM guage i wouldn't trust the reading. Check to make sure your radiator is letting air through. Then check the temperature differential between the top and bottom.

Good luck.

charles_m · 01-18-2015, 04:07 PM

Check the fan clutch. Just seeing it spinning at idle is no indication that it is locking up properly. Also, consider having the radiator checked for blockages. Sounds like your t-stat is good. You should definitely hear a loud roar when that fan kicks in. If you have the side-by-side radiator/intercooler combo you dont have much leeway to compensate for cooling system problems. Though im not sure if that side-by-side config was on the 466. Ive only seen it on the 444e.

olaus · 01-18-2015, 06:09 PM

have you checked to make sure your condensor or intercooler is not plugged up and flowing air- in my pickup i have to blow compressed air backwards through the fins about once a year to clean out the bugs and dust.

EastCoastCB · 01-19-2015, 05:33 AM

Quote:

Originally Posted by cowlitzcoach

I have never heard the DT466 described as a hot running engine. Quite the reverse is true.

When it was designed 60 years ago for combines and tractors it was designed to run at 160 degrees. One of the problems IHC is having with it today is to make it run at 200 degrees for emissions purposes.

Unless your bus is 2010 or newer you should be running at temperatures no higher than 190 or 195 after a real hard pull uphill.

The first thing to check is your temperature guage. If it is the OEM guage i wouldn't trust the reading. Check to make sure your radiator is letting air through. Then check the temperature differential between the top and bottom.

Good luck.

Although I'm just going off the factory gauge and am fine with that, I totally agree with you. Mine runs at 160 almost all the time. It did climb a little bit going up Monteagle in Tn. Less than 200 iirc. That was my bad for hauling so much ass up it though.
I may look into intercooling it once the conversion and general restoration work are completed.

rock649 · 08-06-2015, 08:11 PM

Have you checked your thermostat? Its an easy and el cheapo thing to do...put in a 160'F thermostat. Maybe your old one is starting to cook. Flushing out the rad is never a bad idea either. I take mine right out and stick a gardenhose full blast down its throat til the rust and crap is gone.
First thing I would do is take the thermostat right out and go for a hiway run. If it overheats still...could be the pump. It could also be something evil like blocked oil passages....i cant remember now...starts with an R and its blue liquid. Rislone! Does a beauty job of cleaning everything to brand new and sparkly. Does it sound like a sewing machine? I don't wanna be the boogyman...but throw in some lucas oil too. The beauty about rislone is you can leave it in there...its not a flush and if your only half way to an oil change thats fine...throw it in. Its like 10 bucks or something.

rock649 · 08-06-2015, 08:18 PM

Have you checked your thermostat? Its an easy and el cheapo thing to do...put in a 160'F thermostat. Maybe your old one is starting to cook. Flushing out the rad is never a bad idea either. I take mine right out and stick a gardenhose down its throat til the rust and crap is gone.
First thing I would do is take the thermostat right out and go for a hiway run. If it overheats still...could be the pump. It could also be something evil like blocked oil passagesl....i cant remember now...starts with an R and its blue liquid. Rislone! Does a beauty job of cleaning everything to brand new and sparkly. Does it sound like a sewing machine? I don't wanna be the boogyman...but throw in some lucas oil too. The beauty about rislone is you can leave it in there...its not a flush and if your only half way to an oil change thats fine...throw it in. Its like 10 bucks or something.

onenationundergoat · 08-06-2015, 10:13 PM

Quote:

Originally Posted by nevrenufhp

230 is ABSOLUTELY a no-no!
220, and it's time to pull over. Any hotter will mess up the cylinder liner Orings, they get brittle, and start leaking coolant into the oil.

My DT360 hit the top of the gauge today after a two mile drive. Turns out all my coolant is in my oil now.

opus · 08-06-2015, 10:28 PM

claydbal · 08-07-2015, 06:03 AM

my dt ran hotter than it should when i first got it. that was because some dumnass had removed the t-stat! installed 160 t-stat and the gauge stays at 160 even climbing long grades of the ozarks.

Scooternj · 08-07-2015, 06:19 AM

Quote:

Originally Posted by onenationundergoat

My DT360 hit the top of the gauge today after a two mile drive. Turns out all my coolant is in my oil now.

rock649 · 08-07-2015, 08:56 PM

Straight 6's are a ton easier than a v8 like mine for head gaskets...
And while you're in there you can get a good look at your top end health!
Make sure all the holes line up with the new gasket....

Kubla · 08-07-2015, 09:01 PM

unfortunately, you will now need to replace all the bearings, they are pretty much shot at this point

onenationundergoat · 08-07-2015, 10:59 PM

Quote:

Originally Posted by rock649

Straight 6's are a ton easier than a v8 like mine for head gaskets...

That's the whole reason I bought the straight 6 in the first place! At least we'll leave knowing that everything's in good working order.

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