overheating! radiator? HELP!

little busito · 03-14-2016, 06:17 PM

Im not the mechanically-minded one in the family (husband is), but Im the one here on the forums so please bear with me if this post sounds like its written by a total know-nothing. (Because it is.

)

We drove our bus about 300 miles yesterday down to my inlaws for the big building weekend. (They have a huge shop and everything necessary for us to do our remodel inside, etc.) Twice the engine overheated, going over 230 (whatever that means?).... Husband and another snowmachining, skoolie-owning guy we met in a parking lot looked things over and just added a lot of water (??? remember, I literally have no idea what Im talking about here) and if we kept it under 50pmh from that point on, everything was cool. I think? This was the first time we've driven it more than 40 miles since we bought it, and its been sitting all winter due to nothing but ice on the roads here.

Thoughts? Why is this happening? No leaks or anything husband and other skoolie guy could see. Someone said something about a radiator? Possibly a radiator being gunky?

If this makes any sense to anyone, please chime in. Happy to add more info if you need.

Tango · 03-14-2016, 06:27 PM

Need more info. Not that familiar with a "1990 International/Wayne 8-window".

Front or rear engined? Diesel or gas? What engine? Does it have barn doors on the radiator? Was this on level grades or hills? At what speeds?

If a diesel...230 is indeed getting close to critical temps (about 250 is considered absolute max for many diesel engines and time to pull off). Can be less for some.

CaptSquid · 03-14-2016, 06:28 PM

Sounds as if you have a MAJOR coolant leak. Check the radiator/coolant level and then top it off. Run the engine with ALL heaters running and then look for leaks. I had the same problem with my Thomas. Turned out the T-stat housing wasn't seated completely. Bought some Blue RTV and no more leaks.

little busito · 03-14-2016, 06:42 PM

OK. Front engine 7.3L diesel International Harvester, barn doors (I think. The ones that flip upwards?), started getting hot on level grades, at about 50, then overheated on the hills. Previous owners had this problem too.

ANother important thing I forgot: the previous owners removed the rear heater and cut the lines; not sure why? How will this effect things?

There is no leaking, no blown hose. We did lose some coolant out the vent, so thats why they did the water (I think).

Where is the thermostat on this bus? Does this sound like a thermostat problem? Or a radiator thing? Is it even possible to diagnose with this info? Hubby is outside putting in new flooring so I can run ask him whatever.

Thanks dudes!

little busito · 03-14-2016, 06:45 PM

Not too bad of a place to overheat, though....

CaptSquid · 03-14-2016, 06:54 PM

You have a CONVENTIONAL bus, one with a HOOD. Barn Doors are usually in the rear and open exactly as they might be described - on VERTICAL HINGES.

The T-Stat housing connects between the engine block and the radiator with a big hose.

Do you have heat coming out of the vents or the rear heater? Buses of this length may have TWO rear heaters and one for the driver. Is the radiator getting hot? Turn on all the heaters at max-hot and then, carefully, attempt a short run and see what happens. The T-stats may not even be opening.

little busito · 03-14-2016, 07:44 PM

Quote:

Originally Posted by CaptSquid

You have a CONVENTIONAL bus, one with a HOOD. Barn Doors are usually in the rear and open exactly as they might be described - on VERTICAL HINGES.

The T-Stat housing connects between the engine block and the radiator with a big hose.

Do you have heat coming out of the vents or the rear heater? Buses of this length may have TWO rear heaters and one for the driver. Is the radiator getting hot? Turn on all the heaters at max-hot and then, carefully, attempt a short run and see what happens. The T-stats may not even be opening.

THe one remaining bus heater this has is in the front by the driver and has always been on (we live in Alaska) and blown hot air on all our previous drives and there hasn't been a problem. How can we find out more about the thermostat? I really appreciate your help!

CaptSquid · 03-14-2016, 08:09 PM

For that, we'll need the type of engine. Try looking on your vehicle data plate. You can also take your VIN to a local International dealer (even farm equipment) and they can help you.

IC Buses Alaska

Fairbanks
Anchorage

onenationundergoat · 03-14-2016, 08:34 PM

Did you make sure to downshift on the hills? Seems like a silly question, but some folks don't know. Keep those RPMs up above 2000 on a grade.

Check your oil dipstick and make sure oil isn't milky. If it is, you've got coolant leaking into your oil. Make sure you don't let it overheat. If the needle starts going up, STOP IMMEDIATELY and let it cool back down, otherwise overheating frequently will turn every piece of rubber in your engine into solid plastic. Including the cylinder sleeve O-rings, which will cause a major coolant leak. We had to overhaul our engine because the bus garage kept letting the bus overheat and ruined the O-rings.

crazycal · 03-14-2016, 08:38 PM

You also should check your fan clutch and belt tensioner. When the temp reaches +/- 210, your fan clutch should kick on. It makes a racket when it's working so there is no mistaking if it is working.

cowlitzcoach · 03-14-2016, 11:24 PM

7.3L diesel engines generally do not run hot. So if you are running hot there are not a lot of reasons as to why that might be happening.

First off, as it has been noted before, make sure the fan is operating properly. Most were not directly driven and have some sort of clutch. It is very obvious when the fan cycles on and off as it will create a lot of noise and can actually slow you down if you are going up a grade.
First part B would be a loose fan belt. If the belt isn't tight enough when the fan kicks in it could just be slipping the belt and not really turning the fan. First part C would be a fan shroud that is letting air suck in around the edges instead of pulling the air through the radiator.

Second, your water pump may have an impeller that has eroded to the point where it is no longer pumping enough gpm's to keep the engine cool.

Third, as has been noted, the thermostat needs to be operating correctly. It may or may not be opening when it is supposed to or it may be only opening partially which could restrict the flow.

Fourth, and the most likely problem, is your radiator might be plugged up. It can't be stressed enough how important it is to have the pH nearly neutral in the cooling system of a diesel engine. With the pH too high or too low you can get scale developing which can clog a radiator up.

If you don't already have one you need to purchase an infrared thermometer. You can then determine how hot stuff is or isn't. The factory gauges are only a guideline and they are notoriously inaccurate. The only real use is to know the range in which they normally operate. If suddenly the gauge is reading too high or too low you know you have a problem.

With an infrared thermometer you can determine how hot things are on either side of the thermostat housing. If when things are hot and it is the same temp on both sides of the housing then I would say the thermostat is most likely operating properly.

You should have an minimum of 20* difference between the top and bottom of the radiator. 30+ degrees difference would be a lot better. If it is significantly warmer at the outlet than the lowest temp in the radiator it could signify the radiator is not cooling properly. If it is less than 10* difference from top to bottom then I would say your radiator is not cooling properly.

The size your bus is with as cold as it would appear the day was when the picture was taken the normal state of affairs would suggest you would need a piece of cardboard to cover a good part of the radiator so you could get enough heat out of the heaters to defrost the windows. Running warm on a day that cold is not normal for an IHC bus, regardless of how steep the grade might have been.

If the radiator has good temperature differential, if the fan is working properly, if the thermostat is working properly, and it is still puking coolant out you may have a head gasket that is allowing heat to go directly into the water jacket.

It may not be a reason but when the heaters were removed it is a possibility that an air bubble is stuck in the system. An air bubble won't let water circulate properly. But if you are getting good heat out of the remaining heaters and defrosters then I don't think that is the problem.

Good luck and keep us posted as to your progress.

crazycal · 03-14-2016, 11:53 PM

Cowlitzcoach, I like when you post. You are very thorough with your answers. I don't have the attention span or the energy to do that.

I just want to fly.

little busito · 03-15-2016, 12:42 AM

Good gracious I love you people

I'll show all this to the Handsome Man and let you know what's up. Can't tell you all how much I appreciate the help!

EastCoastCB · 03-15-2016, 07:46 AM

Quote:

Originally Posted by crazycal

Cowlitzcoach, I like when you post. You are very thorough with your answers. I don't have the attention span or the energy to do that.

I just want to fly.

I love this post and can identify with the sentiment.

little busito · 03-19-2016, 11:47 PM

Got some great news yesterday! So my inlaws mechanic friend connected us with the boroughs (our version of a school district or county) head mechanic at the bus pool. Until recently, the bus pool was a fleet of 35 of the exact same buses as ours! Heres what the overheating thing turned out to be: louvres over the radiator that were a part of some add-on that the borough bought for the buses up here called the polar package or the arctic package, or something like that. Basically two louvres over the radiator that help the engine heat up in arctic temps that are supposed to open at a certain temp. Theyre also notorious for getting stuck shut on our rough roads up here. The mechanic told Brad to take them off and lose them forever, and to clean out the grill with an air compressor. We took it out for a long spin up multiple hills afterwards and a long run at about 60-65 and zero signs of anything getting hot.

Had you all ever heard of this aftermarket polar package louvre thing? We're just so glad it wasnt a head gasket we could buy you all a round of drinks

one_eyed_jack · 03-20-2016, 12:57 AM

They're called shutters and a lot of older trucks, busses, farm tractors etc. used them. As long as they were built heavy enough and maintained they were wonderful. You didn't have to use a winter-front or (as most of us poor-people used; a chunk of cardboard and haywire/baler twine/twist ties/bungee cords etc. etc.) when old man winter started blowin up yer keester, just to keep the old girl warm enough to defrost the windows and maybe if you were lucky, keep the toes from gettin frostbit. Never could figure out why they quit making shutters. I often wished I had them on my 97 dodge-cummins(and numerous other trucks I've driven). It was tough to keep warm if it wasn't working hard which it rarely did. But as soon as the day warmed up a bit I had to stop and remove the winter front cause it was overheating. What a PITA.! Guess that's PROGRESS!

one_eyed_jack · 03-20-2016, 02:58 AM

Should have described shutters a bit.
They were very much like venetian window blinds. ie. a bunch of aluminum slats covering the radiator, sometimes vertical, sometimes horizontal. Sometimes in front of the rad and sometimes behind it. So that when closed they blocked-off airflow through the rad. The slats were generally opened by a air cylinder which was controlled by a shutter-stat. Sooo the cooling process went something like this. As the engine temp climbed, firstly the thermostat would open and allow coolant to flow through the rad, if that wasn't enough to cool it down, next the shutter-stat would tell the shutters to open and allow air to pass through the rad. And if that still wasn't enough cooling effect then the fan-stat would engage the cooling fan which pulled even more cool air through.
Which reminds me of a funny story. A few years back I was driving gravel truck for a constuction company out of Red Deer Alberta. Our job was to deliver bedding material (sand and screened rock) to the underground crews who were installing sewer and water pipelines into new residential areas. Quite often we had to negotaite our way through some narrow streets, past schools, existing homes, golf courses and such. So this one time we were hauling past a golf course in Sylvan Lake Alberta on very narrow streets.
So my buddy and I happened to meet up on our rounds at this new subdivision and he practically fell out of his truck; he was laughing so hard. Now anyone who has been near a large engine in the heat of summer when the cooling fan kicks in will know they make quite a noise and the unaware can be fairly startled by the sudden racket. Well what happened was when Frank was rolling by the golf course his fan suddenly kicked-in just as he was passing within a couple feet of a young lady lifting a cooler full of beer, hot dogs, catchup, mustard( well you get the picture I'm sure!) out of the back of her minivan!! Well that cooler with all its contents went flying up in the air and subsequently spread themselves all over that street!!
Of course you know, the truck driver is always the idiot even though he has no control over when or where that fan is going to cut in!
Of course twenty-twenty hindsight a driver could switch the fan on manual so that it runs continual but a guy just doesn't think that way, till after the beer gets spilled!
Carry On!
One_Eyed_Jack

Scooternj · 03-20-2016, 07:07 AM

Sounds a lot like the armored grill on the old Peacekeeper "armored" truck the Air Force had. There was a swap out order for the summer to one made of chicken wire to keep them from overheating

cowlitzcoach · 03-20-2016, 08:04 AM

I am sorry I didn't include malfunctioning radiator shutters.

I can't say that I have ever seen a 7.3L with radiator shutters so it never occurred to me to check to make sure the shutters were opening all of the way.

I am glad it was a simple fix.

Tango · 03-20-2016, 09:36 AM

Glad to hear you are looking at a simple fix. Those are the "Barn Doors" I referenced and a pretty common issue when it comes to over heating. But they are very handy in cold climates as most diesels actually run quite cool and take forever to get up to proper running temp.

You may also like: