Community Forums

Shawn6596 · 05-07-2020, 05:33 PM

I've got a 97 Overland osprey. It has a 300hp Full mechanical engine. We have had the for 3 years. When we were back in Indiana we never had any problems running hot. last December we hit the road full time, and headed to vegas. Day one I ran 65-70 all the way to St Louis with out any problems. as it got warmer out it started to run hotter. We slowed down and pulled over about every 2 hours to let it cool down. 15 min at an idle and the temp dropped right down to the bottom of the gauge. after day 2 of this I parked in a walmart lot and I pulled out both thermostats. The next day I sprayed simple green into the radiator and washed it out as best as I could with a hose. I notice some copper fins from the radiator on the ground. the radiator didn't look bad. We struggled along until we got to vegas. Keep in mind even thought the temp gauge would go up until the orange light came on the trans temp never got over 180*. Unfortunately there are no numbers on the engine temp gauge. we wintered here in vegas. I dug into it and found my belt was shot, and 2 1/2" longer than it should be. I thought that had to be the problem. so I put on a new water filter, new belt, and put in the new thermostats. Nope it's still running hot. So I decided it had to be a blockage in the radiator. I got a factory replacement shipped out to me. I tore into it and pulled the old one out. It was completely rotted. The first row of fins had let go of the tubes, and pressed into the second row of cores, blocking 75% of the air flow. It took 4 days out in the desert in 95* heat, but I got it all put back together. While I had easy access I pulled the water pump off, bearings are smooth, and it looks new on the inside. I took it out today and within 20 miles she was just shy of the red line. I pulled over and within 10 min it was cooled right back down, so I carried on and went to a campground to dump. I left it idle while I dumped and refilled probably 1/2 hour. I got in to leave and the gauge was at the bottom. I figured it must be working out any air pockets in the system. Off I went back to our spot. It was about 30 miles with about a 2% grade for the last 3 miles. It slowly rose all the way almost to the point of the light coming on. I pulled into the spot, and within 10 min it was right back down. Oddly the trans temp never went over 145*. I really need help here I'm chasing a ghost, and really don't know where to go from here. also there is no water in the oil, and no oil in the water. It's not loosing or using any fluids. There is no clutch fan, and it doesn't smoke at all. it just seems to heat up as soon as you labor the engine the tiniest bit.

saddlesore · 05-07-2020, 07:53 PM

A few questions before I hazzard a comment.
Rear radiator or side radiator?
Did You replace all the hoses? (and new clamps) Could have a hose that has split on the inside and blocks the water flow..
Did you check the impeller on the water pump to be sure when it gets hot that the impeller isn't spinning on the shaft?
Are the thermostats installed correctly? (I had just what you are experiencing and I had installed them up side down..ugh)(M-11 Cummins)

randomledder · 05-07-2020, 08:58 PM

Have you checked the actual temperature with an infrared gun?

Shawn6596 · 05-07-2020, 09:22 PM

Quote:

Originally Posted by saddlesore

A few questions before I hazzard a comment.
Rear radiator or side radiator?
Did You replace all the hoses? (and new clamps) Could have a hose that has split on the inside and blocks the water flow..
Did you check the impeller on the water pump to be sure when it gets hot that the impeller isn't spinning on the shaft?
Are the thermostats installed correctly? (I had just what you are experiencing and I had installed them up side down..ugh)(M-11 Cummins)

Rear radiator
I have only replace the 1/4" vent hoses. the rest of them are all in good shape.
I did try to twist the impeller and pulley, when I had it off. it seems to be rock solid, and visually in prefect condition. the thermostats are in correctly. These are all very valid questions. thats my problem, I'm chasing my tail.

Shawn6596 · 05-07-2020, 09:28 PM

Quote:

Originally Posted by randomledder

Have you checked the actual temperature with an infrared gun?

That's number one on my to do list tomorrow. I don't have a heat gun, and finding one right now proves to be a challenge. I thought I could just pop into harbor freight and grab one, but apparently people are using them for no touch temp checks. I had to search online I found one at lower. I'm also wondering if the sending unit is acting a fool, because the trans temp is not matching the coolant. I would think 30 miles would be enough that the trans temp would be close see as how the cooler is in the radiator. I will say when I got home I had my wife idle it up to 1500 rpm and it was like standing in front of a giant hair dryer. it was pretty hot.

Wild Card · 05-08-2020, 09:05 AM

Is the fan on a clutch?

Also without another source for a temp reading, I wouldnt diagnose any further.

Shawn6596 · 05-08-2020, 01:58 PM

no clutch on the fan.

Ray,IN · 05-08-2020, 10:12 PM

Back in my old foggy memory, I seem to remember there is an air bleed on the cooling system, can't remember where/how though. Without using the air bleed air is trapped in the system.
The easiest way is to leave radiator cap off and idle for 15 minutes after reaching normal operating temperature.

Shawn6596 · 05-12-2020, 12:09 AM

So I replaced the air filter, and added 2 16" electric fans to the RAD. finally test drove it, and rode it hard. It heated up. I ran to the back with a gun. turbo was about 900*, exhaust down pipe and muffler were in the 450* neighbor hood, the exhaust side of the head was around 250*, and the intake was around 210*. At the point I pulled over and checked it the dash gauge was about 3/4 of the way up the scale. I spent 3-4 min checking temps, and by the time I got back up front the gauge was down a little below 1/2. I turned around and headed back for camp. This time I kept it under 65, and once I hit the 3% grade I eased out of it and kept it around 55. it only heated up to a little over 1/2. I can live with that for now. It's just to hot to stick around Vegas. the only mechanical part I haven't changed in cooling system is the water pump. It looked good, but maybe there is something I missed. My friend back home asked me what kind of shape the lower hoses were in. I responded with soft and very flexible I can squeeze them flat with one had. In talking we were both wondering if I had a lower hose collapsing once it was warmed up, and was being sucked flat, There by causing a restriction in water flow. The coach is a 97, everything I have worked on seems to be factory, and she has sat a lot. it only has about 43k miles on the clock. There is tons of air flow through the system, it has gotta be a water restriction. Were hitting the road tomorrow and heading north for cooler weather. I'm thinking I'm going to just replace the 2 -rubber 90's in the lower hose and the water pump while I have the system drained. I know at this point I'm just throwing parts at it, but I'm still ahead money wise because freight liner is insane on their parts, and labor prices. Not to mention I am very good with my hands, and have all the tools I need. As an added bonus I really have learned a ton about my coach. What do you guys think?

TR4 · 05-12-2020, 06:55 AM

Is your coolant system using a wax valve to control your hydraulic fan? He’s a good thread to read, it explains how a wax valve works.

https://www.irv2.com/forums/f115/fan...en-376611.html

A faulty wax valve can cause the fan to run too much or too little, causing your coolant temperature to be too cold or too hot.

Bill

Shawn6596 · 05-12-2020, 08:40 AM

Quote:

Originally Posted by TR4

Is your coolant system using a wax valve to control your hydraulic fan? He’s a good thread to read, it explains how a wax valve works.

https://www.irv2.com/forums/f115/fan...en-376611.html

A faulty wax valve can cause the fan to run too much or too little, causing your coolant temperature to be too cold or too hot.

Bill

rear radiator, and manual full time fan

saddlesore · 05-12-2020, 10:10 AM

When you replace the lower hoses (and do the uppers while you are at it)..look inside the hoses and see if you have a "flap" of rubber hose that has separated and acting like a stopper..

TR4 · 05-12-2020, 02:44 PM

Quote:

Originally Posted by Shawn6596

rear radiator, and manual full time fan

Sorry, I missed that. My lower silicone radiator hoses both have the metal coil springs to prevent collapse.

Bill

Mtn. Lion · 05-12-2020, 04:21 PM

The hose should be stiff. My bet is on that. Outside of the collapsing hose, could the old radiator bits have flowed into the cooling passages in the block? Maybe you could push water through the other way (other flow direction) and see if **** starts coming out.

It is strange the trans stays cool while the engine overheats. It has the right cooler on there

If you haven't changed the cooling sensor, maybe at least pull it out and inspect it. If it is inexpensive, swap it. It sounds like you are in the process of elimination now anyway.