Just did a 40 mile test run and now there is a low vibration and audible low noise in the cooling fan area. The bedroom bed stand above them is vibrating and both fans are running. Oil is full. Temperature on engine is 180 and tranny is 160 so that's fine.
What do you guru's think is going on?
Thanks
Have you taken a good look at the fans to make sure there is not some trash tangled up in the blades? Are the hydraulic fan motors leaking? With engine off, grasp each blade and see how much play there is in the shafts of the motors.
It sits in my shop on a cement floor and I have zero leaks on the floor. I'll check for trash and play. Thanks. Anyone know if these can be rebuilt and what about a failed thermostat causing fans to go full speed all the time?
Thanks
The thermostat for the fans could have failed. Lots of info on them in the search.
Just an FYI - I had one cooling fan noticeably leaking and the other just residual weeping. While they were both out my thought was to have them rebuilt. However, the local shop was game to do rebuild them but informed me the seal kits were potentially 8 wks out & they were not so sure they wouldn't start leaking again in the near future. Not sure if this was actually fact?? Jump forward I called Foretravel and they actually stock both pumps. In Feb. 2020 they had 5 of each in stock. Here is the killer...one pump has an extra bracket assembly or something on it. That pump was quoted at $3700.00.(No BS) the other without the do-dad was about $697.00. luckily my leaker was the cheaper pump and I had it overnighted to Wisconsin from Texas for an additional $147. I am going to keep praying the other one continues to function well...
Make sure that you don't have a broken fan blade which would throw the fan out of balance.
Fan high/low speed valve defaults to the high speed if the coil fails, but at idle speed I don't know if you could tell the difference by just a visual inspection.
This info is based on my schematics and personal experience.
Yours may be different.
Dan the factory's selection of hydraulic fan speed controllers causes the fans to go to full high speed at 180 degrees.
Idle speed is ambient to 165. During the 165 to 180 the fans speed increases in a straight line.
I replaced my controller with a 199 degree full speed unit the rest of the industry used.
So mine stays at idle until 184 degrees then starts its ramp up.
Full speed consumes up to 60hp at full revs.
No low/high on these, variable speed.
Foretravel picked a controller that turned the fan on high the moment the engine warmed up,
I have posted the company in Oregon that has the 199 degree units. Less than a CB.
Better mpg and power with the 199 unit.
No heating issues. Gauges look the same.
Question for Dan,is the vibration there whether you are stopped or moving?
Vibration was at idle and 65 mph. Constant. Gone this morning on cold start
Where in Oregon could I get the controller. I don't know how to find where you posted it.
They are available from Source Engineering in Oregon. His are 195 degree, $595 + shipping, says he keeps them in stock. I talked to Jim Hall at (458)207-9442.
Thank you Caflashbob, I know you have mentioned this before, I'll do mine this summer.
You are welcome.
Thanks to those here who showed me VPMS.
The RMPG on its screens large increases in my mpg started me on my search as to why.
Thanks I am working on my coach as to why it runs so cold and if I had my way the low speed wouldn't run until the engine temp
was around 180 and high speed wouldn't start until 200. What does VPMS and RMPG mean.
NO.
While that would be fine for engine coolant temperature, the fans also move air over the CAC. With zero air flow, intake manifold temperatures would rise to dangerous levels.
You do have to have enough air flow to keep intake manifold temperatures in a safe range.
With shutterstats there was no air flow over the engine until they opened, didn't cause a problem. Is there something with the
electronic engines I'm missing.
With a normally aspirated engine OR one with a water to air after-cooler instead of an air to air CAC, no air flow is needed until engine coolant temperature is up.
BTW, a similar concept is used in most cars today-- electric fans do not come on until coolant temperature requires it UNLESS (yes, large UNLESS) the A/C is turned on. Then the fan comes on to move air over the A/C condenser, even if coolant temperature is 40 degrees F.
Does CAC stand for aftercooler. I forgot about the aftercooler so I need a fan. Always something new learn.
CAC= Charge Air Cooler.
Intake air comes out of the turbo-- sometimes up to 300 degrees F-- air (actually any gas) heats up as it is compressed plus it is mm from the extremely hot exhaust.
That intake air then goes to the CAC which is an air to air radiator where it is cooled to close to ambient temperature.
From there it goes to the intake manifold where it goes either to the engine or to the air compressor.
Thanks Wolfe, I've always know it as a aftercooler.
Yes, depending on design/engine manufacturer, the device that cools intake air post turbo are known as inter-coolers, after-coolers or charge air coolers.
Called Sourcerv.com and will get their 199 degree fan controller as caflashbob recommended. May not be this problem but it makes sense going forward to get it.
Thanks everyone
I went and googled the part # on my controller which 190 degree. Northwest RV Supply sells the 210 degree one for $330.00 and
I am checking with Whitehouse Supply some where in Europe for the price. I have dealt with them before.
I have no problem with a "fan WOT" at 199. IMO, 210 is higher than I would be comfortable with.
210 is OK for the engine, but picture yourself climbing a long grade. If the fan doesn't go to high until you are well out of thermostatic control, you could easily go from 210 on up to dangerous temps.
Ideally, I would like to see the fan should go to high 5-8 degrees F above where thermostat is wide open. That doesn't waste HP, but is safer, particularly in hot conditions on long grades.
I agree but the part # on mine was 533 /09S531/190 and the only one that came up was 533 /09S531/210. I would think mine
fan went to high speed at 190 and the other at 210. In my Monaco the high speed fan came on at 210 and as soon as the high
speed fan came on the temperature held at 210. It would have to be really hot out and a long hill for the temperature to get it up to 210. I have not driven this coach in the summer so I have no idea how it will act. I couldn't find a 199.
Thermostat on a m11 starts to open at 178? Fully open at 195. The 199 I purchased was intended and purchased for a beaver coach built by Monaco.
I had a 210 decided not to use it.
There is a fan switch on the m11 engine to run a shutter fan at 210 I understand. On/off.
Where would that switch be?
Shutter stat?
The OTR trucks had shutters in front of the radiators. That is what he is referring to.
Nothing to do with DP's.
Next to the shutter stat is a fan stat