Community Forums

tom chelbana · 04-30-2023, 09:03 PM

Don't have the answer yet but the problem is engine cooling fans running on high all the time. It takes between 25 and 40 HP to run a diesel engine fan. After listening to many FL chassis coaches it was very clear that there was a lot more fan speed on many FL coaches then our 18 LA with X-15 and a Spartan chassis. What I have found out that FL doesn't install a on/off switch for the engine fan and neither does Newmar. Having the fan running on high speed only would cause 1/2 mpg or more loss of fuel economy and maybe 5 mph on 6% grades. FL charges 800$ to check and install this fan drive switch which would still be something I would do.
Watching our display when the fan drive goes on and off is controlling on our LA the fan comes on at 210 and shuts off at 205. The fan is on high speed very little and might be part why we are 7.3 mpg over 42K. I have heard FL chassis tell me there engine never gets above 185 degrees which would also indicate their fan drive is always on.
Have talked to a number of Dutch Star owners who for no other reason moved up to a LA because of west coast 6% plus grades.
Would be good if someone would find out if all FL chassis owners only have high speed engine fan drive which would make their poor engine power on grades and loss of fuel economy?
Newmar Man

saddlesore · 04-30-2023, 09:10 PM

Your wax valve [or the DanFloss] is kaputski..
The side radiator cooling fans /Danfloss valve 's default setting for when it fails is "full on" high speed...

redbaron73 · 04-30-2023, 09:22 PM

Agreed. When the fan is running properly, it will cycle High and low on FL.

My 2013 had a failure and it failed to low speed. They changed this in 2015 to fail to high, which is a good decision.

Dutch Star Don · 04-30-2023, 10:04 PM

It runs on high when the AC is on, not all the time. Mine cycles up and down on a grade when the AC is off, so I know it's not always on high. It's on flat highways that I would like to see it not run on high when the AC is on.

sramer · 04-30-2023, 11:11 PM

I am one of the ones that went from a DS to a LA for the exact reason of living out west and the grades.

I am on a Freightliner chassis and my fan very seldom runs unless the AC is on, and then it still cycles on and off.

My engine temp typically runs in the 180's and on grades will get to 200-205 at times.

tom chelbana · 05-01-2023, 09:44 AM

Traveling with another LA owner [2020 FL] his fan speed was much higher then ours. After checking their LA at FL the report came back that yes his fan was set for high speed all the time. They found that his coach didn't have a fan speed switch because it was never installed. For 800$ which was 600$ labor and 200$ for parts his 2020 LA FL chassis has a high and low speed fan switch. First 500 miles a over 1/2 more miles per gallon and not loud fan drive. FL said Newmar should have put the fan switch which they didn't and FL said they didn't install switch either.
Newmar Man

UMXHAULER · 05-01-2023, 10:20 AM

On my 21 DS, the fan does not run on high all the time with the AC off. Will only kick into high when temp reaches 210. With the AC on, it will run high at idle but the minute you step on the brake when parked or put it into gear it goes back to low. When underway with the AC on, it will cycle the same as it does with the AC off. Seems to be several different configurations from year to year based on these posts.

Frank94062 · 05-01-2023, 03:57 PM

On our 22 DS 3736 on the Freightliner chassis, when going up a hill I can see the temperature climbing and then I will hear the fan coming on. It will run until the temperature drops and then I can hear it go quiet. This will repeat as needed to keep the engine cool. Based on this I would assume that it is in low mode most of the time and only go to high when the engine gets hot.

Jim 75 · 05-01-2023, 07:56 PM

Tom, when I purchase my USED MADP 4336, the fan ran on High all the time .. Took it to a local FL. dealer. They tested it and found the CLUTCH on the fan was frozen. Only repair was to R&R it. $900+ part plus labor, ( they had a small mech. who worked his way in to change it out without removing drive shaft and pump). Problem went BYE-BYE.... Was pricey, ouch, but cheaper than Fuel in the long run Jim

ftharrisiii · 05-02-2023, 07:23 AM

Quote:

Originally Posted by UMXHAULER

On my 21 DS, the fan does not run on high all the time with the AC off. Will only kick into high when temp reaches 210. With the AC on, it will run high at idle but the minute you step on the brake when parked or put it into gear it goes back to low. When underway with the AC on, it will cycle the same as it does with the AC off. Seems to be several different configurations from year to year based on these posts.

Same on my 2016 DS

RVStitchy · 05-02-2023, 09:22 AM

Interesting topic. Whenever I am hooking up the toad or in a camp ground setting up to leave I turn the dash AC off and tap the brake to dramatically drop the engine noise to be polite to others. Is that a sign that it is working properly? That engine screams at high idle with AC on. Our 450hp/8.9L with 12,000 miles is still averaging 6.2-6.5mpg with no generator which I think is a little low based on other reading.

UMXHAULER · 05-02-2023, 12:43 PM

Quote:

Originally Posted by RVStitchy

Interesting topic. Whenever I am hooking up the toad or in a camp ground setting up to leave I turn the dash AC off and tap the brake to dramatically drop the engine noise to be polite to others. Is that a sign that it is working properly? That engine screams at high idle with AC on. Our 450hp/8.9L with 12,000 miles is still averaging 6.2-6.5mpg with no generator which I think is a little low based on other reading.

Yours is working properly. I turn off the A/C in campgrounds to so as not to be obnoxious. It's at high idle and high fan which makes is so noisy. 6.2-6.5 is in the ball park if you typically go 65mph or more. I know that my rig can get about 7 and sometimes a little bit more if I keep speed below 62 on mostly flat driving. Speed, hills, and wind just destroy our milage.

Iron Man · 05-02-2023, 05:38 PM

It runs on high when the AC is on temp will drop to the mid 170's. Mine cycles up and down when the AC is off, comes on around 205 and off around 190 so I know it's not always on high.

tom chelbana · 05-02-2023, 05:59 PM

If I owned a Newmar that ran the fan drive on high when AC was on it would be time to add a electric fan for the AC condenser. Having to use 25 to 40HP when ever the AC is on doesn't need to be set up like that. When AC is on the compressor is taking about 5HP but when you also have the fan go into high speed you are really paying a lot to use it.
Our 1st LA did have a electric fan that came on the condenser. Our current LA has excellent AC operation and the fan drive only goes on when the engine temp hits 210.
Would be interesting to see if any has changed the fan drive to hear their fuel economy and power increase by NOT having the fan on high when AC is on.
Newmar Man