Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-02-2020, 10:00 AM   #1
Winnebago Camper
 
Join Date: Jul 2019
Posts: 25
Engine fans

Hello,
I have a 2003 Adventurer 35U with the 8.1 motor. It seems like the engine fans kick on when traveling at highway speeds (65) more often then I would expect. I understand they would turn on when going up a large hill, running the AC, or with a strong headwind, but sometimes they kick on when there is nothing strenuous happening. They will run for 30 to 60 seconds and shut off.

I was thinking of replacing the thermostat to something cooler. Any thoughts or suggestions?

Thank you.
JimStreit is offline   Reply With Quote
Old 07-02-2020, 11:03 AM   #2
Winnebago Master
 
Join Date: Nov 2018
Location: Pflugerville/Austin, Tx
Posts: 1,722
I don't know what experience you have but keep in mind that we are not driving a truck down the road but closer to a house and it does have to operate different!
Lots of things go into how hot the engine runs and I am not too inclined to mess with the engineering on complex stuff, without having a definite idea of what and why. If it's just a personal bug to hear the fan, I would not change it but the short time cycle does sound like it might need a check.
__________________
Richard
2015 Winnebago Vista 31KE on 2014 chassis
Morich is online now   Reply With Quote
Old 07-02-2020, 02:00 PM   #3
Winnebago Master
 
Join Date: Jan 2020
Posts: 947
I wonder if you just need a new thermostat--not a lower temperature but just that it's sticking some? Can you monitor the actual temperature with an OBD-II gauge or something. Something with a digital display?

I'd be reluctant to change the thermostat to a lower temperature than what the engine was designed for.
__________________
2019 2106 DS
Goodspike is online now   Reply With Quote
Old 07-02-2020, 03:19 PM   #4
Winnebago Master
 
Join Date: Nov 2018
Location: Pflugerville/Austin, Tx
Posts: 1,722
The fan temp sensor might also be a big question due to the short cycle time? Digital temp controllers using solid state probes do lose there mind pretty often, so I would expect much the same on engine temps.
But where and how that is done on a new engine? No idea from me!
__________________
Richard
2015 Winnebago Vista 31KE on 2014 chassis
Morich is online now   Reply With Quote
Old 07-02-2020, 05:43 PM   #5
Winnebago Owner
 
Topsail's Avatar
 
Join Date: Jun 2019
Posts: 170
Quote:
Originally Posted by JimStreit View Post
Hello,
I have a 2003 Adventurer 35U with the 8.1 motor. It seems like the engine fans kick on when traveling at highway speeds (65) more often then I would expect. I understand they would turn on when going up a large hill, running the AC, or with a strong headwind, but sometimes they kick on when there is nothing strenuous happening. They will run for 30 to 60 seconds and shut off.

I was thinking of replacing the thermostat to something cooler. Any thoughts or suggestions?

Thank you.
Jim you say it kicks on for 30-60 seconds, but you don't describe the interval period when it's off. As others mentioned maybe change out an old thermostat for a new one. I don't suggest changing the temperature range unless the wrong one was installed at some point in time. You do know these 8.1 engines can run hot. Is this a new issue with a rig you've had for a while? Tell us more and we may be able to give some better ideas.
__________________
2008 Voyage 35L, Allison 6 speed auto and GM Workhorse 8.1 gas
Topsail is offline   Reply With Quote
Old 07-07-2020, 09:58 AM   #6
Winnebago Camper
 
Join Date: Jul 2019
Posts: 25
Thanks for the suggestions.

The frequency between the fans coming on varies. It might go up to 20-30 minutes, but if I do something that works the engine harder the fans will kick on right afterwards. Like going up a hill or fighting a strong headwind. When fighting a headwind it might kick on every 5-10 minutes.

When I originally got the rig a year ago, the big rubber flap that goes above the radiators to just below the windshield was toast and mostly missing. I've replaced that but it doesn't appear to have changed anything from the fan's perspective.

The engine temp gauge moves up to just under half, and stays there. I've never seen it go above 1/2, even when climbing a large hill and towing a car.

Is there a way to test the thermostat, and how hard is it to change? I agree, I'd like to stay in the original manufacture specs. It looks like I would be able to change it by removing the doghouse and doing the work from inside the rig.

It's a 2003 with about 38,000 miles on it. About 9,000 of those miles have been in the last year since I've owned it. Maybe start with just a thermostat replacement and radiator flush?

Thanks.
JimStreit is offline   Reply With Quote
Old 07-07-2020, 10:00 AM   #7
Winnebago Camper
 
Join Date: Jul 2019
Posts: 25
It's nothing new ... it's been acting this way since I got it a year ago.
JimStreit is offline   Reply With Quote
Old 07-07-2020, 11:55 AM   #8
Winnie-Wise
 
Lv2Roam2's Avatar
 
Join Date: Jun 2014
Location: Somewhere On the Road
Posts: 267
Check the condition of your antifreeze and cleanliness of the radiator and coolers ...
__________________
Steve
2015 Itasca Ellipse QD | 2014 Jeep Grand Cherokee
Lv2Roam2 is offline   Reply With Quote
Old 07-07-2020, 02:25 PM   #9
Winnebago Owner
 
Join Date: Dec 2019
Location: Kansas
Posts: 66
From your comment, it sounds like you have electric cooling fans? Seems like a 2003 might have a thermal clutch fan but I'm not sure about the 8.1 engine. On one hand, a thermal clutch that is 17 years old could have some issues but I also remember seeing a number of posts about wonky fans on the GM 8.1 engine.
__________________
2003 Itasca Sunova 30B towing a
2010 Cadillac SRX
Bones2003 is offline   Reply With Quote
Old 07-07-2020, 04:41 PM   #10
Winnebago Camper
 
Join Date: Jul 2019
Posts: 25
yes, you are correct. There are 2 electric fans on the front of the radiator.
JimStreit is offline   Reply With Quote
Old 07-12-2020, 07:49 PM   #11
Winnebago Watcher
 
Join Date: May 2020
Posts: 1
I think the electric fans in front are to assist the engine driven air cond. The cooling fan making most of the noise is the clutch fan mounted on the front of the engine. It freewheels when temp low then locks in when temp goes up. Driven by the belt. It should have a metal coil on the front of it that senses temp and locks the clutch in. I had a 2005 Sunova 30b with the Chevy it was crazy loud when the fan locked in. As far as engine temp get a OBD 2 reader (40 50 bucks) at a parts store and read engine temp. Good luck
Jksmith is offline   Reply With Quote
Old 07-12-2020, 09:17 PM   #12
Winnebago Master
 
Join Date: Nov 2005
Posts: 1,274
Just be mindful that Motor Homes should be maintained by the Severe Service Schedule meaning that brake fluid and coolant should be flushed out every 2 years to keep the cooling system and brakes at optimal efficiency. Whey you buy a used 17 year old vehicle you really need to level set the maintenance schedule by flushing the coolant system along with the brakes and take the time to do a full chassis lube including cleaning and greasing the guide pins and slides on the brake caliper mounts.

Note that GM/Workhorse had problems with their ABS Controller Valves in that generation requiring premature replacement when brake flushes are skipped so its in your best interest to get these items brought up to date if they haven't already been taken care of.

For efficiency and correct operation you need the specified thermostat or the computer system may try to compensate for what it perceives as an under temperature/cold engine. Some may even fail the smog test with a cold thermostat installed.


If you think the fan clutch is engaging too often it will need to be tested as per the maintenance manual for that chassis. If the fan clutch is defective it will need to be replaced.
__________________
Neil V
2001 Winnebago Adventurer WFG35U
NeilV is offline   Reply With Quote
Old 07-12-2020, 09:25 PM   #13
Winnebago Owner
 
Diesel-Lover's Avatar
 
Join Date: Nov 2002
Location: OH
Posts: 110
Sounds like a huge airplane taking off?

If it sounds like a huge airplane taking off its the clutch fan.


What you describe is basically normal operating process. But so service the whole cooling system to make sure all is well, similarly the oil change etc. Many Rvs have a little air dam below the radiator line... just like in cars to help airflow, perhaps that is also missing or barely there. On one of my rigs I added a floor between the grill and the radiator with some holes for water drainage but to make all the air through the grill go through the radiator. Yes I also had a screen behind the grill but in front of the radiator to keep bugs and rocks out which was kept clean.

I felt the mechanical clutch fan was not only noisy but also robbed power just when it was needed most, so the electrical fans were wired to run manually as well with a switch on the dash. This way while approaching the hills they were turned on to provide cooling assistance while we made it up the hill, after cresting they were turned off and some times the clutch fan would come on after a major hill on hot days else every thing remained quiet. The enhanced air flow management essentially made it such that the clutch fan did not need to come on under normal highway operating conditions, during stop and go yes it would kick on and in very hot conditions or long hills.

Also moved engine battery up from the stair well closer to the engine to keep the starting process viable even after the engine etc was heat soaked at rest area stops. That and improved over all grounding of the coach as there was an issue with that as well which we learned the hard way..
__________________
RUSTIC is good.
Kudos to those who make Local, State & Federal Parks & Campgrounds possible and to those picking up the slack by Providing Private Campgrounds.
Diesel-Lover is offline   Reply With Quote
Old 07-13-2020, 01:18 AM   #14
Winnebago Owner
 
Join Date: Feb 2005
Location: Anderson, IN
Posts: 135
The suggestion to get a scan tool to read actual temps is correct. The temp gauge on the dash does not move until the coolant is in the high 220's. I have a Scan II gauge that will give much more, and more accurate, information.
Has the coolant been changed? I went to a 180 thermostat because of the noise and the coach runs fine. I also insulated the cover and the area around the engine for noise and heat reduction. I used a Dynomat product from Jegs Speed Shop.
The two fans on the front are just for a/c mainly.
Until you get an accurate way to read actual temps you are flying blind.
Good luck and let us know what you found,
Dave
Davel is offline   Reply With Quote
Old 07-13-2020, 04:26 AM   #15
Winnebago Owner
 
Join Date: Feb 2018
Location: Wingate, NC (near Charlotte)
Posts: 93
8.1 heating problems

I bought a 2002 Sightseer 30B with the 8.1 liter Chevy engine about three years ago. It was burning up the driver's side rear spark plug wires. Had ceramic "racing" wires installed, fixed the problem, I thought. Temperature would go up about ten degrees when running over 65 MPH. had the cooling system flushed and new coolant put in, fixed the problem, I thought. Manifold gasket on the driver's side blew, and exhaust pipe gaskets failed, had them replaced, fixed the problem, I thought.

Recently, on an all-day drive home, the exhaust gasket between catalytic converter and muffler blew again. My mechanic suspected a problem beyond what I had experienced so far. He found that the driver's side catalytic converter had failed and dumped all its "pellets" into the muffler, causing an exhaust obstruction and probably the heat related symptoms I'd been experiencing for three years.
jbrattain is offline   Reply With Quote
Old 07-13-2020, 07:22 AM   #16
Winnebago Camper
 
Join Date: Mar 2019
Posts: 14
I also have an 8.1 2007 rig. I had the same issue. The problem was the engine and transmission oil coolers are attached to the condenser. It was full of debris collected over the years. I had it cleaned and the engine runs cooler but like someone said it's a house on the road and if it takes the fans running to keep the engine cooler. BTW I priced the cost of the condenser/oil cooler assembly and it was over $1800 at my door plus another $350 to have it install so I opted to have it professionally cleaned at an AC shop. Good Luck
losone is offline   Reply With Quote
Old 07-13-2020, 07:59 AM   #17
Winnebago Camper
 
Join Date: Jul 2019
Posts: 25
Quote:
Originally Posted by losone View Post
I also have an 8.1 2007 rig. I had the same issue. The problem was the engine and transmission oil coolers are attached to the condenser. It was full of debris collected over the years. I had it cleaned and the engine runs cooler but like someone said it's a house on the road and if it takes the fans running to keep the engine cooler. BTW I priced the cost of the condenser/oil cooler assembly and it was over $1800 at my door plus another $350 to have it install so I opted to have it professionally cleaned at an AC shop. Good Luck
Thanks. Good suggestion. Cleaning the radiators is something that I've recently done, but I'll have a closer look to make sure there isn't something more.
JimStreit is offline   Reply With Quote
Old 07-13-2020, 04:50 PM   #18
Winnebago Camper
 
Join Date: Nov 2010
Location: Surrey, B.C.
Posts: 44
I have a 2007 Itasca Class A, W24 chassis, 8.1 engine. I have had most of the issues you described:

FYI:

1. Within the first 2 years of ownership, I had two spark plug wire failures. Workhorse covered the cost of installing an air duct kit which aims air from the grill to the #2 spark plugs. I had about 6000 miles on the rig at the time, now I have 96,000 miles with no problem since.

2. I had my clutch fan fail which caused my transmission to overheat on a long uphill pull. I had to disconnect the car so the wife drove it while I continued on in the motorhome. Without the toad, temperatures were fine. So for me, I like to hear the clutch fan engage every morning at the start of the day so that I know it is working. It is very noisy, but doesn't stay on all that long and sure beats the engine overheating. If you are handy, it is easily accessible from under the dog house. Very simple to change as it is a self contained housing and spring.
3. I had a shop flush the engine + radiator when rig was 12 years old. The shop guy told me that the anti freeze was not dirty nor did any of the hoses need changing.
4. If you have to change the thermostat, stick with the OEM specs. Do not go to a cooler temperature.

Final note is that the W24 does not have the brake issues that were common in the W22 chassis. The only problem I have ever had with the brakes was the ABS failure light came on, followed by a brake failure light however the brakes continued to work normally. It turned out to be a dirty ABS sensor which triggered both lights.
__________________
Knightly
2007 Itasca Sunrise 35A, W24 Chassis, Blue Ox, Toad-HHR. Retired
Knightly is offline   Reply With Quote
Old 07-13-2020, 05:08 PM   #19
Winnebago Camper
 
Join Date: Jul 2019
Posts: 25
Quote:
Originally Posted by Knightly View Post
I have a 2007 Itasca Class A, W24 chassis, 8.1 engine. I have had most of the issues you described:

FYI:

1. Within the first 2 years of ownership, I had two spark plug wire failures. Workhorse covered the cost of installing an air duct kit which aims air from the grill to the #2 spark plugs. I had about 6000 miles on the rig at the time, now I have 96,000 miles with no problem since.

2. I had my clutch fan fail which caused my transmission to overheat on a long uphill pull. I had to disconnect the car so the wife drove it while I continued on in the motorhome. Without the toad, temperatures were fine. So for me, I like to hear the clutch fan engage every morning at the start of the day so that I know it is working. It is very noisy, but doesn't stay on all that long and sure beats the engine overheating. If you are handy, it is easily accessible from under the dog house. Very simple to change as it is a self contained housing and spring.
3. I had a shop flush the engine + radiator when rig was 12 years old. The shop guy told me that the anti freeze was not dirty nor did any of the hoses need changing.
4. If you have to change the thermostat, stick with the OEM specs. Do not go to a cooler temperature.

Final note is that the W24 does not have the brake issues that were common in the W22 chassis. The only problem I have ever had with the brakes was the ABS failure light came on, followed by a brake failure light however the brakes continued to work normally. It turned out to be a dirty ABS sensor which triggered both lights.
Thanks for mentioning the fan running at start up. My fan kicks on when its only been running for a few minutes and I'm just starting down the block. That is the exact same sound I get. Maybe its the clutch fan that I'm hearing and not the two electric fans in the front.

Is there anyway to test the fan to make sure its still working properly?

Thanks
JimStreit is offline   Reply With Quote
Old 07-14-2020, 12:31 AM   #20
Winnebago Owner
 
Join Date: Nov 2010
Posts: 54
Thermostat

Good info on lower temp stat. here:

https://www.winnieowners.com/forums/...m_medium=email

Oemy's Web Site - RV Chassis Parts Xref W Series

My fan was noisy. First get a scan gage to monitor engine and trans temp. The stock mtr temp gage is worthless. Then I did several other things.

1. Changed to 180 deg stat 12,000 mi ago. No issues. Mtr still runs ~ 195 when cruising. Even in 95 deg heat pulling toad never got above 206 deg. I believe trans runs cooler also.
2. Sealed shroud around fan. Original seals were poor quality in both construction and function. Used 1/8 " plastic and secured with quality tape, not duct tape, from shroud to radiator. You need to reach high to get it to top of rad. Now I'm going to replace old tape with Eternabond tape.
3. Added additional sound proofing under dog house and anywhere under hood I could find.

The motor runs fine, no issues. Did not change mpg. It is now quieter even when the big fan kicks in you can talk normally. Even the air conditioner works better. Stays cool at idle at a stop light. I believe sealing up the shroud forced more air to go thru the radiator helping everything.
__________________
03 Workhorse 22K Winnebago Adventurer 35U
2012 Honda CRV and 2001 Nissan Frontier
Fletcher0077 is offline   Reply With Quote
Reply

Tags
engine, fan


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Defrost Fans Y-Guy Winnebago General Discussions 7 07-20-2010 05:24 AM
A/C Condenser fans? gunny Winnebago General Discussions 13 07-01-2008 05:38 PM
Fridge Exhaust Fans (or what to do with the cute little solar panel) SCVJeff Heating, Cooling and Appliances 9 08-14-2007 07:17 PM
A/C condensor cooling fans CC38EL General Maintenance and Repair 13 06-27-2007 04:12 PM
Adventurer Defroster Fans Clark Dwinell Winnebago Class A Motorhomes 6 09-29-2006 06:14 PM

» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Winnebago Industries or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 10:04 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×