Community Forums

RandyG26170 · 09-21-2010, 10:06 PM

I have a 36ft 2004 Fleetwood Southwind on the Workhorse Chassis with the 8.1 Vortec Engine. It has shut down on me about 15-20 times in the last couple years when changing elevation by greater than 1000 ft in less than 1/2 hour. Doesn't matter whether I'm going up or down the mountain. The engine would idle but as soon as I touched the throttle the engine would die. I could usually wait 20 minutes, restart the engine, and drive away. I've not had any luck at the Workhorse dealers. Anyone else had this issue?

mfire1339 · 09-21-2010, 10:19 PM

WVtravler, Has workhorse changed any parts yet? I've never heard of this problem. Been lucky only had to change complete engine.

Mike

94-Newmar · 09-22-2010, 04:02 AM

Could be a faulty/slow MAP sensor? Is it throwing a "Check Engine" light or anything? If you have a code scanner it might still find a stored complaint of a bad sensor.

RandyG26170 · 09-22-2010, 06:38 AM

No Check Engine Light

Mike Canter · 09-22-2010, 09:27 AM

My guess is that it is a fuel tank venting issue. Does this happen when you have above or below a certain amount of fuel in the tank. Next time it happens undo the gas cap and vent the tank and see if it will then start up right away. If it was a sensor or anything in the motor you would have a Check Eng light. When you stop and get goes do you hear any air rush when you undo the gas cap. One car I had used to blow air out at me when the taknk was low and I opened the cap. Didnt wnat to be smoking when you did that. There can be hidden fault codes that will not light a check engine light on some vehicles.

gbs2320 · 09-23-2010, 05:45 AM

Quote:

Originally Posted by Mike Canter

My guess is that it is a fuel tank venting issue. Does this happen when you have above or below a certain amount of fuel in the tank. Next time it happens undo the gas cap and vent the tank and see if it will then start up right away. If it was a sensor or anything in the motor you would have a Check Eng light. When you stop and get goes do you hear any air rush when you undo the gas cap. One car I had used to blow air out at me when the taknk was low and I opened the cap. Didnt wnat to be smoking when you did that. There can be hidden fault codes that will not light a check engine light on some vehicles.

I second the motion! Had similar related issues w. a VW. The pressure increase can cause so much fuel vapor to be pushed back through the fuel evap system to the intake to cause a temporary too rich situation and a engine stop or no start. My ears always tell me altitude changes cause pressure changes. You evap sys valve etc. may not be functioning properly causing too much fuel vapor to suddenly get to the engine instead of gradually or some other related evap problem. The evap sys will set codes also but most of the codes are for a leak in the sys and or a malfunctioning pressure test pump in the system. Have some one check out your purge valve. Also I would check out MAP (manifold absolute pressure) sensor as well.

RandyG26170 · 09-23-2010, 07:11 AM

I've not had any luck finding a Workhorse Authorized Service Center that has the ability and/or will take the time to even look at this issue since there is no Check Engine Light. As of this month all of the dealers in West Virginia have abandoned Workhorse due to slow payment and in their eyes ridiculous documentation and certification requirements. I didn't have any luck in California, Nevada, or Kentucky either. The list of service centers listed on the WH web site is very inaccurate.

So I have been able to cross reference the Work Horse MAP Sensor part number over to GM for purchase from a local GM dealer. It took less than 5 minutes to install but I have no way of knowing if it corrected the problem until my next trip out West as the smaller mountains in the East haven't been an issue.

I had already tried the gas cap thing with no change.

Workhorse has a serious problem on their hands in that dealers are jumping ship at a very high rate. It is now a 126 mile trip for me to go to the nearest WH service center. Just to drive there and straight back takes over 4 hours assuming there are no delays. Ford has 4 dealers with 40 miles of my home. Guess what chassis my next rv will be on?

94-Newmar · 09-23-2010, 07:49 AM

A MAP sensor can be inaccurate sending an incorrect voltage to the computer BUT if that voltage is still within the range of acceptable voltages for the ECM/PCM, a MIL or CEL (check engine light) for the MAP sensor may not be set. Hopefully that will fix your problem.. its certainly easy enough and inexpensive enough to try!

gbs2320 · 09-23-2010, 07:52 PM

Quote:

Originally Posted by WVTravler

I've not had any luck finding a Workhorse Authorized Service Center that has the ability and/or will take the time to even look at this issue since there is no Check Engine Light. As of this month all of the dealers in West Virginia have abandoned Workhorse due to slow payment and in their eyes ridiculous documentation and certification requirements. I didn't have any luck in California, Nevada, or Kentucky either. The list of service centers listed on the WH web site is very inaccurate.

So I have been able to cross reference the Work Horse MAP Sensor part number over to GM for purchase from a local GM dealer. It took less than 5 minutes to install but I have no way of knowing if it corrected the problem until my next trip out West as the smaller mountains in the East haven't been an issue. As you found out many shops don't want to be bothered with something out of the ordinary. Time to find a competent shop -- it does not matter whether they are a Workhorse service center.

I had already tried the gas cap thing with no change.

Workhorse has a serious problem on their hands in that dealers are jumping ship at a very high rate. It is now a 126 mile trip for me to go to the nearest WH service center. Just to drive there and straight back takes over 4 hours assuming there are no delays. Ford has 4 dealers with 40 miles of my home. Guess what chassis my next rv will be on?

Your chassis is out of warranty so you don't need to go to a Workhorse shop to have it worked on. The engine is GM so any competent shop that works on GM engines should be able to help. The engine mechanics and sensors are the same. Also any truck shop should be able to do other work and simply order parts from Workhorse or the actual component suppliers to Workhorse.

WOODYDEL · 09-29-2010, 08:22 PM

No fix but here at this site sounds similar to what is happening to you.

Suburban 8.1 Liter Breakdown Puzzle - GM-Trucks.com

You can suspect the crank position sensor. I know, what's it got to do with elevation, right?

bldr11 · 12-04-2010, 04:37 PM

Had same type of problem in 2003 Pace Arrow with same engine. Only did it when temp outside was above 80 degrees and after long constant speed and then decelerate. Acted like a vapor lock. Shut down for a few swconds and then good to go.

UFO Pilot · 12-04-2010, 05:04 PM

You should post this in the Workhorse Chassis forum or ask the moderator to move it there. You will probably get a quicker response.

gmwillij · 05-22-2017, 05:55 AM

Did you solve your "8.1 workhorse elevation change engine" problem? I'm experiencing the same problem with my 2005 National Dolphin.

RandyG26170 · 05-23-2017, 07:08 AM

Yes, it turned out to be the Mass Air Flow Sensor was very dirty. My GM truck dealer replaced the sensor and moved the air intake duct so it didn't point at the ground where it was picking up grass and dirt blown around by the radiator fans.