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nuthut · 06-16-2009, 05:48 PM

Just made my first trip with the new-to-me RV; about 1500 miles round trip. The 350 Cat ran great with good power and pulling my toad.

The warning light started coming on for a few seconds (then going off) while going up grade, when I needed more fuel into the engine. It would never happen while on a flat or downhill. It would also happen while accellerating in the entry ramp or taking off from a stoplight. The lights were STOP ENGINE and CHECK ENGINE. All guages were normal. I think the engine had plenty of power, although I am not sure. Driver Information panel said Check engine.

The m/h sit around for a few years with little use before I bought it, so I used some Lucas fuel treatment in the first full tank of fuel. I also changed the fuel filters this spring.

I think the problem is fuel filters. The lucas additive may have disolved some crud lying or growing in the fuel system, then it got sucked into the filters and they are semi clogged.

Has anyone had this sensor go off while the engine is working hard? It is an 2004 FL chassis with 7000 miles now. Thanks

Marv

Family Time · 06-16-2009, 09:51 PM

Have you checked the engine coolant and oil levels? I had a small coolant leak and the surge tank got low enough to trigger the warning lights, it happened on hills mostly as the sensor is in the forward side of the surge tank on mine. I would think if it was a fuel filter issue the power would be low.

nuthut · 06-17-2009, 06:30 AM

Thanks for the tip, Family Time. I will get over to the M/H today to check all the levels. Now that you mention that I had a Freightliner Dump truck that would occasionally get a little low on brake fluid. There was a sensor on the side of the reservor. The alarm would beep when going around a left hand turn. Drove me crazy until I finally figured it out.

Jim Stewart · 06-17-2009, 08:09 AM

If you know of someone with a VMS PC with a 6 pin connector you can borrow, try it on your cpach. It is designed for monitoring, but it has a lot of diagnostics similar to what a dealer would use, it will most likely tell you the reason for the warning.

I believe that the VMS PC is worth the price in what you will save in diagnostics alone.

http://www.silverleafelectronics.com/?q=node/6

Here is website, you can read about it and download a copy of the free software to take a look at. You can get the cable and black box for as low as $340.00 on the internet and with your own laptop or netbook, you are set. The new units come with a USB connector to hook it up to your laptop the current or older stock require a Serial to USB adaptor if your laptop does not have a Serial Port. If you like it and order, make sure you know whether you are getting it with the USB connector or need the adaptor.

nuthut · 06-19-2009, 01:27 PM

Family Time I think you may have nailed it. I hope so anyway. My surge tank (overflow?) is a little low. The tank appears to be about a foot long from front to back, so if the fluid level sensor is in the front of it I can see how it may be sending a low coolant signal. I cant see the front of it without lifting the bed. I will try to find some Cat approved antifreeze and see if that helps. thanks again for the tip.

Jim Stewart, I will save up for the VMS PC. I may try to get my boss to buy one of those since he is running some of those Cat engines.

While I was crawling underneath the engine today I found the water cutoff on the heater hose for the dash heater. That fixed the problem with the dash air being only cool instead of cold. I still have a lot to learn.

Korryp · 06-21-2009, 08:42 AM

Just had this exact problem on my rig. Small leak fixed now no problem.

nuthut · 07-31-2009, 06:21 PM

I wanted to check back in to let everyone know the overflow tank needs to be at or above the full line to keep the buzzer quiet. I poured a gallon of antifreeze into the tank which brought the level about full. The buzzer almost quit going off. I bought another gallon and poured about half of it into the tank and it finally solved the problem. The level is now above the full mark, but there is still some room for expansion. I cannot see how big the surge tank is but it must hold 4 or 5 gallons, as it was not very much low to start with.