BAC Forum
General Boards => Technical Support => Topic started by: Richard Dangel on October 10, 2020, 02:34:27 AM
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Hello All,
I am new to the forum although I have been browsing this site for 6 years. I seem to be having a heat build-up problem in my engine run box. I have a 2009 Marquis, Lapis IV with a Cat C-15 purchased 2 years ago from Beaver Coach Sales. I have had to replace the Big Boy and the smaller solenoid twice each along with the run circuit board (EXPENSIVE). I have to keep the cover off the runbox or the heat builds and I go into downrate. Gerald mentioned on another post that the voltage going through the Big Boy drops after it pulls in to reduce heat. How do you check that it is really dropping? I am considering punching a couple of holes in the runbox and installing a small 12 volt fan and a screened vent. Any and all help, thoughts and consideration would be greatly appreciated.
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Richard,
There should be approximately 4 VDC on 1 of the 2 small terminals of the Big Boy solenoid after it has been engaged for a minute or so. Alternately you can check the voltage at the "Solenoid" pin of the BIRD controller since that is the source.
I highly doubt that the Big Boy is the source of your heat issue however. I don't have a C15 so not sure of the layout but if the muffler and exhaust run under the run box they would be my first suspects. An IR temp probe might help you locate the source of the heat.
Steve
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Thank-you for the prompt reply. I hadn't thought about using a heat gun (sensor). will definately look into that. Muffler and large burn box (?) are directly under the box. Should I pursue the fan and vent idea?
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Richard
First, welcome!
Next if your engine compartment is like ours the amount of dirt would make me seal the run box up tight.
Last;
The engineer at Monaco who worked on the C15 is Scott at Source Engineering in Venetta Ore. (There is a company of similar name in Seattle and google takes you there so be sure its Oregon. )
Jim and Scott are partners and may provide some help or insight.
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If your Coach is going into a "derate" condition, there should be a code stored. Have you checked for codes? Does the Check Engine light come on when this happens?
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Kieth, thanks for the info. I will try to contact Scott on Monday to pick his brain.
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Mike, I have had codes and had them all checked out by Cat. Reset and currently have no codes. Definitely had all my warning indicators come alive, very disconcerting when negotiating in the mountains. My concern right now is how to keep things alive in the runbox. I did quite a bit of travel with the cover off and did not get any alarms or indicators. Thanks. I'll try to post any efforts I do to alleviate my problems. Will be really nice to be able to post an "All Fixed".
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How did you determine that the problem is due to heat in the Run box?
Why/how can a faulty "Run Circuit" board cause an engine derate? I see circuitry that could prevent the engine from cranking (neutral safety switch and starter relay) but I don't see anything obvious that would cause an engine derate. Maybe the wiring diagram I'm looking at is missing some pages or I'm just not seeing something.
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Richard,
Mike makes a good point. To follow up, do you know if the "high temperature" condition occurs only when traveling in the mtns or cimbing or does it also occur when running on the flats? Also what temp does your engine normally run at and what does it reach when climbing long grades? Some of our C15 drivers may be able to give you a comparison.
Steve
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Engine has only gone into derate about 6 times. Always on grades using lots of power. Opening the runbox and letting everything in there cool down has allowed me to proceeed with 2 exceptions. Once coming into Las Vegas at 2 mph and once pushing a big wrecker in Tennessee. I may be all wrong about my heat problem and losing my solenoids in the runbox but I need to do something to keep me from worrying every time I leave the campground. I previously had a 2003 Marquis with a C-12 and had no engine issues. 85,000 miles on this one and wish I had my old C-12 back. I think it had more power too. The pollution control solution on the C-15 has been a costly headache and Cat hasn't said anything to make me think that wont have more problems in the future. I know I may be rambling here but I am experiencing extreme frustration. Thank you all for your suggestions and listening to my rants.
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Always watch the heat guage on uphills and never experience much of a raise in engine or transmission temps.
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Richard, we are talking all around the block on your heating problem, first of all what is your Cat C-15
Serial number. Second did you have motorhome at a Caterpillar service shop and if so could you give
me any code that pertained to your heating and derate issue. I should be able to assist you with your problem. Dave Atherton Retired Cat Mechanic
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Hey Dave, is there a possibility of a fuel starvation issue and is there a code for that?
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Fred
I was thinking more on the lines of DPF over heating on hills triggering a code and consentrating heat below / behind the run box
If Dave gets the codes it should shed some light on the derate
Eric
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Fred, Eric, until I can get more information with Engine s/n number and ET codes we are only guessing.
I will say, the Caterpillar C-15 is a very good engine with very good history. Getting mixed signals
about what is really going but problem is within the engine itself and not within the engine compartment. Dave Atherton Retired Cat Mechanic
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Guys, I really appreciate all your efforts on my behalf. I will locate the serial number tomorrow. It could be two completely different problems.
1. Lots of heat in my runbox cooking solenoids and circuit boards
2. The derating of the engine when I ask for max power.
I thought they were only one problem, because when I opened up the runbox it would start up and run. Maybe not full hp but at least not 2mph. Cat in Boise worked on it last and said all was ok. NOT. Cat in Henderson, Nv replaced the spark plug (?) for the burner and said all was ok. NOT. Cat in Tennessee got me running after a 25 mile tow and told me every thing was ok. NOT. I received huge bills only to have reoccurrences. Very frustrating.
I dont expect to see a fuel problem. New filters and fuel pump tested by Cat in Boise. They also adjusted my valves and replaced 2 part Lifters? with the new style one piece units. Thanks again.
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They also adjusted my valves and replaced 2 part Lifters? with the new style one piece units. Thanks again.
What are these "one piece" lifters?
I know there was an updated bolt design for the VVA housings.
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Richard
Looking at your last post it would appear that the mechanics are chasing a diesel particulate filter regen failure causing DPF slot load to increase until the system set a derate code and limits operation.
More specifically I would think that they are trying to cure a failure to ignite code for the ARD / burner this would be why they replaced the spark plug the problem is that there are many variables that can contribute to a failure to ignite or a flame out code such as DPF pressure differential too high or available boost pressure too low , fuel pressure at the burner too low and or a bad ARD head .
This requires a good tech with Cat ET software and a good understanding of the ARD and regen system diagnostics .
If you can your best bet is to give all the past and present diagnostics codes to Dave and see if he can walk you through the proper diagnostics and at least give you something to go by at the next Cat service shop.
Without being able to connect Cat ET to the vehicle and read the parameters to observe the different components in the system while trying to regen it is nearly impossible to get an accurate diagnoses and the parts we are talking about are too expensive to just start go throwing parts at it .
Again Dave is likely your best bet here even better if he's close enough to you to get a look at it for you
Hope some of this helps
Eric
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I would like to apologize to everyone for my not perfect posts. I am not very computer savvy and my DW did not notice what I had done. C-15 Ser. No. is SPD08542. I used the wrong terminology and called they VVA solenoids lifters. I really don't know what they are but I've been updated with the new 2 piece ones. I think I read somewhere in another post that Dave Atherton has a repair business. Is it against forum rules to ask for the name and phone number? This country is only 3000 miles across and I hope we could hobble to wherever his business is located. I totaled up my repair orders at 8,000 dollars and still don't have any faith in this engine.
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Richard,
We don't want to post member phone #s on a public board. Best way to contact Dave is to look up his phone# in the Member Directory on the BAC website https://www.beaveramb.org/ or send him an email or private message, both of which you can do from the Forum if you are logged in. Just look up his name under Members / Search (next to Log Out on same row as Home).
Steve