# check engine light



## Shadow (Apr 29, 2012)

Motorhome been sitting up for a few months. When we parked it, we filled up with gas and added sta-bil. We decided today to just run down to the coast with it. Made sure all the levels were ok, oil,trans., air and such. Well about fifty miles down the road I noticed the check engine light. Not 100% sure but don't think it was on when we left. Any way, pulled into Walley world and everything seemed fine. Exhaust sounds good, no miss, seems to be fine just looking and listening. So we just turned around and came home. Has anyone had this issue after sitting for any length of time? Only have 26,000 miles on it. May be a week or so before I can get it to a shop.So was just wondering if anyone else has had this happen.  Btw it's a 8.1 gas hog on a workhorse chassi


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## C Nash (Apr 29, 2012)

Shadow you should have just continued your trip on to the coast as long as there were no other guages reading somrthings wrong.  Might just ck your gas cap to be sure its tight.  Hard to say without a code to go on.  Most likely o2 sensor or EGR valve. Your local parts store might be able to retrieve the code and not chg you. Let us know what you find


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## Guest (Apr 29, 2012)

Butch ,, do u know what the code is for the engine light


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## Shadow (Apr 29, 2012)

Chelse, Rod, thanks for the quick response. Thought about continuing on chelse but wanted to be safe. All other gauges were normal and the check light wasn't flashing. Will check the gas cap first and try to find somewhere to get the codes run.


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## H2H1 (Apr 30, 2012)

Hey Butch I put sta bil in mine and had to replace to 02 senor. The following year I put in sea foam, heard it was great, well had to replace the 02 sensor. So my motto is never put in anything but gas in the tank.  I also run it as well as the genset at least once a month. I would think it your 02 sensor, when you can get some one to read it. I f you get to a Auto Zone they will do it for free, also Advance Auto. i ALSO RECOMMEND getting one on line, they are cheaper than either of the auto part stores. Be sure to get one that plugs in, not the one you have to splice. good luck


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## Shadow (Apr 30, 2012)

Think your right Hollis, Told Shirley we had to start keeping fresh gas in it. That means it can't sit to long.  Going to try and get it checked this week. Will let Y'all know what we find out. One fella said to disconnect the battery and let it reset its self. Think I'll wait on the codes.


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## H2H1 (Apr 30, 2012)

Well mine sits all winter long with a full tank of gas. But like I said , I never put anything in my gas tank but gas. I also think ithelps to run it under a load at least once a month, just like the genset. Keep us informed of your finding.


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## C Nash (Apr 30, 2012)

I would get a code first Butch.  You need to know what it is.  Gas dont sit in ours long enough to hurt anything.  Saw gas today for 3.59!!!


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## bandalop (May 1, 2012)

My motorhome will sit for 3 or 4 months over the winter time.  Never used stabil.  I start the generator and run it for 15 to 30 minutes every 30 days or so.  My rig will start up everyting on the 2nd or 3rd crank.  Sometimes you can get that stupid check engine light to go off by disconnecting the battery for a couple of minutes.  I know I can do that on my Ford Expedition.


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## LEN (May 1, 2012)

Code readers are getting really cheap. Scan gauge is one you can hookup(it is a permanent engine monitor) and get all kinds of info on the trans cooling system and will through and reset codes and anyone can hook it up. About a $150 and now they are making one for a Diesel(guess who wants one bad).

LEN


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## LEN (May 1, 2012)

Just looking around and found this. Cheap enough!

http://www.newegg.com/Product/Produ...-_-na-_-na-_-na&AID=10440897&PID=3668349&SID=

LEN


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## Guest (May 1, 2012)

well Len ,, yes a code reader does ok ,, but what really needs to be done is a true scanner ,, one that can get live data. u can not really tell anyting unless u have live data .. the parts places use the code readers as a sales gimick ,, they have no clue what they are looking at other then the code ,, alot of codes have more then one "reason " they were set ,, and unless u know how and have the ability to know how to read the data ,, u are lost ,, but this is JMO


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## H2H1 (May 1, 2012)

AND tnarvs what do you use? the scanner I have and the ones at the store was right on the money with the codes. Once the code is given it can be read as to what it is. And yse they do this free in hope to sale you what you need. But you don't to buy from them. Just free advice as I see it. Just like the one you give out, it free.


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## LEN (May 2, 2012)

That is why I want the Scan gauge, it reads out real time about everything that your system is doing and the codes, plus you can clear them. The only catch is your system must put out the data, but most modern rigs do.

LEN


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## Shadow (May 2, 2012)

May buy me a code reader for Christmas. Went to advance auto and auto zone. Both looked at me like I had two heads when I told them it was for a M/H. Said they didn't have the apps. for M/Hs. Asked why they couldn't just put in engine size and year? But was told it didn't work that way. lol  So found a truck shop that may be able to work me in tomorrow. The r/v dealer we bought it from dosen't even do it!


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## H2H1 (May 2, 2012)

Hi Butch, the first time my SEL came on I drove it to the closest Auto Zone, the guy went out side hooked it to the port and gave me a reading. I was the 02 sensor. They do and can read it, just like you said by the engine, and make , ie Ford , Chevy, Dodge. I think the guy was lazy and did not want to do it, but that HO.  Good luck on yours.


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## C Nash (May 2, 2012)

I agree that a code reader is not always right on.  Just points you in the right direction. A vac leak could set a 02  sensor code.


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## Shadow (May 2, 2012)

Well Hollis was in town today, so I went back to auto zone to raise a little kane. Different fella at the counter and he said he could check it. So ran home and got the M/H. Here's what we got, Definition a. knock sensor condition, explanation aa. the powertrain control module monitors the knock sensor signal for error. Probable cause. aa1. knock sensor defective.  aa2. check connnector and wiring to sensor.  aa3. engine mechanical condition-knock or rattle in engine.  aa4. low fuel pressure.  Now my head really hurts!!  My guess on the low fuel pressure would be the fuel pump. Runs fine though, no miss or lack of power. As far as the knock sensors, think he said one on the right bank.  Here Ya go Chelse....


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## Guest (May 2, 2012)

well Butch ,, i do not see where they came up with low fuel pressure ,, the code readers "kinda" see what the pressure is ,, but IMO u need to see what the long term and short term fuel trim is ,, that will tell u if u are running lean or not ,, but as far as the knock sensor ,, there is an easy test for that ,, go back to where u had the rig tested ,, and have them hook up agian ,, then while they are watching ,, take a hammer or anything hard ,, and hit the engine block somewhere ,,, they should pick up a knock signal ,, it should say "yes" if they have that ability ,, just trying to help .
Btw Hollis ,, i have a tech 2 scanner ,, i can read all live data ,, and even flash the pcm and the body modules ,, alot of that takes care of stupid codes ,, but i thought u already knew what i have


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## Guest (May 3, 2012)

btw ,, butch i forgot to mention in the last post ,, what the code # was ,, if u can give me that ,, and the yr and engine of u'r MH ,, i can dig deeper into it ,, as far as the knock sensor goes ,, most only have one ,, unless u have a german enigine ,, they use 3 ,, but i can say that u might have a programming error ,, there is alot of fixes for that ,, since u said the MH runs fine ,, i realy feel that there is something else causing the knock sensor code ,, (if that is what it really is) i would ck for any loose exhaust system parts ,, and bad motor mounts ,, they will all cause the knock sensor to think u have a prob ,, and trip the ck eng light , with obd2 it takes 3 engine cycles to trip the the eng light ,, but if the folks that scanned ur's ,, can do this ,, they should be able to see the trip montior ,, it will tell when it happend and at what speed and engine rpm ,, and if u applied the brakes ,, or att what speed ,, and also see if once they clear the code ,, and once u drive it ,, they can ck for pending codes ,, that means the pcm is seeing something ,, but not sure of what to do yet ,, but the best way to see the real prob ,, is mode 6 on the scanner ,, that will get u really into what the problem is ,, it shows everything that is happening with the pcm ,, u can get alot of info from that ,, if u know how to read the tiffs


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## H2H1 (May 3, 2012)

dang, now it take a computa to read a computa, to tell the computa what the other computa is computing.now my head is spinning and hurting. Butch get it fix , it time to go camping.


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## Shadow (May 3, 2012)

Thanks Rod. Now like Hollis my head is really spinning.   This printout has no codes other then what I posted. I copied it right off the readout. Know it's not the best. Going to show it to the fella at the truck shop today and see what he says.  One thing it did say was to check the wiring to the sensor. That may be a good place to start. When we parked it after our last trip. We had it serviced (oil changed, ect. ). Will see, think the light is a gremlin. Noticed the rear camera cotrast is fading in and out.


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## H2H1 (May 3, 2012)

crawl under it and see if any connection are loose. OK since you had it service, go look and see if any wires was knocked loose. I change my own oil and filters, this way I can look around and see if everything is OK, or at least looks OK.


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## C Nash (May 3, 2012)

Shadow the knock sensor should be on the side of the engine,  Right side if my memory serves me but dont count on it LOL.  They may have knocked the wire loose while servicing it.  Have yo heard the valves pinging?  I even had a loose fan belt set a knock sensor code but was on earlier model than yours. Its not that hard to diagnos by someone that has the proper equipment and knowledge to use it.  Shotgun method of replacing parts till you get it is to expensive so find a good tech that can help you.  good luck and keep us posted.  the days of guessing are gone.  Dang electronics but when they work they are great.  Now if it was a model before 1981 I could probably tell you whats wrong. LOL


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## Shadow (May 4, 2012)

Hollis I crawled under it so many times the Mrs. thinks I'm hiding money under it somwhere!   Thanks Chelse, the truck shop didn't pan out. All of a sudden their not interested in working on it. Good news is I have a fella coming to the house to run the codes and give it a look over. The knock sensor cost about twelve bucks each. Going to put a new gas cap on also just for grins.


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## H2H1 (May 4, 2012)

naw, Shirley knows where your money is, it is back at the casinos. well I am hoping the guy that is coming can get it fgured out and you can get back at piece with it and head out somewhere. Good luck


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## Shadow (May 7, 2012)

First off let me thank everyone for their help and advice on this thread. Seems like the ole girl decided to fix herself. My buddy was real busy this morning so he asked if I could bring the M/H to his shop. It's about a 15 mile drive. About half way there, the check engine light went out. First thought, great problem solved. Second thought, maybe the light burned out!   Well anyway he checked it for codes. ( he had one like Rod talked about, real time.) It showed no codes. So he did a history and it did show that it had a code on the knock sensor. But no codes now. He thinks maybe it was the gas that set it off. Told me to run it below half and top her off. Any way thanks again guys. Look out Chelse, will be looking for ya this summer!


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## H2H1 (May 7, 2012)

so glad you got that fixed. see you on the road. If you looking for Chelse wish you luck, he moves around alot CG to CG state to state. I am hoping to find him late summer in Paul Grist state park. It seem he likes that CG, or the fishing there.


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## C Nash (May 8, 2012)

Sitting at Grist right now.  Arm and back sore from catching Bass.  Just came in from sitting by the campfire.  Did go and met our son today to ck out a MH he is getting.  Barth 28 ft diesel pusher. camping this week with daughter and her family.  Now maybe our son will be camping with us again.  Life is great.


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## Shadow (Aug 9, 2012)

Just a update on the m/h. Ended up taking to a shop and had the sensor replaced. Light would go out for awhile and come back on. So anyho, alls well and looks like we may get out towards the end of the month! Oh the frig wouldn't work on gas so had that fixed also.


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## H2H1 (Aug 9, 2012)

well we are glad that you got it fixed. So where have you and the wife been this year?


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## C Nash (Aug 9, 2012)

Come on over this way Butch.  Hadn't heard from y"all so was getting worried.


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## Shadow (Aug 12, 2012)

Really haven't been any where with the m/h. Drove it on a few day trips. But no camping anywhere.    Chelse we are going to try and get that way towards the end of the month or mid Sept. Will pm you when we have a date set.


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