check engine light


Shadow

Senior Member
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
 

C Nash

Senior Member
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
 

Shadow

Senior Member
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.
 

H2H1

Senior Member
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
 

Shadow

Senior Member
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.
 

H2H1

Senior Member
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.
 

C Nash

Senior Member
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!!!
 

bandalop

Member
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.
 

LEN

Senior Member
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
 
G

Guest

Guest
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 :)
 

H2H1

Senior Member
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.
 

LEN

Senior Member
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
 

Shadow

Senior Member
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!
 

H2H1

Senior Member
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.
 

C Nash

Senior Member
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.
 

Shadow

Senior Member
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.... :)
 
G

Guest

Guest
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 :)
 
G

Guest

Guest
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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