Community Forums

Rendon · 08-06-2014, 01:19 PM

I have a 2004 Itasca Sunrise with 22,000 miles on it. 8.1 Chevy Workhorse w/Allison Transmission. I recently traveled from MS to PA. On my first day out my service engine soon light came on. I found a garage that hooked their computer up to my MH and it said the knock sensor #2 was bad. The guy reset the computer and the light never came back on. This was in Alabama. I had no issues with the engine pinging or knocking. It ran quite well. I discovered the second day that I had a transmission fluid leak when I saw white smoke blowing out the back of the MH! That was not a fun experience by any means!

So I'm in PA now and the MH is at the Allison Dealer and the guy told me that it would be about $700 to replace both sensors and labor. He's suggesting I not replace the sensors at this time since the service engine light never came back on. Anyone have any opinions on this? I am a newbie solo rv'er and am planning on going back to MS in OCT.

He said I could have gotten bad gas or perhaps just a computer glitch.

Arch Hoagland · 08-06-2014, 04:30 PM

I wouldn't replace the sensors either. I had P0131 codes which said the O2 sensor had detected a problem. The common wisdom on here said replace the sensor so I did.

Guess what...no help. Turned out I had an air/fuel mixture problem caused by a dirty MAF sensor.

If I was you I'd buy this UltraGauge OBDII Scan tool & Information Center

I have one now and always know what's going on.

Rendon · 08-06-2014, 05:39 PM

Quote:

Originally Posted by Arch Hoagland

I wouldn't replace the sensors either. I had P0131 codes which said the O2 sensor had detected a problem. The common wisdom on here said replace the sensor so I did.

Guess what...no help. Turned out I had an air/fuel mixture problem caused by a dirty MAF sensor.

If I was you I'd buy this UltraGauge OBDII Scan tool & Information Center

I have one now and always know what's going on.

Thanks for that info! I noticed a lot of members on here had some kind of device to problem solve. I will definitely look into that!

Samflhomes · 08-07-2014, 07:48 PM

I have had similar issues
I would not touch sensors

Change fuel filters annually
Check your plugs and wires

Good idea to replace them at this age

Max Hubrich · 08-08-2014, 04:10 AM

I also have had the Pax side knock sensor light come on.

I have the Scan Gauge II also. I mixed some high test gas with the old, reset the CEK "check engine light", and the problem disappeared for about 3 years. On my last trip in March of this year, it came back on. I added a bottle of octane booster, reset the light and all was well.

When I got home, I bought a new OEM knock sensor and installed it myself (It is located in the starter area), externally on the engine- easy job. Just the other day as I was underneath my rig doing a grease job and oil change, I noticed the knock sensor, on the drivers side, had a heat shield around it from the exhaust pipe giving it a some protection from heat. My pax side sensor doesn't have a heat shield.

We leave in about a month for our next trip- We'll see if the new sensor helped, but as I said before, The first time I had the CEK, a bit of higher octane gas helped the problem go away for about 10-12 thousand miles.

I'll update my input to this thread about late October, 2014.

My old knock sensor

Rendon · 08-09-2014, 09:25 AM

Quote:

Originally Posted by Max Hubrich

I also have had the Pax side knock sensor light come on.

I have the Scan Gauge II also. I mixed some high test gas with the old, reset the CEK "check engine light", and the problem disappeared for about 3 years. On my last trip in March of this year, it came back on. I added a bottle of octane booster, reset the light and all was well.

When I got home, I bought a new OEM knock sensor and installed it myself (It is located in the starter area), externally on the engine- easy job. Just the other day as I was underneath my rig doing a grease job and oil change, I noticed the knock sensor, on the drivers side, had a heat shield around it from the exhaust pipe giving it a some protection from heat. My pax side sensor doesn't have a heat shield.

We leave in about a month for our next trip- We'll see if the new sensor helped, but as I said before, The first time I had the CEK, a bit of higher octane gas helped the problem go away for about 10-12 thousand miles.

I'll update my input to this thread about late October, 2014.

My old knock sensor

Thank you Max for that info. I have the RV at the garage right now having the fuel filter changed and the spark plugs and wires. I paid the Allison Transmission Dealer $1500.00 to fix my transmission fluid leak and replace one of the hydraulic oil hoses. I think they seen me coming! And they wanted to charge me another $700 to replace the Knock sensor, saying it was hard to get to. Unfortunately for me I have no one to work on the RV for me so I'm at the dealers mercy. I still need to have the right back jack fixed. I'm hoping the reason it wouldn't go up was because of the hydraulic leak. A friend forced it up before I left MS. I got 2 miles down the road, pulled into Flying J, got out and looked at the Jack and one of the springs fell off and the round plate was just hanging by the other spring!

My local camping world will be fixing that. I'm sure they're gonna see me coming too!

terry735001 · 08-09-2014, 11:44 AM

1 tip i found out doing my wiring

the 8.1l has a higher out put sensor and unlike most OEM setups this dos not have the shielded speaker wire type wire that is used on most Knock sensor

so any high AC load like a gen set doing some thing funny with a RPM load can play games

even the ALT on the motor its self can

this is rare but happens and pulling the code and resetting the system makes it go away

Duner · 08-09-2014, 01:22 PM

I kept getting Knock Sensor code (driver's side... bank B?) with no other symptoms and would come back again many times after reset. Bought a new sensor from RockAuto.com for $35. Went under to replace and noticed black soot from exhaust donut leak. Found a chunk of the donut missing and it was spraying hot exhaust right on the sensor just 5 inches away. Either the heat or the loud sound was triggering a false code.

Changing a Knock Sensor is an easy DIY job. On 8.1 there is easy access and on my W22 I don't even have to jack up, just put down the leveling jacks and raise up a few inches. You can change both for just $70 and a correct size deep socket. Only warning is not to over-tighten. Save yourself $630 bucks!!!

Good luck,
Bill

Max Hubrich · 08-09-2014, 08:07 PM

Rendon---

Which Camping World are you using- Hammond LA, or Robertsdale AL?

I know where you are in P.C. We spend our winters in Gulfport at the NCBC (Seabee Base)

Whoever is telling you $700 is thinking that the sensor is located in the intake manifold plenum area- I think. Tell them to crawl under the rig and locate the two sensors. It takes more time to figure out which size open end wrench to use than it does to change a sensor on this engine. They are externally mounted.

Send me a PM and I'll call you when I get to Gulfport in mid- October. Maybe I can help. A Scan Gauge II is a good investment to clear the code and you'll love it's other features. It just plugs into the OBD port under the dash. A $12 can of the octane booster, or some higher octane fuel, and a scan Gauge II can cure your present problem.

Arch Hoagland · 08-09-2014, 09:48 PM

Rendon...I'd ask for the old fuel filter to be returned to you. Check it and see if it is hard to blow through.
I changed mine at about 50,000 miles and it wasn't clogged a bit. I'm curious what you find or what anyone else has found when they changed out their fuel filter.

Rendon · 08-10-2014, 09:03 AM

Quote:

Originally Posted by Max Hubrich

Rendon---

Which Camping World are you using- Hammond LA, or Robertsdale AL?

I know where you are in P.C. We spend our winters in Gulfport at the NCBC (Seabee Base)

Whoever is telling you $700 is thinking that the sensor is located in the intake manifold plenum area- I think. Tell them to crawl under the rig and locate the two sensors. It takes more time to figure out which size open end wrench to use than it does to change a sensor on this engine. They are externally mounted.

Send me a PM and I'll call you when I get to Gulfport in mid- October. Maybe I can help. A Scan Gauge II is a good investment to clear the code and you'll love it's other features. It just plugs into the OBD port under the dash. A $12 can of the octane booster, or some higher octane fuel, and a scan Gauge II can cure your present problem.

Max that would be awesome to have your help! Thank you so much for that! I am currently in PA but should be back in Pass Christian the beginning of OCT if not sooner. I will send you a PM with my number. Everyone has been so helpful on here, I'm so grateful. Being in PA is depressing and I can't wait to get back in my MH!

Rendon · 08-10-2014, 09:14 AM

Quote:

Originally Posted by Samflhomes

I have had similar issues
I would not touch sensors

Change fuel filters annually
Check your plugs and wires

Good idea to replace them at this age

Thank you Sam! It's in the garage right now getting a new fuel filter and plugs and wires!

terry735001 · 08-20-2014, 03:03 PM

yes he is right they are externally mounted but you have to install them to stock speck

i think torque is ????? and use the right sealant
Knock Sensor....... 20 N•m ........ 15 lb ft

with the right tools he is right 3 to 4 mins to swop out

so no 700$ is way to much to install a new one

drive side and passenger side sensors are not the same part number ?
this info is fro a 2002 but i am sure there still the same
213-298 Knock sensor - Drivers side
213-2829 Knock sensor - Passenger

it is a one wire sensor make sure there is no rust on the pin as again this is a AC wire not DC

i think its a deep 17MM or 19MM and again use the right sealant GM has a part number for it but it is at the auto store
Knock Sensor Threads Sealant 12346004

its a sealant used one all most every dolt on the 8.1 even the head bolts

oakcreekeric · 08-20-2014, 03:58 PM

Rendon...

Do yourself a favor and go to a local parts place (Autozone, Carquest, Advance).. Purchase something called Chevron Techron... read the dilution amounts on the back and place in your fuel tank (try to mix a little richer than they suggest) for the next long haul.. once you do that.. try to run your tank to as close to empty as you feel comfortable..

Techron is the same detergent GM sells under their own name... but at about 1/5 the cost... I'm not sure about where you are, but here in the greater Milwaukee, WI area, we have to use reformulated gas.. it sucks.. and... GM injectors are the most complicated and advance injectors out there.. and they don't like it either..

People throw knock sensor codes around here and the first step from an honest garage is to reset the code and tell the customer to go buy a bottle (or two) and run it thru their engine.. if the code persist.. then you may have an issue..

Additionally... while at the parts store.. buy yourself a can (or two) of Seafoam... If you are planning to be camped for more than a month.. add some of the Seafoam to your gas tank (again, read dilution chart)... its is a stabilizer and will help keep your gas "fresh"...

Hope my tip, plus all the other good advice you got helps...