Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Trailer Towing and Tow Vehicles Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 07-23-2012, 07:10 PM   #1
Junior Member
 
Join Date: Aug 2011
Posts: 7
Warning concerning sparkplugs

My tow vehicle is a GMC 2500 with an 8.1 L V8 (496 cui). Last trip it struggled up moderate mountains so when I got home I replaced the plugs which were in Real Bad condition...! The ceramic surrounding the platinum electrode was broken on 5 plugs and one even had some missing half ceramic...! I think the ethanol in the gasoline caused this. This truck only has 42k miles on it and has only towed my 5er about 7k miles.
__________________

__________________
HSVcamper is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-23-2012, 07:21 PM   #2
Registered User
 
Join Date: Mar 2011
Posts: 1,943
Your detonating the engine. What gears in the rear end?
__________________

__________________
Perry White is offline   Reply With Quote
Old 07-23-2012, 07:30 PM   #3
Senior Member
 
Mr_D's Avatar
 
Solo Rvers Club
iRV2 No Limits Club
Join Date: May 2011
Location: Vancouver, WA
Posts: 28,521
I don't think you can blame the ethanol for this. We've had gas with 10% ethanol around here for over 10 years and I haven't heard of any detonation problems from it.
__________________
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '14 CR-V
Mr_D is online now   Reply With Quote
Old 07-23-2012, 07:47 PM   #4
Senior Member
 
mrv8outboard's Avatar
 
Tiffin Owners Club
Join Date: Jul 2011
Location: Cape Cod
Posts: 318
GM has a long running TSB about drivability concerns and top tier fuel. The detonation is destroying your spark plugs and you engine.
__________________
mrv8outboard is offline   Reply With Quote
Old 07-23-2012, 08:40 PM   #5
Senior Member
 
Ford Super Duty Owner
Join Date: Apr 2012
Location: Austin, TX
Posts: 1,885
Ethanol rates out near 100 octane. An EFI motor should self-protect (knock sensor) against detonation... Check motor specific forums and let us know what you find.
__________________
cb1000rider is offline   Reply With Quote
Old 07-24-2012, 01:22 PM   #6
Junior Member
 
Join Date: Jul 2007
Location: Huntsville, AL
Posts: 7
First of all, are any of you automotive engine design engineers? My profession before I retired, from Boeing, was a missile defense engineer. Prior to that I was employed as a design engineer as a NASA contractor. The engine is not pinging, nor have I ever run it at high RPM. When it needs to kick down to a lower gear I let up on the gas peddle so that it doesn't rev higher than 3200 rpm - in other words I treat my equipment well. This truck is "pure stock" and has never been modified. It has a 4.10 rear end so that it's tow rating in high.

I'm in my 60s and have driven for a very long time (51 years) and owned many GM cars and trucks including two Corvettes which I raced. I have rebuilt engines and transmissions and everything associated with cars or trucks including 4 wheel drive systems from end-to-end.

The spark plugs were made by Delco and were the proper part number. So unless any of you are engine engineers who have designed and/or rebuild engines, I still think I have a better opinion than what has been provided so far.

My posting is directed to other owners of RVs or trucks with GM 496 engines. I would like to receive a constructive reply from these owners to see if they have had this similar experience. This engine type and manufacturer is installed in several class A and C motor homes as well as pickups, both Chevy and GMC.

I am trying to be helpful to these other owners as well as to find out what "Really" caused this issue.
__________________
ron4jon is offline   Reply With Quote
Old 07-24-2012, 02:04 PM   #7
Registered User
 
Vintage RV Owners Club
Gulf Streamers Club
Join Date: Oct 2010
Location: Indiana
Posts: 4,954
But.. your still wrong. You are having a detonation issue, and its not from ethanol, which is a higher octane than gas.

Now, you could be having this issue due to heat, like maybe wrong heat range on the plug or improper heat removal from the plug to to the head, which is where I would start.
__________________
Midniteoyl is offline   Reply With Quote
Old 07-24-2012, 02:07 PM   #8
Senior Member
 
Join Date: Jun 2012
Location: Jacksonville, Florida
Posts: 583
Wow! He should know his equipment with those credentials.
What year truck, and where did that trip go? Wonder if fuel mix up at a filling station occur? Maybe someone dropped E85 in the wrong holding tank? Is your truck E85 compatible? Has someone else gone through that area and now experiencing similar woes? Other ideas?

I have a GMC with the 5.3 and recently changed the original plugs at 145000 miles. I know, late, but they looked good for the mileage! I tow at capacity of my truck and appreciate any heads up about something that may destroy it.
__________________
Bob and sometimes - Nina - a Staffordshire Terrier/a SPOILED pit and her kitty Spaz
2006 Dodge SLT 2500 4x4 Cummins Quad Cab w/AT and 3.73
2007 Salem Sport LE 26FBSRV (TH) w/ my Victory Motorcycle in it or a EZ GO Shuttle cart.
NFlcamper is offline   Reply With Quote
Old 07-24-2012, 03:06 PM   #9
Junior Member
 
Join Date: Jul 2007
Location: Huntsville, AL
Posts: 7
I'm not a chemical engineer and I don't know for sure but I have read that ethanol burns at a higher temperature than gasoline. So, that is why I suspect the 10% ethanol blend, while the engine is under a load pulling our 8k lb 5er, caused the sparkplug's ceramic to fail.

One thing I failed to add to my post: This truck has an Allison 5 speed transmission which has a "Trailer Haul" mode that is selectable via a push-button switch on the gear selector lever. I always drive this truck in the Trailer Haul mode while pulling my 5er or my utility trailer or my in-bed truck camper. This mode provides a higher rpm up-shift and delays the torque converter lockup well as downhill "engine braking" assist. The engine is in the lower 2000 rpm range while driving on Interstate roads in the mid 60s mph range. I monitor the engine and transmission temperature gauges as well all other gauges and I haven't seen anything occur out of the ordinary. Actually, I'm surprised that the transmission temperature is never very high.

Here in northern Alabama and southern Tenn., "straight" gasoline without ethanol is very hard to find, and especially while traveling within 100 miles of here. So, up to now, I have been using what is readily available, which is 10% ethanol blend without a concern. Now I have lingering concerns.

I belong to the gmfullsize.com forum and so far no one there has posted a similar thread. I will take digital photos of my plugs and post them there is see if someone has experienced similar issues.
__________________
ron4jon is offline   Reply With Quote
Old 07-24-2012, 03:16 PM   #10
Junior Member
 
Join Date: Jul 2007
Location: Huntsville, AL
Posts: 7
No - this truck is not E85 compatible.

The suggestion that someone dumped E85 gas in the wrong tank may be a good possibility. I am sure I didn't get gas from an E85 labeled pump. I mainly use this truck around town while working on Habit For Humanity construction and I haven't noticed any major performance change except this last trip up to Nashville, TN.

And, there's another question in mind: I've read somewhere that ethanol blended gas has a "lower" energy producing potential therefore, you actually get lower gas mileage using the blended gas than using "straight" 100% gasoline.

Are there chemical or automotive engineers out there that can set me straight on this? Maybe I have been misinformed.
__________________
ron4jon is offline   Reply With Quote
Old 07-24-2012, 03:16 PM   #11
Senior Member
 
Arch Hoagland's Avatar
 
Monaco Owners Club
Workhorse Chassis Owner
Join Date: Aug 2002
Location: Clovis, CA, USA
Posts: 5,911
I had a 2003 GMC P/U with the 8.1 and Allison transmission. I also have a 2004 motorhome with the 8.1 and Allison.

I put about 45,000 on the truck and have 60,000 on the motorhome and haven't run into your problem so far.

I've burned everything in the motorhome while going around the country, including 85 octane which was all I could get in the midwest.

It will be interesting to see how your new plugs hold up. Keep us posted.
__________________
2004 Monaco La Palma 36DBD, W22, 8.1, 7.1 MPG
2000 LEXUS RX300 FWD 22MPG 4020 LBS
Arch Hoagland is offline   Reply With Quote
Old 07-24-2012, 03:19 PM   #12
Registered User
 
Excel Owners Club
Retired Fire Service RVer's
Join Date: Nov 2010
Location: Farmington NM
Posts: 1,822
News flash>>>>> when you post on here you get replys. Maybe not what you want to hear, but non the less you will get them. No need to give the responders a tongue lashing
__________________
chief02 is offline   Reply With Quote
Old 07-24-2012, 03:36 PM   #13
Registered User
 
Join Date: Mar 2011
Posts: 1,943
If you want to know about engines, ask Mike Canter. He works on real engines (FORD)
__________________
Perry White is offline   Reply With Quote
Old 07-24-2012, 03:38 PM   #14
Junior Member
 
Join Date: Jul 2007
Location: Huntsville, AL
Posts: 7
Quote:
Originally Posted by Arch Hoagland View Post
I had a 2003 GMC P/U with the 8.1 and Allison transmission. I also have a 2004 motorhome with the 8.1 and Allison.

I put about 45,000 on the truck and have 60,000 on the motorhome and haven't run into your problem so far.

I've burned everything in the motorhome while going around the country, including 85 octane which was all I could get in the midwest.

It will be interesting to see how your new plugs hold up. Keep us posted.
Thanks for your feed-back. It's good to know someone hasn't had this issue and has enjoyed many trouble free miles. Maybe it was a one time occurrence for me. This is the valuable kind of assistance from a forum like this.
__________________

__________________
ron4jon is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 02:23 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.