Erratic Fuel Gauge - Diesel Place : Chevrolet and GMC Diesel Truck Forums
Home Forum Market Place Garage Lounge (0) Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > 6.5L Diesel Engine
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Auto EscrowAuto LoansInsurance Chat Room

6.5L Diesel Engine Discuss the 6.5 GM diesel engine & associated components. Automatic transmission questions & problems belong in the 4L80/85 - 4L60E - 6L90 Transmission Forum is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
LinkBack Thread Tools
Old 08-07-2011, 08:07 PM   #1 (permalink)
abm's Avatar
Join Date: Feb 2007
Location: Bear River, Nova Scotia
Posts: 63
iTrader Score: 0 reviews

Erratic Fuel Gauge

When driving on rough roads with lots of turns or on steep hills the fuel gauge on my '95 GMC Sierra bounces all over the place as the fuel tank empties although it stabilizes on smooth straight roads. Should I assume that the fuel level sensor is at fault?


1995 GMC 1500 Sierra SLE
Regular cab long box
Automatic transmission
221,000 km
Braided steel oil cooler lines
Remote-mounted FSD behind front bumper
Reply With Quote Quick reply to this message
Sponsored Links
Old 08-07-2011, 08:16 PM   #2 (permalink)
Diesel Champ
Jake's Avatar
Join Date: Oct 2003
Location: Hayes, VA
Posts: 1,572
iTrader Score: 0 reviews

Old School Oil Burners (Old SOBs) Member

DelMarVa Diesel Club Member

That would be my first thought too. Mine acts crazy when it gets to a certain point on the gauge, but is usually quite accurate most of the time. The simple variable resistor used on the float assembly is usually the culprit. Until mine goes bad, I'll put up with a couple of minor defects.


Jake Brodersen

2010 Suburban K2500 Duramax powered

96 K2500 Suburban
Peninsular Diesel 6.5TD
3.73 gears, Heath Remote PMD, Heath Heavy Duty Lift Pump, Banks 3" downpipe, BD 4" exhaust, JK headlight booster kit,
Heath HP4 PCM, manual glow plug switch, vacuum pump eliminated. Hotchkis sway bars on the greasy side. High idle mod. Four wheel disc brakes.

2012 Acura TL V-6 (280hp)
2006 Harley Springer Softail FXSTSI (already modded and putting out more power)
2002 Chevy S-10, step side, regular cab, 2.2 litre w/5 speed
1992 Chevy S-10, extended cab, 2.8 V-6 w/5 speed
Offline   Reply With Quote Quick reply to this message
Old 08-07-2011, 10:14 PM   #3 (permalink)
Diesel Nut
4thesporty's Avatar
Join Date: Mar 2011
Location: DFW....Texas
Posts: 920
iTrader Score: 1 reviews

Mine doesn't bounce around, but reads way over full for the first ~200 miles of the tank, then goes from actually reading full to almost empty in the next ~250 miles.

You can buy a new fuel sending unit for about $130 or so. It would be a good time to clean/replace or get rid of the tank sock too. (ensure you filter pre LP though)

1994 Chevy K3500 4x4 Crew Cab SRW 212,000 miles
-SOLD 05-08-15
HX40WII Turbo
-4" Turbo Back DE Exhaust
-FTB upgrade with SS -6an line from tank to IP
-Walbro FRB-5 LP with pre and post Wix Filters
-New Bosch Injectors (2200 psi)/Duraterm GPs
-Buddy's single tow tune
-RCD 6" lift kit
Offline   Reply With Quote Quick reply to this message
Old 08-07-2011, 11:41 PM   #4 (permalink)
Diesel Legend
JMJNet's Avatar
Join Date: Feb 2006
Location: Richardson, TX
Posts: 15,692
iTrader Score: 0 reviews

The Suburban Club Member

The flapper is erratic. It uses similar to the one in the toilet with that bulb flapper.

No need to change the whole sending unit. PMDCable sells the replacement to the flapper only. It is a magnetic units, that goes up and down. Still have to take out the tank and the FSU.
1995 GMC Suburban:
PMD in Bumper
Leroy Diesel Flight System PMD
Leroy Diesel Oil Cooler Line
4" Warpspeed Exhaust
Kennedy Diesel LP/OPS Harness
Bosch Duraterm GP
Heath Turbo-Master
AD244 Alternator
Offline   Reply With Quote Quick reply to this message
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
erratic fuel gauge happyjack Electrical 3 08-13-2010 12:47 AM
erratic temperture gauge infinityforge Electrical 0 12-04-2008 06:45 PM
fuel gauge fluctuations/ erratic ratmax Interior 0 02-21-2008 01:10 PM
erratic SPA boost gauge... J M B Interior 0 10-17-2006 08:57 AM
Erratic Temp Gauge Hooky 6.5L Diesel Engine 5 03-13-2006 11:46 PM

All times are GMT -4. The time now is 04:26 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide

SEO by vBSEO 3.6.0