Reply
 
Thread Tools Display Modes
 
Old 12-14-2015, 02:57 PM   #1
Senior Member
 
Join Date: Aug 2011
Location: Wyoming
Posts: 321
Sudden loss of MPG

I have a 2007 E350 V10 with 109k on the clock. We got it with 48k miles and was getting over 12mpg all the time, maybe 13-14 (better at sea-level). This last trip I got 9mpg. Has anyone experienced anything like this?

Both valve covers have oil on them so I checked the PCV valve idea, but it rattles just fine like it should, although it doesn't seem to seal all that well to the valve cover. The passenger side valve cover has what appears to be the "heated" PCV valve while the driver's side just appears to have either a regular PCV valve or just a grommet and hose coming out of it. Ideas here?

Also, I have the little puff of smoke on start up but it's very random and hardly ever happens. Thoughts on this? The van runs great and doesn't seem to use any oil. No check engine lights are on either, I have it chipped from 5 star tuning, would that effect check engine light not coming on?

Any help on this would be much appreciated, we are heading out on a trip for The rest of December and start of January and It would be nice to get the "regular" MPG again.
__________________

c7train is offline   Reply With Quote
Old 12-15-2015, 04:12 AM   #2
Senior Member
 
carringb's Avatar
 
Join Date: Jan 2009
Location: Corvallis, OR
Posts: 3,862
Have you changed the plugs yet? You're past due, and when they get worn enough mileage tanks. For me it happened first at 115,000 miles.

As for the puff of smoke.... It's the valve guides. Switching to good synthetic will restore the seals. Mine did the same when I first bought it. By 150,000 miles that went away completely.
__________________

__________________
2000 E350 extended wagon dually
V10 w/ Banks Powerpack, Diablo Predator
Buckstop Outback bumper/grill guard
Reunel rear bumper
carringb is offline   Reply With Quote
Old 12-15-2015, 10:15 AM   #3
Senior Member
 
BajaSportsmobile's Avatar
 
Join Date: Sep 2011
Location: Rancho Nuevo (Cabo/Todos Santos) B.C.S. and San Diego, CA
Posts: 1,952
Is it down on power as well?
__________________
Four time Baja 1000 winner, four time Baja 500 winner. Solo'ed the Baja 1000 to LaPaz/Cabo twice.
4-Wheeling since 1972, Desert Racing since 1989.

AgileOffRoad.com
BajaSportsmobile is offline   Reply With Quote
Old 12-16-2015, 10:00 AM   #4
Senior Member
 
Join Date: Aug 2011
Location: Wyoming
Posts: 321
Carringb, I haven't gotten up the guts to change the plugs yet, maybe that's the next step. I've had the dog house off twice now and the new plugs in hand, but wimped out both times. Soon, soon.

Agile, it doesn't feel as though it is down on power. I can pull the same hills at the same speeds like usual.

I'll keep you both posted on my findings, thanks for replying it's so helpful to have a group of people willing to provide constructive info.
C.
c7train is offline   Reply With Quote
Old 12-16-2015, 06:16 PM   #5
Senior Member
 
carringb's Avatar
 
Join Date: Jan 2009
Location: Corvallis, OR
Posts: 3,862
Yeah do the plugs. And new boots. Make sure you use oem or equivalent AutoLite double platinums. Copper plugs will burn up fast in a v10.
__________________
2000 E350 extended wagon dually
V10 w/ Banks Powerpack, Diablo Predator
Buckstop Outback bumper/grill guard
Reunel rear bumper
carringb is offline   Reply With Quote
Old 12-16-2015, 11:13 PM   #6
Senior Member
 
MadScience's Avatar
 
Join Date: Jul 2011
Location: SF Peninsula
Posts: 696
While I'd take CarringB's advice over my own, here are some _additional_ thoughts:

Simple/dumb thing to check is always tire pressure. That and working my engine oil too long/hard has resulted in similar drops for me. A couple 1k changes fixed the latter, but really it was nasty sludgy looking oil that drove me to that.

(Well, and towing a heavy or non-aero-dynamic trailer, but you'd be down on power if you somehow managed to not notice that in any other way ).

Obviously, 4-low on trails burns fuel at a truly impressive rate.

(my experience is on a 99 v10 on 33.5" tires)
__________________

'99 EB ex ENG KSWB news van, low rent 4x4 conversion (mostly fixed by now), home built interior.
MadScience is offline   Reply With Quote
Old 12-17-2015, 09:55 PM   #7
Senior Member
 
carringb's Avatar
 
Join Date: Jan 2009
Location: Corvallis, OR
Posts: 3,862
Tire pressure is a good thing to check anyways

There's dozens of items that can cause poor fuel economy. But worn spark plugs will cause it, so its best to always make sure maintenance is up to date whenever trying to diagnose a problem.

On the tire pressure note.... A couple years ago mine fuel economy tanked. Like 6 MPG bad when towing. I couldn't figure it out, and didn't think it was my plugs yet. Finally on a whim a decided to check my tires. One of the rear inside duals had ZERO psi! The rim was cracked!. My fuel economy was terrible for over 1,000 miles before I finally found the bum tire. Even with that, I no handling problems whatsoever.
__________________

__________________
2000 E350 extended wagon dually
V10 w/ Banks Powerpack, Diablo Predator
Buckstop Outback bumper/grill guard
Reunel rear bumper
carringb is offline   Reply With Quote
Reply

Thread Tools
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

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 11:30 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.