I wonder if anyone has noticed this as much as I did this weekend. Here's the short story (ok, I lied, it's not that short):

Took a road trip for the holidays. On the trip there and half way back, my truck sounded and ran exactly the same. Milage stayed very consistent at just a shade under 17.5 mpg driving between 75-78 mph. I've been running Diesel Kleen at every fillup, so nothing changed at all. I stopped at a station (can't remember the name of it) in the middle of nowhere Alabama and filled up my tank taking in about 27 gallons. After that, I left the station and immediatly got a phone call. I was talking on the phone for a few miles when suddenly my engine got really quiet. What I mean is it was half as loud as it had been the entire trip and the whole week on vacation. Even the person on the phone noticed that my engine noise was much quieter and could hear me better than before. I continued to drive all day until I got home, engine continued to run very quiet. I checked the milage again and noticed that my milage actually went up a bit to almost 18 mpg, even though I was driving through more and more hills than compared to the flat drive on I-10 at the beginning of the trip. Even my extremely innaccurate trip o meter on my console rose higher (I reset it at the beginning of the trip, hovered around 12.9, then after the fillup quickly rose to 13.6 mpg) Nothing changed in my driving speed or style. Just the terrain which should have made it lower my milage instead of raising it.

So I have two possibilities:

1) Did I just get lucky and find a station with the sweeter than honey #2 diesel? I'm talking the kind of diesel that is so good Jesus himself would anoint his own feet in it. Or....

2) Do I have a sticking EBPV? On the entire trip, I never heard the sound of my EBPV kicking on. I know that sound, and the truck never ran sluggish. However I'm wondering if it is sticking partially closed, and if it just happened to open shortly after my fillup as a coincidence.

When I get time, I will check the EBPV to see if it feels like it's trying to stick. Until that time, anyone else ever had this happen to them after a fillup? Other than after a really bad tank of diesel (yes that has happened to me as well). Funny thing is it ran the same way for over 1500 miles, then suddenly decided to sound completely different. BTW, it has been quiet ever since. But then again, it has been so warm, my EBPV hasn't come on either on first morning crank.

If anyone has any other suggestions other than my possibilities, let me know. I'd like to catch a problem before it happens.

 

Could have been higher cetane fuel. Most of the diesel sold in the US is pretty crappy cetane-wise (and you'll note that hardly anyone even posts what the cetane is.) I know that when I put a slug of biodiesel in the '97's tanks you can hear when it gets to the engine, because it quiets down quite a bit. (Biodiesel has much higher cetane than normal petrodiesel). I haven't seen any mileage improvement though, which is consistent with biodiesel's slightly lower energy content. So that would imply what you got was some high-cetane petrodiesel. You should go back there and see if you can find out what it was!

Duncan

 

My truck sounds different and runs stronger when I fill up with diesel MAX. Sounds like thats what you got. Just better fuel.

 

You'll have to mark that station on the map, so when you go back by there again, be sure to stop and fill up. Sounds like they had some of the sweet stuff.

 

Better fuel!!!! the station I regularly go to usually has good fuel but sometimes they have great fuel!!!! MY truck gets quieter and starts and runs smoother I've been using DK just to even things out a bit. I've also made some of my own biodiesel and my truck really liked it so I'll probably make some more.

 

Thanks for the replies. I have in the past noticed a little difference between fillups when I get good fuel and not so good fuel. I just never noticed such a dramatic change at one time. I'm one of those who can hear any new noise or change in the engine when driving.

Just this past week I was driving with my girlfriend, and kept complaining of a buzzing sound in the cab. I turned the radio off (yes I heard it with the radio on) and asked her if she could hear it. She said no. We ran errands around town for about 3 hours and this continued, still she never heard it. Then suddenly a bee landed on her hand. She finally stopped thinking I was crazy.

 

How do ya make biodiesel. Sounds interesting! I run stanadyne in every tank. The odd time i don't have any and i notice the motor louder without it!!

 

It was just good fuel. In my big rig days, my fuel mileage would vary up to 10% depending where I got fuel. I found I consistently got the worst mileage on Flying J(unkyard) fuel.

 

Everything is better in Alabama!

 

EVERYTHING ??!!

 

Well, not EVERYTHING I guess. Bob sledding really sucks down here....

 

And how about ice fishing ?

 

Why would you want to fish for ice? We just put water in the freezer and viola! Ice!

 

Well, just to keep you guys updated...

I've been driving around town this week after the trip and I've filled the tank at my regular station. The truck is still running very quiet and getting good city milage. Also I have noticed something else this week. On my trip I never really hammered the accelerator, however after yesterday and today I'm noticing a really huge difference in how peppy my truck is. Just a little while ago I had to quickly pull out in front of oncoming traffic and romped on it hard, both tires broke loose and my tach wrapped to redline in no time. It was like I had put a chip in or something it. Yesterday had the same thing happen. It's definatly running much different, and I'm beginning to think it's not fuel related at all. There's just too much of a change.

This weekend I'll spend under the hood looking at my EBPV, etc. and see what I can come up with. I just have the feeling that something must be sticking in colder weather. Any other suggestions would be helpful. I don't want it to start running like a slug again. The thing is, it has seemed to run sluggish for the past few weeks before this, but I was blaming it on the fuel.

 

All things being equal it still could be fuel related . I don't know what would make it run any better with out doing anything to it .