I have an 03 6 liter F350 Crewcab. I purchased it with 112k miles.

I deleted the EGR, new oil cooler, VC9 flush x 2 and used CAT EC-1 coolant plus a coolant filter system when I first purchased the truck. I also sent my FICM to ED and had the full repair plus the Atlas tune. I also did the crank case ventilation mod. Oh yea, I did the blue spring modification too.

Here is my problem,
I noticed on my way home from work my truck sounded like it was missing at cruise speed on the freeway at aprox 65 mph. I was then going up a long hill, rpms aprox 1500 and I noticed a shutter with the engine sounding like it was missing. I thought maybe it was the turbo...maybe. However, I was able to reproduce the shutter while traveling down a flat area at the same rpm and speed.

Then, I was almost home and was at a stop light. I felt my truck shutter at idle! At this point, I knew it was not the turbo.

Now, I recenlty changed all my oil filters, fuel filters, transmission filters and oil/transmission fluid changes. I always run diesel Kleen every tank full. This last time around, I put a quart of 2 cycle low ash oil in the tank as I have read this can be good for the fuel system on all diesels. I had 1/2 tank and added 1 quart. I drove it for 20 miles to work and that's when I first noticed the shutter. I then filled up the tank. That was on my first day of work last week. My second shift (fireman 24 hr shifts) was yesterday. I drove it to work with no noticable issues, but on my way home it was noticable.

What and how can I trouble shoot this? I'm new to diesels, however, I used to work for Art Morrison while I was in Highschool so I know gas engines well. I'm just hoping that the problem is too high of a concentration of 2 cycle oil in the fuel for the first 20 miles...but I doubt it

HELP Please

 

So there's a miss at cruise (certain speed and rpm) and also at idle. It's probably not set any codes but a trip by the parts store to confirm would be a good starting place. It may have set a code to get you started in the right direction (you don't have to have a check engine light to have a code set). Also consider snagging an OBDII monitor like ScanGaugeII or a smartphone app. Highly recommended to have something to monitor the engine's vitals, most of the instrument panel gauges are misleading.

I don't think the 2stroke oil is an issue, but most recommend the ashless over the low ash type.

The recent filter changes could be an issue if one of the cap o-rings are leaking. They sometimes suck air when the pump is running but don't leak fuel when it's off. Inspecting the o-rings for nicks and flat spots and reinstalling (with some motor oil) might help.

A bad tank of fuel from the service station can sometimes act as you describe, it could clear up with some fresh fuel in the tank. On the other hand if it's something mechanical it's likely going to get worse and be easier to find.

A trip to the dealer for a diagnostic scan might be in order. The trucks computer has software to smooth out the engine. The dealer Tech can turn off smoothing with his test equipment and watch each cylinder to find the one(s) that aren't "contributing" to the engine running.

Also, just as a guess, my truck ran pretty crappy for a couple of days with no check engine light or codes and I pulled the EGR valve and cleaned it. Problem solved.

On your crankcase vent mod, did you return the hose to the intake or is it venting overboard?

 

Thanks for the reply! I thought about bad or poor quality fuel. Could be...I'll find out next tank full

No codes are flashing but we all know that means squat.

cap o-rings are leaking from fuel filters. I also considred this. I've seen no fuel leaks and everything looks dry..kind of. It's Fall and here in the PNW, it has been raining constanly I'll doubble check that one tomorrow.

I need to get a scan tool. I'll look into the one for my Iphone.

CCV mod. I have it venting to atmosphere by the rear tire.

This whole surge problem is very short lived. Over a 40 mile drive home, it happened 4 or 5 times for a 5-20 second interval. It kind of depened upon where my foot was in the throttle. Usually my foot was just barely riding on the pedal to keep the truck moving at 65 or at 50 mph, then once at idle?

Thanks again

 

Which scantool for the old Iphone is best and where is one to get the correct cable to connect to the obd2 port?

I drove my truck to the store 5 miles away with no surging? I"m going to Jujitsu tonight which is 25 miles north so I'm hoping for a non-eventful drive to and from I'll keep ya posted

 

Maybe some fresh fuel will clear it up, these can be finicky beasts sometimes.

The iPhone app is called DashBoss, you can download the software for free (App Store of course-no jail breaking required). That will give you a chance to look at it and get some idea of how it works. You'll have to go to their (DashBoss) website and order the Bluetooth dongle for it to work (not cheap btw). A good feature of this app is that it can monitor your truck and create a report in excel spreadsheet format with time being the first column. You can post a log here or even open selected sensor data in a graph format on you computer. Good stuff! Also, if you like it, there are optional kits that allow it to monitor fuel pressure, low side oil pressure and EGT which aren't even monitored by the trucks PCM.
Good luck!

 

What brand of filters did you use? Oil Filter and Fuel Filter namely. Did you also drain the HFCM when you did the fuel filters?

 

If you fuel filter cap(s) are leaking that can be an issue.

 

You can also get the dashboss from amazon, might as well support the local economy.

 

I tightened the fuel filter caps good, I don't think they are leaking but...I'll check tomorrow.

I used Motorcraft filters becasue of everything I had read, they are the best thing for the 6 liters. I got my filters from dieselfiltersonline.com. And yes, I did drain the HFCM. I actually purchased that brass fitting, however, it did not fit as the brass T seemed to be to large to fit into the spot where the orginal fitting came from.

I drove my truck tonight to class and back. NO ISSUES. No surge or funny sound as if it was missing. I wonder if I had a tiny bit of air in the filters when I changed them or some bad fuel? Who knows, but I'm definalty keeping a close eye on her and will plan on purchasing some way to watch my gauges and codes.

Thank you all for your help!

 

Depending on where you live, we could hook your truck to my dashboss and take her for a spin. I'm in Bothell.

 

I recommend you stop driving till you find out exactly what's wrong. I had the same thing happen to my 2005 Excursion and ended up having something break on cylinder #8. I haven't torn the head off yet, but I know I have very low compression on that cylinder. I believe my FICM was the root cause.
Amazingly enough it still runs on 7 cylinders with #8 injector disconnected.

 

My FICM is brand new


I drove to class with no problems, no stuble at all. I wonder if it was bad fuel or maybe I had a tiny bit of air in the fuel filter from when I changed it, which was last week. I don't know what, but I'll be getting the scanner for my Iphone soon Mr Nobody, hey I really appreciate the offer...I live closer than you think Olympia. Still a bit too far to drive for me, but thank you for the offer.

 

You are a braver man than me. I too use Diesel Kleen, especially when towing, but the last bottle of 2 stroke oil I purchased for my Yamaha, didn't have a recommendation as a diesel additive.

I know many here use it but was it just coincidental that just after adding the oil, it started to stumble? Seems to me, many of the additives on the market, are more fuel or chemical based, further up the evaporative ladder, not oil based.

I would run the 2 stroke oil thru entirely and then see if all clears up. You aren't the first to complain about your engine missing after using oil.

I really wonder how it will affect things like the Cat, 02 sensors, long term? Never had to worry about my Yamaha's Cat going bad but lots of oil dripping from the tailpipe at times.

 

The thinking on the 2-stroke oil as a fuel additive is in response to the lack of lubrication offered by the current ULSD (<50ppm). Pulling the sulphur down that far leaves the fuel very "dry". The older LSD (<500ppm) we had until '07 was adequate, but the new stuff has virtually no lube for valves and injectors. Our diesels don't use an 02 sensor but you may be right on the cat.

 

Just noted in another post I started, my turbo needed cleaning due to a stuck unison ring. I really wonder if the 2 stroke oil would have helped lubricate or over sooted it?

With the lower levels of sulfur as you note, I would almost think that would help to avoid sooting, but also maybe instead, under lubricate?

I guess that's why there are some many additives our there to confuse us.