New fuel filter = Now I have a stutter type miss

[motofamily]

Okay our 2006 motorhaome has been awesome not a bit of problems except for normal wear and use issues I changed the fuel filter and now I have an intermitten (SP?) miss and when it misses it makes the check engine light come on and then it goes off the miss clears up and we gain speed and keep on going. I am worried I messed something up I plan on trying a new filter tomorrow and make sure it is full of fresh diesel the first time I did it I don't think I got it all the way full.

[Steve Ownby]

I don't think it's a problem related to the filter not being totally pre-filled. That might cause a hic-cup or two when you first start it but once it runs for a few minutes you're ok. It's possible the rubber gasket was not lubed or not seated good & air is getting into the system.

[motofamily]

We are gonna try a new filter tomorrow just to be safe and lube the seal to make sure it seals real good. I have talked with a couple of friends who either work on diesels or own them and they say the same thing. The filter I used was one that I had been carrying around with me as a backup for over a year and now that I think about it maybe the seal was bad or something. THANK YOU SO much for the help I have anxiety attacks and am extremely nervous and worried I did something wrong!

[Robi.1014]

Oil filters? You betcha: Pre-Fill.
Fuel filters? The Cummins filter I just installed stated (on the label) not to pre-fill.

At any rate, let's hope that a new filter helps clear this us. BTW: my Dip has 2 fuel filters. Yours?

[dons2346]

Sounds like you could have an air leak. Make sure the filters are real tight.

If you have a Cummins, do not pre fill the filter. You use the ignition switch to fill it. Cycle the key, waiting15 seconds between cycles. This will fill the filter.

[Eaglesview]

You refer to "a" fuel filter in the singular. Are you certain that there is not a second fuel filter?

[motofamily]

Well after replacing the fuel filter I still have the miss with the check engine light, I also noticed 3 short "whistle" type sound. Had the diesel mechanic plug it in and the code translated to a bad TURBO WTH he pulled apart the intake tube to access the turbo and he said there was play in there is this normal for a 2006 Cummins to have a turbo go bad after 26000 miles + or - we bought it new in Aug of 2005 so I guess we are SOL on the warranty just a little confused! Any help would be great my Diesel mechanic is a good friend and I don't think he would steer me wrong but you just never know.

[RustyJC]

Does it only do the "stuttering" when under heavy load? If so, check your turbo to be sure the wastegate has free movement and the wastegate actuator is working. If the wastegate is stuck closed or if the wastegate actuator doesn't function (this could also be due to a leak in the line supplying control pressure to the actuator), the engine control module will sense an overboost condition and defuel the engine, then resume normal fueling when boost drops, then sense another overboost and defuel again, etc. This will feel like the power is cycling between off and on until you back off the accelerator pedal. The overboost condition might be setting the code indicating a turbo problem.

If you're lucky, your problem may be as simple as a hose that's split or come loose. Could you possibly have pulled the line loose while changing the fuel filter? The line on my 2002 5.9L Cummins ran from the turbocharger's compressor discharge nozzle back to the wastegate actuator, but the line on my old Volvo 245 Turbo wagon ran from the intake manifold air inlet connection back to the wastegate actuator. The latter split this line once and exhibited the symptoms I described at full boost.

Rusty

[motofamily]

Rusty JC: Thanks for the help... At first it was only doing the check engine light while under a load then it has since gone over to check engine light is on while idle and hums as normal then you will here 3 short whistles and then it hums as normal my mechanic friend pulled the intake boot off and showed me slack/play up and down movement on the impeller thing inside the turbo he said this shouldnt do this.

[motofamily]

I guess the turbo can go bad at anytime but what would have caused it there does not seem to be any funny wear on the blades itself just more of a bearing issue that there is play in the turbo shaft and it is not a ton of play but it is noticeable should I call Cummins about this or just put a new turbo on and not worry about it or would something else cause the computer to put a code in of turbo failure 44 times heck the thing still goes up the road at 60-65 mph after the stuttering stops and after reading the horror stories of peoples engines grenading after they replaced turbos i am scared to death of the whole thing. Guess I will be adding an extended warranty after all!

[motofamily]

Hold up if there is a second fuel filter in the frame rail could that be clogged and causing the Check Engine Light to come on and make it think the Turbo is bad? I just find it hard to beleive the Turbo is bad not working because of fuel pressure maybe but bad its just hard to believe.

[Steve Ownby]

You are stressing yourself out over a bunch of "what it might be answers". Pony up for an hour of diagnostic time at a Cummins facility. You will find out what the problem in short order.

Yes, many diesels have 2 fuel filters. Many times the primary filter is a water separator/filter. You could call the chassis manufacturer with the chassis # and they can tell you how it was equipped.

[HeapBigEngin]

Well said Steve....when in doubt, especially with VERY expensive machinery, take it to the experts. The Cummins guys work on Cummins products, and they have surely seen this before. It will be money well spent. When it comes to diesel engines and turbochargers, this is no time to be penny wise and pound foolish. This does not sound like someting you want to just start throwing parts at....just MHO. PLEASE let us know what you eventually discover....thanks!

[jimkate]

First, the stutter-miss began immediately after installing a new fuel filter. Second, a malfunctioning turbo should not cause a stutter-miss. Third, a malfunctioning turbo should show up on your turbo boost gauge as low turbo boost. Fourth, the turbo shaft has considerable clearance, and when you grab the end of the shaft and wiggle it, it can seem to have a lot of clearance. Fifth,a turbo problem usually happens gradually.

Anyway, I'm in the camp with the guys that thinks you're getting air into the system. The first time I changed my filter, I missed the fact that there was a small o-ring that sealed the inner hole of the filter. It caused a stutter-miss. I got fooled because a new o-ring was not supplied with the filter, and the old o-ring came off with the old filter. I found the old o-ring, installed it, and the stutter-miss was gone.

It didn't stutter-miss until the filter was changed. I think it has something to do with the filter somehow.