Jump to content

6.4 excessive regen

Rate this topic


Recommended Posts

Ok here goes. This is a long story. I have got a 2008 f 450 with a 6.4. I first checked this truck out for this guy about 6 months ago just on the side. I could not find any problems with it. He finally brought it back in may to have it checked out again. This time he left it with me. His complaint is low power and excessive regeneration. It definately had low boost. Ran codes and the only thing it had was a p1000 and a p0297. Asked him if he had a progammer on it and he says he does not. I trust him. So I check it out and find the gasket between the turbos leaking badly and a y pipe gasket leaking. I replaced the high pressure turbo, vgt actuator (because it broke), and all the exhaust gaskets. The truck still was not quite right when it was done. Better but not right. While driving it, it went into regen. I let the cycle complete and bam, it ran great. So I shipped it. 2 months later and 5500 miles it is back. Same problem. Asked him when it started to act up again and he said 6 days after he picked it up. So it did not make it very long. I recheked everything and found the gasket in between the turbos leaking again. This time i replaced the low pressure turbo and resealed every thing again. It still does not feel right. It goes into regen about every 70 miles. I have duplicated it multiple time. When it goes into regen it will not boost over 24 lbs and is very weak. The oil has been changed and the fuel is ulsd and has been checked. The air filter is clean and so are the fuel filters. The dpf and doc have also been replaced to no avail. The oil was not overfilled and it is the coreect type. All tests pass. All module updated to the latest level. Also the pcm will not clear the p1000. This truck was driven 5500 miles and it has never cleared. Last time he brought it in i updated it. He drove it another 1200 miles and then brought it back to be fixed. I ran codes again and it had a p1000. Checked clr dist and it was correct for when it was in last. Sorry the explanation is so long but I am now lost on this one. About to get an engineer involved. Any suggestion will be highly appreciated.

Link to comment
Share on other sites

The recurring P1000 has me intrigued.... If your man had a tuner, I'd expect something like a P0603 in the mix.... But a P1000?

 

Have you tried hotline or OASIS QuickStart? We haven't seen much in the way of 6.4 troubles (other than fuel mileage) in our store.

 

Post a movie or two and we might be able to offer some insight.... All too often we are given thjose circiumstances that require symptom driven diagnostics rather than code assisted diagnostics.

Link to comment
Share on other sites

I have called hotline and am about ready to send an fse out here. I have done plenty of diag, I just have not listed it all. All sensors are in specification. Exhaust gas temp driving down the round is around 600 degrees and i have no egt or egrt sensor problems. Egr valve is operating correctly. Fuel is clean and it is ulsd. Crank case pressure test is at 4 inches. Ebp tube is clean. map sensor is clean. Have smoke tested intake and exhaust and there are no leaks. ect and eot are at 221 degrees. dpf pressure sensor is not biased koeo. This thing just keeps going into regen about every 60 to 70 miles. I have checked everything I can think of and can find nothing wrong to cause this problem. This truck was purchased used about 20000 miles ago and the customer and I do believe it had a programmer on it before because it did have an aftermarket exhaust and a banks sticker on it. All has since then been removed and everything is stock. And it was returned to stock upon purchase of the truck. Any thoughts as to what I may be missing or something else to try would be helpful. Thanks

Link to comment
Share on other sites

Two things come to my mind. Total engine hours is the first as trucks with excessive idle times tend to load up catalytic converters and I have seen them clog to the point where you cant clear them out with hard driving. I believe we can extend this thinking to include the DPF.

 

Second, if this truck DID have a programmer on it the DPF may be ash loaded meaning its capacity is nearing the end its service life. You might also want to consider separating the CAT and the DPF and take a look at the substrate to see if any clogging or heat damage has occurred.

Link to comment
Share on other sites

Keith, the doc and dpf have both been replaced. The engine hours are at 1565 hours. It is off but not by a whole lot. I believe most of this idle time was from the previous owner of the vehicle as the new owner says he does not let it idle more than 5 minutes. I have built a pretty decent relationship with this guy and I do trust what he says. Also there are no missfires, relative compression is good, and the fuel trims are all in spec and not off of one another my much.

Link to comment
Share on other sites

Some thoughts:

 

Charge air cooler (intercooler)?

 

When were the DOC and DPF replaced? It's possible they could have clogged again.

 

You say that the regens are every 60 to 70 miles. Is this unloaded? Highway or city?

 

Also, I assume that you reflashed it back to stock to ensure programmer was removed.

Link to comment
Share on other sites

The charge air cooler is clean and does not seem to be restricted. The dpf and doc were replace 6000 miles ago. It goes into regen loaded and unloaded all the time. The customer states that it was going into regen at the same frequency even after he picked it up after the last repair. It should go into regen less while towing but it does not. He tows a backhoe with it about 90 percent of the time so it is always loaded.

Link to comment
Share on other sites

He tows a backhoe with it about 90 percent of the time so it is always loaded.

I may not be of great help on this, but here's my thoughts: I'd chase the P1000 first and fix that, it's possible you have a bad PCM and are chasing your tail because of it.

 

It's going into regen because of the DPF pressure sensor reading. I'd graph or record the DPF pressure during this 70 mile stretch and verify it's increase.

 

Also, the fact is is running heavy interests me. You would think running hard would keep the DPF clean, but what if the FRP sensor is biased? Could it be receiving too much fuel and causing this problem?

 

 

Good Luck!

 

/forums/images/%%GRAEMLIN_URL%%/grin.gif

Link to comment
Share on other sites

It should go into regen less often because of the hard usage but it does not. When it goes into regen it will not boost over 25 lbs. the frp sensor is at .5 volts koeo so i assume it is ok. You can ramp up frp; desired and the actual frp corresponds with it correctly. I have also assumed that it might have a bad pcm and that is why it is not clearing the p1000. I guess it is also possible that the pcm is commanding to much fuel for some reason and that is why it is going into regen so much. But we all know how diagnosing a pcm without hard faults can be. I am going to put a maf on it this morning and see what happens. If it does not take care of it I am going to have a fse come out and let him decide to put a pcm on it as I have already replaced to many parts on this truck. I hace suspected a pcm for some time now but have no way to prove it is at fault. The reason it may not clear the p1000 and the excessice regen may be the same problem.

Link to comment
Share on other sites

What I was told that due to higher boost pressure and load that the excessive heat of the exhaust alone will keep the dpf hot and clear. It is called passive regeneration. Now this alone cannot handle complete cleaning so then there is activer regeneration to handle what passive cannot handle. Now I have replaced the maf sensor and drove it 120 miles and it went into regen 2 times. I have a fse coming out next week to look at it. It still has a p1000 in memory and no other codes. I am giving it back to the customer for now because he needs it for the weekend. Any other thought would be appreciated in the time being. Other than that I will let you all know what we can come up with next week.

Link to comment
Share on other sites

I suppose, out there on the end of the limb I'm sitting on, that there could be an EGR cooler issue as well.... ?

 

The horizontals are becoming pretty common failure points, however that doesn't necessarily mean that they're gonna be leaking by the gallons every day. Could it be dumping a small enough amount of coolant into the exhaust to biff out the system without creating clounds of smoke and driveability concerns?

 

Granted, you'd likely be noticing coolant loss too (which hasn't been mentioned) but I guess nothing's too far away from possible when it comes to these engines..

 

Dave

Link to comment
Share on other sites

I'd have to agree with Bruce on this one - why isn't the P1000 clearing?

 

It's been some time since I've dealt with a persistant P1000. The WDS had a tool to tell you which tests had and had not passed to clear the P1000. On the IDS, under Toolbox>Powertrain>OBD Test Modes (I think - kinda doing this from memory) does it have a selection that will indicate the pass/fail status of the OBD tests?

 

Might give you a concrete direction to go in...

Link to comment
Share on other sites

There is a selection for obd drive cycle but it does not work on this vehicle. I do not remember exactly what it said but the mode is not supported. Also there are no egr cooler leaks. It does not lose coolant and I had the exhaust off while doing the turbos on it.

Link to comment
Share on other sites

Under the same section as mode 6 is obd drive cycle. Which on a gas car you would look at to see which monitors have passed. Mode 6 is available but I have not fully researched it. I did take a look at it but did not see anything on it that I would consider abnormal. All of the values were in range from what I remember. I will double check it monday morning. Is there any thing you think I should look out for specifically?

Link to comment
Share on other sites

I haven't had to use mode 6 very much... most of the time it has been simply looking for misfire trends.... However, it is my understanding that anything that is keeping a comprehensive monitor from completing will be highlighted....

Link to comment
Share on other sites

  • 2 months later...

Ok. It has been a while since I posted on this truck. Any ways it is still not fixed. FSE has been involved off and on for months now. It has been try this and try that. This is what has been done now. Pcm, tcm, thermostats, 2 radiators, (yes it has gone that far now), dpf pressure sensor, maf, egr cooler have been pulled and tested for leakage and front cover has been inspected for cavitation. I have personally driven this truck over 750 miles. With a trailer and without. It does not matter if you are towing or not it will go into regen every 55 to 80 miles. Fuel is good. Oil changed multiple times. Fuel filters clean. FSE has driven with me for many miles on this concern. Recordings were taken and sent to detroit. No one can come up with anything. They now want me to try a cluster as they think that maybe the hour meter is sending wrong info to pcm causing it to go into regen to much. The dpf pressure is about 2.5 psi when it enters regen. This is not enough to send it into regen so I do not believe the dpf is actually starting to plug up. Any ways just seeing if there are any fresh ideas on this. I am fed up with this vehicle.

Link to comment
Share on other sites

greg,

I don't have much experience with the 6.4, so I can't offer any help to you.

 

Anyway.. One of our customers just picked up an F550 drill rig, weighed on leaving Idaho for NJ, at 18,900 lbs.

 

The drilling manager for the environmental company that owns it asked what "exhaust filter cleaning", as he termed it, meant that was displayed on the information panel. I explained it the best I could.

 

He mentioned it was coming on every 120-150 miles on the whole trip back. Is that considered "normal"? He averaged about 8.6 mpg.

 

It was interesting when we first saw it that the upfitter was told by Ford directly to not tamper with or modify the exhaust in any way, and how "rainbowed" (almost deep purple in color) the entire exhaust was from the DPF all the way to the tips were.

Link to comment
Share on other sites

Ok. It has been a while since I posted on this truck. Any ways it is still not fixed. FSE has been involved off and on for months now. It has been try this and try that. This is what has been done now. Pcm, tcm, thermostats, 2 radiators, (yes it has gone that far now), dpf pressure sensor, maf, egr cooler have been pulled and tested for leakage and front cover has been inspected for cavitation. I have personally driven this truck over 750 miles. With a trailer and without. It does not matter if you are towing or not it will go into regen every 55 to 80 miles. Fuel is good. Oil changed multiple times. Fuel filters clean. FSE has driven with me for many miles on this concern. Recordings were taken and sent to detroit. No one can come up with anything. They now want me to try a cluster as they think that maybe the hour meter is sending wrong info to pcm causing it to go into regen to much. The dpf pressure is about 2.5 psi when it enters regen. This is not enough to send it into regen so I do not believe the dpf is actually starting to plug up. Any ways just seeing if there are any fresh ideas on this. I am fed up with this vehicle.

Have you inspected the turbo and charge air cooler (intercooler)?

 

Remove the HP compressor cover. Look for excessive coking. Some coking is normal and expected. However, highly loaded engines will coke much faster. This coking decreases the turbo efficiency. Decreased turbo efficiency leads to more soot production, leading to more regens.

 

Similarly, if the CAC is plugged, it will lead to more soot production and more regens. Anything that decreases airflow will lead to higher soot output - clogged air filter, restricted exhaust, etc.

 

Another possible factor would be a stuck open EGR valve, but that should throw a code.

 

The 2.5 psi restriction may not sound like a lot, but it depends on the running condition. The ECU uses a complex calculation to estimate the amount of soot acumulated in the filter based on the MAF flow and the backpressure.

 

That gives me another idea. There may be an issue with the MAF sensor. If it is inaccurate due to build up or an air leak downstream, it could lead to more frequent regens.

 

Hope this helps.

Link to comment
Share on other sites

greg,

I don't have much experience with the 6.4, so I can't offer any help to you.

 

Anyway.. One of our customers just picked up an F550 drill rig, weighed on leaving Idaho for NJ, at 18,900 lbs.

 

The drilling manager for the environmental company that owns it asked what "exhaust filter cleaning", as he termed it, meant that was displayed on the information panel. I explained it the best I could.

 

He mentioned it was coming on every 120-150 miles on the whole trip back. Is that considered "normal"? He averaged about 8.6 mpg.

 

It was interesting when we first saw it that the upfitter was told by Ford directly to not tamper with or modify the exhaust in any way, and how "rainbowed" (almost deep purple in color) the entire exhaust was from the DPF all the way to the tips were.

120-150 miles is within the "normal" range, but on the low side.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...