Engine/Transmission (1998.5 - 2002) Dealer proposes to remove head to clean carbon deposits

[fkovalski]

I have been have an ongoing symptom of what sounds like a “machine gun” that can be heard from the engine. It is also felt as a sort of “pulsation” that is consistent with the noise. It is felt and heard regardless of engine or vehicle speed. I feel it most when traveling at a slight up hill condition in 4th gear at about 45 MPH. The lift pump replacement has less than 1000 miles, the truck has 65,000 miles. The valves were adjusted when the lift pump was installed.



It smokes upon start up or after sitting for around 4 hours. It is white smoke and the truck shakes and rattles VERY harshly for about 10 seconds until it settles down to which the symptoms as described above take hold. There are no codes present as shown on the dealer instruments.



The dealer says that it is carbon build up in the combustion chambers and on the valves. We tried the injection cleaning service as a first try to fix this. It did not improve the symptoms at all. The dealer is now proposing to remove the head and manually remove the carbon deposits. I am assured that this is the problem and it will fix it.



I am somewhat concerned about taking this drastic course of action. All I know about diesels is from what I have learned here. When the lift pump was replaced it had been running the engine at zero PSI for around 4 – 6 weeks but I have been assured that the injection pump is fine.



Has any one heard of anything similar to what I am describing? Is this the correct method of resolving the problem ar is there a less drastic measure that could be taken? I could really use the input from knowledgeable members on this one.

 

[Gary - K7GLD]

I would think that the effects of carbon buildup wold be most evident on a HOT engine, rather than a cold one - and the white smoke would seem to be a fuel issue, rather than carbon buildup

 

[RacinDuallie]

When I lost my VP-44 my truck sounded like a low flyin helicopter... ... ... . or machine gun as you put it... ... ..... 4-6weeks on a dead lift pump and they tell you it's a carbon build-up??? Somethings not right there... ... ... ...

 

[MBFARMS]

I would check the codes myself. You can do this by turning the switch of and on three times and leaving it on the third time. Read the codes from the odometer area and then do a search on them. I would also find another dealer to do business with.

 

[fkovalski]

I would check the codes myself... .

I have checked several times using this method. No codes.

 

[PC12Driver]

Seems like pulling the injectors and bore scoping the cylinders would be in order before pulling the head. Unless you do a lot of idling there shouldn't be any buildup. With 80,000 miles on my engine there was hardly any carbon buildup, and most of that was on the injector tips.



I'd guess something like a bad injector, maybe leaking a bit and throwing off the timing once things warm up. Or the VP, of course.



How did the problem start? (all off the sudden, gradually, intermittent, etc)



Maybe you could track down one of those nifty laser-thermometer thingys and check the temps at each one of the exhaust ports on the exhaust manifold shortly after startup. If you find one noticibly cooler than the others that would point to a dead cylinder (works for motorcycles - never tried it with a cast iron manifold). Then maybe try swaping that injector (I'm sure there's hundreds of stock injectors lying around in TDR land that someone could let you try).



Unless, of course, you're still under warranty. Then let 'em hack away.

 

[fkovalski]

How did the problem start? (all off the sudden, gradually, intermittent, etc)

The “machine gun” sound has been prevalent for quite a while (since around 50K miles. ) BUT, it would only happen for about 3 seconds when it would be in sound only. I did not feel it on these few occasions. The sound of the engine would change tone almost similar as if the RPM was increasing. This would only occur sporadically when going on the interstate at about 65- 70.



The sound now is as described above only constant with the feel of the hesitation(?) accompanying it. It was becoming more prevalent at about 6 weeks ago. I put the gauges on about a month ago to which I saw the FP gauge reading 0 for about 80% of the time. (It would bump up to about 7 psi for only a short while, then back to 0)



The symptoms are constant now.

Unless, of course, you're still under warranty. Then let 'em hack away.

The dealer says they will cover it. But I have an uneasy feeling about this whole recommendation.

 

[Fishin Guide]

The injectors need to be checked out first. Pop test and check spray pattern.



BTW, my buddies truck had the same symtoms you describe, it was the injector pump. No codes, ever.



I would also follow the recommendation to scope the inside of the cylinder when the injectors are out for pop testing.



It may be worth it to seek out another dealer. Like a doctor, get a second opinion before you let them tear into your engine without all the facts!!



Dave

 

[Ron Bissett]

AS you said the lift pump was out about six weeks. That is about the time it takes to kill the injector pump . Have the tech check the injector pump ,first ,then try the other things if its on the warranty or not. Ron Bissett In Metro Louisville Ky

 

[fkovalski]

OH, one thing that I forgot to add- When starting up after it has been sitting overnight, there is this “whining” sound that increases in sound pitch when revving. It is somewhat similar to a power steering pump “groan” when it’s low on fluid but more of a “mechanical” whining sound. .

 

[Fishin Guide]

It is somewhat similar to a power steering pump “groan” when it’s low on fluid but more of a “mechanical” whining sound. .

Sounds like the injector pump.



See if they will take it off instead of the head and put it on a test stand!!



Maybe there is a way to check on the truck, but it sounds like it's going.



Dave

 

[RacinDuallie]

VP-44 groaning from being starved... ... ... ... ... ... ... ... ... ... ...

 

[fkovalski]

Have the tech check the injector pump ...

They supposedly did this when they replaced the pump. i do not know what all is done when checking it, but they confirmed to me that it was fine.

 

[Fishin Guide]

They supposedly did this when they replaced the pump. i do not know what all is done when checking it, but they confirmed to me that it was fine.

I can understand wanting to trust what the dealer is telling you. However, did you talk to the tech personally and ask him how he "checked it out"?



I am not trying to beat you up on this, I am just trying to see if there is some info we don't have. For instance. When they checked out your injector pump, was this the same time they replaced the lift pump? If so, how long was the truck actually being worked on?



If the timeframe is less than a few hours, you got the lift pump replaced and that was it. They confirmed your VP was ok by closing the hood, starting it and doing a road test.



I would want to see that pump removed, taken to an authorized Bosch rebuild center, put on a stand and checked for everything. If that's too hard, they could just as easily replace it.



Again, not flaming you. But from the white smoke, machine gun sound, once dead lift pump, violent shaking on startup and the whirring noises you are hearing all point to a VP that is near death.



I am not you, but if I were, I would not want a preventable failure to jeopordize my life or propoerty with a sudden VP death. Not to mention if you are like me out in the middle of nowhere. Including the areas cell phones don't work.



DO what you think is right. But I would start shopping for another dealer and/ or stay and watch them work. Make them tell you exactly what is happening with your truck.



And if thecarbon build up is so bad to cause all this, you may need new valves, cause they have enough carbon on them to hit the piston!



Dave

 

[fkovalski]

I am not trying to beat you up on this, I am just trying to see if there is some info we don't have. For instance. When they checked out your injector pump, was this the same time they replaced the lift pump? If so, how long was the truck actually being worked on? Dave

Thanks, Dave- No “flame” taken- I appreciate all replies!



The dealer had the truck all day two weeks ago to replace the lift pump, adjust the valves and check the symptoms. I even left it over night as the tech was late in wrapping it up. All I know about the injector pump is what they told me. “We ‘thoroughly’ checked and tested the injection pump and it is OK. ” They definitely did NOT take it out.

 

[bmoeller]

“We ‘thoroughly’ checked and tested the injection pump and it is OK. ” They definitely did NOT take it out.

The only way to "thoroughly" check it out, is to put it on a test stand. I think your problem is the VP and/or have the injectors tested.



If the problem was actually carbon build-up, hook up a 10-15k load, and run the snot out of it. I'd do that before pulling the head.

 

[ProspectorTim]

That sounds like a pretty good description of a lift pump gone bad.



I wouldn't want to have one fail on Hoosier Pass. Or Vail. Or Loveland.



Do you tow anything?

 

[MBFARMS]

My friend is a diesel tech for the local Dodge dealership and when my lift pump went out the VP was acting some what the same way. They replaced the lift pump and the method that Dodge gives them for testing the VP is it has to flow a certain amount of fuel per second. He told me the VP was bad but all the DC tests showed it was good and DC would not replace it until it threw a code or the pump tested bad. That is probably the same test they are doing or similar. My VP also was not showing a code. To get it to throw a code I put the truck in reverse and backed up while keeping the truck at about 2600-2700 RPMs for about 500 feet. About that time it started to shudder and puff white smoke and I checked the codes and there was a P0216. I could not get it to throw a code any other way. I even put several loads behind it and it still would not throw a code. Good luck. I would also do what the others have suggested and have the injectors tested and look in the cylinder with the scope.