Stranded (again) in La Grange

[Cj D]

I spent the evening trying to google and YouTube this Venturi. There is no mention of it…anywhere. Like, I’m apparently the only owner to ever have a problem with it. What was that about my rare luck??

The service manual only says to, “be sure Venturi is properly installed before installing the intake”. The parts manual lists the Venturi insert, but then the service manual has a note that, “the Venturi is not serviced separately from the intake”.

I am getting the impression that this is supposed to be press-fit, and/or glued in place. I bet Ed tells me I have to replace the entire intake?!?

[153stars]

I wonder if notch is either tooled for assembly machine or to allow it to be expanded at that edge. Maybe missed final expansion process. I see internal lip/seat I imagine where it goes into..
How close to press fit is it .
Approx. diameter . Thinking muffler pipe type expander tool. Really cranking a bushing puller might expand it Or bead roller to create a inner groove thus makes expansion on outer side. A layer of very high silver brazen in a few spots or mig spot welds ground back down might work too. Also what is the green coloring ....locktite for shaft/bearings is green but not real heat proof.

[tdkkart]

Tell your neighbor to go pack sand........none of her damn business if you want 3 motorhomes in your driveway.

[Cj D]

That's funny, TDK!

153, I think you are right. The tab has nothing to key into, so it must be an alignment tool for assembly. You can see that the entire insides of the manifold is coated with some sort-of green paint. The paint was on the outside of the venturi, so it had to be a light press fit. The green goo either locked it in or helped lock it in. I thought about trying to spin or expand the venturi larger for a press fit, but I can't think of any way to control the expansion. If I made it too big I could crush it while pressing it back in...and the manifold is too oddly shaped to press on with any authority.

I talked to several Cummins techs today. They all said they replace the entire manifold. If the $1450 price was not bad enough, it's a 6-8 week lead time! They say they are special prepared after ordering. That made the bend in the venturi tube make sense. I have no doubt the manifold is placed on a flow bench, and the dent is added or taken out until the flow meets some designated amount for the engine. When I heard that, my first thought is that finding a used inlet would not be an option, as I could never get a venturi on a 15 year old manifold to match my engine!

But, I have a plan to re-install the venturi. The 1/16 pipe plug for the sensor hole drilling currently does not allow the plug to go in far enough to contact the venturi. I will tap the hole deeper, so that the plug can be used to lock the venturi. I will also use a high temp gasket maker or Loctite too.

I didn't have a chance to work on it today...but I'll report tomorrow on the fix...

[Cj D]

153, I just re-read what you wrote and finally understand what you are saying. It's possible the edge could be expanded into the slot around the intake. I will look closely at that possibility...thanks!

[angelman]

Maybe the sensor keeps it in place. Also, I would install it with an appropriate adhesive and install the sensor to keep it aligned. The factory probably used the adhesive as a final assembly tool. They had to keep removing it during venturi adjustment phase then glue it for assembly. Sensor was added last.

[Cj D]

Alas, the story has finally drawn to a close. I know, I am in disbelief too! I installed and aligned the venturi properly, then made a useless attempt to spread it with a tapered socket. I used thick shellac type gasket dressing to glue it in, and then I tapped the 1/16th pipe thread hole just enough so the allen plug would hit and slightly dent the side of the venturi, just as the plug turned snuggly into the hole.

I went for a long spin through city and highway, and I declare the ole' girl is fixed!!

Here is a quick recap of failure and despair over the last one year:

1) The EGR venturi likely began to shift in it's bore at about the 10 year/50k mile point, as I would very seldomly get a warning light that would go away when the engine was stopped and re-started.

2) After the rig would not drive over 25mph, I replaced 7 fuel injectors, twice, to finally get 6 good injectors after one developed an internal leak.

3) The warning light was now nearly constant, and the rig would cut out randomly for a second or two, until it finally died completely.

4) Cummins took 2 months and $6600 to replace the alternator, the ECM that was damaged by Monaco, and kill our coach batteries. Oh...and tell us the #5 fuel injector was inop, but they didn't fix it! I replaced the injector and batteries myself.

5) Leaving the Cummins parking lot, the coach now belched black smoke and had 3 random pressure and temp codes. The new ECM was bad within 5 miles of installation.

6) With the second new ECM installed, the coach now had an exhaust gas pressure code. The engine brake and tranny no longer worked, with the tranny topping out in 4th gear with crappy shifts and a check trans light on. Replaced the Ex gas press sensor, no luck. Replaced it again, no luck. Finally bought Insight software, which showed the 2nd new sensor was, indeed, also bad. That is now 4 brand new parts that were bad!!

7) With a 3rd new Ex gas sensor from Cummins installed, the tranny now worked ( as the derate was released), but now the code was back to EGR Diff pressure (the EGR system was now working after being disabled during the derate). I replaced the sensor...no luck. I cleaned and re-seated the EGR valve and pipes...no luck. I finally discovered the EGR venturi was installed wrong.

What have I learned, and am able to pass along to future owners? Well,

1) Only buy genuine Cummins parts. They are heart-stopping expensive, but anything else cannot be trusted.

2) Don't take your rig to a dealer for any RV out of warranty. Do it yourself, or take the time to vet a GOOD mechanic. If I had listened to Cummins, they would STILL be chasing 37 feet of coach wiring looking for a non-existent broken wire, at $150/hour.

3) Use a fuel lubrication additive, which will stretch your injector life to that of the life of the coach. Otherwise count on injectors dying about 70k miles...and possibly starting a nightmare of chain reactions like happened to me.

4) If you have any diesel engine problems, it is worth buying a (bootleg) copy of the inline and insite software. It allows you to look at and test every actuator and sensor on the rig. It is $200 well spent and will save...$thousands...in guessing expensive parts. If I had the software a year ago, I would only have needed to replace 1 fuel injector, instead of 8.

That's it. Thanks for all the tips and support during my long trip getting back on the road! We are planning a 2 week RV trip through Colorado the end of this month. After that the Ole friend will be going up for sale.

[153stars]

Holy crap . You must of read my mind or got on same wavelength, I thought about set screw or screws. but of course that wouldn't seal. I did think about the pipe plug as a set screw it's about the only idea I didn't post it... because of the drilling and tapping I didn't know depth of material. . I'm glad you knew keep making deeper and test it... until it came in contact with the sleeve. I thought the dent in sleeve was for the sensor to hide behind.
Don't forget the devil you know might be better than one you haven't met. Your not gonna throw in the towel completely are you.

[WVPete]

Wow! Now what am I going to look forward to reading every morning?

I'm glad it is fixed. It has truly been a tortuous journey. I only hope I have the ability to learn all the stuff you have if I ever have such a problem. I started using a fuel additive as a result of your story. Thanks and I hope you have a great trip!!
Pete

[BonS]

Originally Posted by Cj D

What have I learned, and am able to pass along to future owners? Well,

1) Only buy genuine Cummins parts. They are heart-stopping expensive, but anything else cannot be trusted.

2) Don't take your rig to a dealer for any RV out of warranty. Do it yourself, or take the time to vet a GOOD mechanic. If I had listened to Cummins, they would STILL be chasing 37 feet of coach wiring looking for a non-existent broken wire, at $150/hour.

3) Use a fuel lubrication additive, which will stretch your injector life to that of the life of the coach. Otherwise count on injectors dying about 70k miles...and possibly starting a nightmare of chain reactions like happened to me.

4) If you have any diesel engine problems, it is worth buying a (bootleg) copy of the inline and insite software. It allows you to look at and test every actuator and sensor on the rig. It is $200 well spent and will save...$thousands...in guessing expensive parts. If I had the software a year ago, I would only have needed to replace 1 fuel injector, instead of 8.

I totally agree with your sage advice - all of it. I suffered the pain of having an unmarked IMAP sensor, that came in a Cummins branded plastic bag but purchased through an independent source, in my ISM for over a year. Codes were thrown that were not supported by the event data viewed in Insite. It was confusing misleading. After eliminating many possibilities I only had one culprit. I paid 4X for their IMAP sensor over the counter and I'll never, ever, complain about their prices again. I'm sure that a Cummins shop would have replaced the turbo, twice, if I had let them. Instead I learned a lot as I went through the diagnostic process as you did. I often wonder how many turbos, how many weeks/months, and how many thousands I would have spent with Cummins, and still remained a dependent, instead of changing out the "new" defective sensor. Congratulations! Kudos! and Happy Trails.

[Cj D]

Just a little post-script.

I’m sitting in the RV in Durango, CO. Tomorrow we’ll take her over the $million highway to Ourey. For those of you who have driven it, it’s likely the steepest, windiest, and highest road you can take an RV on in the lower 48 states…cresting over 12,000ft. That’ll test her out. She’s run that route 3 times before, but in her “younger” days.

Out of Fort Worth she ran fine for a couple hours, then started dropping a 412 fm16, or 2362 code. That is a moderately high EGR temp, which triggers a 40% derate until you back off the throttle. That’s a “catch 22” situation…use the throttle and you get a derate. Don’t use the throttle and you still have to keep below 50% to prevent triggering the derate. Fortunately, I brought the Cummins software. After running the troubleshooting steps, I added a half gallon of water to the radiator…and no more codes in the 700 miles since. I can’t say enough for picking up a $200 bootleg “Insite” program if you are running a Cummins out of warranty! It wakes you through fixing any code step by step. In this case, I’m not sure I would have ever correlated adding water to the radiator to solve a hot EGR. (Of course Cummins service would likely have charged a couple $grand and taken a month to run the software and add the water, LOL)

A slide cable broke while packing for the trip. I learned that, for some odd reason, Monaco saw fit to cover the motor assembly with stapled wood trim. The cables are supposed to be checked and adjusted frequently, but they were inaccessible without prying the staples out of the trim. With a long afternoon and a $48 repair kit, the slide runs faster than when new. It has likely been out of adjustment since we bought it. I also reassembled the trim box using decorative screws instead of staples…wish I had known to do that 15 years ago when we bought it.

Anyway, nice to just drive and enjoy for a while!! I’ll drop a note from Ourey.

[Joe_Camper]

Originally Posted by Cj D

Just a little post-script.
After running the troubleshooting steps, I added a half gallon of water to the radiator…and no more codes in the 700 miles since.
Anyway, nice to just drive and enjoy for a while!! I’ll drop a note from Ourey.

Wow! I'm having trouble understanding how "a half gallon of water" could make a difference in EGR temps. It's just a drop in the bucket (pun intended) compared to the capacity of the cooling system. However, I don't have to understand it, you just have to benefit from it. Glad it has you running right again and I wish you a trouble free trip. Enjoy!

[Cj D]

Agreed! My coolant tank is coated with 15 years of muck on the inside, even though I change the coolant every 3-5 years. So I can’t read the level accurately, but still no codes after adding the coolant. Today we made it over the Red Mountain pass…over 11,000ft pulling a 6,000lb car. That’s about all I can ask from an old rig like her!

[Florida Rang]

Is it still for sale ? And how much $$$ are you asking ?.