Pudgy Camper Posted June 6, 2023 Share Posted June 6, 2023 Seems like every time I go to fix something on this rig I find another surprise. I've only had it about a month and have found 4 serious issues that were due to just complete laziness from the previous owner. This time it's the waste gate actuator rod and it appears to have been cut with a grinder. Not sure why they did this, I'm guessing the actuator froze up maybe? The coach still runs good but is a little sluggish on acceleration. I just figured that was normal for a 30k lb rig. But after talking with others, my ISL 400 should be putting out around 31psi of boost and the most I've seen is 24 and that's with me really mashing the throttle. I'm going to be pulling the turbo off so I can have it looked at just for good measure. I'll also be testing the actuator and hopefully find that it tests bad. Either way, looks like I'll be replacing the actuator, they're around $600. Just wanted to share with you guys and get your take! Link to comment Share on other sites More sharing options...
timaz996 Posted June 6, 2023 Share Posted June 6, 2023 (edited) There are many shops around the country that rebuild turbos and components. I had my turbo rebuilt in Phoenix in late 2017. Edited June 6, 2023 by timaz996 1 Link to comment Share on other sites More sharing options...
vito.a Posted June 6, 2023 Share Posted June 6, 2023 RV owners are an interesting bunch. The waste gate should bleed off excess boost so with it not working it could theoretically over boost. But I doubt fixing the waste gate will increase your boost from 24 to 31. The boost loss is probably in the turbo, the hose couplers, or the CAC. 3 Link to comment Share on other sites More sharing options...
Rick A Posted June 6, 2023 Share Posted June 6, 2023 Home mechanics takes on new ideas. Link to comment Share on other sites More sharing options...
Tom Cherry Posted June 6, 2023 Share Posted June 6, 2023 13 minutes ago, Rick A said: Home mechanics takes on new ideas. The learning challenged (dumb) can be taught…..but the habitual and unrepentant stupid are candidates for neutering to save the gene pool. I say that with a high degree of sarcasm with no hurtful intentions. Sometimes i do things that qualify me for the latter…. But quickly destroy all evidence of same and hope no one saw….….and then go about my rehabilitation as well as correcting the mistakes and learning from them…. 6 1 1 Link to comment Share on other sites More sharing options...
Rick A Posted June 6, 2023 Share Posted June 6, 2023 I just pucker down and use a screwdriver when I should, rather hitting it with a hammer even if I have to walk 200 yds to get the screwdriver. It pays. Link to comment Share on other sites More sharing options...
Craggar Posted June 6, 2023 Share Posted June 6, 2023 I was pretty nieve about diesel pushers until I bought the one I have now, but after finding and fixing the crap the previous owner did I have learned alot. When I buy my next one I don't think an exprienced inspector will do a better job going over then what I will be able to do. 2 Link to comment Share on other sites More sharing options...
Pudgy Camper Posted June 6, 2023 Author Share Posted June 6, 2023 Yeah right when I think I'm getting caught up, and at least have the known issues fixed, something like this reveals itself. I got lucky to even see it. It it wasn't for being in the process of replacing the radiator, I might have missed it! 1 Link to comment Share on other sites More sharing options...
J & Di Cooper Posted June 7, 2023 Share Posted June 7, 2023 Hello Pudgy, I experienced a similar turbo problem on my 2005 Windsor with ISL 400. It took the 2nd Cummins shop to figure out the root cause. In my case, the rod connection to the turbo, (the ground off shaft in your photo) was seized with rust to the turbo vane lever. The cummins shop diagnosed it as a bad turbo because the rod would not move, hence the turbo was stuck and/or very erratic, and the turbo would need to be replaced. This was a mobile tech, the coach was in my driveway. After discussion with the tech, I elected to remove the turbo myself. Once getting it on the workbench, I removed the actuator mechanism and discovered the rod was rusted (seized) to the turbo however the turbo lever, as in your picture, would move freely with 1 finger in both directions, that was great news as i didn't need to replace the complete turbo ($$$). The short version, I located a new turbo actuator at a truck supply, (much less than $600), chased around the new gaskets and reinstalled the assembly. In my case there was a modulated air pressure line from the top of the actuator to a control box mounted on the intake manifold, which the stuck actuator had caused to blow an internal seal, when the engine was first shut off the leaking air was very obvious when looking into the engine compartment from the bedroom. The new control box was about $1700 from Cummins however I was also able to source from a truck supply for about $500. My suggestion: before you remove the turbo from the engine, ( which requires draining a couple gallons of coolant and replacing several gaskets), remove the turbo actuator from the turbo and check with your hand if the turbo control arm will smoothly move from stop to stop. If yes, easier simpler repair. You can test the actuator operation itself with regulated air pressure, if it doesn't move that's your problem. If the actuator is not the problem you'll have to drain coolant, remove turbo and go from there. In my case, the new actuator came with clear instructions with pictures emphasizing the need to grease the fitting between the turbo shaft and the actuator rod. Interestingly, the new actuator doesn't have a grease fitting???? there is a machined surface where one could drill, tap and install a fitting, just no hole?? It's just basic mechanical process, although the turbo assembly is a bit heavy so be prepared. Lowered it to the ground for removal and lowered through the bedroom hatch with a rope for reinstall. It's all a learning process-- hang it there YOU CAN DO IT !!! John 2 Link to comment Share on other sites More sharing options...
Pudgy Camper Posted June 7, 2023 Author Share Posted June 7, 2023 10 minutes ago, J & Di Cooper said: Hello Pudgy, I experienced a similar turbo problem on my 2005 Windsor with ISL 400. It took the 2nd Cummins shop to figure out the root cause. In my case, the rod connection to the turbo, (the ground off shaft in your photo) was seized with rust to the turbo vane lever. The cummins shop diagnosed it as a bad turbo because the rod would not move, hence the turbo was stuck and/or very erratic, and the turbo would need to be replaced. This was a mobile tech, the coach was in my driveway. After discussion with the tech, I elected to remove the turbo myself. Once getting it on the workbench, I removed the actuator mechanism and discovered the rod was rusted (seized) to the turbo however the turbo lever, as in your picture, would move freely with 1 finger in both directions, that was great news as i didn't need to replace the complete turbo ($$$). The short version, I located a new turbo actuator at a truck supply, (much less than $600), chased around the new gaskets and reinstalled the assembly. In my case there was a modulated air pressure line from the top of the actuator to a control box mounted on the intake manifold, which the stuck actuator had caused to blow an internal seal, when the engine was first shut off the leaking air was very obvious when looking into the engine compartment from the bedroom. The new control box was about $1700 from Cummins however I was also able to source from a truck supply for about $500. My suggestion: before you remove the turbo from the engine, ( which requires draining a couple gallons of coolant and replacing several gaskets), remove the turbo actuator from the turbo and check with your hand if the turbo control arm will smoothly move from stop to stop. If yes, easier simpler repair. You can test the actuator operation itself with regulated air pressure, if it doesn't move that's your problem. If the actuator is not the problem you'll have to drain coolant, remove turbo and go from there. In my case, the new actuator came with clear instructions with pictures emphasizing the need to grease the fitting between the turbo shaft and the actuator rod. Interestingly, the new actuator doesn't have a grease fitting???? there is a machined surface where one could drill, tap and install a fitting, just no hole?? It's just basic mechanical process, although the turbo assembly is a bit heavy so be prepared. Lowered it to the ground for removal and lowered through the bedroom hatch with a rope for reinstall. It's all a learning process-- hang it there YOU CAN DO IT !!! John Thanks for the info John! With mine I can rotate the bottom half and I can feel the flapper operating inside. The only reason I was going to pull the turbo is to have it looked at and verify there's nothing going on with it. I already have the coolant drained and in the middle of a radiator replacement. Maybe I'll pull off the actuator first and test it with the 60 psi testing procedure. Do you recall what truck shop you got your parts from? Link to comment Share on other sites More sharing options...
Jdw12345 Posted June 7, 2023 Share Posted June 7, 2023 Not that this helps your situation but when I start my coach and there is no air in the system, I stand back by the exhaust pipe and listen for the variable vanes to actuate just to confirm it’s operating. It’s pretty obvious when the air pressure actuates the vanes. I’ve never had a turbo from an ISL apart, but, I have had the turbo from my wife’s truck (05 Ford Powerstroke) off a few times for cleaning due to the variable vanes sometimes stick, at any rate, if your turbo vanes haven’t actuated in some time they maybe seized and need to be disassembled and cleaned up, fyi. 1 Link to comment Share on other sites More sharing options...
Frank McElroy Posted June 7, 2023 Share Posted June 7, 2023 2 hours ago, Pudgy Camper said: Thanks for the info John! With mine I can rotate the bottom half and I can feel the flapper operating inside. The only reason I was going to pull the turbo is to have it looked at and verify there's nothing going on with it. I already have the coolant drained and in the middle of a radiator replacement. Maybe I'll pull off the actuator first and test it with the 60 psi testing procedure. Do you recall what truck shop you got your parts from? You are on the right track. With the bottom half inside the turbo working, it's very likely that the rod was cut because the actuator was frozen in a position either providing no turbo boost or too much boost. Likely replacing the rod and your actuator will solve the problem. 1 Link to comment Share on other sites More sharing options...
Pudgy Camper Posted June 7, 2023 Author Share Posted June 7, 2023 (edited) UPDATE: This evening I pulled the actuator and bench tested it with compressed air. It seems to move freely. I'll have to check the Cummins procedure again on the amount of movement that it needs to take place, but it moves close to 3/4" up and down. However, my flapper rotates freely inside the turbo, but the rod is seized to the flapper pivot. This seems to be the same situation that John had about 3 posts ago! So I'm guessing a seized rod was the issue and the previous owner decided to cut the rod in half in order to get everything moving again. When all he probably had to do was spray some PB blaster on the pivot point and work it free. I think I'll still pull the turbo off just to have it double checked, but I'm hopeful that the mystery has been solved. Edited June 7, 2023 by Pudgy Camper 1 Link to comment Share on other sites More sharing options...
Bill R Posted June 7, 2023 Share Posted June 7, 2023 @Pudgy Camper you are doing all the correct tests, also in addition to testing the pneumatic actuator, also test the electronic pneumatic controller that sends the air signal to the pneumatic actuator. @J & Di Cooper describes he had a seal problem in this unit. Cummins Quickserve gives very good procedures for testing these. I also suspect you have a VGT turbo and not a wastegate based on your picture and description. Quickserve will confirm this as well. 1 Link to comment Share on other sites More sharing options...
Happycarz Posted June 7, 2023 Share Posted June 7, 2023 Jason, Your turbo is called a VGT, as Bill stated. Since the arm is moving freely, save yourself a bunch of grief, spelled $$. This air actuated turbo was only used for a couple of years. Previous turbos had a wastegate style turbo, then the air actuated vane type turbo was used, as I stated, for a couple of years. I have the same air actuated turbo as you have. After those couple of years Holset went to an electronically actuated vane turbo, letting the ECM do more precise controlling of the vanes Do your tests. You will need to source an air actuator. Hopefully, the pneumatic controller is still in goo shape. When I had my crankcase blowby issue, I resealed my turbo first to make sure pressure was not being introduced into the crankcase. Needing parts, I talked to Tom, since retired, at Massey’s Diesel & RV Repair in Phoenix to find out who to use for turbo repairs in Phoenix. Turbo Auto Diesel Co., Inc 4859 W Van Buren St, Phoenix, AZ 85043 602 272-5311 I bought seals, had them balance the shat/impellers and give me great insight and instructions. Nice folks Stand on your head and get a picture of the blue Holset tag for when sourcing parts. 3 Link to comment Share on other sites More sharing options...
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