jamesfox Report post Posted November 10, 2011 I have a Country Coach FE 420 with a C9 425 hp. I have 18,000 miles on it . A 16,000 mile I had a check engine light come on. Turns out Cat said I had a blown turbo. They said they had some hot inlet air alert showing on the read out. Cat replaced the turbo but after checking to see if everything was working fine after a few miles Cat is still getting alerts showing hot inlet air but now they are saying it's CC problem, plus now I get what feels like a miss in the engine. Has anyone else run into this. Thanks Share this post Link to post Share on other sites
wolfe10 Report post Posted November 10, 2011 James, Welcome to the FMCA Forum. What is your intake manifold temperature? The CAC (Charge Air Cooler) is between the turbo and engine intake manifold. It's job is to take hot air (sometimes over 300 degrees F) and bring it down to close to ambient temperature. The engine was designed to run on the cooled, denser air. If air flow to the CAC is inadequate, the CAC isundersized, etc, yes performance and MPG will suffer and the computer could derate the engine to keep from doing permanent damage. Have you cleaned the CAC and radiator? Next step would be to verify that the hydraulic fan and fan controls are working properly. Brett Share this post Link to post Share on other sites
lvnrdrm Report post Posted January 1, 2015 Hi All; I have a 2009 Cheetah Safari with a C-9 turbo charged engine- 425 HP. I bought it new in 2009 and 2 years later at 9,300 miles I had to replace the turbo-charger. Today at 23,000 miles the coach is in the shop again and the diagnostic codes point to another bad turbo charger. This is all related to the automatic regeneration cycle, somehow. Still trying to determine how Caterpillar controls the need for regeneration............some manufacturers measure the pressure differential at the DPF (diesel particulate filter) to determine the sooth loading in the filter, and then trigger a regeneration cycle to burn the sooth and clean the filter. Others use miles, others use gallons burned or hours of operation. Don't know how Caterpillar does....still trying to research it! What I believe is causing the issue is that with RV's that stay in storage for some time, the turbo somehow locks up because there is no way to lubricate the moving rotor and impeller vanes. Then when you take it out on the road the system calls for an active regeneration cycle and the locked up turbo cannot respond and the result is an engine fault code for a failure to regen; then you get the power derating and eventual stop engine fault....................which leaves you stranded!!!! If anybody knows of an aftermarket cure for this turbo issue....I would really love to hear about it! Regards, Frustrated Cat owner Share this post Link to post Share on other sites
huffypuff Report post Posted January 1, 2015 I don't think that long storage is the causing locked up turbocharger. It could be lack of maintenance of motor oil or maybe not cooling down after running on open highway. Somehow the oil can coke and cause the bearing to fail in the turbo. I may be also be guilty of not letting the turbo cool down enough at rest stops. A this point it may be best to install a exhaust temperature probe right before the turbo so you will know the temperature of the exhaust gasses before it enters the turbo. High temperature means you are cooking the oil at the turbo bearing. Share this post Link to post Share on other sites
wolfe10 Report post Posted January 1, 2015 Agree with Ray if typical fixed-vane turbo. But, sitting for long periods of time CAN contribute to a variable-vane turbo's demise. Share this post Link to post Share on other sites
dickandlois Report post Posted January 2, 2015 One should be able to get an idea of the condition of the turbo charger by removing the exhaust system at the exhaust side of the turbo. Not all coach owners have the ability to do this, but knowing what to look for or ask the technician when servicing the turbo is a good starting point. Brett, mentioned that a Clean CAC and Radiator are crucial to maintain proper air intake temperature and coolant temperatures.. The spool should turn easy, with no visible damage to the vanes or the housing. Link to more information. http://www.dieselclass.com/Engine%20Files/VGT%20Turbochargers%209-05.pdf By looking at the image on page 2- The shroud plate, yoke and activation link should move freely. The link is moved by ether air pressure or an electric motor. By looking at page 10 one can see the funtion of the Speed Control Valve. This sensor rides on a cam that is positioned by air pressure or an electric motor. The sensor controls oil flow / pressure to bearings. Clean oil helps to maintain turbo temperature by keeping the ports of the valve clean. Proper cool down time is critical for this turbo design in order to reduce the oil in the turbo bearing from coking. The exhaust temperature from the turbo can reach 750+degrees C. under heavy loads. Rich. Share this post Link to post Share on other sites
wildebill308 Report post Posted January 19, 2015 I have a Country Coach FE 420 with a C9 425 hp. I have 18,000 miles on it . A 16,000 mile I had a check engine light come on. Turns out Cat said I had a blown turbo. They said they had some hot inlet air alert showing on the read out. Cat replaced the turbo but after checking to see if everything was working fine after a few miles Cat is still getting alerts showing hot inlet air but now they are saying it's CC problem, plus now I get what feels like a miss in the engine. Has anyone else run into this. Thanks Welcome to the forum James, I will be interested to know how it comes out. I don't know how a bad turbo would cause high temp in the inlet. I would be inclined to go with what Brett said about cleaning the CC. The miss may be from a fuel or injector problem. Let us know what you find out. Bill Share this post Link to post Share on other sites
wildebill308 Report post Posted January 19, 2015 Hi All; I have a 2009 Cheetah Safari with a C-9 turbo charged engine- 425 HP. I bought it new in 2009 and 2 years later at 9,300 miles I had to replace the turbo-charger. Today at 23,000 miles the coach is in the shop again and the diagnostic codes point to another bad turbo charger. This is all related to the automatic regeneration cycle, somehow. Still trying to determine how Caterpillar controls the need for regeneration............some manufacturers measure the pressure differential at the DPF (diesel particulate filter) to determine the sooth loading in the filter, and then trigger a regeneration cycle to burn the sooth and clean the filter. Others use miles, others use gallons burned or hours of operation. Don't know how Caterpillar does....still trying to research it! What I believe is causing the issue is that with RV's that stay in storage for some time, the turbo somehow locks up because there is no way to lubricate the moving rotor and impeller vanes. Then when you take it out on the road the system calls for an active regeneration cycle and the locked up turbo cannot respond and the result is an engine fault code for a failure to regen; then you get the power derating and eventual stop engine fault....................which leaves you stranded!!!! If anybody knows of an aftermarket cure for this turbo issue....I would really love to hear about it! Regards, Frustrated Cat owner Welcome to the forum lvnrdrm. I have been doing some reading on the variable vane turbo. Rich has a lot of good info in his response. I also found that some are capping off their exhaust if parked for more than a couple of days. This prevents moisture from getting up the relatively short exhaust on a motorhome and causing corrosion on the turbo plates that cause the sticking problem. I think this is another reason to drive your coach frequently (weather permitting) so lets go someplace. I think covering the exhaust should reduce the problem I was trying to think of something handy and cheap. Perhaps a shower cap with the elastic or one of those plastic wrap covers that has the elastic. It wouldn't have to be to heavy duty and if you forget, it will just blow off. Bill Share this post Link to post Share on other sites
