wingardc Report post Posted April 10, 2016 We have a 2013 (built in 2012) Monaco Diplomat that has for the last 4 months had serious DPF system issues that have put us in the shop more than on the road. Wondering if anyone else has a Monaco built by Navistar that is having the same issues. Synopsis below - sorry for the length. We bought the coach in Jan 2014 and since then have had over 127 regens with only a little over 39,000 miles. First year, no problems! Then in Dec 2015 the MIL lamp illuminated indicating a malfunction in emission system and that it need to be checked out. Took it to an International svc center in St. Augustine, FL (Where we live) and they replaced fuel pump and filter after troubleshooting. Also had issue with VIN number in ECM not matching up due to capital and non-capital letters. Had to contact a Navistar repair advocate to get help - motorhome would not run until that was fixed. 3 days after getting motorhome back, we left on 2 Jan to go to AZ - 2nd day into trip, MIL illuminated again and stayed on for 3 days. Noted power loss in TX and took it in and had the primary fuel/water separator filter replaced. Power return but MIL stayed on for the rest of the day. Next 2 days no issues. On return trip from AZ to FL, 30 mins into the first day of driving, stage 3 lamp and alarm came on and we had to pull over and do a parked regen. Next 3 days no issues. 4th day, 1 1/2 hrs into trip, stage 3 lamp and alarm and we pulled over and did a parked regen. Following the successful regen, we started back driving and 20 minutes later got the stage 3 lamp and alarm and pulled over again for a parked regen. We got on the phone and found an International Svc center 3 miles away in Shreveport, LA. Contacted them and they said to bring it in the next morning. We did and they had it for 3 days During that time they detected faults and removed the fuel pump and filter housing and discovered what looked like small rocks in the well of the fuel filter. A new assembly was put on. Another fault was the DPF - the removed it and air pressure cleaned it. Fault of a pressure sensor and DPF fuel injection was next and we believe that they replaced those. Leaving there and heading back to FL, the next day, we noticed blue and black smoke coming out the exhaust. No lights, no alarms, no loss of power. We continued traveling home and the smoking continued off and on. Took it to Mauldin International in Jacksonville, FL where they replaced the DPF fuel injector gasket and turbo intake air pressure sensor. Took the RV home and during our every 2 week drive of 25 miles, no more issues. On Mar 15th, we left for Decatur, IN for some extended warranty work on the coach and on day 2 of the trip, the MIL started flashing, smoke, some of power. MIL soon stopped flashing and we traveled to our destination with intermittent smoke from exhaust. Next day, smoke off and on and then 11 miles from CG, stage 1 lamp on and stayed on until we parked at CG. The next day we had to do a parked regen 30 minutes into trip. Smoking. Stage 1 lamp illuminated, stage 2 lamp illuminated but no stage 3. Lamps went off, still smoking next 150 miles to CG. Next morning, 20 minutes into trip, stage 3 lamp and alarm, pulled over and did a parked regeneration. Still smoking. No more alerts before we got to REV Service Center in Decatur, IN While in Decatur, we contacted an International Svc center in town and made an appointment that Thurs to have it checked out. They found that the DPF was cracked and the seals were blown. A new DPF with core and sensors was installed and the ECM updated. We left there feeling that finally the DPF System issues were resolved - we had all new stuff!!! NOT - On day 3 of trip back to FL, at 1 1/2 hour into trip, stage3 lamp and alarm do we pulled over and did a parked regen. Once were on back on the road, 45 mins later we had to do another parked regen, the CO alarm was sounding in the bedroom, black smoke, stage 2 lamp illuminated and MIL illuminated. We contacted an International Svc Center nearby in Macon, GA. They told us to bring in the next day. We limped into a CG and the next morning took the motorhome in for health report - they found some codes, fixed them; still getting codes - now think it is an electrical issue. Can't figure out what to do to fix it!!! It has been there 9 days now. If anyone has had similar issues with the DPF system on Monaco Diesel Pushers built by Navistar and have had resolution, could you please share with us!!!!??? Share this post Link to post Share on other sites
campcop Report post Posted April 10, 2016 If you go over to the Tiffin RV site I think you will find a lengthy discussion about this problem with these engines... Share this post Link to post Share on other sites
jleamont Report post Posted April 10, 2016 Winegardc, welcome to the Forum! Sorry to hear your list of troublesome problems. The new Diesel engine technology is very advanced with all sorts of electronic components all over them which have been prone to headaches like you have described above. Some engine manufacturers are prone to more headaches than others. You have indicated Monaco built by Navistar is the coach powered by a Maxxforce engine (Navistar) or Cummins? Share this post Link to post Share on other sites
manholt Report post Posted April 10, 2016 Joe. Maxxforce is a diesel engine manufacturer. Just like CAT, DD, Cummins and Duramax. It is not part of another diesel engine manufacturer. That I know of! Navistar builds all types of HD Vehicles and they like the Maxxforce engine. Navistar spun Monaco out to Allied Group, who recently spun everything over to REV Group! Wonder who's next? Carl Share this post Link to post Share on other sites
kingfr Report post Posted April 10, 2016 There are class action lawsuits happening against Navistar because of these engines. They were an attempt to do emission control by EGR only and not use Urea injection like Cummins does. The attempt was a failure and is costing Navistar a bunch of money. Share this post Link to post Share on other sites
manholt Report post Posted April 11, 2016 In the meantime, it's costing the consumer who bought these units. Monaco has been real good about letting the customer down since 2007. They are not the coach or the company they once were, nor will they be again. Share this post Link to post Share on other sites
jleamont Report post Posted April 11, 2016 I was trying to ascertain if the unit in fact was Navistar Powered or Cummins powered. No engine make was referenced, just the coach make. I am not familiar with the HR/Monaco products in those years, I know they were owned by Navistar back then but that doesn't always mean they didn't offer a Cummins as an option. I do agree with the product they produced being not being dependable. Here is a link from a previous discussion. Few owners on here didn't mind them. The last time I brought up that product I made someone unhappy. Share this post Link to post Share on other sites
manholt Report post Posted April 11, 2016 Maxxforce or nothing. Navistar the Maxxforce! Share this post Link to post Share on other sites
wingardc Report post Posted May 3, 2016 Thanks for the replies. The engine is not Cummin's. It is International Harvester. However, not relevant now. Went to the dealer where we bought the 2013 Diplomat in 2014 and they traded us (even swap (almost)) with an older model, very well kept, low mileage unit that was before DPFs and before Monaco went belly-up. We are very pleased with the customer service we received and the caring owners who wanted to make sure we were "happy campers" again. Share this post Link to post Share on other sites
jleamont Report post Posted May 4, 2016 wingardc, glad to hear! Wish you luck with your new coach! Share this post Link to post Share on other sites
