This was happened on my old combine, a Fahr M1000 with a F6l912. yes it was the injector tip loose. I don't know what happened. Now i have a Fahr 2680 with a F6l913 and i never had a problem on it. I blow the cilinders every day and change oil every 250 hours. I use a 15W40 mineral oil with some Wynn's For Oil additive and this engine have 12000 hours. If you want to buy another Deutz maybe you can't buy another air-cooled. The new series of Deutz-Fahr combines are air cooled from 150 to 260 hp range, with the 912-913 series and the "big" combines are powered by the water cooled engines BF6M1013, 6 in line and BF6M1015 6 in V. I think Deutz will stop the production of the 413_513 and 912_913 series. I don't know what will happen with the 413_513 but Deutz will substitute the 912_913 series for the new 914.