Combines No Boost Pressure Turbo

look under the intake manifold. You probably have a large plug that has backed out and dumping all the boost to the world.

Had a 7020 with an l2_649I in it. They didn't make pump or nozzle changes when it went from an l2 to the 7020. Always smoked like a coal locomotive and ran away from my 115hp dyno'd 7000. The only time the 7020 didn't smoke was when I was burying the chisel plow or disk. Finally took it in to the shop and had it dyno'd, 150+hp. Had the nozzles changed and the pump reset to make it a 7020 again and the smoke disappeared! Most of the l_M series with the 649 smoked, from what I ever saw. The 670 in the l_N series wasn't much better until they went to the Bosch system in 1982. lack of boost pressure on the gauge can be a bad line or intake manifold leaks as tbran suggested. A bicycle tire pump can check the gauge for working capabilities, just don't get carried away with pumping too much or too fast.

listen to FHB, I have seen a 1 inch plug out in the intake manifold and the hose going to the boost gauge off on several ocassions. If the smoke has changed there is a reason why. 1 other situation I have seen is Robert Bosch or American Bosch nozzles installed with the return line installed towards the manifold instead of between the nozzle and valve cover. The life of the engine is severly shortened in all of the above situations.

Check all plugs in the intake manifold, Check all lines from the turbo to the intake manifold, Check the hose off the intake manifold going to the boost gauge, and check that american or robert bosch injection nozzles are installed with the return line between the nozzle and valve cover. I have seen all of the above happen.

I agree with tbran. Check for a missing plug on the intake manifold. I've had it happen to me causing the same symptoms you described. You end up with not enough air for the amount of fuel being pumped --- black smoke!! Have a safe harvest.

Thanks Goose, Tbran, Gamaman. Sure enough the 1-inch plug was blown out. I had to go into the grain tank trap door and found it on under the oil pan. Now how does this happenIJ My dealer told me to "think positive thoughts". looks like I'm headed for an early engine overhaul, hopefully not this year. Is there anything I can do now or is it just a waiting game until there's too much oil consumptionIJ

Had the same thing happen on a customer's '81 M2. Probably ran a thousand hours before trading with no engine problems. Next owner still running it.