White Engine smoke comes form all four PMDG 747-400 engines after flying for 45 minutes or so. It is white smoke like contrails but but fully blasted from all four engines as if they were on fire or something. It also affects the flight dynamics as the plane become very unstable and unable to follow the flight plan. I have tried the following things to try to determine the problem:1. checked the failure items to see if I was getting some sort of engine failure (not effected)2. tried reloading the flight but even after a computer restart the same smoke conditions occure with the flight that was smoking.3. tried selecting another PMDG 747 with different mfg engines (no effect same problem)4. tried loading my default PMDG 747 FIRST, that is parked at the airport with the engines running. Engine smoke is gone but when I then try to reload the smoking flights, they still have smoke. (this solution was tried a while back and cleared the smoke problem but no longer).The FMC is active with a flight plan and the sometimes get deactivated before smoking. Also, when flying and using the moving map to relocate the aircraft, has also made it cause the engines to smoke.This occurs at any altitude, day or night, time or season, I can reset everything and start the flight over with no smoke until I get airborne and fly for about 30 minutes.I have the following system: I have a Win7-64 i5-650, 4GB, Nvida GTS450, ASUS P8P67-Pro, w/FSX SP2,FSGenesis US,UTX-US,REX2,UT2,Thanks,Any help would be greatly appreciated.Walt

Try doing the flight in "Clear Skies" weather mode to see if that effects the problem (dont turn on any third party weather engines). Also a screen shot may help if you can.

Walt,This actually happens when you load the 747 over top of another complex addon or over top of another 747 variant/livery (which FSX considers to be a different plane, it doesn't know it's the same systems etc). It's a limitation of FSX we've never found a way around.If you're going to switch liveries or switch from the 400 to the 400F etc you need to shut down FS and restart it - just the way it is.

White Engine smoke comes form all four PMDG 747-400 engines after flying for 45 minutes or so. It is white smoke like contrails but but fully blasted from all four engines as if they were on fire or something. It also affects the flight dynamics as the plane become very unstable and unable to follow the flight plan. I have tried the following things to try to determine the problem:1. checked the failure items to see if I was getting some sort of engine failure (not effected)2. tried reloading the flight but even after a computer restart the same smoke conditions occure with the flight that was smoking.3. tried selecting another PMDG 747 with different mfg engines (no effect same problem)4. tried loading my default PMDG 747 FIRST, that is parked at the airport with the engines running. Engine smoke is gone but when I then try to reload the smoking flights, they still have smoke. (this solution was tried a while back and cleared the smoke problem but no longer).The FMC is active with a flight plan and the sometimes get deactivated before smoking. Also, when flying and using the moving map to relocate the aircraft, has also made it cause the engines to smoke.This occurs at any altitude, day or night, time or season, I can reset everything and start the flight over with no smoke until I get airborne and fly for about 30 minutes.I have the following system: I have a Win7-64 i5-650, 4GB, Nvida GTS450, ASUS P8P67-Pro, w/FSX SP2,FSGenesis US,UTX-US,REX2,UT2,Thanks,Any help would be greatly appreciated.Walt

Maybe you forgot to turn on the NO SMOKING sign

Thanks,Removing the third party whether engine in REX seems to have been the problem. After all, the smoke form the engines was the same color as the clouds. I didn't have to have clear skys though. Just disabling the whether engine seems to have done the trick. I'll further investigate why REX (third party whether) causes this.Thanks for the help.Walt

Try doing the flight in "Clear Skies" weather mode to see if that effects the problem (dont turn on any third party weather engines). Also a screen shot may help if you can.

Thanks very much!Disabling the whether engine in REX seems to have solved the problem. At least I was able to fly form KDFW to KLAS without white smoking engine thrust.. The smoke does look like cloud textures. And sense it greatly effects the flight dynamics of the ac, I suppose it like having cloud turbulent s coming out of the engines. I wonder if you manually load or start REX after FSX is started. REX over the top of PMDG 747 would that make sense as having the 3rd party add ons to be the last program?Thanks for the helpWalt

Walt,This actually happens when you load the 747 over top of another complex addon or over top of another 747 variant/livery (which FSX considers to be a different plane, it doesn't know it's the same systems etc). It's a limitation of FSX we've never found a way around.If you're going to switch liveries or switch from the 400 to the 400F etc you need to shut down FS and restart it - just the way it is.