Motor Condition Evaluation thread...I want YOUR opinion
Ok, so I jumped in a little quick after seeing a local van come up for sale. The van is a 1980 Penn 20' Al. bread truck, GM 4speed . I suppose if I found the serial # on the motor I would have an idea of the era of the motor which is the 4BT. Today I tinkered with it and will list some of the things I saw and don't think it are good signs.
1. Oil seepage on the intake side of turbo, assume a seal has gone out.
2. Oil super dirty, oil pressure drops to 30 according to chevy gauges, at RPM it is at 60, didn't change oil but threw in a new filter. Wasn't any oil on rockers after a minute or two of running, a little throttle. After I changed the filter it started to trickle, #7 rocker was bubbling #8 was oozing . Oil pressure gauge seemed to bounce more after I changed filter. Non-bypass filter?
3. Blow by? With the #4 rocker cover off there was a fair amount of "blow"- same as the oil fill plug, but I assume some of this is due to the reciprocation of the pistons.. I guess I could put a plastic bag over the fill plug to see how much air was coming out.
4. Loose/missing bolt on tranny/bell housing to adapter, stripped bolts..I suppose some keyserts or helicoils will be employed.
5. Fuel running down driver's side below or from injection pump-saw someone else had this problem, found loose fuel cut-off or fuel supply pressure sending solenoid.( It sits on top of the injector pump and is almost impossible to get anything on it as the injection lines are on top and around it as well as a threaded stud with a nut... remember this is all new to me) I don't know if that is it though.
6. Valves loose, didn't seem to have much axial play but the #8 would dance fore and aft at a higher RPM. will adjust after I get my manual.
7. Oil line to turbo rubbing pretty good on intake plenum- this will probably change after the conversion.
Removed the intake plenum, turbo spins as motor runs, this rig blows black on accelleration and mildly black while running.. I plan on changing the oil, putting in some fresh fuel and changing the fuel filter, bolting things up tight again and seeing if it still blows black. Could this be oil from the turbo? I will check the oil pressure with a real guage. May look into a compression test. Any advice or input you have is greatly appreciated. I want to make sure I have a good solid motor or be ready to rebuild if that is the case or repair as necessary.
Another question.. How do I determine boost level and should I hear the whine of the turbo? Thanks and already gleaning a lot from your buildups!
Ok, so I jumped in a little quick after seeing a local van come up for sale. The van is a 1980 Penn 20' Al. bread truck, GM 4speed . I suppose if I found the serial # on the motor I would have an idea of the era of the motor which is the 4BT. Today I tinkered with it and will list some of the things I saw and don't think it are good signs.
1. Oil seepage on the intake side of turbo, assume a seal has gone out.
2. Oil super dirty, oil pressure drops to 30 according to chevy gauges, at RPM it is at 60, didn't change oil but threw in a new filter. Wasn't any oil on rockers after a minute or two of running, a little throttle. After I changed the filter it started to trickle, #7 rocker was bubbling #8 was oozing . Oil pressure gauge seemed to bounce more after I changed filter. Non-bypass filter?
3. Blow by? With the #4 rocker cover off there was a fair amount of "blow"- same as the oil fill plug, but I assume some of this is due to the reciprocation of the pistons.. I guess I could put a plastic bag over the fill plug to see how much air was coming out.
4. Loose/missing bolt on tranny/bell housing to adapter, stripped bolts..I suppose some keyserts or helicoils will be employed.
5. Fuel running down driver's side below or from injection pump-saw someone else had this problem, found loose fuel cut-off or fuel supply pressure sending solenoid.( It sits on top of the injector pump and is almost impossible to get anything on it as the injection lines are on top and around it as well as a threaded stud with a nut... remember this is all new to me) I don't know if that is it though.
6. Valves loose, didn't seem to have much axial play but the #8 would dance fore and aft at a higher RPM. will adjust after I get my manual.
7. Oil line to turbo rubbing pretty good on intake plenum- this will probably change after the conversion.
Removed the intake plenum, turbo spins as motor runs, this rig blows black on accelleration and mildly black while running.. I plan on changing the oil, putting in some fresh fuel and changing the fuel filter, bolting things up tight again and seeing if it still blows black. Could this be oil from the turbo? I will check the oil pressure with a real guage. May look into a compression test. Any advice or input you have is greatly appreciated. I want to make sure I have a good solid motor or be ready to rebuild if that is the case or repair as necessary.
Another question.. How do I determine boost level and should I hear the whine of the turbo? Thanks and already gleaning a lot from your buildups!
