Questions and Answers
Toyota Tercel Diesel
Q. I own a 1996 Toyota Tercel (diesel turbo) model no KDNL 50 and having a 1.5 litre engine termed 1NT. Recently it was overhauled, with new pistons having the bore cut to over size (50). Most of the parts were replaced including the oil pump complete, and was done quite well.
It functions well and also is very efficient on fuel (12km /ltr). But I have noticed crank case pressure when I lift the dip stick and also have found traces of oil on the turbo and inlet manifold.
Although I'm knowledgeable of the PCV on gasoline engines, I'm not exactly sure how the diesel system works since there is no inlet manifold Vacuum. I have checked for breather pipes or down draft tube, but there seems to be only one hose connecting the crank cover and the inlet manifold. Is this to suck fresh air or to carry blow-by? When I remove this at the inlet manifold end I see excessive pressure being relieved with a mist of oil.Questions:
1) Is my crank pressure excessive, as still the pistons would not have bedded-in properly? (It has done approximately 9,000 kilometers since the overhaul)2) Is my crankcase ventilation system not functioning properly?
Would appreciate some feedback or some literature on Diesel crankcase emission control. M'thks & have a nice day.
B'rgds
Chaminda - troubled!A. Toyota hasn't imported a diesel into the US since the mid-80's. You must have a European model.
The PCV system in a diesel works the same way as in a gas engine. It will have either a PCV valve or a Crankcase Depression Regulator (CDR) valve. The purpose of the CDR valve is to maintain 0 to 4 inches of water vacuum in the crankcase at all engine speeds, assuming that the piston/ring combustion blow by is not excessive. Too little vacuum or positive pressure in the crankcase will tend to force oil leaks. Bottom line is: either the PCV/CDR system is not working properly, or you have excessive blowby. Excessive blowby is usually indicated by smoke coming out of the oil fill hole.
I would have whoever did the engine work look at it again and find out which it is.
Additional Information provided courtesy of ALLDATA
