Friday, January 6, 2012

1998 Chevrolet Metro oil leak

Finally I think I found my oil leak in the metro. A loose Allen head pipe type plug in the head under the camshaft sprocket is the source of the main leak. The plug looks clean but is covered with clean oil. I backed the plug out 2/3 of the way until it met the camshaft sprocket. (The plug was loose.) Looks to me like a manufacturing port of some sort.

(Note the leaking plug is below and left of the camshaft.)

I cleaned the exposed threads of the plug with some alcohol and applied some special Permatex thread compound then tightened up real good. I am quite sure this will resolve most of my oil leak. In 2009 I installed this rebuilt head and never dreamed this plug was loose.

It did take a long time to find this leak as it is under the plastic timing cover which is under the pulley driving the alternator and a second belt to the power steering pump and the compressor for the air conditioning. Finally I left the plastic timing cover off along with the second belt and was able to see the leak at the source instead of near the bottom of the engine.

I used a product called the Right Stuff to seal the metal to metal surface under the end crankshaft journals where it appeared some oil was leaking to the outside. I also replace the valve cover gasket and used the right stuff for the gasket under the oil pump case and for the oil pan.

(Picture shows the joint in the journals that was not sealed.)

Interestingly enough the Metro Service Manual appears to be incorrect or the camshaft sprocket is labeled wrong. The manual shows to have the “E” at top dead center. However the sprocket has 2 “E’s”. One located near the edge and another in nearer the center support. I used the one near the center as that is where it had been running so well. The manual indicates using the other “E“. The “E’s” are separated by about 100 degrees. Small little error!!!

(Note, picture from the Service Manual.)

(Note, 2 "E's" stamped on sprocket! One is about in the 8 o'clock position. The other is just above the center bolt.)