My car isn't listed, so I chose one at random to ask the question. I have a 1977 Fiat 124 Spyder The clutch has begun to slip and there is an engine oil or gearbox leak that is seen dripping from behind the flywheel cover. How do I determine from where the leak comes, and if it is the crankshaft rear oil seal or gasket, can I repair it by going up through the oil pan with the engine in the car, or do I have to tear the engine apart from top down?
oil or gearbox leak repair on 1990 Porsche 911
by ystephen in Marysville, MI on April 21, 2009
ANSWER by patrick mannion on April 21, 2009
I would suggest washing down the engine (steam cleaning it if necessary) to pin point the leaks. Ensure the engine breathing is OK, ensure the PCV valve is clear and functioning correctly or any blow by will build up crank case pressure and cause oil leaks from camshaft seals, valve cover gaskets and the crank rear seal.The rear crank seal is a one piece lip seal not a rope seal like older American cars or a "scroll seal' like older British cars. With a clean engine the engine can be run to determine where the leaks are coming from. Florescent dye can be added to the to either the engine oil or gearbox oil (but only to one), and when inspected under black light the dye may more clearly show where the source of the oil leak is coming from. To replace the crank rear seal the flywheel has to be removed, you will be replacing the clutch any way. I love old cars, owned and work on a lot of old cars, (French and British). You may want to pull the engine and just reseal every thing if you are doing the work yourself. Timing belt replacement is important on these cars as well.