Engine sitting for 6 years - rebuild necessary?
 

I've inherited a 2.7 CIS engine that has been sitting in a heated garage for 6 years without being touched. The engine was running when it was removed in an engine swap.

What should I check to see if the engine is still functioning properly?
Is a rebuild necessary or suggested when an engine has been sitting that long?

Thanks,

Tim

Tim,
CIS is a good, reliable system. However, it must be clean to function correctly. I would assume that every part that touches fuel is now full of varnish. You will have to remove all the CIS components and flush them with solvent (gas is too expensive these days).

Check for wasps, spiders, mice, etc. in all the engine openings.

Check all the rubber hoses, seals, grommets, o-rings, and paper gaskets that have dried out over the years. Drain the oil (if any) and replace it with a high-mileage oil (for the detergents).

Inspect the wiring for loose fittings, deteriorated insulation, and broken connectors.

Any idea why the engine was removed? Chances are the conditions 6 years ago still exist. Spray some WD-40 into each spark plug hole and turn the engine over by hand. If you have an air compressor, perform a leak-down test. That will tell you if you need an engine rebuild or not.

Good Luck,
Mark

A friend bought a -75 930 that had been sitting for 9 years.
Changed the oil and it fired right up WITH THE OLD GAS!!! It ran a little rough untill he mixed in some new fuel.

Hello, Tuttobono
My educated guess and experience tells me to tell you the 2.7, though running, was removed because it developed head shatter. This I learned as many others have, is this engine was in 1974-77 model years. This fell during when states started requiring smog equipment on automobiles. This was a quick fix by Porsche from Germany's point of view. The equipment involved a "thermal reactor" on both sides of the engine just under each bank of heads where the heat exchanges were. This heat was so severe that it heated up the engine case to where the head studs would pull away from the engine case especially the lower 12 on both sides. This pulling away or loosening let the heads leak air and lower compression. Most people think it's an exhaust leak and several $$ later they find it's head shatter.
My advice to you is given the year and amount of time sitting is REBUILD it with the fixes for studs not pulling again.
Porsches have to be driven or at least warmed up on a regualar basis. Rubber seals and gaskets like in the oil cooler and oil pump can harden and crack with time if not used regularly.
THE FIX is remove the head studs and have a Porsche Machine shop insert course STEEL threads into the engine case. 2nd... remove the thermal reactors if you can get away without smogging.... In California you don't have to smog a car up to and through 1975. 1976 and newer you have to smog. 3rd.... install and exterior oil cooler at the front of the car ....usually inside the front wheel weld.
Also, go through all the gasoline involved components and clean out completely especially the fuel injectors. Also, I strongly suggest you remove the gasoline tank and have it flushed out and cleaned completely.... it's very true that gasoline will turn to varnish over time and in the heat. Chances are you could get it start again but it will run rough because you are running chunks of it through your entire fuel systems. Rebuild it and have no worries.
Relayswitcher / JOSH

Welcome!

Thanks!