I have found a 1992 Oldsmobile Firenza with 83,000 miles and the engine needs to be rebuilt. The current owner fried the engine twice and cracked the head. It seems that this engine is a SHOC design. I need to know <BR>if this engine is a SHOC version of the Quad-Four or is it a completely different design?<BR>If I properly rebuild this engine, will it go 250,000 or more miles with proper maintenance, i.e. oil changes with Valvoline's best engine oil every 3,500 miles and all other factory recommended maintenance procedures. Please list strengths and weaknesses of this engine.

If this is a SOHC Quad Four, the "engine cover" (this covers the spark plugs/ignition module) will say "Quad OHC" molded in the cast.<P>If I'm not mistaken, there was a 2.0 liter OHC that is not a Quad 4 that was used in the Firenza.

To the best of my knowledge, the Firenza was discontinued after 1988.

My late great uncle had a 1990 Cutlass Calais with a Quad 4. Very peppy engine. The Quad 4 is a DOHC engine with 4 valves per cylinder.

The car has the 2.0 liter sohc engine that was is in the sunbirds. It is not the best engine produced. It is very slow and has a problem with head gaskets and cracked heads. I owned an 88 sunbird with the 2.0 turbo engine, even more troublesome, but very fast. I would not but it. The best milage I have heard on that engine is 180,000 miles. Mine only lasted 160,000 after a new head and turbocharger. However the 2.0 N/a is very common and is in alot of cars at the junkyard.