- 02-01-12 08:57 PM #16Cadillac Owners Fanatic
- Automobile(s): 1981Cadillac Fleetwood Brougham D'Elegance Coupe m
- Join Date
- Mar 2008
- British Columbia
Re: Ultimate Database/FAQ of the 500 | 472 | 425 | 368
A tidbit of info on the 368 engine. Often overlooked because it's so darned hard to see.The EFE valve which is on the exhaust manifold, passenger side.The purpose is to direct hot exhaust gases through the intake manifold during cold startup. The shaft on this valve must be kept lubricated and moving freely because it is operated on vacuum only.Some of the symptoms of a sticky or non functioning EFE are as follows. Poor operation at start-up(rough idle, stumble) Poor operation after warm-up (lack of high speed performance,surge,miss at all speeds) The EFE is controlled by the TVS (Thermostatic Vacuum Switch) on the 6.0 and electronically on the 4.1 engine. The TVS is located on the left front of the cylinder block . Make sure the vac. lines to the EFE are sound and have tight connections.
- 01-15-15 04:28 PM #17Cadillac Owners Member
- Automobile(s): 1967 sdv with 73 472
- Join Date
- Jan 2015
Just something i learned. Frankenstein-ing caddy bigblocks. 425 heads on a 472/500 will add compression.