Experienced mechanic

[dst2680]

I am searching for a mechanic familiar with the 500ci engine to do a general once over and tune up on my 1975 deVille. Does anyone have any recommendations in or around Rochester/Buffalo/Syracuse NY?

[Ken Perry]

One of the main things to remember with a 500 ci. Cad,is when changing the oil, make sure it's warmed up,have a filter with oil ready and change the oil fast as posible and fire it back up!!!!Becouse they will lose prime on the oil pump and you will have to take out the distributor and run the oil presure up wth a drill ! So watch the oil light and make sure it goes off and no lifter noise. They have a very long oil pick up tube for the oil pump. Also never run a cheap distributor cap,they will burn threw and ground out the ignition and the car won't run. They have a top timming gear that has plastic that falls off the teeth,that can make them jump time and can get plastic  into the oil pump.If it has'nt had a chain and gears it needs one.The Q-jets have metering wells that leak,if this happens,you can fix them with JB-Weld. These are some of the top things to look for and remember.Hope this helps. Ken Perry       

[Scot Minesinger]

What Ken said.

The Cadillac is extremely vulnerable to poor/rough idle due to vacuum leaks.  All rubber vacuum hoses should be replaced under hood, especially the ones that go thru fire wall and the one at the trans that connects vacuum modulator.  Check all vacuum devices, such as diaphragm on cruise and etc.  The vacuum line to the snorkel damper should be plugged (piece of 1/8" round stock), as even though the damper actuator may be good, the switch activating likely is not and it will cause the car to run in warm up mode drawing intake air across exhaust manifold instead of at front thru snorkel.

When you drop the oil pan to replace the timing chain the fuel pump also among a few other things has to be removed.  Replace the fuel pump, just a piece of rubber between gas and oil (best to not have it be 39 years old).  Also replace rear main seal, they all leak after 30 years generally, especially low mileage originals (this is a $15 part and all the work is in dropping the oil pan, so this is a no-brainer) 

You are on the right track only used a mechanic who has been recommended by someone you value their opinion.  Around Washington, DC I feel most comfortable doing my own mechanical work.  I was prepared to write checks.  Never found anyone who does the work the way I want it done.

Good luck.

[936CD69]

I believe Dave Shepard, a frequent poster on this site, is in your area and a go to expert!