1972 472 tune-up?

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 2 of 2
500, 472, 425, 368 Discussion, 1972 472 tune-up? in Cadillac Engine Discussion; Hi everyone, this is my first post. I'm Bill, from Ohio, and I just bought a 1972 Cadillac Sedan DeVille ...
  1. #1
    billsif is offline Cadillac Owners Member
    Automobile(s): 1972 Sedan Deville
    Join Date
    Apr 2004

    1972 472 tune-up?

    Hi everyone, this is my first post.
    I'm Bill, from Ohio, and I just bought a 1972 Cadillac Sedan DeVille for $300. It needs some body work on the passenger side - it was side swiped so the two door handles are gone and there is a streak of surface rust and minor dents along the whole side, and a dent to the front passenger side of the hood. I'm glad the car even ran for $300, and the transmission seems to be in good shape, but I'm a little worried about the engine.. It started up and sounded fine when I test drove the car, but today when I went to pick it up, I started it and it sounded like it was maybe making a 'slapping' sound, but more like a knock... maybe 3 slaps every second at idle.. coming from under the hood somewhere. I don't know if there's maybe a stuck valve or a piston problem or what.. I'm used to a 302, not these huge gm engines... I plan on doing a tune up over the next couple weeks as I have the money, but does anyone know what I might look for when bringing back to life this 472 that has basically been sitting for a year? The car seems like it has a fair amount of power, but I don't know if it feels like 220HP... I'm not really confident flooring the gas pedal though, since I was concentrating on getting it the 20 miles home. There's also a moment of hesitation also when pressing the gas pedal suddenly at idle. If anyone has anything to contribute - advice of any kind - please let me know!


  2. Remove Advertisements

  3. #2
    capn_zoom's Avatar
    capn_zoom is offline Cadillac Owners Member
    Join Date
    Jan 2004

    Re: 1972 472 tune-up?

    Bill, first things first: Check the oil level and condition (simple, yes, but I almost bought a car with a blown head gasket once for lack of performing this simple step). Does it sound more like a tick or a knock? Ticks usually indicate valvetrain noise and would be loudest around the valve cover area. A tick can also come from an exhaust leak (check around the exhaust manifold gaskets and the manifolds themselves) or even from a belt that has an imperfection or wet spot on it (you wouldn't BELIEVE how loud a screwed-up fan belt can sound). The worst knocks come from the bottom end of the engine and tend to indicate excessive clearance in a bottom end component. Try to determine where the knock is coming from.

    A few questions: Does the engine run smoothly or does it misfire (especially under a load)? Does the sound get louder or softer with higher RPM? Does it go away as the engine warms up, or does it get louder? How many miles on the engine? If you have a piece of fuel hose, you can use it as a crude stethoscope. Press the tip of the hose against the valve cover, and press the other end against your ear. Do this VERY CAREFULLY-- there's a lot of dangerous stuff moving around under the hood of a running car (if you have long hair, for God's sake tie it back). STAY FAR AWAY FROM THE FAN AND BELTS!!! This may allow you to hear a valvetrain noise (press the tip onto the valve covers on the engine). Bottom end noises will be trickier, and I STRONGLY DISCOURAGE crawling under a car with a running engine to press a chunk of hose up against the oil pan. Let me know if you can narrow it down at all.

    The hesitation is likely a carburetor misadjustment or the need for a carb rebuild. This is relatively simple territory, and I would worry about the noise first.

  4. Remove Advertisements
    Cadillac Forums

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

What Cadillac(s) do you own? (Or type NONE)

Please select your insurance company (Optional)

Your date of birth and age are displayed in several places on the forum. Only the administrator will have access to your date of birth should you choose to hide it via the privacy option below.


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts