[Bad66Chevelle454]

Hey Everyone,

I have this old 62 Cadillac Limo that I like to cruise around in. Well a few months back, it started to make a rattling type noise under load. I thought maybe it was timing, and it was pinging. Adjusted the timing, ran 89 instead of 87, but didn't make a difference. Around that time I had replaced the old generator with a new alternator, and thought maybe the new belt was flopping around hitting something. Took the belt off and drove around the block, did the same thing.

It only makes the noise when the car is under a heavy load. It seems like if I stomp on it from a dead stop, it doesn't make it until the car shifts into second gear and sorta bogs down....if I keep my foot out of it, it won't make the noise. If its parked, and I rev the engine, it won't make the sound.

I'm thinking it's some valve train issue....the oil pressure light isn't coming on when it's running(it works), has plenty of oil, and its definitely not a loud rod knock.

Any ideas? Or things I can check?

Thanks for your help,

 

[Guest]

You are at 10.5 to 1 CR'd so watch it or you will detonate the old 390 engine to death!!

Back off the timing and burn at least 92/94(?) and even then a little E85 IF your fuel system will handle it only b/c of age. Install new modern hoses and such and you should be good to go IF the fuel pump diaphram(Sp?) can go it??.

And, believe it or not, an old 390 Cad engine is a hell of an older rodders engine "Old-School" here!

Just like the old 394 Olds and the 425 nailhead Buick!

pdq67

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[Bad66Chevelle454]

So you think it's not getting enough octane? I ran it all last summer with plain ol' 87 octane. I'll have to fill it up with 91 and see what happens.

Do you think maybe the points or advance is worn out or something like that???

 

[Mike]

You might check the advance weights (under the rotor) to see if there free to move.
Sounds like detonation so it's probably ignition related.
Could also be excessive carbon built up in the combustion chamber causing hot spots that cause detonation.

After thought:
You might verify the dampner's actually at TDC when it shows to be or your timing will be off.

 

[Bad66Chevelle454]

Mike,

I will definitely check that out. I'm going to put some 91 in it(tank is on "e" right now anyways), and fiddle with the timing. I've honestly never touched the distributor, other than a new cap and rotor when I bought the thing over a year ago.

Thanks for all the help!!!

 

[kettbo]

Tim,

OMG, you ran UL Reg in an old school high compression, small cam torque engine?:sad: I hope you didn't hurt anything.....

I sell auto parts...
I had a customer come in with a Chevy HEI distributor in his hands
vacuum advance stuck
advance springs rusted and fell off, parts inside the distributor....
Bet vacuum or mech adv parts, or both, are inoperative.

Good luck

 

[Guest]

Cad's needed "Ethyl" back then at 10.5 CR. regardless!

You can de-coke her a couple of ways, Good old MMO and Sea Foam down its throat and in its gas tank as well as a drizzle of clean water down her throat warm at a fast idle. just don't kill her and hydro-lock her b/c you can destroy her EASY if you aren't careful..

Remember, imho, a 390 Cad is a part of Hot Rodding History!

pdq67

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[Bad66Chevelle454]

Well I just went and dumped 25 dollars worth of 91 in it. That pretty much fixed the problem, its just barely pinging under WOT with a heavy load. So now I'm just going to tweak the timing a tad, and I should be good to go.


Thanks again for all the help!!!

 

[Bad66Chevelle454]

Paul,

I'll be sure to dump some MMO in it. I don't want to try the water method for fear of screwing it up.

I can see why guys like you liked them for Hot Rod engines....even with that boat of a limo, it still gets up and moves it pretty damn good! Here's a picture of it....

 

[Guest]

Oh, be still my heart!

And the cars nice too!

Onna my old Buddies Dad gave him his '62 or so 4-Dr H/T Cad Calais DD and I'm here ta say it was a real road machine! I want to say like in '69 or so???

And to top it off, the big monster got GOOD gas mileage to boot!

He was the Bass Player for a local band called "Plato and The Philosophers" and packed all his gear in the trunk of it plus a case of fine wine!

http://thepiratebay.org/torrent/340...torrent/3400260/Plato_and_The_Philosophers-Thirteen_O_Clock_Flight_to_Psychedel

Ben White is my Buddy's name.

I miss those days............

pdq67

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[Bad66Chevelle454]

Paul,


That's a cool story. I just fell in love with this 59 Limo one day at a car show and said I gotta have me one of those! So I found this 62 Limo on Craigslist and bought it! It's such a blast to drive, nice and smooth...Never in a rush with that car.

I just retarded the timing a bit, dumped a bunch of Lucas top end lubricant/cleaner in it, and it runs like a top again!!! Going to cruise it down to a show here in a few more minutes.

So how come it ran so long, and so well on 87?

 

[Bad66Chevelle454]

Just an update....

After filling it with 91, retarding the timing a bit, it ran perfect. Drove it to a car show yesterday, and home without a single glitch or problem. I even had 6 people in the car on the way home, and going up the hill from the next city over, it didn't ping or anything.

Thanks again for all the help.

 

[Hi-po SS 454]

Paul,

What Limo....Daaam !!!!!