: 1983 Coupe Deville; lots of engine noise



Benzilla
04-27-06, 07:03 PM
Ok, so ever since I raced a Talon last winter, my Coupe Deville seems a lot louder on the inside. I thought so since I raced it, but today my Dad had to drive it, and he said it was REALLY noisy for a Cadillac, and now he hates the car. Anyway, whats wrong? Think it might be the muffler? I hate noise in a car, and this almost sounds like an old pickup truck to me. then again, it always seemed a little noisy to me, is it just the way the HT4100 is?

I~LUV~Caddys8792
04-27-06, 07:06 PM
Who Cares?! You're gettin' HENRY HILL's '79 Coupe Phaeton!!!! Woot woot!!! :worship: :worship: :worship: :worship: :D :D :D :D

Benzilla
04-27-06, 07:12 PM
lol, yeah I know, but the '83 is my baby! I took it from a crappy used car lot, and made it really nice, I just hate the noise... other than that its a great car.
http://i24.photobucket.com/albums/c40/Cadillac_guy/100_0275.jpg

Benzilla
04-27-06, 07:27 PM
BTW where is CoupeDevilleRob when you need him? haha

I~LUV~Caddys8792
04-27-06, 07:49 PM
Whats with the headlights? How come only 1/2 light up?

Benzilla
04-27-06, 08:17 PM
Thats the low beams, the brights are in the middle, thats how it is on older cars with 4 headlights :)

DopeStar 156
04-27-06, 08:56 PM
Whats with the headlights? How come only 1/2 light up?
No, no, that's a shade. It's like a visor over the headlights. My dad had them on his 64 Oldsmobile Dynamic 88.

77CDV
04-27-06, 09:28 PM
Ben,

Can you describe the noise? Where does it sound like it's coming from? Underhood, undercarriage, rear end? Does the car run smoothly? The 4.1 isn't known for being noisy, merely short-lived due to being horribly overworked in these 4500 lb beauties. More info, please.:)

Craig

Benzilla
04-27-06, 09:39 PM
No, no, that's a shade. It's like a visor over the headlights. My dad had them on his 64 Oldsmobile Dynamic 88.
Oh I thought he ment that only the outside lights are on, and not the ones more in the middle hehe. I've had the shields for so long I forget that other people don't have them.

CoupeDevilleRob
04-27-06, 09:39 PM
BTW where is CoupeDevilleRob when you need him? haha

Everything's OK, I'm here now. LOL. My car seems a little noisier than it should be to me, it's probably a combination of 23 year old motor mounts and one or two budding exhaust leaks. Oh yeah and 111,000 miles. It sounds nothing like an old pickup truck though. I can't see how a street race would make the car loud all of a sudden. Once in a while when I'm feeling nutty I'll floor it and watch the speedo needle slowly disappear past 85. Doing that never made my car louder. Maybe its just a weird coincidence that while you were racing that guy the muffler or a chunk of exhaust pipe blew out or something. I agree with 77 CDV though, a better description of the noise would help.

Benzilla
04-27-06, 09:42 PM
Ben,

Can you describe the noise? Where does it sound like it's coming from? Underhood, undercarriage, rear end? Does the car run smoothly? The 4.1 isn't known for being noisy, merely short-lived due to being horribly overworked in these 4500 lb beauties. More info, please.:)

Craig
The sound is coming from under the hood I think, it sounds like a big old 60s caddy with no muffler, not quite that loud, but thats how it is, really rumbly, like I said, kind of like an old pickup sounds. The car still runs smooth, just loud.

Benzilla
04-27-06, 09:46 PM
Once in a while when I'm feeling nutty I'll floor it and watch the speedo needle slowly disappear past 85.
You mean you can do that without it blowing up?!? I've just heard a lot of bad stuff about this engine, so I'm a little paranoid.

77CDV
04-27-06, 09:54 PM
Ben,

I'll take a flyer and say you've developed a leaky exhaust manifold. Probably the heavy back pressure from your improptu showdown, and it just keeps getting worse with time. Anyway, that's where I'd start looking.

Craig

Benzilla
04-27-06, 09:55 PM
That sounds bad... how do I tell if I have that? and how could it be fixed?

CoupeDevilleRob
04-27-06, 10:09 PM
You mean you can do that without it blowing up?!? I've just heard a lot of bad stuff about this engine, so I'm a little paranoid.

In the almost 5 years I've had the car I've only gone flat out maybe 3 times. It's not like I subject it to constant abuse. Running it to the eastern end of the speedometer once in awhile (meaning like once every year and a half) shouldn't hurt it. I've got some confidence in this engine, mine has been to hell and back and it's survived. I honestly think the tranny will go before the engine.

Exhaust manifold sounds like a good bet. Check the exhaust pipe near the flange too, maybe the leak is coming from there. If it is the manifold its probably going to be a nightmare to fix, like everything else on this car, but it can be done. Don't worry, I seriously doubt this is the end of the motor.

77CDV
04-27-06, 10:11 PM
Ben,

Anything can be fixed, it only requires $$$$$.:) It all depends where the leak is (assuming I'm right and there is a leak). If it's on the exhaust header, easy and cheap, just replace the header. If it's on the engine manifold, then it may be costly. I don't know if the manifold on the 4.1 is iron or aluminium. Iron welds easy and holds a weld well. Aluminium, not so much. But, the leak doesn't harm the car, it just sounds really bad and very annoying. Don't give up the ship yet!

Craig

Benzilla
04-27-06, 10:21 PM
If I had$$$$$ I would not be worried. right now I don't. any luck that it's just the muffler/exaust pipe?

Benzilla
04-27-06, 10:25 PM
I wish you guys could hear it, its not too loud, just loud enough to be annoying for a luxury car. my '90 Brougham in not nearly as noisy. thats what gave me a clue that theres something wrong.

77CDV
04-27-06, 10:40 PM
If I had$$$$$ I would not be worried. right now I don't. any luck that it's just the muffler/exaust pipe?

Ben,

It could be, but I'm going on what you had said about the noise sounding like it was from under the hood. Don't worry, the car is in no danger. I'm sure you'll get it squared away when you can.

Craig