1984 Porsche 911 Euro Engine Noise

[911 Euro]

I have bought this car recently and after watching videos of other 3.2 engines running i am hearing a low noise towards the front of the motor that doesn’t sound normal. Here is a video let me know what you think.

https://youtu.be/7O5r2Cu5yQc

[Marc718B]

Do you mean that rattle noise? Could it be the air box clips are loose on the back (front - that you cant see from the back)?


Sent from my iPad using Tapatalk

[Bill Douglas]

Also you could remove that air con belt so there is less going on. Nice clean looking engine, I wouldn't assume the worst.

It's not the oil getting dumped back in the oil tank is it?

[proporsche]

sounds like from you AFM air flow meter .What is that spacer doing there?
Between the AFM and the filter housing.I would look there for loose bolts which holds the filter body to AFM...also get your self an original S shape bracket which holds it down to the intake manifold...(the black one)

Ivan
here is mine and you can see no spacer, it does not belong there
https://www.youtube.com/watch?v=Out_PKGkYYY

[911 Euro]

Originally Posted by Bill Douglas

Also you could remove that air con belt so there is less going on. Nice clean looking engine, I wouldn't assume the worst.

It's not the oil getting dumped back in the oil tank is it?

It does sound like a gurgling sound. This is my first porsche. Is it normal to here the oil going back and forth?

[da Vinci Dan]

I hear a low tone “gargling” noise. Was the engine warm in the video? Like others, it sounds like something is loose. AC clutch bearings? Motor mounts? Take off the AC belt, bring it up to temp and re-shoot video.

[da Vinci Dan]

Just listened a few more times. I now remember that sound from loose muffler straps causing the muffler to shake. Look under the car between the rear bumper and the motor. There should be two metal straps about an inch thick each wrapping around the muffler. An original one is pictured below.

That’s my bet!

[proporsche]

Also, if you are talking about the deep rumbling sound , that is your alternator.The bearings are a little loose ,check your belt if it is tight.What do you have the idle set up at?What RPM?

Ivan

[911 Euro]

Originally Posted by da Vinci Dan

I hear a low tone “gargling” noise. Was the engine warm in the video? Like others, it sounds like something is loose. AC clutch bearings? Motor mounts? Take off the AC belt, bring it up to temp and re-shoot video.

I will take the ac belt off later. I’m involve in another painful project right now. Lol

[proporsche]

it has nothing to do with the A/C ...or engine mounts...as i said ,your alternator bearings are loose .........possibly idle is too low...plus loose alt.belt
Ivan

[911 Euro]

Originally Posted by proporsche

it has nothing to do with the A/C ...or engine mounts...as i said ,your alternator bearings are loose .........possibly idle is too low...plus loose alt.belt
Ivan

Thank you. I will take the alt belt off and start it briefly to see if the noise goes away. I will take the ac belt off also while I’m there.

[proporsche]

once you remove the alt.belt check for play..but i would not worry too much..just adjust the alt.belt after correctly..those bearings get loose by time and if the idle is too low or you have the belt loose that is what you hear....what is your idle RPM?
Ivan

[911 Euro]

Originally Posted by proporsche

once you remove the alt.belt check for play..but i would not worry too much..just adjust the alt.belt after correctly..those bearings get loose by time and if the idle is too low or you have the belt loose that is what you hear....what is your idle RPM?
Ivan

The idle is between 850 and 900 when warm. When cold it is at 1000.

[proporsche]

that is fine just take the belt off..make sure you have 6 shims for the adjustments no less no more it is very important...look here.Check the alt.shaft for play and again it will be there but not to worry too much.Also remove the filter and look if all 4 bolts are there which hold the black plastic filter housing to the Air Flow meter.Use a mirror.



bolts 10mm head are from inside the behind the filter....

[Bill Douglas]

Originally Posted by 911 Euro

It does sound like a gurgling sound. This is my first porsche. Is it normal to here the oil going back and forth?

Yes, I got a surprise when I first got my 911. It comes back into the oil tank at the top and has quite a drop before it reaches the rest of the oil. Plus it pumps quite a quantity around. You could take the cap off and listen closely. It would be nice if this is all it is.

[911 Euro]

Originally Posted by proporsche

Also, if you are talking about the deep rumbling sound , that is your alternator.The bearings are a little loose ,check your belt if it is tight.What do you have the idle set up at?What RPM?

Ivan

I am talking about the deep rumbling sound. I wasn’t sure anyone could hear it on the video. I haven’t had a chance to remove the belt on the alternator yet. I will try that later.

[proporsche]

i can hear the sound ..it comes from the alt...............i also hear the clicking sound when you go with your phone towards the Air Flow meter....as i pointed above;-)
Ivan

[RMartinez]

Interesting - I also have an 84 Euro Coupe - engine at idle makes the exact same kind of sound. I have replaced the alternator, tightened and double checked everything listed above and more. It still makes the same noise. Engine runs strong, no oil consumption, compression test 150+ all cylinders, leak down 3-5% across the board. I have put 4K miles on the car with no issues. I stopped worrying about it...

[911 Euro]

Originally Posted by RMartinez

Interesting - I also have an 84 Euro Coupe - engine at idle makes the exact same kind of sound. I have replaced the alternator, tightened and double checked everything listed above and more. It still makes the same noise. Engine runs strong, no oil consumption, compression test 150+ all cylinders, leak down 3-5% across the board. I have put 4K miles on the car with no issues. I stopped worrying about it...

That is good to know. I am still going to go through the paces and see if i can track it down. The only noise I’m worried about is the low grumble noise. See if i can track it down this weekend.

[Dave Kost]

Get a stethoscope or a 3 foot piece of hose to your ear, and carefully move over the engine until you find the noise.

Careful around the belts.