: Is my 472 running ok?



CADforce69
07-27-11, 07:14 PM
Hello guys,

now that I can drive my 69 caddy after some fixings, tuning and repairs, I can check if it runs as it should in different circumstances. One problem it has is a manifold leak in the right hand side. At idle is just a "click-click" noise that disappears when you rev engine up while car is stopped. When the car is running, it increases noticeably if you step on the accelerator determinedly to climb a steep hill or increasing speed. At these moments, sometimes I can smell of gasoline in the passenger compartment. On the other hand idle is very regular in every moment.

A friend of mine, who is a mechanic (but who is not familiar with these cars but European models), has the opinion that one cylinder does not work well, so I decided taking out plugs to see if I could find some sign of bad combustion in any of them. The result is that all of them except one showed a light gray tone. The other one (front right) showed a dark gray color but not excessive. Back right one was somewhat loose but I think now its ok (See pics below).

After that I made a mild performance test, filming a video to share with you all in order to get your opinion, as I confess that Im not very familiar with V8 engines -Im just starting my learning-. This is the video: http://www.youtube.com/watch?v=WQSm_sm-YkU (A/C belts squeals sometimes at high RPM; I think I have to tighten them). In these tests from inside and outside I stepped accelerator down to floor; curiously, I hardly smelled of gas at these moments. Speedometer is in kilometers. 60 mph = 96 kph.

Well gents, What do you think?

Plug pics:
Passenger side, back to front:
http://s3.postimage.org/wnr6mymxo/IMG_1068.jpg (http://postimage.org/image/r9r6oy6c/full/)

http://s3.postimage.org/wnr8ahzfq/IMG_1067.jpg (http://postimage.org/image/r9su8ao4/full/)

http://s3.postimage.org/t45c88980/IMG_1066.jpg (http://postimage.org/image/r9uhrn5w/full/)
This is the dark one:
http://s3.postimage.org/t45fjay7u/IMG_1063.jpg (http://postimage.org/image/r9xsuc5g/full/)
Driver side, back to front:
http://s3.postimage.org/pkjms3wzo/IMG_1062.jpg (http://postimage.org/image/ra2rgdms/full/)

http://s3.postimage.org/pkjq36lzi/IMG_1061.jpg (http://postimage.org/image/ra62j2mc/full/)

http://s3.postimage.org/wnrn6c3x4/IMG_1060.jpg (http://postimage.org/image/ra7q2f44/full/)

http://s3.postimage.org/be446kcmk/IMG_1059.jpg (http://postimage.org/image/rab1543o/full/)


gif upload (http://www.postimage.org/)

Theyre Autolite; when I bought them did not know AC Delco are best for these cars.

77CDV
07-27-11, 08:17 PM
Looks like normal combustion residue, nothing out of the ordinary. If you had a cylinder misfire, the engine would be unbalanced and the car would vibrate at idle. Other than the minor exhaust leak you mentioned, the engine sounds healthy. As far as the intermittent gas smell, check all fuel lines, especially at the fuel pump and fuel filter at the carb. Also, check the gaskets between the carb and the engine block. Finally, make sure the carb is properly adjusted so that it's not dumping gas under full throttle.

csbuckn
07-27-11, 09:13 PM
So did the smell and tic go away after you put the plugs back or just the smell? Just thinking the loose plug caused the issue.

outsider
07-27-11, 10:54 PM
I don't think these cars have a filter at the carb. the factory service manual only shows one in the fuel pump.

CADforce69
07-28-11, 06:47 AM
Looks like normal combustion residue, nothing out of the ordinary. If you had a cylinder misfire, the engine would be unbalanced and the car would vibrate at idle. Other than the minor exhaust leak you mentioned, the engine sounds healthy. As far as the intermittent gas smell, check all fuel lines, especially at the fuel pump and fuel filter at the carb. Also, check the gaskets between the carb and the engine block. Finally, make sure the carb is properly adjusted so that it's not dumping gas under full throttle.

In fact, in decided (not top) acceleration I noticed a slight vibration. But in these top accelerations I felt engine balanced. Dont know if slightly loose plug had something to do with this. Combustion signs in that spark plug seemed normal. Ill check if gas smell happens again and in that case Ill check what you mention.

CADforce69
07-28-11, 06:53 AM
So did the smell and tic go away after you put the plugs back or just the smell? Just thinking the loose plug caused the issue.

Its the smell who did not appear (at least noticeably). Tic is still there, as it comes from the manifold leak. One bolt fastening it to engine is broken and at least another one stuck. Well try fix it by a special filling paste with metallic components.

Maybe youre right about smell. Ill watch this in my next ride.

Sponson
07-28-11, 09:08 PM
Sounds like lifter/valve tap.