MDchanic

Yeah, with good suspension components and tires, and a reasonably tall rear, these things will cruise right along.

- Eric

Seff

2.56 posi and full FE2, that's all.

MDchanic

That's all you need !

Miles71

Still waiting for new tires to arrive.
The last time I had my 71 Supreme on open highway, my 2.73 (non-posi) and 180HP would top out at 115 MPH. The RPM was in the 4k range. The tire flats spots seemed to smooth out at speeds above 80 MPH.
How did yours feel at 125 MPH.

Movie Quote, Top Gun: “I feel the need for Speed”.

Seff

Windy, but like it was flying. The aforementioned vibrations were completely gone.

Just looked at your picture, man she's shiny and nice. o.O

rustyroger

I think Opel Corsa wiper blades fit straight in.
If not just measure them and get a pair the correct length. In the UK we have a better American parts supply than a lot of Europe, but often European parts like trim clips, wiper blades, bulbs etc are identical to American ones.
Wiper blades don't know what car they are fitted to, they either fit the arm or not.

Roger.

Seff

I found out the Mercedes GD series wipers we have in the army are a direct fit, so I acquired a pair of those.

Seff

Today I had a recurring vibration while holding her on the brake, waiting at a red light. It would vibrate/hum 3/4 of the time, then be silent 1/4 of the time, then vibrate again. It's very pronounced up through the floor and seat, making my knees shake. Engine was hot enough to yield plenty of hot air for the heater. I didn't have the heater on when I noticed the vibrations, though.

I noticed the same at high speed on the way to base Sunday, so I put her on a ramp and tightened her engine mounts, thinking that was the problem. No change.

I'm thinking either exhaust being leaky somehow, leading to uneven pressure and thus shakes, or my spark plug wires touching, leading to too weak a spark on one cylinder. Driveshaft and wheel balance are out of the question on this one.

----

Second problem: Steering squeaks when I hit full lock, and has begun squeaking at other times too. Loose pump belt? Ball joints looked good when I put the car together; I read that checking them is easiest by changing from reverse to drive with the brake down, and listening for clonks from the front end?

----

Third problem: Shifter light flickers. I suspect a corroded bulb attacher-cup-thing-I-can't-remember-the-term-for. That doesn't explain why the dome and quarter lights come on when I brake hard or swerve noticeably, though.

Miles71

Dome Light:
The dome light problem could be something simple as a bad door pin switch.
If the switch or wire is touching a ground, it will cause the lights to come on. Unscrew each door switch and unplug wire and tape it to prevent it from grounding. Then go for a test drive. If it still comes on, keep searching for a loose wiring in the harness that is shorting.

Power Steering Squeak:
A squeak while at full lock stop is normal. Squeak while normal driving means loose belt. Search classic olds for proper tips on tighten the belt (do not pull on the fluid reservoir, it will break off). The belt deflection should be approximately ˝ inch.

Engine Vibration:
Interesting. While stopped, with foot on break, engine idling at 600-700 RPM? It’s not the propeller shaft and not the Rear-end, and most likely not the Transmission. I am not an expert here, but the next time you change your oil, look closely for unexpected sludge (bearing parts) in the oil.

PS:
I finally replaced my 15 year old tires with new set of Radial T/A’s. Most of my vibration problems have been solved and the AM radio no longer rattles at 65 MPH.

Seff

Tires are the solution 80% of the time.

MDchanic

A vibration at idle with foot on brake makes me wonder about whether the brake booster has a vacuum leak when applied.
Checking vacuum with the brake applied and not applied should clear that up (The vacuum may dip for a second when you push in the pedal, as the booster takes a gulp, but should go right back to normal once it's "full").

- Eric

Seff

The vibration was also evident when going 70 MPH, foot very much NOT on the brake. :P But, I'll check.

Notable here is that the vibration wasn't significantly different at 70 MPH than at a standstill.

Miles71

Is the vibration related to Engine speed?
If the car is vibrating can you shift into neutral (safely) and see how it changes.
I think we can eliminate the Suspension system since the vibration happens while stopped.
Does the vibration come and go like a bad bearing?
Check for loose or missing exhaust system hangers.

Seff

I tightened my exhaust and my spark plugs (have had them come loose back in the day) today, the shake got better, but still noticeable. Neutral has higher RPM and thus less shake, but that was at a standstill. Will check at speed on Friday.

What I HAD set forth to do and forgot in the darkness and coldness was to tighten my tranny mounts, as a loose tranny mount would transfer engine vibrations at any RPM and whether the car is driving or standing still, yes?

jfb

hey buddy congrads on the ride and it will take dedication to finish. I want to suggest that you check your coolant level and carpet for a coolant smell also. I think unless you have a leak otherwise that your heater core might be leaking.check level and the smell of the carpet for diagnosing. The heater core is behind your glove box in a black plastic box the rest is self explanatory. You stated that your carpet was wet before check it for piece of mind.

Seff

My carpets have been dry ever since I reglued the front windshield and the screw holes for the lower front windshield chrome strip. I'm checking them religiously every time I get into the car at this point, since they used to be wet all the time.

Now that we're talking coolant and checking the level - there is supposed to be a "index when cold" mark, yes? I can't for the life of me find it. Anyone know where it is?

Miles71

A loose transmission mount could cause loud floor banging while idling.
A shaking engine can be caused by 1 or more misfiring cylinders. If you are at idle and running on 7 cylinders, the engine will shake but will still run. As you accelerate it will shake a bit faster and sort of smooth out at highway speeds. My 4 door cutlass had 1 bent intake valve on the # 5 Cylinder. I could not afford to fix it so I remove the intake push rod, readjusted the carb and drove the car for a year on 7 cylinders. It shook bad starting from a stop, but was ok after that.

Seff

Would it cause floor banging if it wasn't loose enough to hit the floor?

Misfire was the reason I checked the plugs. Wanted to make sure they were in tight and all the wires were on right. I had my plug wires routed badly when I started driving the car and had the steering column rip the nr 7 wire off the plug, the shaking was a lot more 'rough' than this is.

Miles71

Hi Seff: I am running out of suggestions. Let’s hope some of the more experienced engineers can help.

Any more details on the vibration / banging?
How bad is it at Idle stopped, more details.
Does it get much worse when you accelerate from a stop?
What is it like at a constant highway speed on a smooth road?
Does the engine seem like its running smoothly throughout the normal RPM Range?

Do you have a Digital RPM gauges for testing. If so, check your Idle RPM (park). Let’s assume 750 RPM is your normal Idle (warm engine). You will see a small amount of RPM drift while idling. If you see big changes in your idle RPM then you have some type of miss-firing problem. On my 71 stock I will see a drift between 725-775 with my goal value of 750 in the middle. Approximately less than a 25 RPM drift above and below my goal of 750. This is what I consider to be normal while watching over a few minutes.
When I saw 50 RPM drops randomly, it told me I had a problem which turned out to be a bad gap on 1 plug.



https://classicoldsmobile.com/forums...sitates-3.html

Seff

I have nothing to test my RPM. I have considered getting any kind of tach that fits in my car, just so I have one.

Miles71

I was able to find a Digital Volt Meter with built in Tac at a local Car parts store. The price was less than $50 US. If you can borrow a friends analog or any Tac that would also help you fine tune your Idle, etc.
I also installed a cheap Dash Tac too. Some day if i win the Lotto, ill get a rally pack.

Good luck.
M

Seff

I'd go for a tic toc tach, but they're expensive as well.

White_Knuckles

We used to make our own tachs outta wood.

Keep chasin' that monster Seff!

MDchanic

... And seashells.

- Eric

Miles71

Radiator Fill Mark:
There is a hard to see fill marker on the stock radiator. On my 71 Cutlass, the marking is below the top transmission cooling line “FILL COLD”, with an Arrow pointing to the top of the tank rib. It is very hard to see. Fortunately I was able to get a good picture of the markings. (image 8099)

Ignition Cables:
My car came with ignition cable clips(not sure if they are factory) that help keep the wires neat and prevents cables from catching on the steering column. Here is an image of my driver’s side cables. I have three clips/spacers to support the cables. None of the cables come in contact with the steering shaft or Hot parts. (image 8095

Temporary Tachometer:
It’s held in place with nylon tie-wraps. It’s not accurate enough for engine tuning, however it’s close enough to see any major issues. I use a digital tach for engine tuning. During shows, I can easily remove the Tach and tape it up under the dash out of site of the judges. (image 8092)

Seff

Gotcha on the fill mark and wire clamps, got both issues under control now.

I've considered finding a junkyard and simply fishing a suitable tach.

Seff

Tire shop couldn't balance my crooked-*** rear tires. The subject has been taken up here.