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Discussion Starter · #1 ·
Yesterday I took the car for a little spin.
It had been parked for a week.
After startup there was a knocking sound present and a rough idle. The knocking stopped soon, the same for the rough idle.
I don't have any extra gages installed for oil pressure, the light does work though.
This will flicker during the rough idle.

Could the oil pump be worn?

Currently the stock M46 version is still present.

Thanks
 

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Assuming your oil level is good and not a real thin oil, I would try to hook up an oil pressure gauge to see if the pump is bad, there may be another way so hopefully someone that knows more will chime in soon.
 

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Discussion Starter · #4 · (Edited)
Yes the oil level is above the minimum, in the middle.
The oil used is 20/w50, this is thicker than it should be, but given I don't know much about the engine life and wear. so i heavier oil boost the pressure a bit.

I'll see to get an oil pressure gauge, this will have to be a direct one that plugs into the oil of the engine?

Thanks :)

edit

What kind of pressure readings would be OK?
I don't mind psi most gauges are dual :)
 

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Could it be that a lifter leaked down? Not sure of the sound of your "knock"-obviously- but that will cause a form of a knock and when it pumps up again- after a short time, the engine will smooth out and the knock will go bye-bye.
 

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Discussion Starter · #6 ·
That could be indeed.
Yes, accurately describing the sound is a though one.
The sounds lessens after some time.
The oil + filter have been replaces not to long ago, also the sump was cleaned out. all the old sediment has been removed.
 

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After reading your description of the problem, I agree with 57sc. Sounds like one or more of your valve litters bled down. Hopefully the problem won't continue.

Ray
 

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Yesterday I took the car for a little spin.
It had been parked for a week.
After startup there was a knocking sound present and a rough idle. The knocking stopped soon, the same for the rough idle.
I don't have any extra gages installed for oil pressure, the light does work though.
This will flicker during the rough idle.

Could the oil pump be worn?

Currently the stock M46 version is still present.

Thanks
Check out the rockers first but look to see if the oil pump is the problem. Put a long stick on the block near the bell housing and hold it close to your ear to see if it is coming fom that area. It's an old guys trick and I'm old.
 

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Could it be that a lifter leaked down? Not sure of the sound of your "knock"-obviously- but that will cause a form of a knock and when it pumps up again- after a short time, the engine will smooth out and the knock will go bye-bye.
That would explain the running rough.
 

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Discussion Starter · #10 ·
Check out the rockers first but look to see if the oil pump is the problem. Put a long stick on the block near the bell housing and hold it close to your ear to see if it is coming from that area. It's an old guys trick and I'm old.
Thanks :)
Do you mean this area?

Should be easy to check.


On the lifters.
How are these to be checked?
I could put some engine cleaner in the oil and see if this helps.
An oil change is due anyhow.
I have been reading about adding ATF oil, but don't understand the details about it.

If the lifters are bad it might be an idea to change all 16 of them.
The timing chain + gears are also of unknown condition.
There are some nice kits available on ebay.
this one for example.
Since the 283 is only a small engine a small cam should work out ok.
 

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Yes the oil level is above the minimum, in the middle.
The oil used is 20/w50, this is thicker than it should be, but given I don't know much about the engine life and wear. so i heavier oil boost the pressure a bit.

Just wondering why 20/50 , Try thinner oil as in 10/40 or ? as in knock, not good, sounds like a tear down is comming, :anim_25:
 

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Discussion Starter · #12 · (Edited)
The idea behind 20/50 is this.
I don't know the mileage on the engine.
It was assumed that through age the bearing clearances have loosened. So the engine will loose more oil pressure here.
The thicker oil should compensate for this.
The oil it self was advised to me for this reason.

Today I took another spin, no knocking during start up.
But very hard starting and a lot of blue smoke!
Completely flooded.
Usually I have to pump the accelerator a few times to prime it extra.
Works fine starts up just fine than.
Today it didn't :(

A tear down would be bad news, just spend my budged on a new transmission.
While driving all is well, no smoke at all.

Here is a short film from the startup, finally i pulled the air filter of and floored it. It would start with quite some blue smoke, not black as expected form a flooded engine.
startup

Here is another film after a nice long trip in the hills.
It dark, but the sound is audible.
after the trip
There is a slight knocking, very little.
The timing has been checked and is ok, the fuel is regular 95 octane.
 

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It certainly could be lifters since it cleared up, a crank or rod bearing would get worse as the oil/engine heat up. . You might try a lighter oil like a 10-30, the heavy oil could be the cause as it is harder to "pump-up" the lifters when it's cold. I agree install an oil pres. gauge.
 

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My '66 283 engine made the same kind of noise last year when I had 20W-50 oil in it. Changed to 10W-30 oil and the sound went away.

It's an easy and cheap thing to try.
 

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Discussion Starter · #15 ·
OK, thanks for the advice :)

The gauge will be a few days before I have a good one.
Is the thread in the block is 1/8" NPT ?
The oil change is for this weekend I think.
Is there a specific type of 10/w30 oil to use?
Like fully synthetic / semi synthetic or all "natural" oil.
 

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I use an ordinary mineral oil.
 

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After looking at the start up I would have assumed thats it was a carby flooding. The knocking noise would not make it hard to fire up.
I would check the plugs making sure that there not fouled up & or wet. Check the timing sounds like the motor isnt reved up enough in park. The points gap could also effect the timing. :anim_25: keep us posted
 

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Discussion Starter · #18 ·
The startup indeed was messy.
It usually doesn't do that.
The spark plugs have been changed about a month ago (100 mls) The ignition also had a tuneup, new point and readjusted @4 deg. The car ran fine after that.
One thing i did remember.
In this oil also a bottle of additive was used especially for high mileage engines. The next oil change will be without this stuff. Later I read that it thicken the oil a bit.
 

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After looking at the start up I would have assumed thats it was a carby flooding. The knocking noise would not make it hard to fire up.
I would check the plugs making sure that there not fouled up & or wet. Check the timing sounds like the motor isnt reved up enough in park. The points gap could also effect the timing. :anim_25: keep us posted
^
!
!
:congrats:

I would look for timing, including plugs, and flooding, CARB! Regardless of just beeing done, But if money is tight, you could skip this step for now

I'd install a preassure gauge AND THEN, AND ONLY THEN, Would I change the oil to a different viscosity, Start And check preasure cold and hot, then, if too high cold I'd decide the viscosity to use.
:anim_25:
 

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Dry knock? I couldn't hear any worrisome knock when I looked at your video, but maybe my ears aren't what they used to be. All cars should have a gauge installed.

One possibility for your knock at startup could be what we used to call "dry knock", on worn engines with wide bearing clearances. After an engine has set for considerable time, much of the oil drains back into the sump, away from the bearings and oil passages. When you start up, the bearing may knock until the oil gets there. I once had a Ford with this problem. I continued to drive it daily for several years and the last I heard, it had 225000 miles and was still reliable.

With 20W-50 oil on a cool day, after the engine has set for a week, it may take a little while for the oil to get where it needs to be. That could also pose issues for hydraulic lifters too. They need oil pressure to work properly, which may explain your rough running prior to oil pressure buildup, especially if your engine starts quickly.

If "dry knock" is your problem, that isn't good, but it may not be catastrophic either.
In my opinion, for most cases 20W-50 is too thick until it gets warmed up. I understand that if your bearing clearances are wide, you may not have much choice.
I used to run heavy oils like 20W-50. Over the years I've come to prefer thin oil like 5W-30 or 10W-30, but plenty of it from a high volume pump. In my opinion, 20W-50 is for old air cooled Triumphs and Harleys.
 
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