Any Pontiac guys on here? Need insight.

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plymouth67 said:
You sir may be on to something. The first thing I noticed when I popped the intake off is how much offset the cam has compared to the lifters. I know the lifters don't run on the center of the lobes but, this seams extreme to me. The other thing was the end of the oil pump drive rod has some scoring on it so, I wonder if the cam is so far deep in the block that it's pushing on the distributor so hard that the drive rod was actually rubbing the block where it slides down to the the oil pump. The drive rod also has a couple gouges where the distributor shaft key locks into the rod maybe, as if the cam is so deep he had a hell of a time getting distributor in and he laid the wood to it. I also want to add that the first few times we started it the noise was not immediate, the engine would run 5 to 10 seconds then the noise would come in.

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Your photo of the shaft shows heavy scoring on the shaft. Note the smooth diameter of the last quarter inch. Also note the gob of metal stuck in the hole of the next larger diameter. This would cause noise.

Your first picture of #42 shows a casting defect resulting in a paper thin [and cracked] piece of metal. This may have caused the original problem?

good luck.
 
Cut the oil filter open and see what is in there for metal?

Magnet on the paper element helps pick up the steel.
 
Check the oil pressure psi. Pontiacs are known to throw rods.

Bad rod bearing going low on oil? Mains too if low oil pressure.
 
pt70 said:
Your photo of the shaft shows heavy scoring on the shaft. Note the smooth diameter of the last quarter inch. Also note the gob of metal stuck in the hole of the next larger diameter. This would cause noise.

Your first picture of #42 shows a casting defect resulting in a paper thin [and cracked] piece of metal. This may have caused the original problem?

good luck.
Click to expand...
The scoring on the shaft is definitely a red flag when I pulled it out. On the next biggest diameter is not a gob of metal in it, these are tabs that help from letting the shaft pop up through the hole. The Pontiac motors have these as the theory is to put the drive rod in the oil pump and then install the pump. Those tabs are supposed to keep it from moving up out of the hole once it's assembled, most people grind them off and feed the rod down from the top side.

The spot in the block where the casting is broke looks to have been that way for a long time so, I'm not thinking it has caused any of this but, ya never know.

I'm waiting on an oil pump primer rod to show up so I can run the pump just to see if it's quiet and check the volume of oil getting to everything. I'm also going check the alignment of the distributor to the camshaft. I wonder if the camshaft is not sitting in the motor correctly. I wonder if the camshaft is sitting too far towards the rear of the motor pushing so hard on the distributor that it has pushed the shaft on the distributor back causing a misalignment of the pump drive rod causing it to rub the block but, at this point anything is on the table.
 
Found this if it helps.

Pontiac 400 oilpump shaft and clearance​

 
So circling back to post one where it was said that it had an electrical problem.. And then you said you got it running after five or six years...
Was it an electrical problem? And what did you do exactly to get it running again?...
Just trying to get back to making this simple if possible...
 
j par said:
So circling back to post one where it was said that it had an electrical problem.. And then you said you got it running after five or six years...
Was it an electrical problem? And what did you do exactly to get it running again?...
Just trying to get back to making this simple if possible...
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Yes, the main battery ground was very intermittent at best. He had been trying to figure it out so, there was all kinds of wiring unhooked and moved around when I got it. I just moved the ground to a better spot then, traced down wires and put them back in their proper places and we had power everywhere.

He had been turning over with a breaker bar about once a month and he had put a little oil in the cylinders at one point. I did not start it immediately. We cranked it over a bit with no ignition source hooked before it was started. To add a bit to this story as I talked with him yesterday, he told me that his wife heard the noise the day he pulled in the garage and, asked him what that noise was in which he replied I don't know, didn't hear anything. This just now came to him as he never heard it as, with the hood down and inside the car its faint. She heard that day and, I have a very short video of it so, she heard it again and it jogged her memory of hearing it that day. So, it did make this noise on its last ride but, I don't think it was doing it before that.
 
The scruffy intermediate shaft is common for an original shaft. The noise? Maybe it's not the engine, maybe it's the transmission and just transferring the noise up.
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plymouth67 said:
Yes, the main battery ground was very intermittent at best. He had been trying to figure it out so, there was all kinds of wiring unhooked and moved around when I got it. I just moved the ground to a better spot then, traced down wires and put them back in their proper places and we had power everywhere.

He had been turning over with a breaker bar about once a month and he had put a little oil in the cylinders at one point. I did not start it immediately. We cranked it over a bit with no ignition source hooked before it was started. To add a bit to this story as I talked with him yesterday, he told me that his wife heard the noise the day he pulled in the garage and, asked him what that noise was in which he replied I don't know, didn't hear anything. This just now came to him as he never heard it as, with the hood down and inside the car its faint. She heard that day and, I have a very short video of it so, she heard it again and it jogged her memory of hearing it that day. So, it did make this noise on its last ride but, I don't think it was doing it before that.
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Only heard from the front of the car, not heard inside the cabin. Likely coming from the front of the engine…

The intermediate shaft is a red herring.

Just open the timing chain cover and inspect the timing chain and gears. Nothing to lose but a bit of labor and a couple of gaskets.

If it isn’t that, one less thing on the list of what it might be.

If it is that, problem solved.
 
The spark jumping from a damaged hei to the ignition rotor can make noise similar to arc welding.
Gear drive eh ?
Agree shaft is red herring.
 
Max1196 said:
The scruffy intermediate shaft is common for an original shaft. The noise? Maybe it's not the engine, maybe it's the transmission and just transferring the noise up.
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Even though you just burst my bubble...lol..I want to thank you for that tid bit of info on the scoring on the pump drive rod. I'm sure it's motor related. I worked in a trans shop for several years in my younger days and I believe it's not coming from the trans.
 
plymouth67 said:
Yes, the main battery ground was very intermittent at best. He had been trying to figure it out so, there was all kinds of wiring unhooked and moved around when I got it. I just moved the ground to a better spot then, traced down wires and put them back in their proper places and we had power everywhere.

He had been turning over with a breaker bar about once a month and he had put a little oil in the cylinders at one point. I did not start it immediately. We cranked it over a bit with no ignition source hooked before it was started. To add a bit to this story as I talked with him yesterday, he told me that his wife heard the noise the day he pulled in the garage and, asked him what that noise was in which he replied I don't know, didn't hear anything. This just now came to him as he never heard it as, with the hood down and inside the car its faint. She heard that day and, I have a very short video of it so, she heard it again and it jogged her memory of hearing it that day. So, it did make this noise on its last ride but, I don't think it was doing it before that.
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Thank you for that, and I'm glad we re asked the question. Is it something that didn't develop under your tender...
I remember seeing someone saying or showing a scope Of some sort or a piece of rubber hose up to your ear touching around areas...
I know these engines have a tendency to run very hot and possibly getting something with tight clarences to start rubbing or the opposite, Once it warms up, it stops making the noise...
It sounds like opening up the front is going to be close to the final frontier... You don't feel it's coming from the back by the tranny, and it's not a low end noise. You've taken off the top and the only thing left is....
 
j par said:
Thank you for that, and I'm glad we re asked the question. Is it something that didn't develop under your tender...
I remember seeing someone saying or showing a scope Of some sort or a piece of rubber hose up to your ear touching around areas...
I know these engines have a tendency to run very hot and possibly getting something with tight clarences to start rubbing or the opposite, Once it warms up, it stops making the noise...
It sounds like opening up the front is going to be close to the final frontier... You don't feel it's coming from the back by the tranny, and it's not a low end noise. You've taken off the top and the only thing left is....
Click to expand...
Yes, I feel the front of the motor will be the next stop on the tour of DaPontiac...lol
 
plymouth67 said:
, I have a very short video of it so, she heard it again and it jogged her memory of hearing it that day. So, it did make this noise on its last ride but, I don't think it was doing it before that.
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Post the video...
 
I wanna see that '68 get fixed and hopefully see a video of it running no noise....
 
timing gear backing into front of the block.... been years since i messed with pancho power but pulled front off one years ago put a new gear and chain in it, customer came to get it and was setting in it talking to boss when oil pressure went to 0, ended up oil pump dropped the drive shaft, pulling oil pan on a 6.6 in a 78 trans am ant no more fun than pulling timing cover off! has notta thing to do with your issue that i can see,..just how i fillled my evenings one week back in 10th grade,..was real happy to go back to wrenching on big trucks!!
 
Did the sound change from idle to acceleration? Maybe I missed you mentioning that.
 
1WildRT said:
Post the video...
Click to expand...
The problem with the video is there are a couple different noises going on that would be hard to know the difference between the one I'm talking about and it's only like 12 seconds long and I'm standing at the back of the car.
 
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