What's wrong with my motor?

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DionR

DionR

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I have a 74 Duster with a 360 and since last fall when I got it running again, it has been making a huge rattling noise on the passenger side of the motor. It sounds more like a deseil tractor motor than a gas motor. I've replaced the lifters thinking it was lifter noise (which my brother agreed with after listening to it), and just recently I dropped the oil pan to check the windage tray, which was all fine. So far nothing has changed the noise.

The motor sat for a couple of years when my buddy owned it, but while it didn't have gaskets, it was buttoned up with heads, intakes and sheetmetal. I put it back together before dropping it in the car with the heads he had been running on the other motor he had in the car. The cam is the same one I put in the motor back in 92, but it all looked visually ok and probably only has 50,000 miles on it.

What I can tell is that it does not look like it is getting oil to the rockers. When I look down in the oil fill holes, the rocker is not filling with oil. So, it seems to me that the noise I am hearing is the lifters not pumping up because they aren't seeing any oil pressure.

When looking at how the oil passages run , it doesn't appear that the lifters on that side of the motor could be starved without the rest of the motor not seeing any pressure. Does that make sense? The oil pressure seems fine and the left side of the motor is quiet.

Would the rockers make a bunch of noise if they weren't getting oil, if the lifters are pumping up? I could see the passage being blocked to the rockers with a bad headgasket, but I'm not sure it would make the noise it is.

Any ideas?

This is the numbers matching block, so I'd rather not screw it up. Really don't want to pull it, but I'm running out of ideas.

Thanks.
 
is it a solid lifter motor? cuz solid lifters dn't give so valve springs start to get weak on those cyl making issues....
 
did you plug the exaust smog holes on the heads some times if your manifolds dont cover them holes on the 360 and it will sound like lifter are rocker arms clatering when its really one exaust leak i thank that they used them heads on alot of trucks and the truck exaust manifold would cover them holes but the car manifolds are headers wont
 
moparisbest said:
did you plug the exaust smog holes on the heads some times if your manifolds dont cover them holes on the 360 and it will sound like lifter are rocker arms clatering when its really one exaust leak i thank that they used them heads on alot of trucks and the truck exaust manifold would cover them holes but the car manifolds are headers wont
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The heads are early U heads, no smog holes. The manifold is an early 340 freeflow on the passenger side.

It is possible that it is an exhaust leak, but it sure makes a bunch of noise and the fact that I'm not seeing any oil filling up the rockers and running down the springs makes me think it is lack of oil flow.
 
sumbitmopar said:
Any chance one of the oil galley plugs was removed?
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I suppose it is possible, but I wouldn't think the motor would build any pressure at all then. If the one in the back of the block were missing, it would make a huge mess all over my clutch and drip all over the ground, but I know that isn't happening. I suppose the front one might be missing, but again, it seems like the oil pressure light wouldn't go out then. Are there any others?
 
Pull the dist, prelube while a buddy slowly turns the crank. At some point you should see oil.
 
Oil on one side and not the other?

Oil passage blockage?
Just simpley a worn out engine/oil pump?
 
rocker shafts oil holes need to be pointed down and towards the exhaust...

another thing...there are right and left rockers arms..if you are using stock rockers...

that does not mean right and left side of the engine...it means each cylinder has a right and left rockers
 
green1 said:
Pull the dist, prelube while a buddy slowly turns the crank. At some point you should see oil.
Click to expand...

Done that, before I started it the first time. I got oil on the drivers side, just figured I missed some hole lining up on the passenger side and buttoned it up. I was the one running the drill and turning the crank at the same time.

Either way, I'm looking at the rockers while it is running so I should see oil there, and I am not.
 
swinger 367 said:
is the rocker shaft installed properly?
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70aarcuda said:
rocker shafts oil holes need to be pointed down and towards the exhaust...

another thing...there are right and left rockers arms..if you are using stock rockers...

that does not mean right and left side of the engine...it means each cylinder has a right and left rockers
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Yep, I'm aware of that all of that.

But would lack of oil at the rockers, or incorrectly installed rocker arms/shafts, make enough noise to make it sound like a diesel? I wouldn't expect it to rattle so much if that was the only problem.

My gut tells me that for some reason, the right side of the motor is being starved and the lifters are not pumping up.
 
1wild&crazyguy said:
what yr bottom end?
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1wild&crazyguy said:
hope the cam bearings were installed correctly....
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Bottom end is factory 74 crank and rods. Motor was rebuilt back in 92 or 93 with rebuilder pistons (shooting for 9.5:1, got 8.2:1 :angry7: ), and I drove it as a daily driver up until about 2000 when I traded it to a buddy. He drove the car as a weekend toy with the same motor until around 2004 when he swapped a different shortblock into the car so he could stop worrying about the numbers matching block. I put the original shortblock back in when I got the car back last year. I think he might have had the cam out when he was swapping motors, but I know he was careful to match the lifters with the original lobes, so I don't think anything went wrong there. Even if, the car probably didn't have 10 minutes of run time before new lifters went in.

Thought about the cam bearings. Wouldn't make a difference on the lifters, but it would explain the lack of oil to the rockers. Just can't believe the rockers would make the motor rattle like it is, though.
 
Popped the valve cover off and ran the motor without it this weekend (after confirming that the shaft was installed correctly).

The rockers did fill up with oil, it just took a little bit of time. So, looks like oil is flowing to the rockers.
 
Maybe pistons are not installed correctly and the valves are hitting the pistons because the valve reliefs are not oriented correctly? If you get a Mechanics Stethoscope that can help you pin point the source of the noise. You can get one at Sears. And yes the passenger's side lifters and rear mean get oil before anything else.
 
340sFastback said:
Maybe pistons are not installed correctly and the valves are hitting the pistons because the valve reliefs are not oriented correctly?
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Short block has been together for about 17 years and has always run fine. Piston's didn't come out, and these are the same heads I had on the motor when I owned it the first time.

Used to have a stethoscope, need to track it down or get a new one.
 
Crap lifters? I just bought a set from Napa; 1st 2 would not pump up by hand.
Swapped them for same brand (ordered), they worked. Fed Mog
 
green1 said:
Crap lifters? I just bought a set from Napa; 1st 2 would not pump up by hand.
Swapped them for same brand (ordered), they worked. Fed Mog
Click to expand...

Possible. These came from Motion and were Sealed Power.
 
Going to revive this thread, but only because I never updated it after I found the issue.

No replies necessary, we can let it die for good now.

First thing I should have asked was "what did I change?". The answer - the timing chain. When I put the motor back together and dropped it in, I put a new timing chain on it since the old one seemed pretty loose. Any guesses as to what the noise was? That's right, because I mistimed the cam, all the intake valves were hitting the pistons. There was another thread where I fessed up to my mistake, if someone is curious they can go look for it.

Was looking for some of my old posts related to freeflows on Magnum heads and found this thread. Thought I should at least close it out with an update on what the problem was.
 
Glad you cleared it up!!

Let me guess....... crank key straight up..... top gear dot straight down.
 
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