LA318 problems

[patrick66]

It's not in a C-body, but in my '68 D100 pickup with automatic. I just finished the lowering job on it last month (Sid's dropped 3" stock axle, along with a 5" dropped rear with modified rear shackle mounts). Engine is a bone-friggin'-stock 2-bbl with original everything - exhaust, carb, points distributor. I fired it up and had a slow time getting the lifters pumped up. There was 60 lbs of oil pressure at this time. I added Seafoam and removed the valve covers. I changed the filter to a WIX 51515, and added a quart of 10W30 oil. I started the truck and the lifters were pumping away, with plenty of oil now reaching the rockers. The rattles went away, and it sounded pretty good. Reattached the valve covers and let the truck sit for an hour. Started it back up, and it sounded like ****!!! It has some major noises coming from the front of the cam gallery! I figured I'd bent a pushrod or three, so I left it alone for a few days.

On Sunday, I removed the rocker assemblies and the pushrods - I have 16 perfectly straight pushrods! So, where else might the noises be coming from??? A couple of dead lifters is all I can think of right now. It holds 65# of pressure cold, then about 40# as the engine warms up. It now started popping back occasionally through the exhaust, which it was not doing before. The truck had sat for a little over a year as I was doing the suspension mods. It ran beautifully beforehand!

So, before I remove the intake to check the cam and lifters, anyone have any ideas what's up?

 

[commando1]

You need a stethoscope to better pinpoint the origin of the noise.

 

[patrick66]

It's in the front, up high, so that pretty much isolates it to the lifters, cam or cam bearings.

 

[MrMoparCHP]

You need a stethoscope to better pinpoint the origin of the noise.

Just take you longest screwdriver, place the end of the handle against your forehead while you poke the other end around.

Alan

 

[Wollfen]

Just take you longest screwdriver, place the end of the handle against your forehead while you poke the other end around.

Alan

Is this the right way round?

 

[MrMoparCHP]

Is this the right way round?

uh, no.


Alan

 

[commando1]

LMAO. The face was concealed to protect the stupid.

Posted via Topify using Android

 

[patrick66]

A little help, here, guys...stay focused...my engine problem...I realize that many are easily distracted by bright, shiny objects...focus...focus...

 

[Wollfen]

On a serious note, now that you have the pushrods out use that extra long screwdriver or similar object to press down on each of the forward lifters and see if you feel a sponginess or springiness when you press down, if so, they aren't getting oil. That could point to a clogged oil gallery. If they feel solid with no give at all, that means they are still fully pumped up , next you would have to check to see if the cam lobes are getting oil.

 

[Dale Michaels]

The noisy lifters could be from lack of oil from sitting,,not sure if the LA and the BB motors share the same oiling,on a BB the cam berrings have oil holes and the oil preasure is kind of timed to reach the top end espically on a new build,,that's why priming is important,,now your engine runs even worse popping through the exhaust and a louder noise in the front of the motor I would guess the timing chain cam gear is toast since you didn't mention a rebuilt motor,,you could put a timing light on it and watch for your timing mark bouncing around or pull the dist cap and rotate the motor back and forth and watch the rotor movement,,,on almost every old MOPAR I have ever owned the first thing I do is replace the timing chain setup and 8 out of 10 times it's ready to go bad or is bad already,

 

[Big_John]

Cam sprocket and timing chain is my bet.

 

[patrick66]

I checked the lifters this evening, and they do not appear to be the problem...they have not collapsed, and I did not have any bent pushrods or broken rocker arms. I'm going to reinstall the pushrods and rockers tomorrow, restart it, and see what noises it makes again. I'm thinking now as you guys are, that the cam sprocket may have gone away and the noises I was hearing is the chain slapping against the front cover. This would also explain the popping back through the exhaust, with the cam timing going all to hell while it's running. As there is also very good oil pressure, this eliminates the possibility of spun cam bearings. At least, on this 318, everything up front is easy to access in the truck, and a timing set replacement is pretty straightforward. I would not be at all surprised if the truck still has the original nylon timing gear in it!

 

[mopar383]

timing chain also

 

[theos911]

How many miles are on it? 318s tend to eat a timing chain by 75 or 80k. Our 74 sportsman did and everyone of my Dad's fusie fury wagons did.

 

[detmatt]

Before you put anything back together do the simple check for slack in the timing set as one of the guys mentioned. Distributer cap off and rotate the engine back and forth by hand and watch the rotor.