Possible Rod Knock

[Pinger]

I'm wondering if the PO just added oil when he heard the knock.

.

Chicken and egg.
Did the oil that came out look new like it was recently changed? I'm wondering if someone changed the oil and overfilled it at that point. Gross overfilling can damage pistons and/or rings. Damaged piston skirt and some slap from it?

 

[LVJJJ]

I've used those band clamps, they work great. I've got a knock when its cold but its the crankshaft hitting the oil pan as we didn't pound out the oil pan enuff when installing the 383 stroker. Not sure that would be the case with your 454, but might be worth putting your stethescope on the back of the oil pan.

Btw- I used to tow with a 1988 Burb with a 454 and I found that the 383 has gots more power.

 

[1952Chevy]

Chicken and egg.
Did the oil that came out look new like it was recently changed? I'm wondering if someone changed the oil and overfilled it at that point. Gross overfilling can damage pistons and/or rings. Damaged piston skirt and some slap from it?

It wasn't a recent oil change. Looked like your average 3-5k mile oil. Unfortunately I'm going on vacation and won't be able to dig deeper for a few weeks. I'm eager to get back and dig into it more.

 

[kenh]

A connecting rod will knock when the engine is in a "float' mode. Not accelerating or decelerating. You can test that by lightly accelerating and decelerating. As the engines passes through the float you will hear the rod or rods knock. Main bearing will knock under load.

Ken

 

[RichLo]

What about top end problems... broken rocker arm, bent P/R, collapsed lifter, etc?

 

[1952Chevy]

It's been a while since I've been able to work on the truck. Finally got some time yesterday. I finished pulling each plug wire individually and there were not noticeable changes in the knock sounds. I decided to pull the plugs, cylinders 5 and 7 are both completely carbon fouled and have a strong gas smell to them. The rest of the plugs are a little dirty, but not near as bad. I'm probably going to pull the injectors, as well as valve covers and check everything out on the top end.

I've heard leaking injectors can cause a sound similar to rod knock. So here it goes.

 

[1952Chevy]

So I got the upper plenum off, and jumped the fuel pump relay. Instantly the 5 and 7 injectors started leaking.

So I ordered a set of Bosch style 4 hole injectors. I decided to try Precision Auto Injectors instead of Five 0 simply due to price. They were 183ish for a set of 8. So I'm going to install those, change out the cap and rotor while the upper plenum is off. Then oil change again. Then we'll see what happens.

Mind you this picture was taken about 5 seconds after jumping the relay. By the time I removed the jumper wire it was even worse.

You must be registered for see images attach

 

[454cid]

I don't know how I missed this thread. I've also got a 99 454. No knock... well it does rattle at startup a bit, bit goes away. I believe I likely have leaking injectors. My oil level never goes up, though...my engine has always used oil, and it leaks too.

I get high oil pressure with a cold engine, but it drops to a much more sane level hot. I just recently replaced my oil pressure sensor, and pressure may be slighly lower, but doesn't jump apround any more. I had been getting erratic, with steady rpm.

 

[stutaeng]

So I got the upper plenum off, and jumped the fuel pump relay. Instantly the 5 and 7 injectors started leaking.

So I ordered a set of Bosch style 4 hole injectors. I decided to try Precision Auto Injectors instead of Five 0 simply due to price. They were 183ish for a set of 8. So I'm going to install those, change out the cap and rotor while the upper plenum is off. Then oil change again. Then we'll see what happens.

Mind you this picture was taken about 5 seconds after jumping the relay. By the time I removed the jumper wire it was even worse.

You must be registered for see images attach

Wow. Is that fuel going into the combustion chamber? You didn't have any codes?

I'm glad you found the problem.

 

[1952Chevy]

So I forgot to update after working on the truck(had to leave town for work).

So I replaced the injectors. While I had the upper plenum off I replaced the oil pressure switch, plugs, wires, cap and rotor, and EGR valve.

Fired it up, and seems to be making the same noise, hard to tell though because either some of the wires/plugs are bad(I doubt) or my timing is off. Its running pretty rough, and throwing a code that I need to read and figure out.

One of the screws for the cap broke and I was unable to remove the screw. I attempted to hold the cap in place with some epoxy. I believe it may not be quite right. I am going to redo that, and double check connections on all the plugs and wires make sure everything is fully seated where it should be. Check timing and go from there. New injectors were nice and easy to install. I didn't even break any of the pegs on the fuel rail! I was happy about that. Unfortunately it's too early to tell if this was a fix or not.