Now with full compression on both heads the 43,000 mile 1997 454 vortec has the same noise that it had prior to it shutting down completely. The noise was checked by removing spark plug wire and hearing the noise change. So off comes the pan and a check of the bushing on the piston for signs of it spun or a piece of the distribution worm gear stuck in the oil intake at the bottom center of the rod cap. This noise occurred after a slight ticking started back in New Jersey in September. It progressed to a knock South Carolina. It was preceded by a pinging in New Jersey, just after a 55 gallon fill up. That pinging we think was the antifreeze in the 3 and 5 cylinders just in front of the 7 on the right bank. It caused the distributor gear to grind on one side and perhaps drop some metal down to the pan where it got hung up in the #7 bushing as it was dropping down the oil throat of the rear mounted distributor which is just above the # 7 piston. We are going to check all piston bushings and torque on the piston caps when pan is off. All metal and other particles will be cleaned from the pan and the oil pump intake will be checked for metal stuck in the screen, which pumps to the upper end of the engine. So far with two tows, parts, and labor we are at $2,300. Not close to the opinion of replacing the entire engine at $8,500. No problem with down time as it is a mostly summer driven RV.

Take out the oil pump and take it apart. Check its gears for contamination and damage. I would pull the caps off several rods and mains and check the bearings (bushings?) for contamination. If you find anything in the bearings then the eng is done and needs a complete tear down. Anything less and you will have even more knocking down the road.

I assume the 8500 includes labor for the install. If not, you can buy a crate 502 for less.

You said you put the heads back on so you did the top end and not the bottom? If you got water in the cylinder you may have a bent food, did you check piston hight when you had the head off? Buy a crate motor and be done with it.

454 Head back on engine started #7 piston noise

34 Replies

trop-a-cal
Explorer
Jan 17, 2014
Called shop and they are backed up with work and I'm getting better pricing with being fill in work as it's not needed until late Spring.
okhmbldr
Explorer
Jan 15, 2014
If he took his hearing aids out he wouldn't hear a thing, and then drive it another 50,000 miles.
When we're going down the road, my wife says "do you hear that noise?", I reply "What noise", and just keep driving!
willald
Explorer II
Jan 15, 2014
C-Leigh Racing wrote:
One thing he will know in the end, with as much of a job as that 454 engine has to do, he would be way ahead of the game just replacing the engine with new, than trying to patch what he has up.
Now if he did like Dave & went the 502 route, he would probably be one happy camper afterwards.

Haha, its always easy to recommend the most expensive route (crate motor), when its not your $$ being spent.

I wonder how many would see this issue quite a bit differently than posted here, if the cost for the repair (or replacement) was coming out of THEIR wallet. :)

Will
C-Leigh_Racing
Explorer
Jan 15, 2014
One thing he will know in the end, with as much of a job as that 454 engine has to do, he would be way ahead of the game just replacing the engine with new, than trying to patch what he has up.
Now if he did like Dave & went the 502 route, he would probably be one happy camper afterwards.
Neil
Daveinet
Explorer
Jan 14, 2014
Or wrist pin.
JimM68
Explorer
Jan 14, 2014
connecting rod bearings typically knock "at the top"
If you rev the engine briefly, the rod will clatter near the peak of the rpms and a lil on the downhill side.

A connecting rod knock = excessive clearance between the rod bearing and the crankshaft. the rod bearing may be worn to copper or worse, and the crank may be worn as well.

A "spun bearing" = the bearing shell has come loose in the rod, and moved. This will ALWAYS damage the crank.
PaulJ2
Explorer
Jan 14, 2014
My experience has been--A knock when cold but quiets down when warm is piston related. A double knock sound is usually a piston pin problem. A knock that quiets with the plug wire removed is usually a rod bearing (too much clearance).
Keep us posted what you find.
FunTwoDrv
Explorer
Jan 14, 2014
No holes in the rod caps...Oil enters the rod journals via the crankshaft. The hydralic question could certainly have some impact. (No pun intended.)
On another thought, it isn't unusual to hear a little piston slap at startup on some of these engines.
Looking forward to what you find once the pan is off.

Good luck,
Gary
topflite51
Explorer
Jan 14, 2014
Back in the good ol' days of automotive repairs, repairs like this were performed all the time. Some worked and some didn't. Good luck!
trop-a-cal
Explorer
Jan 14, 2014
Yes spark plug wire was removed, no exhaust gasket is not problem, the pinging preceded the tick which became knock after 1000 miles. Liquid does expand into vapor, it also contracts, we shall see what exactly the problem is with pan drop. Yes the dizzy probably was worn and had little to do with end problem, but did cause performance problem. Worms are a type of gear, bushing, bearings, one is static, other is dynamic,( moves). A worn bearing rubbing a bushing, is what I'm referring to. Holes in rod caps take on oil and release heat from rod cap, does the 7400 Gen VI L 29 have them ?