That's impressive!
Where did the rod break?
Where did the rod break?
2003 Chevy 5.3 Knocking
- Thread starter 151Viper
- Start date
rod
i worked in utah a couple of winters and realized real quick that when its negative degrees for awhile oil gets real thick and starters dont move is any of this making it clearer for you sad but truth
i worked in utah a couple of winters and realized real quick that when its negative degrees for awhile oil gets real thick and starters dont move is any of this making it clearer for you sad but truth
S
skidoorulz
Well-known member
This will explain everything for you!
C ranks
H ard
E very
V alve
R attles
O il
L eaks
E very
T ime
C ranks
H ard
E very
V alve
R attles
O il
L eaks
E very
T ime
Two broke. One broke near the piston and the other broke near the crank. I have not pulled the pan off yet to see ehich one is which but I did pull the heads off and the top of both pistons look very different. One looks normal but the other is beaten badly by the valve. One of the valves is slightly bent and not seating by about 1/16". All of the valve springs look ok which I was thinking one would be broken but it does not appear to be. I am going to be putting in a used engine this weekend and I will finish tearing down the old one and post a few pics of the internal damage.
Please clarify. Are you saying that the oil gets thick enough to cause a rod to break??? I have lived in this climate for 30 years and never had this happen to me or anyone else.
Here are the pics of the pistons, rods, cylinders and the crank. I am still unsure why it went down. I put a used engine in yesterday and it is running excellent. I sure would like to know why this one went down. My amateur opinion is the first piston broke and then it was bouncing off of the valve which was the knocking sound and then the 2nd rod broke the last time I started it and caused the block damage????
The broken piston looks really strange. I've never seen one that looked like that. I can't see how it would have gotten those swirl marks in it. Is it cut across the top? Or is that just the picture? I've seen diesel's cut pistons like that when an injector clogs and gets a weird spray pattern, but never a gas engine. Even if a cylinder does go extremely lean on a gasser, the edges of the piston around the ring land is usually the first to go. My best guess from the pictures is that the bottom of the piston broke away around the wrist pin and snowballed the rest.
The piston is cracked right down the middle. The swirl marks are from the valve hitting the piston. The piston and rod broke free and the piston must have been forced against the valve somehow and just sat there and spun in circles while the valve was hitting it. I am sure this was the "knocking" sound that I was hearing. for now I am chalking it up to a faulty piston usless someone can give me a more probable cause. Thanks for the input.
Sorry to hear about your bad luck. Hopefully everything is good to go now for awhile.
Yea this was $1,100 I didn't want to spend on an engine in my pickup. I could of found alot more fun things to buy with it. Oh well I guess as long as it stays together now it will be OK.
Iv'e worked at a gm dealer for 13 years now and have only replaced 2 5.3 engines. Sorry to hear about your misfortune
Back in 99 I seen two do the exact same thing. If my memory is correct it was a deffective rod. They had been over heated up near the wrist pin and were brittle. When I say two, when I replaced the motor under warranty the replacement crate motor did the exact same thing. GM sent out thier regional engineer thus the above statement.
Sorry
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Yeah, the rod breaking at the top sounds the most likely. I didn't realize it was still attached to the piston.
That series of engine has been a great engine with very few problems. The only one that I've seen come apart like that was helped along with nitrous that wasn't set up correctly, and I've been with GM longer than this engine.
That series of engine has been a great engine with very few problems. The only one that I've seen come apart like that was helped along with nitrous that wasn't set up correctly, and I've been with GM longer than this engine.
