Spun a Rod Bearing :(

SrtBrad said:
When our stock engines are at or close to redline and then we let off the gas sometimes #3 and/or #5 cyclinders get starved for oil thus spinning the rod. The exact same thing happened to me road tuning the truck.
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Usually, some type of cavitation from the oiling system will cause a main or rod bearing failure. The main oil galley feeds all mains and rods, with #3 / #5 being in the middle?!?

Has anyone been able to determine the #3 / #5 failure issue?!?

Cheers!
 
Psycho1122 said:
Usually, some type of cavitation from the oiling system will cause a main or rod bearing failure. The main oil galley feeds all mains and rods, with #3 / #5 being in the middle?!?

Has anyone been able to determine the #3 / #5 failure issue?!?

Cheers!
Click to expand...

Some do an oil pump modification with the spring to bring up the oil pressure/volume combined with a swing arm for the oil pump pick up tube. Our factory pickup tubes are stationary.
 
Psycho1122 said:
Usually, some type of cavitation from the oiling system will cause a main or rod bearing failure. The main oil galley feeds all mains and rods, with #3 / #5 being in the middle?!?

Has anyone been able to determine the #3 / #5 failure issue?!?

Cheers!
Click to expand...

I've been told there is an issue with the stock crank being cross drilled causing the #3 Rod bearing cavitation. Some engine builders will plug the cross drilled holes so it is less prone to bearing failure.
 
SrtBrad said:
Some do an oil pump modification with the spring to bring up the oil pressure/volume combined with a swing arm for the oil pump pick up tube. Our factory pickup tubes are stationary.
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You are talking a spring on the oil pressure relief valve correct? If so it would allow pressure over 75 PSI?

Volume would be affected by the gear / rotor style pump and lobe condition.

The good news on our pick up's is the location at the back of the pan, in the deepest part of it.

I wonder if cavitation could occur if you were just a quart low on our 10 quart systems. These trucks can develop some decent G loads for a truck.

Cheers!
 
Psycho1122 said:
You are talking a spring on the oil pressure relief valve correct? If so it would allow pressure over 75 PSI?

Volume would be affected by the gear / rotor style pump and lobe condition.

The good news on our pick up's is the location at the back of the pan, in the deepest part of it.

I wonder if cavitation could occur if you were just a quart low on our 10 quart systems. These trucks can develop some decent G loads for a truck.

Cheers!
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This is a common yet totally misunderstood issue for our trucks. Lets start with the basics:

there are two types of oil pumps. The first one (2004 and early 2005) is a 3 piece. The second one (late 2005 and 2006) is a 1 piece. The first oil pump pressure relief valve is problematic and will cause a certain whining effect with different oil filter types. Mopar oil filter will deaden most of the sounds. Also this 1st oil pump tends to "balloon" or spew oil out of the certain types of oil filter due to extremely high pressure from the relief valve. It is an extremely good idea if you have the oil pressure relief valve changed over to the 1 piece as soon as possible if you have the first design.

Maybe a few other members can chime in to verify my understanding for the sake of accuracy.

Lets agree on this first point and then move on to the next point.
 
SrtBrad said:
there are two types of oil pumps. The first one (2004 and early 2005) is a 3 piece. The second one (late 2005 and 2006) is a 1 piece. The first oil pump pressure relief valve is problematic and will cause a certain whining effect with different oil filter types. Mopar oil filter will deaden most of the sounds.
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My truck does this now. It makes a funky whining sound with every cold start.
 
Other issues.

1. Due to our intake manifold designs #3 tends to run lean causing premature detonation thus pounding the bearings producing excessive heat and resulting in a spun bearing or worse.

2. Our engines due to the long crankshaft design tend to warp in the middle under extreme torque causing the sandwiching of the middle bearings (#3 and #5) causing oil starvation issues which can also result in a spun bearing or worse.

3. Ring land clearance is so thin that detonation can cause fractures causing small pieces to break off and getting stuck in the piston wall or bearing area causing a spun bearing or worse.

4. Having a reading on later 05 and 06 models with more than 1.0 volts on the knock sensor will produce undesirable hammering on the rods which over time will most likely spin either #3 or #5 rods first. I recommend making sure that the knock sensor voltage reads no more than 0.5 volts. At 1.2 volts the knocks sensor retards the timing by 2 degrees.

5. Having too much timing causing most issues listed above will also result a spun bearing at the least.
 
But people can determine if they have to much timing your truck will let you know by knocking. It's all about using great fuel an recommended oil,and not dogging your vehicle all the time.
 
raymondwebb said:
But people can determine if they have to much timing your truck will let you know by knocking. It's all about using great fuel an recommended oil,and not dogging your vehicle all the time.
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If you hear knocking it's too late with our engines. At 1.2 volts on the knock sensor you will not hear engine knock at all in the cab. People with loud exhausts will be even more vulnerable to hear engine knock. It is VERY important to have a good tune with a KNOWLEDGEABLE tuner for these specific engines. That is why I recommend Chris Jensen at Specialty Performance Team (formerly DC Performance) out of Los Angeles CA.
 
What I liked about the Vec3 was you were able to make the #3 and #5 cylinders run a little richer than the rest of the cylinders. I'm not sure if the SCT is capable of that?
 
I agree but would like to add that injector flow rates can vary over time (90k miles) due to partial clogging and mechanicals getting worn. Being we can't change our F'n fuel filters also can contribute to this as well as clogged sock on pickup therefore losing pressure /volume slightly under load, causing detonation as well. Our engines are still great when tuned correctly, maintenanced often and driven correctly ;)
These trucks that sit with low, low miles are asking for all kinds of issues.:D
 
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