231 3.8 Carb Knocking Issue

[81 Regal Man]

Hi, all.

My current engine, the 231 3.8 Carbureted V6 has had a strange band of weird behaviors. One time about 3 months ago, the oil pressure relief valve opened up and dumped about a good half a qaurt of oil for no apparent reason. After an oil change, it never did it again. Then the car started to develope a knock that only occured when the "Oil/Choke" light would come on. I sourced that to a bad oil pump.

While on the way back from the part shop with the part in the car, the daggon oil pump failed and the cylinders NEARLY ran all the way dry. I heard the "Chicken Coop" squeaking internals and shut er down before any severe damage could be done to the cylinder walls, internal components, etc.

After an oil pump replacement, 4 qaurts of 10W-30 non-synthetic, ACDelco filter, and 1 qaurt of motor honey, all was going well and no knocks, motor wasn't sluggish and was actually very responsive and fuel milage increased.

Then, a LOUD knock at high RPMs. I immediately jumped to a bad lifter being the source of the issue. Well, before I could get the car looked at, the "only knocking at high RPM" then changed to a permanent knock with some squeaking, rattling, and what sounded like a loose part bouncing around inside the engine.

My first gut instinct was "Check the oil". I did so and she is full.

Needless to say, the car is now permanently parked. My mechanic says "Bad rod" and that I should do one of 2 things or both. 1. Drive her till she quits or 2. Replace the entire engine.

I am not sure, but I think I will pass on paying a tow bill when the thing goes out. My question for you guys is "Have you had any similair issues or sounds?" What would be the best solution? Also, do you agree with my mechanic's diagnosis?

Any and all help will be greatly appreciated.

Thanks.
-Terence.

 

[TurboDave]

Your second paragraph tells the whole story!!!! When you heard the squeaking internals, the damage was already done, and nothing you did as a follow up was going to reverse that. It was only going to become worse, hence the rod knock you're hearing. What you thought was lifter knock, was actually the damaged rod bearing(s) failing further. Lifters don't knock, they tick.

 

[charlief1]

Hate to say it but Dave's right here. YOu spun a rod bearing and I'd bet it's the #4 or #5. Most common ones to have a problem with.

 

[81 Regal Man]

Thanks for the help, guys. So the cheapest option to fix the issue would be.... New engine or rebuild? I would imagine that a new engine would be the best bet.

 

[mat231v6]

rebuild it. now you can do some upgrades.

 

[charlief1]

rebuild it. now you can do some upgrades.

Tear the engine down first and then this really will be the best choice.

 

[81 Regal Man]

Copy that and thanks. I was thinking the same thing. I found a set of connecting rods for cheap. Going to get them, place FI internals, adjustable cam gear, camshaft, valves, valve seats, springs & retainers, OEM compression FI pistons. All that kinda stuff followed by maybe a Garrett T4 50 trim turbocharger. New rear end and gearing to hold the power. It will take a while for ENTIRE build to be finished, but it WILL get done and you best believe that pictures will be coming up once the project starts.

Any input, advice, part corrections? Please, feel free to share.

Thanks again.
-Terence.