3.5 Engine Knock - connecting rod brg replacement

3.5 has engine knock coming from oil pan, gets louder when engine fully warmed up. Suspect connecting rod bearings. 99 Intrigue has 203K on it and otherwise in excellant condition. Is it possible to replace connecting rod bearings with engine in car. What is involved in removing lower crankcase after oil pan is removed. Car has been trouble free so far and would like to get another 60K out of it

Generally if a rod bearing fails, the engine has metal circulating around it and further damage usually occurs, also you can almost be sure the crank journal is damaged.

These cars are only worth 2-3k at most. =Not worth a rebuild.

I have a special additive I use in my LX5 for the knock of death. Let me know if you want to try it. If the bearing is damaged I wouldn't risk it, but if only noisy you can reburnish the bearings.

I run Mobile 1 (true) synthetic.

Can the connecting rod bearings be replaced without removing the crankshaft?

Not familiar with this engine but I'd say if it has a lower crankcase then no, you'll have to remove the engine. Besides the crank is probably damaged too.

http://cbmmotorsports.com/Pages/shortstar.html
If you are looking for engine rebuild parts you will need a LX5 rebuilder since these engines are not rebuild by GM (only replaced with new). With a used Intrigue only worth ~2k I feel it is time to buy a new car.

Buy a magnetic oil drain plug to check for damage, switch oil out to synthetic and email me if you want some ceramic to add to the oil.

You could maybe try a straight synthetic 10w oil and see if that helps => I wouldn't try going much higher than that. LX5 is graded for 5w-30 and at one time 10w-30.