Wanted to get some advice from some who have rebuilt engines in the past. I have a 3.8 that has a loud knocking noise coming from the front of the engine. I have not taken it apart yet to see exactly what it is but I am guessing it is going to be a rod. What are the possiblilities that the crank is messed up? The motor runs pretty smooth except for the knock and very low oil pressure. I'm guessing at minimum I will be looking at replacing bearings and rods. I have looked online and cannot find a rebuild kit. Curious if anyone else has found a complete kit.

 

the crank might have to be resurfaced,but you wont really know until you tear it down

 

There are a few out there that make performace parts for the 3800 engine. A lot depends on your budget if you are going for performace good pistons and a higher CR will go a long way. But less your looking at bearings and balancing

 

A lot depends on what caused the rod knock. If you had the low oil pressure before the rod knock started you may have wiped the bearing out. In which case you now has metal all through the motor. In that case you will need to do a complete rebuild. Its the only way to be sure there is not metal pcs stuck someplace in the motor.
If the knock is from a streched rod (due to over reving) and the bear has not "spun" then you can have the rod resized and new bolts installed.

You should to address the oil pump with either situation.

I had the same choice not that long ago. I bought a car with a knock in it. I weighed all the options Rebuild/New/Used. For me the used route was the way to go. My motor was high miles but the rest of the car is in Garage kept shape. I found a 3800 from a 2002 with 40K on it for $600. You can find motors cheaper becasue you can use a motor from a FWD 3800 K, making it one of the most common motors in Junkyards. I have read stories of guys finding FWD 3800 with 30K on them for $400

 

I bought one from a fire damaged car for $300 but don't know the mileage. Oil pressure is ok on it, but not great. I want to rebuild this motor because that is something I have always wanted to do. I have no time frame and don't want to spend a fortune but want to tear it completely apart, clean and at least go back with new bearings, rings, oil pump,rollers, pushrods and gaskets. Stock and running is my goal for this one. No time frame and pay as I go.

 

Do you have the tools to check the parts? Step one after you pull the motor is tear down and inspect all the pcs parts. If you can not inspect the parts you will need to have a machine shop do it. Maybe you should start with a good set of factory manuals. I got mine from Ebay. You really want to get a good inspection of all the parts. You want to know what your into before you start buying or machining anything. If it needs a ton of machine work things can get out of hand real quick.

 

I have a couple micrometers,feeler gauges, ridge reamer, ring expander, lifter puller, hand tools, torque wrenches but I am going to have to rely on machine shop to do alot of the inspection. I know that can get expensive. Only manual I have is a repair manual from the local auto store. My thoughts are, since rebuild kits are not all that popular for this engine, is have the machine shop clean and inspect and set me up with the correct bearings, rings, and whatever else I need then put it all together. Heads will also have to be done by the machine shop because I have no vavle grinding tools.