I am new to this list and am working on a 90 240SX, it has bad comperssion, indacating rings have gone south. My question to the group is can the pistons be pulled without removing the engine(can the oil pan come off without removing the engine). I am a retired master mecanic but worked on mostly VW's and got into this car by my Niece buying it, now I have to fix it so, help!!! Phil(bear)

 

Guess no one on this fourm knows anything about the auto that they drive. Thanks for nothing of any importance. At least the VW list will respond to a request for information. Phil (bear)

 

After going out and getting a manual on the car, I have found that the oil pan can be removed with the engine in. Thank you for your time and trouble. In a little while I'll be able to tell you if the pistons and cylinders can be refurbished with the engine in place. Phil

 

To remove the oil pan the motor mounts must be undone to allow the engine to rise up high enough to get the oil pan out. remove rod caps and push the pistons out, it all works well and will be going back together soon. Bear

 

getting the pistons out is one thing, getting them back in from the bottom while compressing the rings is something else. let us now ow it goes.

 

Just got the pistons out, took off the rod caps and pushed them out the top. They will go in just as easy, I hope, installation is from the top, set the new rod bearings in the rod & rod cap push the pistons in till the rod seats on the crankshaft put the cap on and torque it down. I know it sounds easy but it is a hard job laying on my back on the floor. I will be refurbishing the pistons and honing the cylinder bore tomorrow(time to measure and checking cylinders to make sure I can do this), I'll let you know how the installation goes for real in a few days, I know how, I just have to do it, I am used to working on VW air cooled and this job is taking the wind out of my sail's.. Phil

 

[:@] made a discovery, the rods need to be reworked, when I put the first piston in it locked down, took it right out and found the rod needs to be resized, so back to the machine shop, more to follow tomorrow. Phil(bear)

 

Picked up the rods from machine shop, all is looking better. Started to work on installing the Pistons at ten this morning, takes a little bit of a fiddel to put the rod caps back on, it was 96 degrees so when I finished at one,(yes it took three hours) I was done for the day, soaking wet with sweat. I got the pistons on and the rods torqued to 30fp and all is well in South Carolina, I'll put the oil pan on tomorrow , I have everything clean ready for the stickey. The only problem I forsee is getting all the little vacuum lines connected back where they go.. Phil (bear)

 

oh man have fun i totally feel your pain on that end.. i had to help a friend figure that out a while back and that thing is just crazy confusing sometimes .

best of luck to ya... and haynes manual and FSM is your friend.

 

Are you changing the main bearings?