Bad piston ring question

[rpg_dog]

So after performing a leakdown test on a 92 GSX I purchased yeaterday, I determined my #4 piston has a bad ring. I'd plan to rebuild the entire engine, but not now since I dont have the money to spare, so I want to replace all the rings. Is there any other important (and inexpensive) parts I really should replace as well while I'm in there? Is it possible to pull the pistons without pulling the entire engine? How many labor hours would an average shop normally charge for this type of job? I know if I pull the engine I might as well rebuild the entire thing, but I don't plan to do many major HP upgrades, and I just want it running good right now. I can maybe afford $600-$800 right now to try and get it repaired, realistically is that gonna be enough if I plan to find a shop to do the work? Thanks in advanced for any help you may be able to provide.

 

[Stainbox12]

It all depends on yours plans with the engine/car. If you are really sure a ring is shot, and you don´t want to spend big money, you can buy a set of rings, take of the head, the oil pan, unscrew the rod from the bottom, and take it out from the top, install the new rings on that piston that is suspected to be bad, reinstall and call it a day. You don´t need to drop the whole engine, to do this though, and it might solve/help your problem. Now, if you are into dropping the engine, obviously, take everything to the machine shop, per example the block, to have it inspected, since the cylinders might be scored and its damaging your rings, the head, to have it cleaned, and inspected, install new main and rod bearings, etc, basically a whole rebuild. All timing components, oil pump, gaskets, seals, etc. It all depends once again on your budget, and the willingness to either do it yourself with patience, or pay somebody else to touch your car. If i were your i would buy a couple tools, take off the pan the head, take off the piston/rod reinstall new rings, and test compression after driving for a while, it´s cheap and an easy fix, and if that doesn´t solve your problem, then you can move to the other big step to remove the whole engine, and pay big money, once again depending on the kind of rebuild you are looking either a budget one or an expensive one with all brand new parts. Good luck.

 

[BoredDSM]

Might as well do headgasket and head studs while your at it. You would have to replace them anyways since your removing the head. You should get the block honed.

 

[rpg_dog]

Thanks guys, I wasn't sure if I could pull a piston if I didn't remove the block. I think I will just replace the ring(s) for now to get it running until I can save the money for a proper rebuild. How easy is it to tell if my cylinder is scored?

 

[Stainbox12]

The easiest way, is with your hand touch the surface to see if its scratched somehow. If, there´s no visible wear, but in fact you think there is some, use a vernier or a micrometer, to measure the clearance and compare to stock specs. A block with a bad cylinder clearance might wear the rings very quickly. Good luck.

 

[mentalTSiAWD]

You're most certainly going to want to do the head gasket and timing set and gaskets. You should consider doing rod and main bearings throughout since you're already there. They are fairly cheap (relatively) and can be done without removing the engine or transmission.

If your budget allows, get the head rebuilt/pressure checked.
Piston/Rods/bearing caps have to face a certain way. Pay close attention during disassembly and don't mix up the pistons. ie.. make sure #2 piston goes back into #2 cylinder and so on.

 

[redyute1]

look at the top of the cylinder where the piston ring stops and make sure there is not a ridge (this happens when the ring eats into the cylinder,if no ridge then just be sure to hone it and install a new set of rings.I would recommend dealer rings though,go ahead and change the rod bearings while you're in there,dont bother with the main bearings cause they will be a little work,personally i think you should be fine.Oh be sure to stagger the piston rings when u install them

 

[cano86]

make sure if you put the piston rings yourself that the gap from the rings are facing different direction from each other and not align all together. Also if you plan on running it like that for a while then yeah highly recommend rod bearings, head gasket and studs

 

[funkbuster]

I would at least replace the main and rod bearings while it is apart.

 

[rpg_dog]

Ok, so piston rings, rod bearings, head gasket and studs for sure. Sounds like I can get to all of this with the block still in the car. I'll check for wear in the cylinders. While looking for parts I found some used blocks for sale locally and I think I may snag one and rebuild it fully, but still think I will fix this one so I can drive it until then. I read somewhere that OEM pistons were pretty cheap at the dealerships and come in a .5 and 1mm overbore? Any truth in that (their closed Sundays)?