Sorry if this has been posted before...

You all know my truck...and well she got t boned...which ive been fixing...well im laid off from work right now so it gives me a chance to do some projects around the house and one of those is my truck.

Well since i have time to do it and have another reliable vehicle im just going to do everything. I did a compression check last year and none of my cylinders were above 100psi...but when id add a little oil compression would go to 135psi or so on each cylinder...i was told this is piston rings is this true?

I ask because bad piston rings mean oil consumption...we i put in advanced mobil 1 full synthetic and an expensive bosch filter stating its good for 10000 miles....well ive gone over 5k miles and im less than a 1/2 quart low and thats with 229k miles on the motor. So could it be piston rings?

And also im pretty good with mechanics ive done timing chains clutches front and rear ends by myself and i feel im pretty knowledgable in mechanics...plus im a gearhead and love projects like this....but how hard would piston/rings be? Should i replace other things while im in there except obviously head gaskets...and what special tools are needed if i replace pistons in case the heads need to be bored. 030 over due to wear...

 

And by the way my motor still fires up without hesitation and oil psi is always above 40100psi psi...motor still runs great

 

Sorry im on my phone and dont have a link to edit post...i meant 40 psi not 40100the psi obviously

 

The oil rings are separate from the compression rings. It's possible the oil rings are in pretty good shape since the oil consumption is pretty low but the compression rings have worn more giving you low compression.

The heads do not get bored, the bores in the block get bored... AFAIK the wrist pins need to be pressed out of the rods to remove the pistons, then to reinstall the small end is heated to allow the wrist pin to drop in, not something the average DIY'er can do, best to have a machine shop do it.

Also, oil pressure is not a good indicator of the condition of the rings, only bearings, which you should replace if you tear the motor down, which may require having the crank turned if there's any scoring. Plan for having your truck down for at least a couple weeks in case you need to have machining done. Or build another motor on a stand and do a swap.

 

I like the idea of a second motor....

If you can beg/borrow/rent a leakdown tester. (need an air compressor as well....) and do a leakdown test on the engine. That will tell you where the compression is going, past the rings, or past the valves. (you can hear the air escaping....)

 

Theres nothing around me at a good price for a second motor....prices are around $700-1000 unless i want to travel over 100 miles....my motor still runs strong id rather rebuild that...i can have it out of commission for a while i just need it for hunting season so by october....im gettin excited its going to be fun...this is what im planning to do to it.

-control arms
-fix where i got t-boned....beds done
-take out xfer case and re-seal it
-engine work...head gaskets at the moment
-flush ALL fluids
-check/replace oil pump/screen
-repaint the whole truck with bedliner...my paint is starting to peel