wannafbody

iTrader: (1)

I have a truck that the crankshaft is warped on 2.8 S-10........
Anyways, the oil pressure is good but I am certian the crank is warpped.
I just got to thinkin if the crank was warped there would be alot of slack in some bearings and wouldnt be much oil pressure.

Sorry for posting this in a F-body fourm, just dont know were else to put it.

thanks

Crazy 84 Z28

A warped crank would be one cause of low oil pressure

wannafbody

iTrader: (1)

but coul dyou have a warped crank and still have good oil pressure?

84z28350

pretty unlikely. If that crank has a slight wobble it should be puking oil out of there!

five7kid

iTrader: (14)

What makes you think you have a "warped" crank?

Those engines were well know bearing eaters. There doesn't have to be anything wrong or "warped" about the crank to lose oil pressure.

wannafbody

iTrader: (1)

well thats the thing, there is no loss of oil pressure. I HAVE GOOD OIL PRESSURE.
The just has a very bad vibration, coming from the engine. I have checked the flywheel, replaced the ballancer, all ignition components, intake gasket, pluged all vacume lines. there are no leaks, its no missfiring. It is just vibrating. Clutch in or out, its not the trans and it does it sitting still with the engine at idle or revving.

pizza_guy

Is that 2.8 a v6? That's a good reason for shaking right there. V6's are known to shake at least a little bit(at least the ones I've owned). Maybe your motor mounts are worn and transmitting more vibrations into the car. Might look at your motor while revving it(in neutral of course). If it shifts around alot, you may look into some new mounts.

Low compression on one or more cylinders? You didn't mention a compression/leakdown test. That'll completly eliminate or implicate something in the long block.
That would cause uneven power levels between cylinders, but it could still run and not misfire. However, it would shake like a love motel bed. At all rpms you say? Yeah, I'd put my money into a comp test.

I'll bet on some bad rings or leaking heads. If you've properly replaced all those componets you mentioned, that would be about it. MAYBE(big maybe) an exhaust leak right at the manifold. That's probably about as lucky as your going to get.

And IF your crank is warped(can't imagine how that could happen without damaging other parts as well, or massive overheat, or running without oil), I don't think that motor would be running much if at all.

Did this just start suddenly? Over time gradually gets worse? Since you got the truck? These are big helps in diagnosis.

How did you "check your flywheel"?

Last note: Are you reading your oil pressure off the stock gauge? Getting a seperate MECHANICAL gauge will be the most accurate by far. You could use it just for a minute(remove pressure sending unit and attach gauge there) to verify your stock gauge is accurate.