Need advise about 4.2 crankshaft!
 

Hi guys!
Will you tell me is it possible to make grinding work for crankshaft of 4.2 s/c engine? And whether exist are bearings of the repair sizes for 4.2 s/c engine crankshaft?

Thank you!

What does Google say?

Miscellaneous. Frankly speaking I am afraid. Someone writes that it is normally to grinding a crankshaft. Someone writes that the surface of a crank is tempered at its manufacturing. And after polishing the shaft will inevitably break. I do not know what to do.

Pai what is the extent of the damage to this particular engine

Excuse me Steve do you ask about the engine of my car?

Once heat treatment is done it would still need ground at the factory. Heat treatment is only a few thousandths of an inch thick and is more for wear versus controlling stresses. How much needs turned off to clean it up. I was more concerned about what undersized bearings were available. Physically refurbishing the crank should not be an issue.

Why do you need a crank .

Did your engine sustain damage ?

I left from car wash. Suddenly on the display the inscription appeared: "Engine Oil Pressure Low". The engine began to make sounds as the old sewing machine (chok-chok-chok). I switched off ignition at once. On mechanical shop removed a case pallet. The oil receiver and oil pump were clean and dry. There was a metal shaving in a pallet of a case. The soured reducing valve was the reason for everything. As a result oil starvation with all that it implies. I think that the crankshaft is damaged. Now the motor is taken out from the car. Until now the engine did not give signs of malfunction. Level of engine oil always was in perfect. Always changed oil for 5000 km. But the car was used seldom. There are such affairs(((

sorry to hear that

With oil starvation your going to need more than simply a crank your entire bottom end will mostly likely be shot and the block will have to be honed , decked to make way for new pistons as they will be scored.


The way I see it is you have two options .

Option 1- source a second hand
engine and simply change it over somewhere in the region of $4-6k

Option 2 - full rebuild , very expensive however if you do go down this path whilst in pieces it'd be sourcing down larger pistons increasing capacity . Anyone's guess of how much ?? $8-12k +


Lastly what do you mean by a soured reducing valve was the case did the mechanic say this and how did it get there

Yes, now the engine is ready to pull out from the car. I think that in 2-3 days it will be already possible to examine the engine from within.

Could tell me please, cranks in 4.2 are tempered by currents of high frequency?

Steve will you give me advise please! Bolts on engine 4.2 disposable? Usually what bolts need to change at capital repairs?

Whilst the engine is in pieces I would take a look at the timing chain guides if there is any wear replace .

Also replace the water pump whilst engine is out

Obviously new head gaskets and head bolts will also be required

Bottom end bearings will should also be replaced on the rebuild

Thanks! I will follow your advice.