# how does engine go bad after high millage?



## MickeyKnox (Jun 17, 2006)

So I have 1995 altima with 190K millage.
I take good care, change oil, filters etc.
why do engines with high millage break usually?
what exactly happens to those high millage engines.
how much more will my car drive?

thanks.


----------



## Asleep (Jan 19, 2003)

you can hope, with regular maintenance, to go about 250k with a ka. possibly more. there _are_ ka's out there with more than 300k. i personally had an engine with 165k miles on it, that, when i tore it apart, still had the cross hatching from the original boring of the cylinders. no noticeable cylinder wear either. 
on most high mileage engines, the cylinder rings are wearing out, the cylinders have an egg shape worn into them, the bearing measurements are larger. not to mention chain tensioner wear and valve wear and tear. taking good care of it though, will increase its life expectancy.


----------



## MickeyKnox (Jun 17, 2006)

so is replacing cylinders and rings something doable at home?
or special equipment is needed.
basically is it an expensive procedure to get the high millage engine running
again.

or by that time the whole engine needs to be rebuilt.

also is it ok to take off the top cover of the engine(where the spark plug entries are) on 1995 altima. I heard if I take it off then I will screw up some gasket alignment.

thanks.


----------



## Asleep (Jan 19, 2003)

the cylinders you cant replace. but you can have them honed. the cylinders would need to be measured first though. you can have the cylinders bored (cut bigger) and new pistons and rings installed. but then, you might as well have the bearings for the crankshaft and rods replaced as well. all of this costs a bit of money though, as you can expect. youre probably actually better off just finding a lower mileage engine from a private party or salvage yard. i found my first replacement engine at a salvage yard for 950 dollars and it only had 500 miles on it. 
replacing the engine would be cheaper and create less downtime for you.


----------

