knocking

[gonzo891]

1056982

my AMC 258 knocks when i start it up! but it seems to go away after a couple of minutes of running is there any way to fix it or is a new motor in order? should i stick with a straight 6 or go with a 350? i have plans for a 4" lift and 33's any help would be great :-x [addsig]

 

[Tug-n-pull]

1057125

this is from a cold start not a warm start or is both. How many miles on the engin. If it is just at cold start it jsut sounds like you have a few miles on the old motor and it takes a min to get the oil up in the engin and moven around. This would be a good canidate for a K&N oil filter. They say that the K&N will keep the motor oil from all draining back down to the oil pan when it sets for a while thus allowing a wet start rather than a dry on. A dry start is the #1 cause of engin parts wear. maybe I read to much or maybe it will work. Any ideas out there on this one. May not hurt to run a quart of Slick 50 in your next oil change either.

As for the replacement of the engin. 1 does it run good other than the knock? if it does don't change it till it goes bad. 2 does it smoke or show other signs of wear? if not keep the one you have till it goes bad. Do you feel the need for more power? If you do move over to the V8, note I did not say move up to a V8. the change over will be harder than just droping in another I6 to replace the one you have if needed. Less to change and have to rig up. I6 or V8 is a personal preference.

A 4" lift and 33's should not be to taxing on the I6 and if it is you can change your gearing to suite your needs. good luck Tug[addsig]

 

[Bullet3600]

1057129

Good advice Tug, He may want to go with a thinner oil also ex. If the vehicle is outside in cold temps with a heavy oil 20-50 or so he may want to put in 5-30 to circulate faster........Bullet[addsig]

 

[bigTlilODD]

1057163

Good points you two. I run a thinner oil in the winter and a thicker in the summer. I also run a synthetic.[addsig]

 

[MudderChuck]

1057175

The snythetic I run in my motors, seems to stay thinner at colder temps and helps some with the lifter rattle and cold start knock. But in an older motor, probably won´t do away with it all together. Slick 50 or a moly oil additive will also help, by leaving a coating on the dry parts.
It´s not recommended to rev the motor until the knock stops.
The Jeep I-6 motors are known for being a little loose in the main bearings, but I´ve seen them run, for most of a decade, with pretty low oil pressure. Doesn´t seem to hurt them much, most times. Of course I´d always be a little careful, about over reving, a loose motor.[addsig]