Archived '90 CTD w/piston blown

[Ram4]

Last week we lost the #4 piston, in our '90CTD. . just melted the top of it. Cummins said it probably had injector failure, and over-fueled. Truck has ~400,000 miles, and we're ready to semi-retire it. . just going to use it for a 'back-up' rig. . probably won't get another 50k of use. Cylinder walls look perfect. Can I just replace the piston and rings, on the one cylinder?? Can I find a used piston, or should I go for a new one?? Someone said it will have to be 'balanced' (same weight??) with the others?? Anyone done this before?? Anyone have any pistons??



Any help will be appreciated.



-- email address removed --

 

[Forrest Nearing]

shouldn't need to balance everything... Cummins spec should be close enough, and these engines turn such low RPM, it won't really be a factor for a lo-po engine...



keep an eye out on ebay, and you should be able to find a used piston cheap...



push comes to shove, just buy a new slug... you can install it yourself. you SHOULD be able to buy a new ring set for just that piston as well.



I'd at least put some new Lucas POD injectors in there while if you're gonna be replacing the injectors anyhow!



Forrest

 

[Ram4]

What are the Lucas POD injectors??

I'm a bit of a newby, at going into these things! Thanks.

 

[Forrest Nearing]

Sorry, it's a big nasty smokey injector that's a nice, affordable upgrade for the first generation trucks... not necessary, but if you're about to spend money on a fresh set of injectors, you can probably get them a little cheaper, and they'll make a nice amount more power!



Forrest

 

[ata]

The Pistons in all 5. 9 Cummin`s are Graded. There is a number on the top of the piston make sure you get one with the same number. (all the pistons in your engine have the same number) What the grading is, is the measurement from the top of the piston to the top of the piston pin hole.

 

[dseabaugh]

you can do the one hole. Since you have to have the pan off anyway, with that many miles you should put in a new set of rods and main bearings all the way through . maybe even rings all the way through... not that much more work. That will help you keep from throwing a rod later ..... maybe you'll get another 250,000 miles out of. it. Check the exhaust side of your turbo to see that the fins are not covered with splatter of melted piston. Been there did that to a tractor , but melted down side of number 6 piston due to bad injector.