cummins isx '06 oil leak and weak jake brake

Personally, I think it is a complete waste of money to spend hundreds or thousands of dollars to fix cosmetic oil leaks. All engines leak oil, they just do. If your not loosing much off the stick I would just power wash it and run it until it is time for overhaul or trade in. Drip, drip, drip type of leaks need to be fixed. Something that takes a few days or a week to form is nothing I would be concerned with.

 

I had a gasket go bad that sits between the turbo and the block. It made the worst noise at higher altitudes, thought the turbo was going to blow!

 

wouldnt worry about the leak since the head gasket will get replaced at overhaul time, the noise sounds like a exhaust leak, i would check around the turbo area and the exhaust for leaks.

 

I would never get a salvage engine, period. Engines last a lot longer than they used to. There really is no set interval for an overhaul. As long as your engine has good power, doesn't burn too much oil and is still decent on fuel I would keep going. I would recommend getting oil samples done and when metal counts in the oil same start to get high, then you can think about overhauling.

 

You're looking at $6800 for a gasket overhaul on that motor, providing the head and everything else is in good shape. Sunk liner? Cracked Head? Might as well just rebuild it at that point since 75% of the cost is in labor due to that stupid ISX design. Rebuild or replace.

I'm in the same boat: I have an 04 ISX 475 with 950k ecm miles. It has had work done to it I think because it dyno's at 98%, and with less than normal blowby. The oil analysis report even suggested that I could run extended oil changes because it was so clean. BUT! It's leaking on the head gasket especially in the back drivers side corner. About a gallon every 20k miles. Burns no oil, but leaks like a harley. Cummins denies any problem, while all of the shops I've talked to say it's a known problem. Since there isn't coolant in the oil, I will just run it and add oil. Probably take it in for an overhead at which time they should check the head torque for me and inspect the rack.

Either way, once you get into it just for labor on the gasket overhaul, you're 3/4th of the way there for a rebuild.

 

im glad i looked here cause im having same problem. got 09 isx cummins dont no size but oil pressure way down but my transmission is acting bad. Going downhill it sounds bad like trying to get in gear but cant and my jakebrake stopped working. Anybody help a poor old lady never drove a peterbilt before.