if your guna rebuild i would just have them install new rings and bearings in the bottem end, and all new gaskets this shouldnt cost to much, if ya got the money studs and valve springs also make sure your getting good parts like from cummins and it will run fine for along time, performance parts get pricey so if your hard up for money dont try streching it

 

I like this idea. Will I still be able to sell my old motor with it being run-down?

If compression isn't low why would it have blow-by? I dont put my faith into only one person; thats why I'm checking in with you guys to see what everybody thinks.

I'm pissed this motor only has 256k on it and it's beat. I think it runs awesome.. but what the mechanic tells me I think otherwise.

 

You say it needs a rebuild because it has blowby. If that is true, then it needs rings. Bad rings are what causes blowby, not bearings or cams or valves or studs. If you burnt a piston, then that could be the cause of the blowby, but we can't tell you that. If you cracked a cyl liner sleeve, then that could cause crankcase pressure, but we cant tell you that. If the bearings are bad, you need to change them, but we can't tell you that.

No one knows what the leakdown numbers are unless you give it to them. No one knows what the compression numbers are unless you give it to them. No one knows if you killed the bearings by running it out of oil unless you tell them.

You want everyone to tell you what to do without giving anyone the information needed to properly make a suggestion.

With the only info you have given, which is "it has blowby", no one can tell you what needs to be done over the internet.

If it has excessive blowby, but everything else is good, then the only thing you "should" need to do is a light hone and new rings. If the cyl walls are worn out, you need new sleeves or bore it. If the pistons are burnt, you need to replace them. If the bearings are bad, you need to change them. If the cam is worn, you need to change it. Etc, etc. etc.

 

people will buy cummins engines with just about any damage done imaginable. As long as its nothing major like a cracked block I would say someone would buy it to build for a racing or pulling engine but I dont know for sure.

 

this is nothing to do with your engine but it is to do with a shop. took a western star to freightliner because jake brakes werent working. they called me back told me to come up there. the "mechanic" told me that the engine had excessive blowby and needed rebuilt. i laughed and said ok show me. he cranked the truck and pulled the oil fill plug. i said were is it. he said you cant see it you have to feel it. i told him he must be the dumbest SOB i ever met. if it needs an overhaul you will see it and see it very easily. needless to say this truck is still running more than 100,000 miles a year about 2 years later. Not all shops are there to help people. This one wanted $15,000 when the actual problem cost me $250.

 

Thanks for the input guys. I see what your saying guhfluh. I guess we'll know those answers once I have more money saved up.

5.9bronco thanks for the input. How much could I get for my complete motor or just my stripped block?

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Wow what a guy he is! I think this motor runs AWESOME. Very crisp, responsive, runs amazing etc. But everybody on here says to rebuild it and my mechanic says the blowby is "a lot"

 

was there any oil in the crankcase at all. if you can have an oil analysis run on it and it will tell you if the main or rod bearings are getting thin or anything else that may be wearing out. we have a place that changes the oil in over the road trucks that does the analysis for $14. not bad and tells you alot about your engine. also when you do try to start this engine dont hold the gas pedal like you usually do to try to start it. let it turn over a little bit and build oil pressure before it cranks. you never know. you may be hopping yourself up for the worst and it may be just fine. I have a good long block to bad your along way from Texas.

 

Dunno about oil in the cc... the shop took the dipstick out and said it's bone dry (though I've heard that there is so much oil in these motors that even if it's not registering on the dipstick there is still a lot in the motor).

Why when I try cranking it this time dont put my foot on the gas pedal to make it start? Why does my truck not start w/out putting my foot on the throttle in the first place?

 

I have no idea how much your specific engine would bring but just look on craigslist or ebay and check out the prices. Like someone said earlier you can buy one for 2k for the whole engine.

 

When you put your foot on the pedal and start it, it starts up and hammers on the bearings before they have gotten any oil pumped through them. The only oil that is there is residual.

When you keep your foot off of it and turn it over, there is less load on the bearings before the oil gets pumped back to them.

Using a FULL synthetic oil helps dry starts extremely, where regular dyno oil shears at like 300psi, full synthetic shears at like 8000psi. You can easily make 300psi of force starting a big diesel, but 8000psi sounds a lot better protection to me. Once running with full oil pressure, I don't think the synthetic is a whole lot better, but dry starts is where its at. That being said, I don't run full synthetic because of the expense of changing it so often but If I had some of those real good bypass filters and could run my oil for 15k, then I'd run full synthetic, but 3k mi and 3 gal per change gets expensive.

I would really be suprised if your truck has excessive blowby. I would bet its just fine.

Now, if you ran it out of oil, the bearings might be toast and depending on how long you ran it, the crank, cam, lifters, etc might also. A good oil analysis might be able to tell you, like mentioned above. Other than that, they need to pull the pan and pull a main or rod cap off and look.