Motor longevity?

[texas503]

I bought a 1999 4x4 auto with about 104,000 miles a couple years ago which idled fine, but when under any load would smoke alot .... no modifications. I did not know any better and thought it had O.K. power until I rode in someone else's 24v. Well I looked for everything that would cause smoke. Ended up being a bad injector, replaced with RV 275's and now have good power.My question is, would me running the truck for about 15,000 miles, and I don't know how long before I bought it with bad injectors, cause issues with longevity of the motor. The truck now has 170,000 and runs fine and does not blow oil.Also the short block only had about 40,000 miles when I bought it.Sorry for the hypothetical question.Thanks

[jlwelding]

So you bought it with a new short block already in it?

[dripley]

i would think as long as you did not over heat the engine you would probably ok. do you have an egt gauge, that would give you a better idea than the temp gauge.

[jlwelding]

I find it sad that it has a short block and old injectors is what I understand. But it is more than likely ok, if you where hauling heavy loads it could take it's toll. :shrug:Get some gauges as soon as you can.

[texas503]

When I bought the truck, the records show that in 2002 the original owner took the truck in for regular maintenance but the truck did not pass compression test. So Dodge put a short block in under warranty. So the truck had 104,000 miles but the short block had 40,000 miles on it when I bought it.

I have never towed really heavy with it. Maybe 600 miles pulling about 5,000 lbs.

I know I need an EGT guage, but am a little leary about drilling my manifold. It is my only daily driver.

The truck runs O.K now, it does smoke some in low rpm's but I attribute that to bigger injectors.

When I was trying to figure out why the truck smoked, I pressurized the intake system and had alot of air coming from oil fill cap and blow by tube. Does that show excess wear?

Thanks

--- Update to the previous post...

I have fuel pressure and boost guages. How do I show my profile, i.e. the truck and modifications without writing it each time?

[jlwelding]

Go to private messages then scroll down and click on my signature.

[Junkman]

I know I need an EGT guage, but am a little leary about drilling my manifold. It is my only daily driver.

When I was trying to figure out why the truck smoked, I pressurized the intake system and had alot of air coming from oil fill cap and blow by tube. Does that show excess wear?

Thanks

--- Update to the previous post...

I have fuel pressure and boost guages. How do I show my profile, i.e. the truck and modifications without writing it each time?

You can drill away. I drilled most of the way through then started the engine & finished drilling. All of the metal chips blew out because diesels don't have vacuum.

How did you pressurize the intake? I suggest googling "leak down test" for proper procedure. Piston needs to be @ TDC with valves closed when you pressurize.

[dripley]

i installed my thermo couple in the back half of the exhaust manifold where it connects to the turbo. the exh manifold in my 02 is divided in half at the connection. the back half is hotter than the front and will give you a better temp reading. take your turbo off and stuff a rag in the manifold, that will stop any fillings from going back inside. drill and tap the hole. a vacume will suck out any of the filings, a mganet will work also. remove the rag. you could start the engine like junkman says a blow it out. i had no trouble using the rag. ther are other ways thna this. just be sure you get installed pre turbo for a proper reading. it is not difficult to do. Might need someone else to chime in, but when you pressurize your intake you should not be getting air in your valve cover or the crank case wether the valves are open or not. maybe a little blowby in the crank case, but i think it should minimal. A leak down or compression test of the individual cylinders would help localize a problem and the valve must be closed to do either.

[texas503]

To pressure test I just hooked a fitting over the intake of the turbo and pressurized it with an air compressor. I did not get it to TDC though, I did not know about that. I just thought it was weird to have air coming up through the head. I could understand the blow by tube.

I will eventually have to bite the bullet and install an EGT gauge, it is just hard when everything else continually breaks. I keep hoping to find a nice 12 valve 5 spd.

Thanks

--- Update to the previous post...

With the way it sounds, do you think the motor would go to 500,000 miles. That and fuel mileage is why I bought a cummins in the first place.

[flagmanruss]

If you put a big strong magnet on the manifold right next to your drill bit, it will attract any steel/iron shaving & prevent them from falling in. After you punch through, use a mechanic's retrieval magnet to check inside just to be sure. Same when tapping. I tend to tap deep which is wrong for a temperature probe where you don't want the threads in the passageway, just the probe.

[dripley]

To pressure test I just hooked a fitting over the intake of the turbo and pressurized it with an air compressor. I did not get it to TDC though, I did not know about that. I just thought it was weird to have air coming up through the head. I could understand the blow by tube.

I will eventually have to bite the bullet and install an EGT gauge, it is just hard when everything else continually breaks. I keep hoping to find a nice 12 valve 5 spd.

Thanks

--- Update to the previous post...

With the way it sounds, do you think the motor would go to 500,000 miles. That and fuel mileage is why I bought a cummins in the first place.

the egt gauge is as important as the fp gauge. fp to keep the vp happy. egt to keep the engine happy. you have agood truck, but you will have to :spend:some cash on it or buy a new one. the choice is yours.

[texas503]

So does it sound like the truck might be worth keeping? Or is the opinion to drive it until I have major motor issues.

[flagmanruss]

Feed it well (good fuel), maintain your filters. I predict a long & happy life together. There is a wealth of information here on the in's & out's of the various vintages of these trucks. Read & learn. You'll know better how to take good care.

[dripley]

sounds like the truck is running good from what you say. the air leaking by as you described would give me some concern. i just dont know enough to know if it is a big problem. hopefully someone here could enlighten us as to what it could be. i would not throw the truck away but i would like to know if it is a problem.

[pepsi71ocean]

you are saying that the when your pressurize the intake you have air pressure coming out of the valve cover oil fill? I think a proper compression test is needed, and i wish i could find mikes write up on it. either you have a weak valve, or a dead cylinder, this can explain the smoke down low. do you have fuel in your oil? does she blow blue smoke at idle? EDIT: found it http://mopar.mopar1973man.com/cummins/general/compression/compression-test.htm Check that out, and report back.