Archived 12v ticking and blowby

[summitgreasecycling]

So I am driving up Vail Pass today towing about 2-3,000#'s. Truck started to get hot so I down shift from 5th. Egt's around 1200F and t-stat at the white line on the hot side. Maybe 200-210F. Noticed a ticking and almost like the motor got a little tight. Eased back and cooled her down. At off ramp I noticed the ticking again and a bit of a rough idle. Got back to my shop and noticed crank oil blown out of the dip tub and blow by tube. Truck had 215K miles and stage one injectors, 4in straight exhaust. Gets about 22#'s of boost at 10k feet altitude. Any ideas?

 

[Sticks]

Oil coming out the dipstick tube (I presume you mean) would be excessive crank case pressures, or obstructed crank breather tube, which would be odd as you were highway driving not off roading.



Rough idle could be cylinder/piston, or a blown valve seal (which would explain the excessive crank pressures), or an injector/injection pump issue.



First off, verify that your crank case breather tube is not pinched or obstructed/plugged. Slight possibility that oil/dirt buildup inside the tube may have broke loose, briefly plugging the tube, pressure built up then it blew out - excessive oil now around the blowby tube exit.



While at idle, start breaking loose the injector lines and the one that makes little or no difference to the idle will be your problem cylinder. Remove the valve cover and inspect the valve springs, rockers and valve clearance (intake . 010 +/- . 005 - Exhaust . 020 +/- . 005 with the engine in the correct TDC position for that cylinder).



If it were me, given the excessive blowby, I would do a cylinder compression and leakage test to verify if it is valve clearance, valve seal, or piston/cylinder, then pop test the injectors since I have them out anyways.



Is it possible that you did not fully seat the oil dipstick last time you checked your oil level? Maybe a missing O-ring? Normal pressure will push oil out the dipstick tube if not seated or sealed, especially at the right angle while climbing/descending a hill or turning.



Engine temps sound normal for summer holiday mountain traffic driving (I gave up heading for the hills on a holiday weekend, I will not sit in traffic for 6 hours on a drive that should only take 2).

 

[Vaughn MacKenzie]

If you held it at 1200F for awhile you're getting uncomfortably close to the danger zone. I know of a couple of 24-valve trucks burn pistons pulling a grade at 1250F. Usually when a piston gets damaged it makes a noticeable knock.

With your engine idling at operating temp and with the oil cap removed watch the vapor coming out of it. . . if there is a noticeable pulse to it in sync with the engine that is an indicator of a bad cylinder.

 

[summitgreasecycling]

Yes so there is pulsing from the oil fill cap and the dip stick. You guys know the best way to go abouts fixing this thing? Swap the motor or send it some where to rebuild it? If we have a 1st gen 5. 9 can we drop that in and transfer everything off of this 2nd gen including P7100?

 

[Sticks]

Whoa! Lets find the problem first. This might be something as simple as pulling the head and getting new valve seals.

If you don't have the tools or skills, find a reputable diesel shop and have them do a cylinder compression and leakage test. This is a simple test, and you should be able to get quotes over the phone. IIRC 1. 5 - 2. 5 hours flat rate.

Go back to my first post and try those steps. All you need is a 3/4 or 19mm wrench to crack open the injector lines at the injector.

Another option is to take the truck to a car wash, wash the top of the engine real good, especially between the valve covers, get back home and pull all 6 valve covers (I presume yours is a 12v engine) and start the engine. At idle you will be able to hear and fell the air pulses being pushed out either from the crank (push rod tubes or oil galleys) or out around the valves. Where the pulses are most prominent will be where the problem is.

If it does turn out to be a bad piston/rings, or galled cylinder, you can have the engine rebuilt or swap it out. If it is the worse case, a reman long block will be somewhere in the $3-$5k + additional parts and labor. I'd go this route before I dropped another used engine in.

 

[summitgreasecycling]

Where's the best place to get a remaned motor?

 

[Sticks]

Cummins Rocky Mountain, Jasper Engines, IIRC Source Automotive has a tweaked complete drop in but I can not remember if it is 12 or 24v.

 

[summitgreasecycling]

$7200 drop in Jasper Motor alternator, starter, IP, Turbo. etc

 

[Sticks]

Not bad considering it is complete. Most Long blocks, you still have to transfer over everything that is bolted to the outside of the block.

New pump, injectors, starter, alt... $2. 5k easy.

 

[SMorneau]

There is an add on the minneapolis craigslist for brand new 215 hp manual transmission motors. Says they are right out of dodge parts inventory and ready to drop in ?? Wants something like $6500

 

[Sticks]

Shipping will kill him. Jasper is in Denver.

 

[summitgreasecycling]

Hey Sticks you ever come up to Summit County?

 

[Sticks]

Used to come through there quite often on my way to Kremmling, I have a cabin on Gore Pass (east side). But between my current job and the #@$%! weekend traffic on both I-70 and 287... now it is maybe once a year.