Excess blowby

[bazdan902]

Not saying folks should copy them. Just an example!!

[in2trux]

Thanks Marajin!

I can add a little background on this engine. According to the sparse records I got when the truck was purchased, the head was replaced under warranty for a crack in the head. I'm going to guess it was #3 but can't prove it. After getting set up with insite we found there was a high EGT event before we bought it that likely cracked the head.
It is possible that the damage was already done then and progressed.

Oil pressure and temperature were always solid. Hot idle was 25-28 psi, 38-40 psi running. I never saw oil temp over 225 on hard pulls. Oil pump was replaced before purchased, now I have to ask myself why? One thing is for sure, that pump is going to be shimmed to bring the pressure up!
We'll see what the rod and main bearings look like this week when they all come out.

Oil was changed every 10k miles, maybe twice at 12. There will be a bypass filter on it before it hits the road again!
I have been adding 1 gl. 80w90 to the mix, with Delo 15w40 and the engine was smoother and quieter with it.

Power Service was added regularly to the fuel but I'm going to look at changing the primary filter to Davco.

We really weren't planning on doing this this year, maybe next year since the average mileage is 55-60k/year.
Just goes to show, unless you start with a fresh engine, you never know what you're getting when you buy a used truck.

I will feel a whole lot better about the engine knowing exactly what has been done to it and the guy doing the job knows what he is doing!

[in2trux]

Just wanted to update,

The truck is back in revenue service thanks to Gearhead! I couldn't be more pleased with the way it runs!

I want everyone to know that he is my #1 go to guy for engine work!

While turning your own wrenches is the the most profitable and worth while thing you can do for yourself, unless you have the experience, internal motor work is best let to a pro!
Finding one is another story! Lots of guys out there that are a legend in their own mind! Lots of shops ready to take your money and stroke your ego.


Without a doubt, having to do an unplanned in-frame is the most stressful scenario you can go through as an O/O. As the miles and hours climb it's always in the back of your mind,
you know it's coming, just not when. While it would be great to have a fresh engine sitting ready to go in, all the bills paid and plenty of cash in the bank. that is not the reality of trucking today. With razor thin profit margins and increasing competition from the rats, you better have your s__t together if you want to survive in this business!

It actually took longer to get the counter bores cut than tear down and reassembly BUT that is an important point!
Liner protrusion is CRITICAL for head gasket crush! Cut corners here and you are going to have problems down the road!

I've seen enough "fresh in-frames" blowing coolant into the oil or pressurizing the coolant system to know why. I'd bet dollars to dounts they slapped in new liners. pistons and rings and called it a day and never measured the counter bores. Add to that, you never know how it was driven. They were all painted shinny new Cummins red! Not the same as rebuilding the engine in your pickup or building a hot rod. No where as much riding on doing it right!

We picked the truck up Tuesday. My 95 year old father in law came along for the maiden voyage ,120 mile joyride back to the yard.
Needless to say he was impressed. Glued him to the seat a few times and his reaction was "HOT DAMN"!

This is a guy that started driving when trucks had chain drive and solid rubber tires, worked for Autocar and Cummins long before I was born! Priceless moment.

In my wifes words when asked what she thought about how it runs, "It's an animal"! It will be driven with respect and care.
I couldn't agree more.

THANK YOU Brian!

[T680]

In2trux what was that egt number that u suspect did that damage to the head??

[in2trux]

(06-17-2016 )T680 Wrote:  In2trux what was that egt number that u suspect did that damage to the head??

I'd have to go back and look, it was like 1000+ if I remember right.

[ynot]

are you talking 1000+ on the outside of the manifold?? cause I've got a prob inside the manifold and I'm topping out at 1150 with no issues what so ever, I keep reading about 1250 being melt down for aluminum pistons and the isx's use monotherm pistons, so you should have been fine I would think. man she must have gotten some hot in there for that too happen.

[Unilevers]

(06-17-2016 )ynot Wrote:  are you talking 1000+ on the outside of the manifold?? cause I've got a prob inside the manifold and I'm topping out at 1150 with no issues what so ever, I keep reading about 1250 being melt down for aluminum pistons and the isx's use monotherm pistons, so you should have been fine I would think. man she must have gotten some hot in there for that too happen.

lol i ran one at 1650 pre turbo temp on a dyno - it was terrifying but it held....

[Hammerhead]

(06-17-2016 )Unilevers Wrote:  

(06-17-2016 )ynot Wrote:  are you talking 1000+ on the outside of the manifold?? cause I've got a prob inside the manifold and I'm topping out at 1150 with no issues what so ever, I keep reading about 1250 being melt down for aluminum pistons and the isx's use monotherm pistons, so you should have been fine I would think. man she must have gotten some hot in there for that too happen.

lol i ran one at 1650 pre turbo temp on a dyno - it was terrifying but it held....

Ok so since I have my shiny new pyro and I'm going to install it when I get home...I have a few other repairs to do at the same time, which position is best to place the probe, pre-turbo or post-turbo and why?
I'm going to have the coolant drained anyhow, and I'm planning on doing a turbo inspection (likely replacement) anyhow, turbo removal to drill & tap the manifold isn't a big issue so that removes the ease of drilling and tapping downstream of the turbo as the obvious reason. What I'm looking for, is there a reason pro or con upstream or downstream that I don't know to ask?

[gearhead]

I think the best place for it is pre turbo right before the turbo drill and tap manifold. This way egts are true pre turbo readings. After the turbo is good but because of turbo your temps are between 200 to 300 degrees cooler than pre turbo. Also clamping the probe to the manifold works but i think it takes a little long for true heat to be measured ( just opinion here) on a long hard pull like a mile or so the clamped probe will pick up on it.