Hello everyone, long time no talk. Life has been busy and health has been bleh...

 

Long story short i was coming back from utah for a friends wedding and he was moving as well. I towed the uhaul trailer 6'x12' densly packed and very very heavy. Had no problems going through the mountains on HWY 80 EB till about 80 mi from lariamie WY. I was heading up a very long grade and towards the top something bad happened.

 

Here are the stats of when it happened

 

speed 70

gear 6

EGT under 1250 (no more than 60 seconds@1250, i saw it and turned the cruise off and throttled down)

boost around 20psi

rpm appx 1800~ cant remember exactly but was below 2000

oil psi normal ~65

fuel psi 18-20

temp rose from normal 180F to appx 200F when i powered down (within the white brackets)

 

What happened was a knock appeared and progressed to a loud knock quickly. I unloaded the engine and babied it to the crest which was less than half mile. Pulled over and the knock rose to a certain level and stayed there, excess blowby is observed and nothing else abnormal aside from the knock.

 

I havent torn into the engine but i am presuming either a cracked/melted piston or a conrod bearing went to hell or both.  I have my backup vehicle that ill be using for my trip and when i get back ill tear the engine apart.

 

Things i did learn from this, My RPM's were too low, egts were too high and in too high of a gear pushing too hard too long.

 

Fresh oil/filter air filter done before trip 3 weeks ago. zero issues aside from a cam sensor that gets fussy here and there. (was going to replace it when i got back this week as its bolt is stripped...)

 

Anyone have any thoughts or questions?

I had me comp turned off and only was utilizing my bigger injectors at the time. I maxed out my turbo and still had high egt's. I was in 3rd unlocked and had the rpms up high enough to keep going but my EGT's were still hot.

 

If you keep giving it fuel, it will just get hotter. I have to watch how much pedal I put into it, because even if my gauges say its good, if the EGT is high its telling me I'm putting in too much fuel that is not being combusted to create work.

I had me comp turned off and only was utilizing my bigger injectors at the time. I maxed out my turbo and still had high egt's. I was in 3rd unlocked and had the rpms up high enough to keep going but my EGT's were still hot.

 

If you keep giving it fuel, it will just get hotter. I have to watch how much pedal I put into it, because even if my gauges say its good, if the EGT is high its telling me I'm putting in too much fuel that is not being combusted to create work.

You can still burn it if the RPMs are too high and the turbo isn't flowing enough CFMs of air to keep up with the engine. When I had an hx35 I ran out of air at 25-2600 rpm and it made the EGTs spike. I've never ran out of air with this new turbo though

Interesting. This is all new to me. I never put on an EGT gauge.

Is there another way to watch that your not pushin' engine too much?

Interesting. This is all new to me. I never put on an EGT gauge.

Is there another way to watch that your not pushin' engine too much?

 

No. The engine temperature will only slightly rise at 1,200*F going up a grade. I typically run 4th gear at 53-55 MPH holding 1,100-1,200*F and engine coolant temperature will only slightly rise like 205*F for me. Pyrometer is the safest bet for monitoring cylinder/exhaust temperatures.

No. The engine temperature will only slightly rise at 1,200*F going up a grade. I typically run 4th gear at 53-55 MPH holding 1,100-1,200*F and engine coolant temperature will only slightly rise like 205*F for me. Pyrometer is the safest bet for monitoring cylinder/exhaust temperatures.

Don't be confusing people here now.........................cylinder temps can be significantly different than overall exh temps.

 

There are many things that can affect cylinder temps which unless you are running a large engine with a pyro probe directly in the exhaust port next to the valve like Cat has or other big engines we are limited to checking egt of all cylinders as a combined unit within the manifold which is ok but not overly accurate in the grand scheme of things versus seeing individual cylinder temps right at the cylinder.

EGT temperatures in the 1250 degree range don't necessarily = melted pistons. Unless a piston cooling oil jet is plugged or some other issue restricting piston oil cooling jet operation is occurring, the Cummins B series engine should be able to handle this excluding excessively extended periods of operation in this range.

If a piston was melted, partially melted, or damaged, I think there would be other symptoms like a dead miss, and possibly extreme crank case blow by to the extend of blowing extreme amounts of engine oil out the crankcase vent tube. The engine oil may exhibit diesel fuel contamination.

Do a compression check or at least scan each engine exhaust port where the exhaust manifold joins with an IR heat sensing temperature gun to find a cold cylinder or a substantially different EGT temp on a particular cylinder or cylinders.

Verify internal engine damage BEFORE you tear it apart.

The engine operation envelope you were operating the engine in when the knocking noise occurred is exactly the operation envelope that Cummins/Dodge outlines in their TSB.

http://dodgeram.info/tsb/2002/09-008-02.htm

Dodge did not have a lot of complaints about this issue but from those who towed heavier loads for extended distances.

Checking and changing a thermostat takes about a 1/2 hour, an hour tops. Do the other tests and checks and if your results are inconclusive, try replacing the thermostat with the thermostat listed in the TSB. Might save you a lot of money, time, and effort.

Edited August 6, 201410 yr by LiveOak

Being I'm running a Smarty and mild injectors I won't go above 1100 degrees before I either downshift or get out of the throttle or both....too many variables with the advanced timing and the accuracy of your pyro to risk pushing any harder. 1250 may be OK on a stock engine but advanced timing will increase cylinder pressures/temps, and your not necessarily going to see the difference on your pyro.

I stand corrected W&F... Thank you.

Pistons are damaged way more often from injectors be it bad or weak spray pattern or too big or wrong spray angle ect than any other reason then throw timing on top of that makes for a bad combo when loaded, this is where an individual high cyl temp can be created but not picked up on with a manifold mounted probe seeing the collective temps of all cylinders mixed.

 

I had my 02 at 560hp for many years and I rarely ever saw less than 1200-1300 while towing long hauls with it consistantly, ran it like that for close to 100K with no issues at all along with all the power pulling and a few drag races over the years with BD 155 sticks, and II silver 62 turbo and HRVP44, had over 150K on it when I sold it and the head had never been off, she was still a virgin engine.

 

 

But until the OP does some more troubleshooting and reposts his results before ripping and tearing into it first we will not know for sure. Could have broke a valve spring and dropped a valve/ could be a bad rocker arm bent push rod, bad cam who knows.

Lots of things to create a knock and more blowby than a bad piston.

hey everyone, sry for the late response (im on the road traveling still) lol i had no white/black smoke out the exhaust but a bit of blue/white haze out the vent.

the pyro is pre turbo on the header reading the rear cylinders. the edge was on setting 2x2 and i was pulling up similar grades with no issues along the way.

i could have cracked a piston as well with the excessive blowby and the heavy loud knock is happening even at idle. it wont be till oct/nov before i get to it.

I do know its something in the engine, i do have loss of power, bubbly oil on the stick (which was still full. I will troubleshoot from the top down before ripping it apart. i will keep everyone posted.

for now lets not speculate but rather give possibilities of what to check.

Edited August 9, 201410 yr by CUMMINSDIESELPWR

My recommendation is to pull the head and physically look at the pistons and cylinders. You possibly could have had an injector fail and burn a piston too. You won't know until you look.

hey everyone, sry for the late response (im on the road traveling still) lol i had no white/black smoke out the exhaust but a bit of blue/white haze out the vent.

the pyro is pre turbo on the header reading the rear cylinders. the edge was on setting 2x2 and i was pulling up similar grades with no issues along the way.

i could have cracked a piston as well with the excessive blowby and the heavy loud knock is happening even at idle. it wont be till oct/nov before i get to it.

I do know its something in the engine, i do have loss of power, bubbly oil on the stick (which was still full. I will troubleshoot from the top down before ripping it apart. i will keep everyone posted.

for now lets not speculate but rather give possibilities of what to check.

 

Try to identify any bad cylinders by using a IR heat gun on each exhaust manifold outlet runner.  If you see a cylinder that is notably cooler or hotter.  Pull the injector on that cylinder and see if you can find a 7mm borescope to put down the injector hole and inspect that cylinder.  Or buy one. 

 

http://www.amazon.com/Waterproof-Inspection-Borescope-Endoscope-Attachment/dp/B006SNRUL0

 

https://www.google.com/#q=7+mm+borescope&tbm=shop

 

http://www.ebay.com/itm/like/351125482641?lpid=82

 

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2054897.m570.l1311.R1.TR4.TRC2.A0.H0.X7mm+borescope&_nkw=7mm+borescope&_sacat=0

 

The image on the cheapee bore/endoscopes may not be great but hopefully good enough to tell you whether you need to pull that damn near 150 lb. hunk of cast iron which is at least a 2 man job in my book although I suspect it can be done by one but he needs to be really careful. 

starting to investigate and teardown the engine today yaaay

Edited September 13, 201410 yr by CUMMINSDIESELPWR

here is a short vid just for audio, cold start and you can barely hear the knock but then at 8sec it goes, heard better with headphones on. its a subtle ping then lights to a bang

 

ping

.

.

.

ping

ping

.

.

.

.

.

ping

bang bang bang bang bang and so on...

 

i believe its #4 and it doesnt light up immediately like the others but when it does its noisy.

Video.MOV

Edited September 13, 201410 yr by CUMMINSDIESELPWR

Not only a knock but a definite dead miss right from the instant it starts.

NOT the type of knock or noise I was thinking of.  That does NOT sound good at all.  I concur with W&F as well as taking the head off.  Very sorry you are having to go through this. 

It sucks that you are going thru this with your truck. When I logged in today your post was at the top of the heap and scared the crap outta me. Here's why:

 

Brutus is down!! That got may attention then made me laugh because that's what my kid's named my truck right after we got it on account of the rather less than smooth ride. When I saw the headline the first thing that flashed thru my mind was "Holy crap! My truck is dead?" Oh, wait. Whew! 

 

In any case, I'm done post whoring now. Carry on! LOL

1. ya probably have a scuffed  cylinder.     That'll explain the miss,  and  foamy oil..
2.  not sure who posted it in this thread,  but  someone said  their coolant  rose  dramatically?     I  witnessed  2 times  personally  when my  903 cummins   scuffed  ONE  cylinder,  the  coolant  rose  30-40 degrees  in    10  seconds..  the   friction  must've been horrendous.   I  stopped the engine,   let it  cool  half an hour..  and  limped it home.    yep... she was   dragging a leg.

 Now,      If   you only had  1  bad  cylinder,  and  the other 5  look perfectly good,    Wouldn't  an injector  be  more  probable...  and  not so much  lugging??   (high egt )    I'd  think  all 6  should  have signs of    overheat.

 

Edit.  Just  listened to your  audio..   Man that sounds  familiar.    I hope  I'm wrong.

Edited September 14, 201410 yr by rancherman

ok so i got the injectors out, no visible signs of issue. I took all the front guts off to get to the engine, all that is left is the turbo/exhaust manifold and fan. the head will be off tomorrow afternoon.

 

I am expecting

cracked/melted piston

bore will be fouled (hope i can hone it clean)

i will end up putting some ceramic coated stock pistons (or oversize dependent if bores need oversized) new rings and wrist pins.

new gaskets too

 

i will still check the bottom end by dropping the pan and inspecting the rod ends for ANY play at all, also inspect the oil for any brass

 

when its time to order parts after i assess the repair, i will ping the forum for best MFG's of parts and gaskets.

 

I will be replacing the head studs with stockers as im not putting stupid power out of this and keep it below 30psi

as he sits right now

UPDATE

 

the head is off and was a clean pull. The head is perfectly fine, head gasket was in great shape (no penetrations). I found #6 to be only cracked at appx 10 o'clock if you were looking at it from the front. The bore is scuffed but not gouged and a heavy hone should clean it up. i will still measure the bore before i purchase pistons and that will determine if the block needs to come out. I am hoping i can just hone it and it will be fine, i felt all the way around and there are no light or heavy gouges, just surface burnishing. It looks like when i realized i was pushing it too hard i backed off just in time before i had total meltdown and a effed up bore.

 

I will take pics of the piston and bore tomorrow once i pull it out. If i can replace with a stocker i am going to order the ceramic coated stock size pistons with rings and wrist pins and have a whole new set ready to fire up. Plus gaskets water pump while it out and a couple sensors that are not wanting to come out (stripped cam sensor bolt...)

 

So with that, where are good places to purchase new piston kits and which head gasket should i go with?

 

again thank you all for your assistance in my screw up.