"Valvetrain Knocking" is NOT what we find on this Engine. 

Thanks for watching. What the heck is that manifold on the coolant reservoir? I bet some of you know. Amazon affiliate links to Recommended Tools: Fuel Pressure Gauge, Compucheck 0-300 psi: amzn.to/3YeBldu Airlift Cooling System Vacuum Filling System: amzn.to/3D9AlPu Radiator Pressure Tester Kit: amzn.to/3QGBumn Milwaukee 3/8" Right Angle Impact Wrench: amzn.to/3D2CvAk 2 Pack M12 Style Batteries for Milwaukee: amzn.to/3D2mdHE Adjustable Height Parts Tray 100 lbs: amzn.to/3CBusZB Engine Oil and Fuel Dye UV: amzn.to/3z34zkv UV Professional Grade Light: amzn.to/3gzxPc0 Allstar Oil Pressure Priming Tank: amzn.to/3L5pASm

Back in the day, shop had a customer with a drill truck 12v-71 highway engine in it. They kept burning up the engine. Oil sarvation. After the second warranty overhaul, we found out wht they were doing. In order to drill, they had the front of the truck up on a platform. The oil went away from the pickup. The fix was to put a industrial setup w/scavenging pickup oil pump. Never saw them again.

That is an aeration hose, to bleed air out of the cooling system. I am a Diesel Mechanic on heavy transport in New Zealand, generally that hose goes from the thermostat housing to a header tank behind the cab on cab overs, or high on the fire wall for bonneted .Quite common down here worked on many 3406B's. Like the videos keep it up. Mike Kay

Thank You!! I will be watching this series carefully, as I have almost the exact symptoms on a 1998 Cummins N14 in a motorhome. I really appreciate your videos, I have learned so much from them!!

It's a peterbilt airsweep, it's supposed to get air out of the coolant

6:32 the Fumoto drain valves are great. Never seen a problem in 20 years. It sure beats stripped out drain plug threads. Only issue, was when I used to be a transit bus tech. Bus engines are at the back. When a bus would go through a speed dip in a road too fast, the engine oil pan would kiss the pavement. The drain valve on the bottom would go through the pan.

I always put a ziptie on the oil drain valves to keep the tab in place. Probably not needed, but extra security.

Off this subject but on another you mentioned a while back. A/F on Cat gaskets stands for asbestos free. 14 years working for a Cat dealer and I finally figured it out. I enjoy your stuff. Keep it up.

Just wanted to answer the issue about the oil film on the windshield. If it was anything like my drill rig, it's the residue of compressor vapor and the oil we run in the airstream to lubricate the down the hole hammer. It's vapor because you can't perfectly seal the pipe connections and it collects on the drill mast. The mast is down for travel and when parked. Then rain, dew, etc trashes your windshield.

I tested one of those oil drain valves for my company in 97. I was off road a lot, in deep mud and everything else you find on Michigan farms, never had any issues.

I have learned A Lot from you. Thank you. You are an excellent teacher.

On your game, as usual. Liked your comment on the quick drain oil pan plug. I couldn't agree with you more. Had one the Dealer put on a Mack 676. Caught a healthy tall weed coming out of a farm field loaded. Drained the motor and seized. Had to Line bore the block and do a major. That was 30 years ago. Never had one on any of our trucks since. Thanks for alerting people of the possible danger of having one. They judge for themselves if it's worth it. Please keep up the excellent work!

I heard that engine and I could tell it was piston slap. To do it right, it needs an engine replacement or out of frame major. It looks like that piston cooler is not aimed right to the underside of that piston. I used to insert 3/32 welding rods in all 6 coolers during overhaul and get them in the correct position in the quadrant of the pistons. This looked like the cooler may have been bumped out of position during overhaul or just was not aimed. It is very important on todays high horsepower engines. You do have good diagnostic skills. Keep it up, you can learn something every day. I try too. Good luck.

One fellow mentioned the piston cooling jet. At Cummins, I witnessed one time these parts were discovered to be made wrong, and the oil jet wasn't targeting the center of the piston. Was important enough to shut the engine down and wait for and install correct parts.

Hope you do a part two video showing what caused the scoring of the cylinder wall !

Great video thank you for sharing, I'm praying for a part 2🙏🏻

In all honesty it does look like theres a bridge on number 2(?) Cylinder that's moving around a bit.

That was smooth how you dropped your oil filter wrench in the pan but didn't mention it but yet still left it in the video. I hate when that happens!

Excellent video!

Everything breaks eventually but the 3406B was the best diesel engine ever made I think. Don't see them too much anymore but what a great engine.

0:06 guessing off the thumbnail, Bottom main cap on #2 is backwards, an the rod is bent

Thanks for the educational video and sharing how even though your highly experienced you still can be surprised

That is a bent rod. Not visible to the eye but it’s enough to push the piston out of square and chew up the liner. Good job on the reman work CAT!

Nice diagnosis, good logic

If you rebuild this old 3406 remember to check the liner packs will work with the oil jets. 3/8 old type won't work with the. Newer 0R liner packs and must use the 7/16 style. Also the thick injector tube washers must be used.

Great work dude 👏👏

Australia here.That was interesting. I would have picked conrod myself. As a Massey Ferguson trained diesel mechanic I've seen a lot of weird things with motors. But as a farmer I fix all my own machines. Whenever I hear tapping like that I always pick bottom end first. I once had an interesting experience with a Land cruiser diesel, where a big end conrod began to fail. Not much I could do as I was in the middle of nowhere. Started with a tick tick hour later it was tap tap hour later it was like a roaring sewing machine. Bang. hole in the side of the block. And I was still a 100km from the nearest town.

Just had a Toyota 3B engine knocking like crazy and after taking it apart we found #2 piston and cylinder like the one in the video, and a lot of play in between. Crankshaft and bearings all almost perfect.

Very well done on the editing!

I have a quick drain plug on my c12 and have had it for 7 years and a million miles and have never had any problems with it coming open. I also have them on my cars and also no problems. It is so much easier and cleaner to drain the oil. I can also drain it right into a container. Since I don't have my own shop it helps out alot.

good job!!!

Man your video is so helpfull and teaching- explaining what to look for 😊.

Thank you for a good video. You can learn a lot from an oil filter and remove the sump.

Maybe you can use all of that superstructure to hang the engine when you install it. In any case it look like you have your work cut out for you. Keep the good stuff coming.

Josh, I would say the little tube is an air bleed. If there's a T-stat in that housing it's to purge air out of the pocket at the top of the housing w/ filling coolant. The noise is probably coming from the piston, not the rod. The rings are probably broken and maybe ring lands too. I've heard it befor on huge gas engines. It sounds too quick for a lifter/ rocker but not deep/ solid enough for a rod. Of course can't tell any of that from a YT video, condenser mic's pick up light metallic sounds disproportionally. ben/ michigan

I'm curious what the story is on that burning trailer.

Oh you nailed that ending!

Hey, I have a suggestion for you to help retain the mess. Go to Lowes and get a plastic washing machine pan. The grey ones are the best, they handle abuse better.

Really good info as always, Keep up the good work, God bless.

Great video

That would be a very interesting video to show how it will come out. Then going back in with the spare motor.

Nice find 👌

Good job.

Thank you for that.

Hey Josh. I’ve had those quick release drain plugs on both my trucks. I always make sure they’re locked and aimed in a direction where rocks shouldn’t be able to open them. I suppose a guy could put a zip tie on them after every oil change so they couldn’t unlock. My main concern is some other driver having a bad day and dumping my oil at a truck stop as I’m sleeping and it’s idling. Oof. Trucking isn’t the brotherhood it used to be, unfortunately.

The oil jet which cools the base of the piston could be blocked causing the piston to overheat . Might be the cause or the effect of the issues.

That was great, thanks.

Looks like you’ll be using a forklift to change the engine unless you have a large C frame to work around the Derrick or unless you have a dual hoist bridge crane with the spreader bar to straddle the Derrick. Good video thank you

Great to see the inner workings of a cat motor…my 1st thought was a bent piston oil spray cooler…or a plugged one….I did not see the culprit that caused the sleeve and piston carnage…please elaborate on your final thoughts….I’ve seen plenty of diesels and rebuilt some…I’ve never had one comeback except a rush job final hour going to Baja Nissan/scout that got us almost almost home and grenaded on the grapevine pass.

Pretty great diagnosis Josh. Deep deep scoring. Filter cut never lies. Cheers Josh.🥂👍💪🍻

Air throttles are pretty common on older rigs - they use a "L" valve in cab to switch from foot throttle to rig control throttles - good prank on the unitiated is to switch it to rig controls and tell people to move the rig

Those quick drain valves do come with a locking version to prevent twigs and rocks from opening it.

Great video! You have a nice camera...

Excellent

That just looks gnarly.

Lots of fun

Not as tricky as putting an engine in a cabover fire truck. The last one I witnessed was done by suspending a C13 from a pipe after lowering it into the frame as far back as possible, then walking it forward with a forklift on one end and a transmission jack on the other end. That was a delicate ballet for sure.

How timely of a video, I have a 3406b that developed a rattle suddenly also. It runs go no loss of power, no excessive smoke it gets louder as it warms up, good oil pressure 40-45 lbs at idle warm . Noise seems to quiet if you bring engine off idle to 1000 rpm and oil pressure comes up to 50-55 lbs. What caused the failure in your truck? What should I look for in mine. I checked over head, pulled air compressor / power steering and ac / alternator belt still has noise.

That was piston slap probably overheated distorted the piston. Good informative video thanks

Ever notice how when you drop a tool and there's a pan of oil around they kind of home in on the pan of oil? If you are lucky it's just go fishing for it in hot oil, or, what you dropped upsets the pan and now it's a work area of floor that gets impromptu clean up. All in good fun.

What model of camera are you using when you showing the cylinder wall? Nice clear close up. Thx

Never had issues with my Fumoto drain plug. 25 years on my E7 Mack.

On that truck the "solenoid " is a second throttle access point to control hydrolic pressure as needed from the rear of the vehicle during a drill or pump...

I have a quick drain on my cummins but it has a locking tab that you have to pull before you can rotate the ball valve. work great as I can drain it hot and go inside for lunch

Josh bet the customer says, putter back together. Our shop will swap the engine out 😊.

My 2 liter aluminum block Kia looked like this from the top, with a bore scope ( though not quite that bad) ., funny they have machined spots for piston oilers,& a plan for future turbo option (which I don't think happened) ...Later engines, including their all aluminum six cyl have these jets installed . Some how caught early the compression was perfect ,all being at 204 psi exactly. I added 4.5 ounces of synthetic 2 stroke oil per 10 gallons of gas & drove it another 24,000 miles with the same noise your diesel has ., scary but it hasn't gotten worse & yup I would be interested what caused your failure...Ya , no warranty!

4 corner scouring usually lack of warmup or overheat. Cam ground pistons not round till warmed up some. Couldn't tell for sure if gallery cooled usually two piston cooler jets. Remember single unexplained rod bearing failures-9Y9497 late 80s.

I had a lifter clip break and the roller rotates and it makes a awful noise and puts metal in the system on my 3406

reminds me of having to pull the engine on my service truck. You have to pull the cab to do this, almost have to. Never forget to move the hoist from over the cab before you make it so it will not start.... Haha. Job got done.

2:29 Lmao, I feel stupid. That chime sounds EXACTLY like the one my fridge makes when it has been left open too long. I paused and unpaused 3 or 4 times and thought I was going crazy before realizing it was coming from the truck in the video.

What is the part number of that block plug? Does it fit into the dipstick hole?

Ouch to the costs, ouch for the guys who have to swap the engine.

Is the piston oil cooling nozzle plugged?Seen it happen.Causes the "black hole" condition.

Legend.

Just now coming across your channel. I really enjoyed it. I liked and subscribed 👍 I have ADHD which requires my brain to need a lot of information very fast or I become disinterested. Your video moves along quite well which keeps me captivated. Thanks again for this video that teaches while at the same time keeps me interested 🙂

Is that rod in the thumbnail bent?

I use those fumoto drain valves on everything, even my dirt bike 👍

Awesome

You love it

at 9:12 just before you get the prybar is there a crack in the block? right under the connecting rod with the two X's there is a very nasty looking line going up the block wall starting at the pan then looking like it got thinner as it goes up towards the crank.

I wonder if there is a leaking injector on 2# cyl. Did you send a oil sample out?

Ive just had a 2018 2.0 tdi passat come in with the same issue, oil squirter bolt came out, got mashed to pieces by the counterweight and contaminted and subsequently wore out the skirt on the piston on another cylinder. Discovered it after new squirter, new bg end and main bearings and cleaning everything up (in situ obv) and the thing had what sounded like a top end rattle, but a proper stripping showed the skirt damage. So yeah, we do it right cause we do it twice😢

Mike is correct , Peterbilt trucks used this assembly even used two on 8V71 series engines . It was mechanical coolant Snake Oil . Why did you not crack the fuel nozzle line fittings on the fuel pump to isolate the engine noise cylinder location ?

I'm curious if you could tip the drill rig upright, then pull just the front half of the truck into the shop to change the engine

Hey, I have a C7 acert 2006 in a freightliner. It runs fine when cold but after heats up, will start white smoking crazy and shut down. When you try to start back, smokes up the whole shop and if it does start will smoke and miss fire. If we leave it for a day come back next morning when engine is cold, it starts and runs perfectly. Checked all injectors all good, turbo had oil in it, we removed both turbo and exhaust manifold, manifold had oil in it. Ran engine without turbo and manifold same thing when gets hot. We tested the HEUI pump by stepping up and down the demand with the computer but everything seems ok. Also has no blow by Not sure what the problem is any ideas @AdeptApe

Could the oil be nice and clean because it was freshly topped up once the noise started

Something else did any metal plug up the oil squirter what is the metal fragment from.

Don't come knocking when the Valvetrain is knocking and the vehicle is ROCKING!!!! Nuff said?🇨🇦😄😇

I would just disconnect the Darrick and lay it on some cribbing. Two big pins, some bolts, lay the draw works on pallets, disconnect the weight indicators from the draw works, disconnect electrical from the Derrick, viola. Call it a day.

It is supposed to remove air bubbles from the coolant system. Air bubbles in a pressurized coolant system can create hot spots as well as wear the block, liners, liner seals water pump etc. It serves some of /similar functions of a “swirl pot” like used on engines where the radiator cap is below the highest point of the cooling system. As for what the thing is called I honestly forget. On a side note GM used to have coolant system supplement pellets that years ago and Ford had a coolant system supplement for the 7.3 idi engines because cooling system cavitation was major problem especially on engines that had lots of idle time (Ambulances, Tow trucks, etc) that could cause coolant leaks from casting porosity. Side note if you do not have some side play of the connecting rod the rods will bind or lock the engine. If I were replacing the engine I would definitely be looking very hard at the oil cooler as the source (repository) of the metal going through the engine from a previous engine problem. As for replacing the engine looks to me like an outside job so the drill rig can be erected out of the way, O joy

By 2:10 it was evident that the engine has excessive oil leaking and was always being topped up. It 100% was run too low on oil....prolly more than once. Moghta had the wrong inhector on that scored piston.....causing the scoring which leads to blowby which leads to oil puking out which leads to carnage

As a heavy wrecker driver we hate those drains because of you don't pay attention you'll shove it through the oil pan

remove and replace the engine from the front .remove the hood radiator and support and transmission . remove the rear mounts and support the back of the engine .remove the front mount from the engine and frame .now move the truck back until the front axle is at the rear support . now block the engine in front of the axle and remove what was holding the back of the engine .now move the truck away from the engine . set the new engine in place , and push the truck in to it .

Not a Cat engine issue here but, similar to this, maybe? I have a mid 90's Cummins L10 that makes what sounds like valve train rattle/injection rattle sound at low throttle but goes away when putting out some power. Good power when it feels like it, okay power when it does not. New injectors and no oil consumption. Anyone got any thoughts?

Before watching, I’m guessing wrist pins, based on the scraping visible on the cylinder wall in the thumbnail. Edit after watching: yeah I think it’s the wrist pin on that piston. Seen that kind of damage with loose wrist pins on multiple engines. It lets the piston rock side to side on the pin by more than the clearance between the piston and the wall, which then digs into the cylinder wall.

It's an overheated cylinder. Radiator is probably just cooling the engine at partial load. Running it hard overheats the engine. I service 30 year old pivot irrigation engines. Really common event, to have the radiator plug up internally from the crap in the tap water they put in these engines. Buy and use only 50/50 premixed anti-freeze.

Doesn't anybody use a mechanics stethoscope anymore? I think they work for getting a little closer to pinpointing a problem. Magnifier, Loupe or Digital Microscope would allow you to see more detail of metal particles in filter media and possibly pinpoint source by type of metal. Have all three for Troubleshooting and Failure Analysis. Digital Borescope or Endoscope would allow you to reach up and view areas like the Cam lobes, Cylinder walls from below in better detail. Mine Wifis to Android Phone or Tablet for viewing. To bad they didn't oil sample at regular service intervals. Drill rigs almost always have to be worked on outside with mast raised and locked for access to the Deck or Truck engine.

I just recently had to put a gear case on a series 60 in a freightliner cabover because it was leaking oil. The only reason I found the leak is I blocked off the blowby tube and it began coming out from the leak😂

Hey quick question for you because I get mixed answers. I am buying a 1997 RV with a cat 3126 I believe. What engine oil should be used? I've heard 10-30 and I've heard 15-40 also read that 15-40 is hard on the heui pumps. Do you recommend changing that heui pump out after x amount of miles as a precautionary or just run it until it dies?

A cylinder that is hitting harder than the rest is a leaking injector that's causing the noise