Name that noise

[99GreenCummins]

Brother's 02 is having some sort of knock/tick going on. Video isnt great but you can really hear it when videoing under the truck.

Knock started when he was hauling his 77 ford home from buying it, said the truck just died after topping a hill, pulled off the side of the road, let it sit then it took a few cranks but fired up, drove it the rest of the way home. He parked it thinking it was a wrist pin or main bearing bad. It sat for 2 months, he fired it up and no knock, drove for a day and knock returned and had fuel in oil.

Took to a local shop and had injectors pulled, found the bodies were banged up and wouldn't seal. Installed new Bosch injectors. Knock gone, not adding fuel to oil. Truck still the slightest of ticks. Had valves adjusted, was gone for a few days.

Now the knock is back. Last time he drove it was yesterday. Went out and started it, idled for 8-10 seconds without knock then it started knocking again.

I have no clue and no one local is exactly sure what it is. Starts fast, good power, all the usual. Knock sounds like its from back of motor but can't tell.

Video:

VP Cummins knock/tick - YouTube

 

[VMacKenzie]

How's the blowby, if it seems excessive and especially if it pulses then likely it's a scuffed piston caused by getting too warm and swelling or starting to get soft. One issue that happens on occasion on 24-valves is piston cooling jets breaking and leaving a piston vulnerable to meltdown.

 

[99GreenCummins]

No blowby. Pull the oil cap and no air moving, pull breather off front cover and nothing again.

The cooling jets crossed my mind but haven't pulled the motor apart enough to know. I haven't been around in time to check to see if it has been holding pressure like a blown head gasket.

 

[Cummin_un_glued]

pull the oil pan, that sounds like its in the bottom end to me

 

[Newdieselguy]

Could maybe be a cracked flexplate or the convertor bolts could be a little loose?

My buddy has a cherokee that he thought the lower end was knocking, would only make the noise as it was turning off or if he would cover the TB and snuff it out, ended up the converter bolts were loose.

 

[hotrod04]

I had same problem a yr or so ago. Changed nozzels and it cured it.

Sent from my SCH-I545 using Tapatalk 4 Beta

 

[99GreenCummins]

I never thought about a cracked flex plate, might have to check into that. Make sense since it started when he was towing, or loose converter since it starts a few seconds after idling.

 

[mathews8pt]

I never thought about a cracked flex plate, might have to check into that. Make sense since it started when he was towing, or loose converter since it starts a few seconds after idling.

power brake it a little and it will usually go away if its loose bolts. The couple ive heard were VERY loud though and start as soon as you started the engine.

 

[cetanefreek]

bad injector washed the cylinder and causing a scarred cylinder wall? I know when one we had at work got overheated and scarred #6 I thought it was a knocking rod when I first heard it.

 

[99GreenCummins]

bad injector washed the cylinder and causing a scarred cylinder wall? I know when one we had at work got overheated and scarred #6 I thought it was a knocking rod when I first heard it.

The injectors were leaking around the connector tubes. The shop that installed the injectors supposedly bore scoped the walls and said they didn't look scarred.

 

[99GreenCummins]

Ok, I am beginning to really lean towards some sort of trans issue. He hauled some equipment for me today. It would make the same noise as in the video, he could drive a block or 2 and have to stop for a light and noise would be gone. Anyone have an idea? Flex plate or converter bolts loose? I am not at all an auto expert.