Diesel Knock? L2350DT

[DrakeRemoray]

Here are 2 videos. Both on cold start of the engine. Is this diesel engine knock.

Backstory, pulled the injectors and fuel pump and cleaned them. Replaced the 2 injectors on the left (Chinese made) and bench tested and adjusted with shims to get the proper pop off pressure. Cleaned and adjusted the 3rd. All are within specs.

I’m getting fuel on the return line as shown in video 1.

I feel like the tractor has always sounded this way…the knock goes away with higher RPM.

Pull them apart and clean again before I purchase new?

Kubota diesel engine knock

Kubota engine diesel knock test

 

[North Idaho Wolfman]

I'm not hearing anything that abnormal?
These IDI engines tend to sound knocky on cold starts.
Try adding some stanadyne (cetane booster) to it.

It possible that the timing is off a little, that will cause more of a knock too.

 

[DrakeRemoray]

The oil is pretty runny as well...I should have added that. Ill add some stanadyne and see what we get. Looking at a replacement price of $210 for all 3 injectors from a reputable place.

As far as adjusting the timing...Is it that difficult...and if you say im going to have to split the tractor, im going to loose it!

 

[Flintknapper]

I have the same tractor, sounds fine to me.

But....I'd put some 'decent' (read OEM) injectors in it just for longevity sake

 

[DrakeRemoray]

Just pulled the trigger on the injectors. I will add some stanadyne or will any other cetane booster work as well?

I will report back when I get it back up and running. It just sounds like a metal slap and I don't like that the oil is showing runny. If nothing else this may help someone else down the road.

 

[Flintknapper]

Don't know what weight oil you are running in the tractor, but in hot climates (such as I have in Texas) I run 15W40 diesel oil.

Holds up better and reduces a little bit of the 'clacking' sound at start up and idle speeds.

But from your videos....I am not hearing anything I would say was a 'knock'.

 

[RCW]

I’m far from an expert, but was idling my BX this morning.

Sounds normal to me.

I agree with the others. Normal.

 

[armylifer]

Another vote for normal sounding. To answer your question about a different cetane booster try Power Service Diesel Kleen in the silver bottle for summer and in the white bottle for winter. Here is a link to it from Walmart.

Robot or human?

 

[DrakeRemoray]

Sweet! Thanks for all the replies fellas. I will go ahead and install the brand new injectors for peace of mind and longevity of the tractor. Looking at the oil and the other products mentioned as well. Thank you!!

 

[Russell King]

Take the dipstick out of the engine and see if it is higher than expected, and put it near your nose and smell it for diesel fuel. I am not 100% sure but I would expect to be able to smell diesel if it is in the engine oil enough to be making it “thin”.