2020 T394 engine knocking noise

[bdl67]

I have a 2020 T394 with a Yanmar engine. The tractor has 304 hours with proper maintenance. It's making a hammering or tapping noise and it sounds like it's coming from the bottom end but it's hard to locate. The noise stops when the engine is hot but if you let it sit for 30 minutes it'll come back. I tried attaching a video but I'm not able too.

 

[5030]

I'd say a crank thrust washer has failed Couple Yanmar forums on the net where you can get a more definitive reply.

 

[bdl67]

I'd say a crank thrust washer has failed Couple Yanmar forums on the net where you can get a more definitive reply.

thanks! I have been researching but I can't find anything except Yanmar in boat applications

 

[5030]

Try www.tractorfourms.com they have a Yanmar specific sub forum.

 

[bdl67]

Shared album from Brad ð¸

Tap to view!

photos.app.goo.gl

 

[bdl67]

Try www.tractorfourms.com they have a Yanmar specific sub forum.

I posted a video. Hopefully it works

 

[TractorTYMe]

You should still be under powertrain warranty with that one.

 

[bdl67]

You're right it is. I spoke with the dealer today. They thought the sound was valve related. It's going to the dealer tomorrow. My dealer has 2 shops 2.5 hours from me in either direction, i chose the one that could get it in right off.

 

[bdl67]

My dealer's (Scotts Recreation) mechanic is quite positive just based on the sound and symptoms it's a bad injector. I'm really happy how they treat me and I'm confident having them as my dealer. I will update when fixed which is estimated to be a week from monday.

 

[TractorTYMe]

That would be GOOD news, AND a plus having such a good dealer.

 

[bdl67]

That would be GOOD news, AND a plus having such a good dealer.

Absolutely! Scott's recreation went from 1 dealer to 2 since i bought my tractor and they're opening 2 more in New England. They're doing something right I'd say. It's nice to have a dealer on your side that's for sure.

 

[bdl67]

update: dealer called and told me they can't duplicate the noise. When It started up to be driven off the trailer once I got it to the dealers I couldn't hear it and I thought " how typical". The mechanic starts it multiple times a day and varies the rpms and hears nothing. he checked the injector lines for tightness and is continuing a search for "suction side air leaks". I am very happy for the update but mystified why this phenomenon occurs. things always run fine when you bring it to the shop.

 

[bdl67]

Fixed:
They found a metal broken cross member under the motor that would slap against the engine at certain RPM's. I can't believe i missed during my many searches. I'm really happy with the dealer and relieved it wasn't anything major.

 

[TractorTYMe]

Glad they found the culprit.

 

[bdl67]

Final update:
The rattle was caused by the front driveshaft Shroud not a crossmember. There is only a tiny spot weld that broke from vibration. They said it was only to keep grass from getting tangled around the drive shaft so i opted to keep it off.