Yanmar Engine, What happens when/if the Timing Belt breaks?

[slimjim]

my question is if saltwater gets into the area of the timing belt (due to a leaking water pump) and belt tensioner frose/seizes anf the belt breaks when running what kind of damage can this cause?

can it cause damage to the pistons/valves/cylinder head? What could be total damage done to engine? Thanks for any and all replys.

[loubennett]

I assume you are referring to the 315 HP 6LPA engine that is common in the 28TE. My understanding is that this is an interference engine. That means that if the timing belt breaks, the pistons can collide with the valves causing major damage. Yanmar says the timing belt should be changed every 1250 hours or 5 years. Many owners seem to ignore the 5 year recommendation since it takes them much longer to get to 1250 hours. I don't think this is wise due to the potential consequences. A new engine is 25 to 30 thousand dollars. Quest has had the timing belt changed twice at 1200 and 2400 hours. The time factor is not really an issue since I put over 200 hours per year on her. The original owner (a boat club) put significantly more hours on her each year.

My advice is to follow the Yanmar schedule. A timing belt failure will leave you stranded and be very expensive.

[Pitou]

I assume you are referring to the 315 HP 6LPA engine that is common in the 28TE. My understanding is that this is an interference engine. That means that if the timing belt breaks, the pistons can collide with the valves causing major damage. Yanmar says the timing belt should be changed every 1250 hours or 5 years. Many owners seem to ignore the 5 year recommendation since it takes them much longer to get to 1250 hours. I don't think this is wise due to the potential consequences. A new engine is 25 to 30 thousand dollars.

My advice is to follow the Yanmar schedule. A timing belt failure will leave you stranded and be very expensive.

Or my advice ... Buy a 28TE with a Cummins 370. No timing belt maintenance with that engine as Cummins uses a timing chain. I do happen to know of one that is For Sale.

[slimjim]

I assume you are referring to the 315 HP 6LPA engine that is common in the 28TE. My understanding is that this is an interference engine. That means that if the timing belt breaks, the pistons can collide with the valves causing major damage. Yanmar says the timing belt should be changed every 1250 hours or 5 years. Many owners seem to ignore the 5 year recommendation since it takes them much longer to get to 1250 hours. I don't think this is wise due to the potential consequences. A new engine is 25 to 30 thousand dollars.

My advice is to follow the Yanmar schedule. A timing belt failure will leave you stranded and be very expensive.

Or my advice ... Buy a 28TE with a Cummins 370. No timing belt maintenance with that engine as Cummins uses a timing chain. I do happen to know of one that is For Sale.

Thanks guys for the input. My question should have been more clear, its whats the worst that can happen to an yanmar 315 diesel engine if you are running her and the timing belt breaks?

Could your engine blow? Anyone have this happen before and if so what damage did it do to the engine? Kevin, you know we could work a deal if I was up out your way. You have one of the best looking and best set up Albin 28TE i have seen. She I am sure will sell soon and someone is going to get a great boat.

[loubennett]

I'm not sure what "engine blow" means, but I would expect any or all of the following. Bent or broken valves, piston damage, cylinder wall damage, head damage. I guess the connecting rods and crankshaft would survive, but maybe someone else has a different opinion. In my mind that adds up to a very large repair bill.

[slimjim]

I'm not sure what "engine blow" means, but I would expect any or all of the following. Bent or broken valves, piston damage, cylinder wall damage, head damage. I guess the connecting rods and crankshaft would survive, but maybe someone else has a different opinion. In my mind that adds up to a very large repair bill.

Lou and all the rest thank you all for the replys. This is the info I was looking for. I hope to be a owner of a nice Albin 28TE soon. Thanks again for a great forum. Slim

[jleonard]

Or my advice ... Buy a 28TE with a Cummins 370. No timing belt maintenance with that engine as Cummins uses a timing chain. I do happen to know of one that is For Sale.

Cummins uses timing GEARS not a chain. Big difference. No chain to break or wear either.

[Pitou]

Or my advice ... Buy a 28TE with a Cummins 370. No timing belt maintenance with that engine as Cummins uses a timing chain. I do happen to know of one that is For Sale.

Cummins uses timing GEARS not a chain. Big difference. No chain to break or wear either.

Wow, gear driven. That's some quality engineering. The engine was pulled summer of '11 for a transmission replacement and I asked my diesel mechanic about replacing the timing belt and he responded," you have a Cummins, no timing belt" and I assumed a chain. .... Never Assume . Thanks for the education J.

[johnmurray]

According to my mechanic, because the Yanmar 6LPA-STP is an interfering engine, a timing belt break would cause very severe damage. He was not more specific but the implication was an engine replacement situation.
I waited seven years before having mine replaced at 650 hours. The belt showed no sign of wear when removed, but my piece of mind was improved. The belt cost me CAN$ 105.60 and the installation cost was about $500. (Some other minor work was done at the same time.)

[Carl]

Lou, can you please send me the contact info for the mechanic you use to work on your Yanmar? I need to get this done this season along with a few other little things.

Thanks!!

[loubennett]

Carl, I use Andy Hoyt for my engine work. His company is Dock Call and his cell number is 410-570-4618. His email is dockcall at Verizon.net. I've been using him since I bought Quest and he has always been responsive and less expensive than the big guys. Give him a call or email.