Removing oil cooler from Yanmar 6LYA-STP

[Waterant]

Hi guys,

I'm happy to report that after three weeks of scrubbing, fixing, and replacing my "new" Mainship 430 is getting back to life nicely.
I'm working on the engines now and need some help.

The starboard engine works well and starts right away (I replaced all the fluids and the filters) but has a busted oil cooler.

Looks like raw water was not drained before the winter, and the freezing pushed both end cups out. I did not see any water in the oil yet (had the jar of drained oil sitting for a week and do not see any separation), but most likely, the oil cooler has to be replaced.
It's all good if i could see any way to remove that thing without disassembling half of the engine!
I thought those coolers are supposed to be cleaned periodically and for that, need an easy way to be removed?

Has anyone removed an oil cooler from Yanmar 6LYA-STP? Can it be removed without removing the Inter cooler, which is on top of it and restricts the access to 3 oil pipes behind the oil cooler?

Thanks

 

[porman]

I just did this job two years ago. I removed all the coolers for cleaning and resealing because they were 17 years old and had never been off. Some of the rubber seals were starting to show signs of seeping. I don't see any way to remove the oil cooler without first removing the intercooler. There's not enough room. The hardest one for me was the port engine heat exchanger. That sucker is heavy and lifting it up and over the engine while laying on top of the engine was all I could do.

 

[Waterant]

Thanks, at least that gives me hope it's possible without taking the engines out of the boat.
Sooo little room there. Being 6.2' is a real disadvantage on a small boat with 2 large engines. whoever designed that room probably thought the little children will service those engines.

 

[Comodave]

Might as well go ahead and service the aftercooler while it is out. Who knows when it was last done, if ever.

 

[Waterant]

good point. i'll look into this.
most likely, it was never taken out as the engine has only 280 hours on it.

 

[Comodave]

Yes, but it is 20 years old according to your profile. If it looks good then the other engine is probably ok. But if it looks questionable then you may want to do both aftercoolers.

 

[DavidM]

Any 20 year old engine, regardless of the hours which hasn't had at least two after cooler maintenance jobs, is probably in trouble. The after cooler is probably the most vulnerable part on the engine because it has sea water on one side and compressed air on the other which is burned by the engine. Lots of room for problems!!

So definitely pull the after cooler and service it. Read how Tony Athens does his Cummins after cooler on https://www.sbmar.com/tonys-tips/ as well as a short article on the Yanmar's. With the aftercooler off, the lube oil cooler should be easy.

David

 

[Waterant]

thanks. I will remove and service both on both engines.
one advantage of having 2 engines is that i can practice on the port side with easy access so it will be easier to do starboard engine working upside down

 

[DavidM]

That is the first time I have heard of any ease of maintenance advantage for twins .

David

 

[Comodave]

I have to service my aftercoolers and change the coolant. The starboard engine has them right in the middle, easy access. Port engine not so much. I will practice on the starboard engine and learn how to do it before attempting the difficult port engine.

 

[Waterant]

I will practice on the starboard engine and learn how to do it before attempting the difficult port engine.

yes, that's the plan

 

[porman]

That's what I did. Took apart one and sent the coolers out. Left the other one alone to see how everything went back together. Then took the other one apart.