2002 TE 28 Yanmar 315 - Valve seal

[rellwood]

2002 28TE Yanmar 315 6LPA-STP Serial M50698

from a previous post "The Class consists of all persons or entities who as of March 15, 2007, are current or former owners of Yanmar 6LP or 6LPA series engines manufactured by Yanmar between September 1996 and February 1, 2002, specifically including those which a) have a model designation of 6LP-STE, 6LP-STZE, 6LPA-STE, 6LPA-STZE, 6LPA-STP or 6LPA-STZP and b) bear a serial number in the range of 50101-53988 or M50001-51195"...

I purchased boat in Fall 2008, 300 hours. no mention by Owner or Broker of a possible seal problem. No engine survey was completed. After purchase, I found the information on the valve seals and as part of maintenance had the valves adjusted by a Yanmar authorized mechanic at 600 hours. The seals were "grey" not "green".

My question is whether to change the seals now after 600 hours. Sometimes changes create other problems. The information, I have gleaned from other posts is that most problems occurred at low hours, less than 100 hours and many engines have not had the seals replaced. I would appreciate any comments from Owners who have not changed seals and have 500+ hours and from anyone who has had problems with the "grey" seals at 500+ hours.

[RobS]

The mechanic who did the 600hr valve adjustment - what did he say?

My 6LP had ~440hrs when I bought the boat. There were no issues detected but I was not comfortable without changing the seals as the failure is detrimental. I had mine done right away. The seals can be changed without pulling the head, the cylinder is pressurized with air to keep the valve from dropping down.

I know one 6LP owner who heard the interference ticking (valve sticking) noise at ~1,000hrs.

[carolmarie]

Had mine done a month ago.
A 2001 engine, SN 53732, with 800 hours that ran flawlessly for the 10 years I've owned the boat. Learned about the valve issue last winter!!!! Talked to Mack Boring, both at their HQ in NJ and their NE service center, both recommended immediate changeout of the exhaust valve seals. (By the way, I attended MB's three day diesel engine maintenance course in '07 and they never mentioned the class action suit.)
Talked to Yanmar too -- long, long story.
Bottom line :
Recommend you have them done.
Recommend you register your engine (via MB or Yanmar) with Yanmar, for the record.
Repair was done w/o head removal. All valve clearances were also done at the same time. Engine runs noticeably quieter.
Carolmarie, 2001, 28TE, 6LP-STE.

[rcwhite]

When we started looking I spent some time looking into this on various forums
as well as the Yanmar bulletin on the subject. While this seemed to be more of
an issue for engines that spent a lot of time at low RPM's, I considered this
required maintenance and included it in my review of the records and cost
calculations. I wouldn't hessitate to replace the seals myself. Oil starvation is
nothing to be taken lightly.

Chris

[carolmarie]

Chris:
I could be mistaken, but I was under the impression that an exhaust valve seal failure could result in major engine failure, and quickly too. Seems that it would be prudent to heed the advice of so many to change the exhaust seals ASAP.
Carolmarie, 2001, 28TE, 6LP-STE.

[rellwood]

Thanks for all the advice. The comments reinforced my thoughts...that the seals must be replaced as soon as possible. The seals have been ordered and they will be installed as soon as they are available.

[TimQ]

If damage has been done figure on $10K (Mac Boring's suggestion). The seals can be changed for considerably less so I don't know what stops an owner from doing this, especially before listing it.

[Tree]

My Buddy over here is just going through the process of having his changed - however...

Although he is having the seals replaced he has found another issue, the inlet valves have all needed replacing, the exhaust valves are fine, but the inlets valves are scored up on the shafts.

Thankfully, he took the option of removing the head to do a full investigation so at least when it all goes back together it will be a fully rebuilt head and last for many years to come.