Oil sample results, worried.

[james]

I got a verbal update from my mechanic today, oil samples on both engines showed elevation in Chromium and Aluminum, which has me worried.  The engines are running flawlessly with no smoke at any RPM and good load carrying, producing correct boost etc.  I will get specific numbers on the readings when the report is delivered to me.

Last year, I pulled apart and replaced badly worn after coolers.  Even though I’d hit the two year mark to the day, of the stated and receipted disassembly and servicing (Prior to my ownership), both coolers where hopelessly corroded and frozen together.

Would it be possible that the after coolers were shedding some aluminum to the engines, causing an uptick on the Aluminum reading and potentially capturing a bit of chromium from the piston rings?

 

Trying to keep a postive attitude and not worry to much.  Thanks for any input.

Topic

[Dalton]

If this is worth anything….when I bought my boat the oil sample failed in a few areas. A mechanic noticed the previous owners used the boat for 10 hours per year (really didn’t use it at all) and he said change the oil/filters etc and run the boat for 5 hours and retest.  They did and it passed.

I could be wrong here but the theory was something like this. The boat sat, salt water air put a little deposit or rust on the walls, then when they ran the boat (got it warm) and took oil samples the first time it mixed with those ‘deposits’ giving false readings.

[Clark Leighs]

I’ll butt in.    Post the actual oil test reports.   There may be something else that you are not noting that will be  a clue to others more knowledgeable.

[james]

That was a typo in my post above.  The first set of numbers were for starboard.  The prior sample had no elevation, but who know’s, it might have been taken with clean oil in preparation for the sale.

What I thought was a fuel leak was a small amount of dirty water leaking down on the engine from the wire serving a speaker (Part of the entertainment system) mounted in a seat above the engine room.  Of course, it will require some PIA disassembly to correct that issue.

I’m pretty sure that the engine which is starting harder is due to my trying to adjust the idle and bumper spring.  When I give that engine 1/8th throttle at start, it kicks and fires on the first revolution.

[Rob Schepis]

So as bad as the aftercoolers were they weren’t leaking from the raw water side but some of the AL in the results could be from the condensation/corrosion.

Were the AL and CR #’s elevated at all in prior samples?

You’re above post list the AL and CR numbers both as the Port engine.  Is the one with the more critical #’s the one that is getting harder to start?  Did you ID that fuel leak?

Well you’ve clearly got your ducks in a row as far as good maintenance and operation so like you said, use the boat, monitor all and sample again in due time.

[james]

The sodium level was not called out, it was @ 7 ppm, which is slightly higher than the 3 ppm I saw on the reports I received with the boat.  Those reports were performed about a month prior to our purchase.

This was the first oil change after the Aftercooler and turbo change outs.  I do oil every December.

The levels in the report are:  Port engine AL – 23 ppm, cr 17 ppm.  Port engine – Al – 65 ppm, CR – 28 ppm.

When we pulled the after coolers, the port engine had the worst cooler, as we separated it AL peeled from the housing.  Starboard was salvageable with a little machining.  Both cores were replaced.  My mechanic, who is a graduate of the Merchant Marine academy, served on large ships and has been turning wrenches all his life, is baffled by the information.  Things that puzzle both of us is the performance characteristics of the engines: Start on the first turn even when ice cold.  With correct throttle management able to get the boat over the hump and on a plane with a dirty bottom and full load with out even a hint of black smoke.  I’m going to monitor closely and resample in 20 hours or so.  I’m still leaning towards somehow being related to the coolers, in hind site, I should have changed the oil after doing so much work.

[Rob Schepis]

Was there elevated sodium indicative of the aftercoolers leaking?  The oil that was sampled – how many hours on it?  Was the oil changed after your aftercooler replacement/repairs?

Was this your first and only oil sample?  (So only a snapshot).  What about at time of purchase, oil samples conducted at that time?

[james]

Good Morning Tony – You do start your day early.

1.  Tach’s have been verified as in-accurate with a phototach.  I have a cross reference table, so the numbers I put up are corrected.

2.  No load RPM’s go up to a bit over 2900.

3.  We are in the 2675 range at WOT, perhaps a bit more, the tach’s bounce around a bit at the highest rpm.

4.  Coolers were taken apart, thoroughly greased and reasembled prior installation.  I’ll probably pull them off again at the 1 year point, it takes me less than 3 hours to do an on and off, and I would prefer not to have that problem again.

5.  Engine hours at purchase 1075, at replacement of injectors 1175 or so, turbo’s at 1200.

6.  boost at WOT, which I only run for tests, is 30 on each engine.

7.  Typically start on the first revolution.  Port engine is starting to require spinning, but I spotted a small fuel leak near the injector pump yesterday.  I think a big of fuel is escaping causing it to loose some prime.  Going back to the boat today to look at it further.

Lacking fuel flow meters, I tend to use boost as a proxy for load on the engines, and tend to run while on a plane at 2150 rpm and 18-20 psi boost.

[Tony Athens]

1)  Tach readings have been verified in neutral at the dock in the 2200-2500 RPM range?

2) No Load RPM ( engines warm) have been checked and you make over 2800 RPM in neutral?

3) WOT RPM , loaded as you use the boat,  is 2600 or more (preferably over 2700 RPM) ?

4) When you eventually replaced the aftercoolers with new, did you take them apart, grease properly  before installation?

5) Engine hours when you got the boat, engine hours when you replaced the injectors &  turbos, and engine hours now?

6) Boost now at WOT RPM loaded as you use the boat?

 

7) Engines start easy when COLD and have not been run for a week or more  ?

 

Tony

 

 

 

[james]

Tony – The engines are CP: 1282, 400HP with Nippon Denso Pumps.  Application is in a Tiara 4000 Express which tips the scales at around 32500 loaded for bear.  Serial numbers are 44908536 & 44908437.

Regarding the Aftercoolers, I took them off at exactly 2 years after they were supposedly serviced.  I could not separate either core from the housing.  I replaced one unit completely, and had the other unit machined and rebuilt, (both decisions with the concurrence of a very good local cummins person).

My history is two years of ownership, in that time, I’ve done the following:  Replaced after coolers due to problem stated above, Replaced turbo chargers due to boost stopping at around 20 PSI, dropped an inch of pitch to take load off engines, adjusted valve clearance, replaced injector tips, and rebuilt both raw water pumps.

We’ve put around 150 hours on the boat and drive it very easy.  Typically utilization pattern is, out of harbor, get temps to 160 or so, then onto a plane at 2,100 rpm.  We then spend the bulk of our day at around 1100 rpm for easy cruising and fuel economy.

I also do a fresh water flush of the engines after each utilization.  When bringing the boat on plane, I ease the engines to 1,500 or 1,600, then listen for the turbo’s to kick in.  I then watch the boost gauges and keep them as even as I can as the boat goes over the hump.  By going slow and easy through this load situation, I get zero black smoke.

We get a little smoke and fuel sheen in the water on start up.  Can’t think of any other information points at this time.  When I get the actual reports, I’ll post the numbers

Thinking about doing a blow by test, but we have nothing coming out of the puke tube (no airseps).

 

[Tony Athens]

Not sure what you mean in the post–“hopelessly corroded and frozen together”——————-Were they replaced, or serviced as best you could?   Got pics??

As to your oil sample–To me it’s 100% meaningless based on your comments on how the engine run if really accurate,  and the fact I have zero history of the past.. But with that said, what EXACT engine, total history, serial number, application?

 

Tony

 

 

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