The real value and proof of oil anaylis

[Canuck Dennis]

so, one my 12 71 n's has had very high chrome and iron for the past 2 yrs analysis, inspection showed nothing drastically wrong but certainly wear, approx 6700 hrs on thew engine.

4 starts ago from a preheated engine showed a fair amount of blue smoke in exhaust, cleard after 5-10 min under load, last start , embarrassing....covered the Marina, so, it's rebuild time, starting this coming Monday, will try and do as much teardown over the weekend and this old fart can manage
then the certified DD mechanic at 120.00 per hour can do the rest.

Will keep records and report results and costs for info.

 

[Avenger]

So let's see if I'm following this correctly, the rings started to fail four starts ago, and completely failed on the last start? How many hours did you run between those starts?

 

[Dan Mapes]

Indeed. All of a sudden if puked?

 

[Canuck Dennis]

No, had not re done oil analysis for a while but figured it should be done again, inspection even showed no serious wear in rings and liners 12 mos ago and 3 yrs ago ..so am assuming it was a creeping wear issue and then of course as it went on it accelerated.

 

[Avenger]

What were the results of the compression test?

 

[dottieshusband]

You'd better have some very strong friends! The bare head weighs 230, about 270 with valves, rockets, bridges, etc.

 

[Canuck Dennis]

No compression test, the combination of oil analysis and start up excess blue indicated a potential piston/rings/liner failure and I was not prepared to do just one cyl, at the number of hours it just made sense to do the 12.
I personally will not be lifting cyl. heads and we are just going to do the exchange head deal.

 

[ddctech]

You could have something as simple as a bad injector or stopped up fuel filter. have seen one emergency shut down flap close as well. Don't condemn it until you have it properly diagnosed. If you need any advice or further help, feel free to contact me at 912.658.2960

 

[Avenger]

A visual inspection shows no signs of serious wear you've decided to to a complete engine rebuild based on a few smokey starts and oil analysis? How do you know it's not something like blower seals or a bad injector as ddctech said?

It's your money to spend. And if you want the comfort and shine of a rebuild do whatever floats your boat. But I'd be hard pressed to justify that kind of expense without knowing for sure that the engine was shot.

 

[Canuck Dennis]

so, when the lab calls and says your wear factors are 30 times above normal and should be addressed right away, why it's only a stopped up fuel filter or bad injector.at close to 7000 hrs it is no big surprise to see something like this crop up. as you say it's my call.
Why I had one "mechanic" suggest I have the intercooler cleaned as that would clean up the smoking issue,

 

[brico]

so, one my 12 71 n's has had very high chrome and iron for the past 2 yrs analysis, inspection showed nothing drastically wrong but certainly wear, approx 6700 hrs on thew engine.

4 starts ago from a preheated engine showed a fair amount of blue smoke in exhaust, cleard after 5-10 min under load, last start , embarrassing....covered the Marina, so, it's rebuild time, starting this coming Monday, will try and do as much teardown over the weekend and this old fart can manage
then the certified DD mechanic at 120.00 per hour can do the rest.

Will keep records and report results and costs for info.

Hi Dennis,
Are you in Vancouver? If affirmative, which DD mechanic are you using for this work?

 

[Dan Mapes]

Could a plugged airbox drain cause this at start up?

 

[rsmith]

Sounds knee jerk to me. I'd pull the air box covers first and check ring tention. Could be a stuck or broken ring causing the high chrome and iron readings. As I've said before oil ankylosis is highly subject to how the sample is taken and time between samplings. If the engine is alouwed to cool down all the normal crap in the oil will settle and cause a bad reading.

 

[rsmith]

so, when the lab calls and says your wear factors are 30 times above normal and should be addressed right away, why it's only a stopped up fuel filter or bad injector.at close to 7000 hrs it is no big surprise to see something like this crop up. as you say it's my call.
Why I had one "mechanic" suggest I have the intercooler cleaned as that would clean up the smoking issue,

Hey Dennis! I hate to break this to you but there is no inter cooler on a 12/71N!

 

[saltshaker]

Hey Dennis! I hate to break this to you but there is no inter cooler on a 12/71N!

I was just about to post the same when I saw you beat me to it. 7K hours for a 12V71N in a MY is not that high. I'd get a good evaluation before I ripped it apart.

 

[capttonyf]

Hey Dennis! I hate to break this to you but there is no inter cooler on a 12/71N!

Those Sons a Bi!che$. Always trying to pull a fast one on an unsuspecting Canadian, Floridian, Bostonian, or any other, ian you can think of. I'll tell you what.
Seriously though, If it does need rebuilt, good luck, and hope it stays simple with no surprises.

Tony

 

[Avenger]

We can't see it from here, but when you make statements like this:

No, had not re done oil analysis for a while but figured it should be done again, inspection even showed no serious wear in rings and liners 12 mos ago and 3 yrs ago ..so am assuming it was a creeping wear issue and then of course as it went on it accelerated.

And decide that a couple of bad starts = sudden terminal ring wear, combined with a lab report that shows chrome and iron you've concluded that the engine is worn out at 7K hours which is normally not excessive for an N. All the analysis people said was address the problem. They didn't say rebuild the engine.

Clearly you are bent on an overhaul, and it may be that it is necessary. But the facts you're stating do not necessarily support that conclusion and you've gone right to the most complex and expensive solution available. How do you know those metals didn't come from a ball bearing in a blower which failed and is now leaking oil? Maybe it is and maybe it ain't, but I'd sure want to know if I was bulldozing a house to fix a burned out lightbulb.

 

[Canuck Dennis]

So Mr ,Smith, and few others can't read eh, my post said a "MECHANIC" told me to get the intercooler cleaned,that's why he did not get the job, and you want me to take your advice ????

 

[saltshaker]

So Mr ,Smith, and few others can't read eh, my post said a "MECHANIC" told me to get the intercooler cleaned,that's why he did not get the job, and you want me to take your advice ????

We're just trying to help you fix the problem efficiently. If your mechanic wants you to clean the intercooler on a 12V71N, you need a new mechanic. There are no intercoolers on a naturally aspirated 12V71.

 

[Avenger]

You guys are missing the sarcasm.

However Dennis is also missing the point that a fair number of experienced people are suggesting that he could possibly save tens of thousands of dollars and a healthy part of his month and a half boating season by not skipping over all the other possibilities. But hey, it's only Canadian Loonies and Twonies. It's not like it's real money or anything.