6BTA 370 HP quits at 2700 rpm in 46 Maxum

[Russ Keyes]

Coming back I ran the engines up to 2700 RPM and after a few minutes the port engine quits. Close to home so go back on one engine. Mechanic comes down we start port engine runs fine, we change fuel filters, and go for sea trial. All is fine at WOT for a couple of minutes and 2800 for 15 min. When we got back noticed coolant under engine. Went back and found a small crack in head back by aft fuel injector. Had minimal lost coolant year ago, could not find leak, used stop leak went away. Since we felt we had cured engine issue decided to replace the head. Installed head went out for sea trial and port engine made 2800 RPM but quickly started to loss RPM’s and finally dies. Started back up but each time we got past 2000 it would quite but would start back up. Went back at reduced RPM all ran well. Mechanic could not figure out what was causing problem. After asking a couple of his friend questions it was suggested to remove the air filter and look at the turbo. It was dripping with oil. We had serviced the intercooler when doing the head and tech mentioned air side was oily. We then decide to pull the breather hose from the filter and go out see what happened (extended breather pipe into a bucket). Up to 2000 RPM normal when the turbo kicked in oil came out enough to fill 5 gallon bucket with 1″ to 1 1/2″ of oil. Back off to 1800 or so no problem. I had never overheated the engine but only owned boat for a couple of years. Now since the head was cracked and we have blow by it is assumed we have ring problems, but why only when the turbo kicks in. One of the shops, very reputable, I was talking to about pulling the engine suggested with a great deal of confidence that the problem was the turbo not the rings. Personally I do see how it can be the turbo but that is my question is it possible it could be the turbo? Sorry this is so long for a short question. Thanks

Topic

[Russ Keyes]

CCV

Thanks Tony appreciate all your advise. I am going to sell the boat this spring and will fix the engine rather and wait and be told to do it or loss a sale. Looking at a 52 or 56 Carver hopefully with Cummins instead of Volvo.

Regards,

Russ Keyes

[Tony Athens]

Russ,

As I said, no CCV system will stop engine blow-by. At best it will contain it without causing other issues like the Walker can with the hose trap loop used on 100’s of early “B” series engines..

If your “suspect engine” starts easy with cold, not to worry–Go fishing, just keep an eye on the bottle & keep the oil pan level at the LOW MARK of 12 qts or so…

Tony

[Russ Keyes]

CVV

Here are the install pictures

[Russ Keyes]

CVV

Yes we discussed it quite a bit and it is exactly 12 quarts. It did solve the oil being pushed into the air filter.

I’ll send a picture.

Thanks,

Russ

[Tony Athens]

Russ,

Send me some good pics of the CCV install–I want to see it all..

If you have excessive blow-by from an engine and it starts fine when cold and runs good overall, a properly set up CCV system can mitigate to to where it is “out of sight & out of mind” so to say..

Let’s see the install..

Next–That engine–Have we talked about EXACTLY how much oil is in the oil pan, sitting at the dock, engine off?

Tony

[Russ Keyes]

CCV

Good Evening – Would seem we are at the end of the trail. Installed your new CVV and still have substantial blow by on the port engine. Puffs out of the filler cap at idle and significant pressure at cruise. The pressure difference at the filler cap between the two engines at the same RPM’s are remarkable. Mechanic is convinced it got hot at some point cracked the head and expanded the pistons and rings. Got any good deals on a 5.9 370 HP? Russ

[Russ Keyes]

CCV

I have read about and seen the CCV system you have on your tips site. Do you think that is the problem and not blow by. The airseps were installed last winter. The other engine has the same set up and no pressure at the oil cap. Do you sell the system as a set, or is it available else where? It’s worth a try, I’m thinking short block right now. Russ

[Tony Athens]

Russ,

Now that I see what you have for a CCV, it all makes more sense.. You have Walker Airseps with “sink loops” that fill with oil and then will not allow the engines crank case to breath properly.. That is most likely why the one engine was puffing out the oil fill cap…………A complete Couch engineers design–Do some reading on my web site..

Don’t worry about the comment on “piston pick-up”.. ..

Tony

[Russ Keyes]

Blow By

Here are a couple more. Russ

[Russ Keyes]

Blow By

Here are some more pictures. Russ

[Russ Keyes]

Blow By

Both engines start quickly and run well. They both smoke when cold and hardly at all when block heaters used. We were in the process of getting another boat, then this happened. I want to be sure the engine is right before I sell the boat. Is that much blow by OK? What is piston “pick up”. I do have these pictures. Thanks for the reply. Russ

[Tony Athens]

Russ,

This is good and not so good… Looks like you have one engine that has suffered some piston “pick-up” and that’s why the blow-by on that engine…………..

Answer this:

Does that engine start pretty good when cold? Compare to the other engine?

Understand that “blow-by” can be mitigated………………….Need to see your engine as installed in the boat.. Good pics of all–all angles and all perspectives..

Tony

[Russ Keyes]

Oil Change

Good Afternoon – Finally completed the requested items. 1.) Drained all oil and added 12 qts. 2.) Marked dip stick at 12 qts. 3.) Checked both solenoids again, Good 4.) Primed injector pump, Started cold engine (5 days) 100% throttle. Started right up lots of blue smoke. Did the same for starboard same result 5.) Did a sea trial engine ENGINE DID NOT DIE! at WOT Good news, Bad news, lots of blow by with oil filler cap off and there was dip stick pressure and slobber. With cap off there was smoke, pulsing, lots of pressure when you put you had over the hole. Compared it with starboard, which had no pressure. You solved the problem unfortunately it seems the underlying issue still exists. Thanks Russ

[Russ Keyes]

Oil Change

Will do.

[Philip]

Don’t worry about the high mark. So many people want to run at the high mark and end up causing themselves more issues than they realize.

Drain the engine dry dry dry 100%, add 12qts, marks the dip stick and do the 100% throttle start, report back.

We will get you fixed up….

[Russ Keyes]

Oil Change

Great suggestion. Thanks

[Russ Keyes]

Oil Change

Agreed that is the plan did not know where to put the high mark. Russ

[Bill Desmarais]

Russ,

Bill D here.

I now own my 5th 6BTA 370.
One of the 1st two I owned burnt up real good due to an overheat back in 2008.

I didn’t know Tony @ the time but got to know him very well over the past 9 years.

I’ve learned to follow his suggestions…step-by-step…no deviation or you’ll be wasting your time, his time and the $$ in your wallet.

Do the two steps Tony wants done. No mechanic needed.

Drain the oil out of engine. You just put 15 qts in it.

Poor 12 qts of the oil you took out back into the engine…nothing more…. and leave the filter alone..you just changed it and it’s brand new. Do worry about putting the 13th qt in for now. The 6Bs run safely @ 12 qts.

Stone cold fire off the engine 100% throttle at the dock and report back.

[Tony Athens]

Russ, this next time around, don’t even touch the filter.. Just drain the pan 100%, add 12 qts, mark the dip sick for the low mark, and use that mark as low and high will be no more than 1/2″ above that. The oil filter will take care of itself this time around.

Tony

[Philip]

Russ-

Sucking doesn’t says get every last drop out of the pan. It’s a good start, but then you need to remove the drain plug and get the remainder out before you start adding oil back. What you put in the filter has nothing to do with pan capacity. Once you have established a true 12 qt mark then you won’t have to worry about residual oil after sucking rather just fill to the mark.

Get that oil drained dry dry dry and add 12 qts, mark the dip stick! Then we can go from there to next steps.

[Author]

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