sea trial cummins 6bta's

[1956olds]

saturday 3pm,port engine didnt get temps over 163,possible t stat?starboard engine temps 180-185.wot rpms unknown as tachs both stopped at 1900 port and 2100 starboart but they were syncd (by ear) and she ran at 29-30 knots very smoothly,cruised at 25 knots also syncd by ear.Coming into the fairway from the no wake zone of 1/2 mile starboard alarm for high heat came on and temp went to 230-240,i tried to give it some throttle but no power just lag ,port still running fine so we docked.I didnt have a IR temp gun to check temps directly and the guages still read 130-140 after an hour and a half on starboard engine.There were other small issues like the water in the forward engine room bilge that was dry previously,may be leaking hot water heater but possibly it blew a fw cooling hose somewhere it isnt antifreeze so my tast buds tell me but i could smell very slight anti freeze.I am thinking thermostats as i found two new kits on the boat ,thinking it was a previous condition.I called the broker and told him what was up,he said a mechanic would be on the boat today,he owns the marina alsne other thing the gen wouldnt start.It ran for the survey after a fuel leak was repaired ,now it is spitting out oil ,i think it was over filled when the oil was changed last month and it shows on the dip,would excess oil cause shutdown ?It dose start to run then dies.Any ideas? boat has 1516hrs . PS the boat handles well and rides great in 1-2 ft chop,i love it,the bed is too hard and there appears to be an oil leal at bell housing but may be due to idleing up the river .Glen

 

[trit21]

WOW, lots of questions and kind of jumping all over the place so let me try and answer some of them for you.

First, get the tach working or better yet get an IR tach to determine the REAL WOT. 6bta's run at about 180-185 maybe 190 when you push to WOT for 5 minutes or so but you have to make sure you are turning over rated RPM. RPM's I assume are 3000 although you don't mention the horsepower of the engines or the rated RPM so if may only be 2800. So you have to determine which 6BTA you have as well. Look at the engine plates.

Alarm for high heat is not good at idle. Why would you give it some throttle? This only creates more heat. There are many things that could be going on with the scenario. Do you have any of the maintenance records? If so, when was the last time the raw water pump was changed? fuel cooler cleaned? transmission cooler cleaned? aftercooler cleaned, heat exchanger cleaned? All of these items are in the cooling path and should be cleaned every 3-4 years to ensure proper cooling path and effective cooling of those components.

Another very important thing is how is the configuration of the exhaust shower and turbo junction. Not sure what the engine room has for space but many times the manufacturer does provide enough height or any height and there is a possibility for sea water to back up into the exhaust side of the turbo. I can't tell you how many times I have seen this on boatdiesel.com and it ruins so many turbos or worse costing big money to repair.

Generator not starting. What type of generator? Spitting out oil from where? It may not be oil but it may be a diesel soot coming out the exhaust from sitting for a long time.

Go to boatdiesel.com and get yourself a membership, $25 for year. It will save you so much in the long run it is worth the money. 6bta's are great engines but like anything else, they have to be taken care of correctly and the correct maintenance has to be done otherwise they break just like anything else will regardless of the color of the engine.

 

[1956olds]

I have 300 hp at 2700 rpm 6bta m2s ,the plate dosent specify what wot rpms are.I gave it some throttle not much ,i was turning 90 degrees into a different fairway when the alarm went off,then i had to turn 180 degrees to get on the wall/slip.I had both raw water pumps rebuilt this winter and the exchangers removed and checked ,also the aftercoolers were opened and checked ,they were very clean.Do not think i have a fuel cooler,trans coolers were not very warm and trans fluid is clean with no burnt smell,i just had samples done on the engines and transmissions, they were fine.I didnt hear from the broker today i will call him tomorrow and see what they found.
The generator is a quicksilver 8.0 diesel,the black stuff is coming out the exhaust port on the side of the boat.It was run in december for the survey,i changed the fuel filter saturday and the oil was changed last month by the marina.I am 5 hr drive from the boat so i doubt i will get any troubleshooting done myself.I probably wont get much sleep either.Thanks for posting .Glen

 

[trit21]

I am going to assume you date plate says 300 hp at 2700rpm. That is your WOT. The boat should turn approx. 2800 rpm or even a little higher with a loaded for bear load easily. This will verify boat is not being overloaded. For example, mine is a 370 hp at 3000rpm. But when I full load, my WOT is 3120.

My generator also emits just a little black soot looking stuff when I first start it but is fine afterwards and has done that since I have owned it. Unless I run it every weekend, which in the summer we do, it will tend to show that soot exit the exhaust.

230-240 degrees once you shut came to idle is worrisome <sp> . Mine run at 185 give or take a degree or 2 and less when at idle. Enclosed here, I hope, are area that need to be checked with an IR gun. I will assume you have one or you should get one. Regardless of what your broker says, I would take her for another ride, WOT and get the engine hot and try to repeat what happened. Have someone else drive and take some measurements if you can or have your surveyor do it for you.

http://i690.photobucket.com/albums/vv266/trit21/330-370_Diamond-IR_FULL.jpg

I have all kinds of pdf's and information about 6bta's. Mostly the 370hp version but they transfer to most any 6bta. Just ask.

 

[1956olds]

Thanks tom,i also want to add that we had only 1/4 tanks of fuel on the initial seatrial and no waste or water on board.The second trip we had full tanks all around except waste was pretty much empty still.No word from the broker yet either.I may add he still has the hold back money from the sale and i expect him to use it to fix the issues.I just wanted to know what the issues actually are so i dont get a bandaid instead of a repair.Glen

 

[trit21]

so you own the boat or is it just under contract?

 

[1956olds]

Been making payments since december,pending seatrial,survey was completed in december included running engines .

 

[1956olds]

Well the diesel mechanic says it had a air bubble from setting over winter and it is quite common because the system was low on antifreeze,I will have to keep an eye on it but he couldnt get it to over heat at all.Monday they will be checking the grounds throughout the boat to see if that is the cause of the tach situation and the blowers and manual bilge switches being intermittent now.They have found a problem in the circuitry for the genny that shuts down the fuel valve as soon as it starts running and will have it fixed monday .Then the broker will take it out and make sure everything is working.Hoping to bring her home at the end of the week.Fingers crossed.I will get a ir temp gun this weekend and possibly a touchless tach meter,also a membership to boat deisel.Glen

 

[trit21]

Losing antifreeze is not common. It is a closed system and there is no place for antifreeze to go unless there is a problem. Now, if the antifreeze was recently changed, the 6bta's are easy to get an air bubble in and it does have to be refilled on occasion after antifreeze changeout. Keep an eye on it but refilling coolant is not common unless a problem is present.

 

[1956olds]

I did notice there were new caps on the tanks also.and the old ones were in a drawer,so mabey it had been filled recently.All the hoses look good.I wonder can i use a pressure tester on these systems,i have a snap-on set that would work if its doable.

 

[trit21]

I have heard people using these pressurized units to test the coolant system yes.

 

[1956olds]

Great,i am having tool storage issues on this boat now.i wish they would have put a few more drawers under the convertible salon couch.between the two spare waterpump kits two spare thermostats spare belt,my spare parts tacklebox,color borescope tool kit ,and two drawers full of "special"tools ,someones going to loose a shoe drawer me thinks.Perhaps i need a tool dinghy,with a mechanic in it.

 

[1956olds]

Well the broker pressure tested it this morning and it held for 3 hours,then he took it for a ride and found water dripping from somewhere on the outboard side of the starboard motor.He is going to have the helm side seats removed and get the floor out of the way and find /fix the leak.He said it wasnt a big leak but he wouldnt let the boat go without fixing it.So another weekend without a boat,and next weekend looks iffy for the 400 mile trip home.Also the generator needs a new circuit board and oil pressure sensor.Any one have a manual for genarac qs8.0D?

 

[1956olds]

Well i joined boatdeiesl. com,havent found much pertaining to my issues though,still curious about the low temps on port engine 163 at cruise.Also trit i would never reprop or tweek props without professional help,if i did things like that the boat would be at my dock or somewhere between cleveland and bay city mi being repaired by now.I have a contract and am making the broker stick to it,otherwise they would be sticking it to me.I like the broker but in some ways buying anything with engines you have to stick to your guns or take on the responsability of the PO not disclosing issues.

 

[kevin27]

Take a look here. Take some time and read all section to do with the Cummins. Good stuff you will need to know.http://www.sbmar.com/tonys-tips.php

 

[trit21]

Low temp at cruise could be bad gauge, bad sender or bad thermostat (stuck).

 

[1956olds]

Thinking thermostat ,i have two guages for each engine and two senders both guages match and ir thermometer matches them.The leak has been fixed on the starboard engine,it was the thermostat housing,the rubber seal let loose and it was squirting out the back edge,hard to see whith the seats and floor on.I guess i will need to keep my borescope on the boat too now.The control board and low oil sensor should arrive monday for the genny.Now i need the weatherman to fix the rain and wind he is predicting for next friday saturday and sunday.Thanks kevin 27 i will read as much as i can.

 

[alnav]

Glen, if you haven't already, you ought to go to https://quickserve.cummins.com. If you register for an account (used to cost but now it's free), enter your engine serial numbers, you should get on-line Cummins manuals, parts X-refs and lots of other stuff. Not sure what's there for your engines but for mine there are troubleshooting and repair manuals among other things that might be helpful.

 

[1956olds]

Thanks alnav,i do have the original manuals and parts catalog but as i understand it a few part numbers have changed,like for air filters ,oil filters and fuel filters.I will register for the troubleshooting and parts x refs.