6BTA trouble

wlbsr · Post by **wlbsr** » Jun 29th, '14, 13:07

one engine turns 3000 in neutral but smokes and only turns 2000-2200 under a load, smoking stops at about 1900. had an issue with fuel so now fuel has been cleaned, injectors on the troubled side have been cleaned, and filters replaced but still same issue. seems like turbo kicks in earlier that normal and makes a more pronounced whine. other engine runs perfectly. any thoughts? Bill

Bob H. · Post by **Bob H.** » Jun 29th, '14, 19:55

Bill if your getting black smoke when getting over the hump that is ok , smoke all the time is an air issue. Do you have turbo boost gauge.? Pyrometers? After coolers cleaned? Check the rubber hoses that connect the air plenum from the turbo to the after cooler, I had a cut in mine and lost the boost, turbo sounds the same but not getting the air into the cylinders. Also look at the exhaust side of the turbo and look for pitting, if you find signs of corrosion you may be injesting salt water mist from your shower head or mixing elbow. I have a few more ideas but let's start with the basics. BH

wlbsr · Post by **wlbsr** » Jun 30th, '14, 09:23

Thanks BH - going into exhaust side, after cooler, and checking hoses at turbo today. will post what we find. BB

wlbsr · Post by **wlbsr** » Jun 30th, '14, 13:04

looks like the after cooler is compromised. going to need an inner core. any suggestions besides cummings... already checking with them.

dougl33 · Post by **dougl33** » Jun 30th, '14, 15:03

Try Tony Athens at Seaboard Marine in Calif. (AKA boatdiesel.com)

Good luck!

wlbsr · Post by **wlbsr** » Jun 30th, '14, 15:40

inner core on the way from tony athens. other side looks to be in pretty good shape so i am just going to do one for now and watch the other. at least i should have a head start on the symptoms if it happens to the other side.

Bob H. · Post by **Bob H.** » Jun 30th, '14, 20:16

Bill, Tony Athens is the Cummins go to guy..check those rubber boots as well, I found a slice in one of mine tonight..keep a few as spares just incase. Keep me posted on your progress.BH

wlbsr · Post by **wlbsr** » Jul 1st, '14, 06:02

cummings did not have one anywhere in their dealer network yesterday and were checking with the factory. thank goodness for 3rd party vendors.

wlbsr · Post by **wlbsr** » Jul 3rd, '14, 14:54

OK. call seaboard on tuesday and got the after cooler inner core over-nited and the mechanic got it yesterday afternoon. put it on this morning and pulled out of the slip at noon just as the wind was starting to pick up. made it to my 1:00 haulout but guess what..... same symptoms. black smoke starts at about 1900 rpms. i get a really shrill whine or whistle at the time the smoke starts. back off to 1700 and the smoke goes away and the whistle stops. back up to 1900 and both start and increase with the rpms above 1900. other side running perfectly and no whine.

i saw the replaced inner core and it looked rotten just below the top. also pulled the after cooler on the other side monday and that inner core appeared to be in good shape. mechanic looked at both sides of turbo monday and says its in good shape. letting someone else look at it this week while on blocks. thoughts? could it be a hose or some part of the turbo that the damage isnt visible/

Kevin · Post by **Kevin** » Jul 3rd, '14, 23:50

A lot of black smoke would be a sign of not enough air, right. Or is it too much fuel? The whining you hear makes me think boost is escaping at higher pressures. I would expect loss of boost to radically decrease the power output/RPM. Could your filter be collapsing or clogged? Just a thought.

wlbsr · Post by **wlbsr** » Jul 4th, '14, 09:26

I agree. from what i am seeing it seems like it would have to be an air issue

from Tony Athens...

This is where we start (a VISUAL of the exhaust leaving the vessel, under your normal operating conditions): If you are seeing any dark or black smoke during some or all of the operational RPM range, you most likely ARE NOT experiencing a fuel restriction problem. I am going to stress that again. This IS NOT a fuel supply or restriction issue (clogged fuel filters). You are either overloaded during some or all of the engine operational range, or you are not getting enough air (this can be from one or multiple reasons).

AIR issues: Not getting enough air can be caused by a dirty/collapsed air cleaner, a leaking turbo hose, a filthy aftercooler or air restriction inside the aftercooler, a worn out or partially stuck turbo, or a poorly ventilated engine room. Any combo of these can restrict air to the engine causing dark smoke and further, low power.

Marshall Mahoney · Post by **Marshall Mahoney** » Jul 5th, '14, 07:56

I had a smoking issue as well (although no turbo whine ), and trouble shot it for a year (aftercooler re-work, injectors, pump timing, fuel system, etc.) I even tried to check turbo boost but could not make heads or tails of the results since I could not determine exactly how much load I was under. I ended up taking a chance and changing the rotating assembly of the turbo with an aftermarket version. I believe it was about $250. Easy replacement -- I did not even have to remove the turbo housing. This reduced the smoke by 98%. I still see some faint smoke when the sun/wind is right but I am calling victory. My fishing buddy ordered the parts and can get the info for you if you decide to go that route.
--Marshall

wlbsr · Post by **wlbsr** » Jul 5th, '14, 11:31

MM: it would be great to get that info. i am going to really go over all the turbo related hoses etc with a fine tooth comb when i put back in next week. if we still dont see anything, i think the $250 would be a reasonable investment at this point. I thought about trying to swap out a turbo temporarily to diagnose... just dont know how feasible that would be in terms of time and labor.

Bob H. · Post by **Bob H.** » Jul 6th, '14, 06:25

Bill, remove and visually inspect the rubber bellows that connect the turbo to the aftercooler, should be three, look carefully for any slice or cracks on the inside. A turbo boost gauge will tell you how much boost you have, easy install should be an extra plug on the intake manifold. Also look at the small plastic line that goes from the intake manifold to the pump, that is your aneroid valve that opens when you get 15 to 20 lbs of boost, that dumps more fuel. Make sure the tube is clear and not plugged up. Did you find excess oil in the after cooler ? Sure sign turbo seal let go and turbo is NG.

wlbsr · Post by **wlbsr** » Jul 9th, '14, 08:10

Bob H: everything visually looks good, aneroid OK. Going back in the water from Arthur Fri. a.m. have a boost gauge lined up and if nothing there going to check compression. will report back

wlbsr · Post by **wlbsr** » Jul 9th, '14, 08:12

and there was no oil in the aftercooler when we had it apart.

Marshall Mahoney · Post by **Marshall Mahoney** » Jul 11th, '14, 10:08

My fishing buddy has the box that the turbo assembly came in -- he's been out of town, but will call me with the info when he gets it. I know he bought it on ebay. Some on e-bay now for $189 free shipping. Wait until I send you the particulars on my order for comparison...

wlbsr · Post by **wlbsr** » Jul 11th, '14, 12:34

it turns out that upon inspection of the outside of the boat before putting back in after arthur, my struts are about to come off the boat. the backing plate was plywood coated with fiberglass and the plywood has rotted out but i guess thats another thread in itself. hopefully I will get back going next week so whenever you get that info just post it. my plan is to get back on the engine when i go back overboard.

BTW, the worse strut is the same side as the engine in question.... any chance the strut could be putting the engine in a bind enough to seem like loss of power?

Marshall Mahoney · Post by **Marshall Mahoney** » Jul 13th, '14, 10:29

Turbo info on e-bay:
Seller: turbopartscity02
model H1E, turbo pn 3545096
Make: Gaoyuan Turbos, aka GY Turbo

Keep in mind these are after market -- but they seemed to be good quality and I have had no issues so far!

As far as the loose struts binding the motor to reduce power -- doubtful. My engine mounts on my starboard motor loosened and the engine walked way out of alignment. I didn't notice any performance issues until the coupling bolts sheared. That was exciting to say the least...

wlbsr · Post by **wlbsr** » Jul 13th, '14, 11:41

thanks Marshall - hopefully be able to test the boost later next week and then i will have an idea. hoping its turbo related and not a top end rebuild but the way my luck has been running, who knows. just ready to get back in the water before i miss the whole summer. Bill

Carl · Post by **Carl** » Jul 13th, '14, 11:57

I managed to install a defective cutless bearing in my boat years ago. Turned hard and swelled up.

Started as light squeal when i went in and out of gear at low rpm. Shaft was well aligned, spun free i kept running. Then i lost WOT, by a few hundred RPM then had to bring up idle to keep from stalling as I put in gear...by the time i pulled boat you couldn't turn shaft by hand. So a loose strut i can see adding lots of load to motor...but my case was pretty severe and running gas. Not sure how it translates to diesel. But if it twisted enough causing it to bind...maybe a contributing factor.

Bob H. · Post by **Bob H.** » Jul 20th, '14, 19:09

I have also heard a slight strut misalignment can cause those few hundred rpm mysteries, I if you can't spin it by hand freely it's bound up..I doubled checked the strut angle with a digital angle gauge and checked the shaft as we'll if not the same number it's out. My problem was with the aneroid valve on the injector pump. BH

wlbsr · Post by **wlbsr** » Aug 8th, '14, 16:50

went back in the water today with turbo boost meter in hand and sporting new struts. must be living right because boat performed almost like normal so i am thinking 70-80% if the engine issue was strut / cutlass related. looks like i had a nagging engine problem that the strut escalated to a larger problem. with the new struts, i am now back to a nagging problem. starboard engine is putting out a little black smoke but it has been reduced by 80%. turbo is still kicking in early but rpm and speed performance are basically normal. starboard engine is a little sluggish coming up and like i said there is still a little black smoke. turbo boost pressure was equal for both engines at wot.

plan of action appears to be check compression next and if all ok there focus on injection pump.

what do you think Bob Higgins?

Kevin · Post by **Kevin** » Aug 8th, '14, 18:38

Did the boat sit in the water for at least a day or two and have a final alignment done prior to sea trial?

wlbsr · Post by **wlbsr** » Aug 8th, '14, 20:48

No. dropped and went with two marine techs and a diesel mechanic on board. techs seemed to be more concerned with packing adjustment, mechanic was checking boost. what should i be looking for now?

Terry Frank · Post by **Terry Frank** » Aug 8th, '14, 21:31

Email me. I have no problem sharing the guy that I use from Beaufort.

wlbsr · Post by **wlbsr** » Aug 9th, '14, 04:46

Terry - I am using Mike (L and M). You gave me his name a couple of years ago and i have been using him ever since. He is going to check compression on Tuesday.

Bob H. · Post by **Bob H.** » Aug 9th, '14, 10:24

Bill, does the turbo boost kick in and climb at the same rate? If one is sluggish a slight tweak of the aneroid may do the trick.BH

Al C · Post by **Al C** » Aug 9th, '14, 11:03

Had a black smoke issue with my cummins and after going through everything else it turned out to be the props. They looked fine to the naked eye, even the prop guy said they "looked good" but after closer inspection he found them to be out of specs and cured my smoke issue.

wlbsr · Post by **wlbsr** » Aug 9th, '14, 16:40

BH: the bad side turbo kicks in very early compared to the other side. imho it seems like engine is calling for the turbo as in it needs some help. or are you saying engine may be fine and not need turbo and the turbo is just kicking in early and needs to be adjusted via aneroid? bad side feels like it is being pulled along by the good side but eventually eveyrthing gets to top end at expected speed with equal boost pressure. still not exactly sure i understand aneroid valve so maybe i will do a little research.

prop was sent to shop last year although that doesnt guarantee that something hasnt happened since then. maybe something caused the strut problem and also damaged a prop. i guess thats an outside shot and since the boat is back in the water we will continue to chase mechanics. i will keep this in the back of my mind and will probably have run all the mechanical rabbits next time i have the bottom cleaned so it would be easy to have the props taken off and checked.

Bob H. · Post by **Bob H.** » Aug 10th, '14, 07:12

Bill, first check the small air line that feeds the aneroid valve blow out both and make sure there is no goop in there. The aneroid opens at 15-20 psi and dumps more fuel once this pressure is reached. Tony Athens describes a lazy aneroid condition that makes an engine sluggish. The lagging engine may need the adjustment. Turning the wheel inside the aneroid towards the engine will give you more fuel as the turbo kicks in. Adjusting the valve away from the engine will reduce amount of fuel and black smoke. Take a few pics of your pump if you need more help. BH

wlbsr · Post by **wlbsr** » Aug 10th, '14, 19:29

Bob H. · Post by **Bob H.** » Aug 11th, '14, 16:32

Bill take another shot from the back of of the pump looking forward on a bit of an angle. I can't see the aneroid in that shot. What year motors? Is it a Bosch pump? Will get to the bottom of this no worries. BH
I like the zip tie cable clamp..

wlbsr · Post by **wlbsr** » Aug 11th, '14, 20:15

going to look at compression tomorrow and i will take a picture or two of the injection pump. i think its a nippon denso pump and am thinking that it might not have an aneroid valve. just figured that a logical step would be to eliminate cylinder and valve issues and if we do then it will pretty much have to be in the injection area.

wlbsr · Post by **wlbsr** » Aug 12th, '14, 14:29

i cant find any mention of an aneroid valve with the nippon denso pump

Update:

compression high (maybe too high) all around as in 360 to 420 assuming gauge was correct. i am told the variability is a little concerning. we did not run the other side for comparrison.

did another boost test. both sides the same although we got 12 psi which looks like it converts to 24ish INHG which is nowhere close to 50 but once again could have an issue with gauges.

fuel pressure good at 25 psi

general performance on water:

good engine turns 2900 with little to no smoke at 2400 cruise. turbo really kicks in around 2200 under a load. Good engine will turn up to about 2200 by itself (single engine test) and still no sign of significant smoke.

bad engine turns 2900 WOT but takes a while to get there compared to the good engine. the turbo kicks in almost immediately (maybe 1500 rpms) with heavy smoke from 1900 to about 2200 and light but constant smoke at 2400 cruise. with a single engine the bad side only gets up to about 1800 rpms with heavy smoke. comparing the single good engine to the single bad engine under a load is really where the problem jumps out at you

going to check back pressure and if nothing there the only thing i know to do is pull the injection pump and have it bench tested. suggestions?

mike ohlstein · Post by **mike ohlstein** » Aug 12th, '14, 14:50

Any soot in the engine compartment? (assuming that the turbo isn't covered by a jacket)

wlbsr · Post by **wlbsr** » Aug 12th, '14, 17:46

No soot. No back pressure. No excessive crank case pressure. Injection pump coming off tomorrow.

Bob H. · Post by **Bob H.** » Aug 12th, '14, 19:11

Bill, no aneroid on the nipo pump, since you do hit the max rpm on both I'm leaning towards the pump as well. I wrapped a wad of abandoned lobster line on the way back from Greenport, damaged my pump engine wouldn't fire after I made it back to the dock. Make sure to bring the injectors as well, good practice to check them at the same time. BH

wlbsr · Post by **wlbsr** » Aug 12th, '14, 21:12

man sorry to here about that line wrap. what did it take to get you back going?

i had some pretty dirty fuel earlier in the summer so maybe it is the injection pump. will updated when they get a look at it. why doesnt this ever happen after labor day when you have all winter to chase problems?

Kevin · Post by **Kevin** » Aug 12th, '14, 22:39

Bob,
How does the trap line affect the fuel pump on the engine? Is it an over loading issue? I am not familiar with those engines or pumps.

Bob H. · Post by **Bob H.** » Aug 13th, '14, 09:06

Kevin, When the line wrapped the prop I was cruising at 2350 rpms doing 27knots the governor pegged trying to "make up" for power loss, rolled the plunger in the injector pump and scored the cam in the pump. The motor wouldn't idle after that but I managed to get home and the engine wouldn't fire the next day. Took about three hours to time the engine and strip down the lines and remove the pump. BH

wlbsr · Post by **wlbsr** » Aug 15th, '14, 09:31

Diesel shop says injection pump is worn out. they are saying $2500 to rebuild but i am thinking a new is about that also. checking around on prices, not sure if there are any aftermarket options but thought i would check with seaboard/athens. thoughts / suggestions are welcomed. BB

wlbsr · Post by **wlbsr** » Aug 22nd, '14, 13:26

OK. put on the new injection pump and ran he boat this morning and............ worse than ever. less rpms and more smoke than before.

to recap:

compression high (maybe too high and not very uniform)
back pressure ok
fuel pressure ok
fuel polished
new filters
boost read low but was same as other engine which seems to be running fine
injectors adjusted
tips good
new after cooler inner core. looked like a little water had been getting into air
new injection pump
all turbo hoses are good

still hear a turbo whine in bad engine when 1800 rpms and beyond. do not hear that in good engine.

maybe boost is low on both turbos but injection pump on good engine is weak and masking the boost problem while the higher fuel delivery of the new pump is exacerbating the low boost problem

next step. leak down test for valves and then maybe pull the turbo. the way the turbo is we have visually inspected part of the blades and everything seems normal but they cant all be seen unless we pull it.

i know very little but am i thinking correctly that if the problem got worse with more fuel delivery than it is likely to be an air problem?

Kevin · Post by **Kevin** » Aug 22nd, '14, 14:10

Did you try the 8 ounces of water and one ounce of dawn dish soap trick? Put it in a spray bottle and shoot it through turbo while at cruise speed/load.
Chasing a ghost is no fun.

wlbsr · Post by **wlbsr** » Aug 22nd, '14, 14:48

leak down test showed multiple valve issues although hopefully no noticeable leakage into the crank case. one cyl. showed no issues so we had a benchmark to look at the next couple against. stopped after the third cyl. looks like we are out for the season. going to pull the boat next week and take the head off and see what kind of shape the cylinders are in. hopefully it will be just a valve job.

Bob H. · Post by **Bob H.** » Aug 22nd, '14, 19:45

Bill, if you have gotten water back into the turbo your #6 cylinder will be weak and or ng...you mentioned you had water in the after cooler.. If so where did the water enter? If it went through the turbo the exhaust side will be pitted..do you have stock cummins exhaust elbows and mixing elbows? What is the height of the water injection point for the mixing elbow? Hate to see you spend $ On a new turbo only to have it head south in a couple years. I chased rpm problems as well, turbo and rubber bellows were the culprits, I'm running a good 18 pounds of boost on both engines at cruise, also found the valves were way out of adjustment. Keep at it you will get it squared away. Great engines, will give you long life if installed properly and not pushed to the max. BH

wlbsr · Post by **wlbsr** » Sep 8th, '14, 14:23

Before letting someone else take the head cover off I bit the bullet and called Cummings Atlantic. They are 5 hours away and the labor and travel time is premium price. They basically told me that they never worry about compression or leakdown but just check crankcase pressure. Once i described my problem they said that it was most likely the turbo even though two other people had confirmed boost to be OK. They said they would bring a turbo but first check crank case pressure and boost and at that point determine weather it was worth trying a new turbo. Crank case pressure was in the normal range for an engine of my age and usage so hopefully it has a few more years in it. Boost was about 85% of normal but the cummins guy noticed that it went up to 50 pretty quickly and hung there for about 15 seconds before going on up to 75ish. the good side reached full boost almost immediately at 85#. we also checked crank case pressure on the good side for a baseline and all was basically good. He put on the turbo in about 2 hours, we ran the boat and everything was back to normal. you could see soot on the compressor side so there must have been a bad seal and possibly a bearing problem as well. on trial the boat was out of the hole with only a little black smoke equal on both sides and WOT at 3000 rpms with little to no smoke.

the cummings guy had an interesting trick to check boost. it was a pressure transducer that once plumbed into the block, plugged into a normal digital multimeter. checked crankcase pressure by plumbing off the breather tube that runs to the aircep with an old analog manometer to measure in. of HG. 3 in. is brand new, 4-6 is normal, and over 9 top side problems... i was in the 4-5 range on both engines. the price for the turbo was about what i had seen on line, the labor was thru the roof but i am back running normally after 4 months and i am pretty sure that it would not be that hard to do the other side myself if all the bolts and fitting would cooperate.

is there anyway to rebuild the old turbo or is it just a doorstop now?

Navatech · Post by **Navatech** » Sep 8th, '14, 18:04

wlbsr wrote:is there anyway to rebuild the old turbo or is it just a doorstop now?

I guess it depends on the specific turbo in question... FWIW, my DD 8V92TI's turbos can be rebuild...

mike ohlstein · Post by **mike ohlstein** » Sep 8th, '14, 19:09

I was thinking seals, which is why I had asked about soot…...

wlbsr · Post by **wlbsr** » Sep 8th, '14, 19:19

the cummins guy took the clamps off the airsep and took it off the turbo and you could hear the magnitude of the whine double at about 1600 rpms. didnt see the soot on the cool side until we got the turbo off. at that point he said this is your problem. i remember you saying that and didnt know exactly what you were talking about. you were right.