CAT 3208 new knock

[Capt. Jon]

You should be able to go on line and mail order sample kits. It really does not matter who you get them from (IMO). Usually they come with their own mailer envelope and the results will be sent via email.

If you put 110 hours on the engine since purchase and it suddenly starts knocking on startup sounds a little strange. Just checking but your sure you did not hear this noise at anytime before? Not even lightly?

What makes me think it's not the lower end is that you have not mentioned any change in oil pressure at all. I would think if it was a rod bearing you would at least see some change in oil pressure.

Also when it comes to a rebuild if needed, you can spend as much or a little as you want to. I have seen plenty of engines that were only repaired and are still running today without a major overhaul. If you do find that your required go that route of repair then you may have to do it yourself. Most shops will not touch that because of liability of work.

 

[BryanF]

I just got off the phone here at my shop with an engine rebuilder and while I was on the phone I asked about a 3208 Natural. Not turbo. I can buy one off the shelf for under 9 boat bucks and that is with the core charge they would charge if your old engine is not rebuildable. One would still have to switch all the marine accessories over of course. But that should give you some idea of what you are looking at in the worst case.

 

[Edelweiss]

Anyone have an opinion or knowledge of any differences in the build between an industrial diesel engine verses a marine engine, such as injectors, pump, compression or cam duration.

(Looking at refreshing one of my Perkins and at around 6 boat dollars with exchange, a rebuilt industrial Perkins seem very reasonable compared to rebuilding mine. The rebuild includes new or reconditioned pumps, injectors, everything except marine specific accessories.)

 

[Ski in NC]

Rob- Thanks for the synopsis. Now it is much more clear where things stand.

A few thoughts:

Noise sounds like it is in sync with half engine speed, which is in sync with firing and individual bits of the valve gear.

Could be anything in valve train, could be piston slap, could be debris in cylinder. Could be other things. You've checked valve lash, good. You've kept intake ports protected from getting birds and small rocks in there, good. And noted that noise preceded pulling intake, got it.

One thing I've seen before was where a chunk of carbon came loose off the top of a piston or head, and then wedge between piston and head and made for bad piston slap. Once cleaned up, all was good. Did require pulling the head, though.

A good tech can probably narrow it down and get a good course of action. Hard to do remotely.

I still would like to know about the blowby flow and whether it is pulsing, and that require you putting the rocker covers back on. Yes, you can see the flow out around the pushrods, but that is a much sloppier check than with the unit buttoned up and all flow coming out of one path.

Good luck!!

 

[vonovik]

I'm going to go out on a limb here. At first I was with most here... valve, rocker arm, etc. But then I read the time line.

"June 21- The boat is loaded up and we’re ready to start the family vacation. Engines have been running in the harbor and are warmed up. We go a few hundred yards to fuel up and after getting fuel, I restart the motors and notice more white smoke than I remember seeing before coming from the starboard side and make a mental note to pay closer attention. About 20 or 30 minutes later, I was going a little faster than cruising speed to make up for lost time but nothing extreme. Then all of a sudden I hear a very loud knocking sound."

I find it odd that this happened right after fueling.

Question.... Are both engines running off the same fuel tank or different ones? If different ones, sounds like you may have gas in your diesel.

Just a long shot.

Best of luck,

Jim

 

[FF]

a rebuilt industrial Perkins seem very reasonable compared to rebuilding mine.

On some engines the injector pump will be different, and of course the exhaust manifold will differ.

Below does Perkins, Cat , DD , Cummins and will have the answer for your specific engine.


- Industrial Diesel, Inc.

www.industrialdiesel.net/


Detroit, Cummins, Caterpillar, engine cores. Diesel engine rebuilder and core supplier.

 

[Edelweiss]

FF
I did contact a couple of different rebuilders and they all said would match the spec's for cam, pump and injectors to my original engine. For Perkins 6.354M rods, pistons and cranks for the NA engines are interchangeable.

Would be just a long block and I already have custom stainless MESA exhaust manifolds, so i'm good there.

Thanks
Larry B

 

[robs523]

I'm going to go out on a limb here. At first I was with most here... valve, rocker arm, etc. But then I read the time line.

"June 21- The boat is loaded up and we’re ready to start the family vacation. Engines have been running in the harbor and are warmed up. We go a few hundred yards to fuel up and after getting fuel, I restart the motors and notice more white smoke than I remember seeing before coming from the starboard side and make a mental note to pay closer attention. About 20 or 30 minutes later, I was going a little faster than cruising speed to make up for lost time but nothing extreme. Then all of a sudden I hear a very loud knocking sound."

I find it odd that this happened right after fueling.

Question.... Are both engines running off the same fuel tank or different ones? If different ones, sounds like you may have gas in your diesel.

Just a long shot.

Best of luck,

Jim

I don't know if fueling had anything to with it or not, may have just been a coincidence when I noticed it. Each engine has it's own fuel tank though, but man that would be embarrassing. Hopefully I'd notice the difference since I tend to spill enough fuel each time that I end up smelling like it for a while. Thanks!

"One thing I've seen before was where a chunk of carbon came loose off the top of a piston or head, and then wedge between piston and head and made for bad piston slap. Once cleaned up, all was good. Did require pulling the head, though."

Thanks Ski, I will keep that in mind when I get back home. It would be great if it's something "simple" like that. Would that produce the metal flakes though?


"I still would like to know about the blowby flow and whether it is pulsing, and that require you putting the rocker covers back on. Yes, you can see the flow out around the pushrods, but that is a much sloppier check than with the unit buttoned up and all flow coming out of one path."

I'm nervous to fill the oil back up and start it up again in case I cause further damage. Hopefully we can get a mechanic out there when I get back to help me keep from breaking anything worse than it is. I think the first I'm going to do is figure out how to jack up the engine and pull the pan, then I guess get the oil sample done to try to see where the flakes are coming from.

 

[Conall63]

I'd do an oil sample before pulling pan off. Removing the pan can turn into a big job.

An oil sample is pretty reasonable price and will tell the type of metals in the fluid, the concentration of metal, and the most likely source of whatever metal and other fluids are in the oil.

Conall

 

[Capt. Jon]

I'd do an oil sample before pulling pan off. Removing the pan can turn into a big job.

An oil sample is pretty reasonable price and will tell the type of metals in the fluid, the concentration of metal, and the most likely source of whatever metal and other fluids are in the oil.

Conall

Amen! There are lots of pan bolts in an 3208 oil pan. It's also tough to get the pan gasket back on properly while in frame. It can be done but man it's a pain. With an oil sample you might find pulling it off is not needed.

 

[Island Cessna]

I'd give the gasoline suggestion some thought and investigation. I had someone fuel a forklift with an 1160 Cat (predecessor to 3208) with gasoline back in the '70's and it knocked and smoked. Your timeline gives about the right time after fueling for the gasoline to work its way through a primary and secondary filter.

 

[vonovik]

Hello Rob,

Quick question if you don't mind. What did you cut the oil filter open with?

Jim

 

[FF]

What did you cut the oil filter open with?

The usual is a tubing cutter that will accept the filter diameter.

Doesn't add chips when cutting.

 

[robs523]

Heres the latest-

the oil sample is in the mail and should get there tomorrow, I'm hoping for results on Monday or Tuesday

Against all logic and in spite of my conscience, I cut the filter canister open with a Dremel, but I didn't use a metal wheel. Because hey, that's what the guy on youtube did. It's been eating away at me since I did it, so I ordered the $60 filter cutter and did it the right way on the other filter on Monday. Unfortunately, there were still the same shiny flakes staring back at me in the filter media.

I don't think it could be gas because I filled up both tanks at the same time. I found the receipt and it says diesel, and I really think I would have noticed if it was gas, so between that and the metal flakes, I'm ruling out that possibility

The mechanic thought he'd be available when I got back in town. Now he says he's 3 weeks behind schedule and doesn't know if he'll be able to take a look at it next week or not. If I hadn't talked to so many people here that have had similar experiences, I'd start to think I must have done something to tick the guy off but I think it's just how it goes in small fishing towns during fishing season. We have a local Facebook page for the town so I think I'm going to see if I can find anyone that way for now.

At this point, I'm really hoping the oil analysis tells me something that I can use to move forward. I have a hard time being at the mercy of people like I have been with the local mechanics, and I don't trust the dealer I talked to out of town after their first suggestion that I go ahead and order the part from Germany and spend the 35k they wanted. But I really don't know where to go next. I guess the bright side is that all of the projects I was putting off until winter might get some attention now. Unfortunately that doesn't fill my freezer with fish! Thanks everyone for the replies, you all have been a huge help.

 

[123]

In my opinion
Now just wait for the results of the oil analysis, based on the outcome you can scedule your next steps.

 

[FF]

With big metal flakes in the filter, I think I would contemplate some sort of Plan B.

IF there is room lifting the engine to take a look at crank and rod bearings,

OR simply figuring out a source for a running takeout or rebuilt engine.

Do not overlook scrap yards , a crashed engine with few miles would be a fine transplant.
And not that expensive.

R&R the block will be the big hassle , and unless the boat is steel do not contemplate carving a hole in the bottom and patching the hole.

A hole in the cabin top for a crane R&R is rational, if required.

 

[Hawgwash]

Heres the latest-

the oil sample is in the mail and should get there tomorrow, I'm hoping for results on Monday or Tuesday

I'm still wondering if you did a pre-purchase mechanical and oil sample.

 

[Old deckhand]

Rob, the cat 3160 is the earlier engine to the 3208 and would work as a replacement if you are unable to find another 3208. If you need to remove your engine it may fit through a window. I have stuck a fork through a boat window to remove an engine. Just some random thoughts.

 

[robs523]

I'm still wondering if you did a pre-purchase mechanical and oil sample.

I did not. I had read mixed opinions about that and decided that with the lower hours and what I thought was a good overall survey that I could pass on it. In hindsight I do wish I had at least sent in the old oil when I changed it upon taking ownership but nothing I can do about that at this point

 

[Ski in NC]

Oil sample of minimal utility here. If a bearing has failed, often the chunks are too large to get through pump screen, they get captured in filter and are thus not in sample. They also can be too large for the lab analysis to pick up.

Sample will detect submicron wear products that are created when something wears gradually, not so much when something breaks.

There's a decent argument here to pull heads and see if anything is amiss. Only takes half a day to get them off, then another day and some gaskets to put them back on. If there is a problem that requires getting into the bottom end, engine is now much smaller and heads would likely have to come off anyway.

Other option is RTF. Run to failure. If it is a big chunk of carbon on a piston top, it might clear up with running. Risky, but an option nonetheless.

 

[BryanF]

I would not run to failure as it will just make the rebuild that much more expensive. You have metal in the filter. You can not get metal in the filter unless there is metal in the pan. So you can carry on wasting money or you can just pull the engine out and get after it. Metal in the pan is never a good thing. Pull the heads- you can do that yourself. Pull anything else off you can and get ready to lift the engine out. The only way you can be sure you have all the metal particles out of the engine is to completely disassemble the engine clean everything and start over.

 

[FF]

"I would not run to failure as it will just make the rebuild that much more expensive".

I would disagree.

THe world is awash with 3208s , there might not even be a core charge depending on the rebuilder.

If the engine were one of the Volvo unobtanium items , a quick removal might save bucks.

If you look to the recyclers the usual rule of thumb is 50 miles is an hour of engine time in non waste gathering vehicles.

 

[BIG CAT]

Running it to failure is a terrible idea and dangerous. The last thing you want is an engine to kick a rod out the side and spray hot oil and coolant everywhere. The potential for fire alone makes it a very bad idea.

 

[vonovik]

Rob,

Sorry but I don't remember how long it has been since the engine has been rebuild but did the PO get a Warranty of any kind? If there is no Warranty, I think in may be time to start taking her apart. I would get a box ziplock bags, a marker and take lots of pics. Nothing worse then forgetting how to put it back together weeks from now or just losing the parts.

Best of Luck
Jim

 

[123]

Why you all push so hard to start dismantle the engine? Again wait for the results and make your plan...

In advance you can start with measuring everything to make a plan how to get the engine out, complete.. head(s) removed.. etc. If half possible leave the sump on to protect the cranckshaft and to protect your boat against oil spils..

 

[robs523]

Rob,

Sorry but I don't remember how long it has been since the engine has been rebuild but did the PO get a Warranty of any kind? If there is no Warranty, I think in may be time to start taking her apart. I would get a box ziplock bags, a marker and take lots of pics. Nothing worse then forgetting how to put it back together weeks from now or just losing the parts.

Best of Luck
Jim

The rebuild was done in 2004 and now has 1700 hours. I was told it was going to be used as a charter boat but that fell through. Since then, I think I am the third owner, so I don't think any warranty would carry over that many years and owners.

I have most of next week off. By then I should have the sample analysis results, hopefully it will tell me something. Next week I can formulate a plan to get the pan off and get someone to help me get the head on the head off and see what happens. Who knows, maybe then someone will be able to come take a look at it

 

[clynn]

As the owner of a late 80's boat with 3208's, I've been following your thread and appreciate you continuing with your updates.

It sounds to me like you're handling it the right way. Do the simple checks and look for obvious issues. I've learned over the years that there are times to try to tackle a job yourself and others that are best left to the experts. Complex engine internals is probably one of those left to the experts, so I would encourage you to continue to be patient and let the expert look at it when they can. Nothing worse than figuring out the issue you were trying to solve was simple but you broke something expensive trying to fix it yourself.

Good luck and please keep us updated.

 

[robs523]

well, the results are in. I haven't dug in yet to try to figure out what they mean, but it sure doesn't sound good initially from my uneducated perspective. I am supposed to meet the mechanic tomorrow morning, hopefully nothing else comes up and it really happens.

The Microscopic results in brief:
Ferrogram Interpretation: There were significant amounts of abrasive/dust/dirt particles and moderate amounts of ferrous rubbing wear particles and nonferrous white metal rubbing wear particles present on the slide. Also, there were a few ferrous/nonferrous cutting wear particles, ferrous/nonferrous white metal rolling wear platelet particles, and ferrous sliding wear particles observed on the slide. There were a few black oxide particles and fiber particles found on the slide. The presence of rolling wear platelet particles suggests possible surface fatigue and/or rolling contact failure due to metal-to-metal sliding and/or abrasive contamination. Sliding wear particles are indicative of possible excessive running speeds, lubricant degradation, overheating, and/or heavy abrasive/dust/dirt particles. The presence of cutting wear particles suggests possible misalignment and/or abrasive contamination. The presence of black oxide particles suggests possible overheating and/or lubricant starvation. The morphology of the abrasive/dust/dirt particles suggests possible contamination of the sample and/or reservoir from an external source.

The general sample showed 58ppm Fe and 55ppm Al. The rest of the results were unremarkable. The report they gave me says (I deleted all of the other elements that were not listed as a concern):

Aluminum (Al) Iron (Fe)

POSSIBLE ORIGINATING SOURCE
Al-Bearings - Bushings - Blocks - Pistons - Blowers - Pumps - Clutches -
Fe- Blocks - Bearing - Cylinders - Pumps - Liners - Gears - Pistons - Rings - Discs - Shafts - Screws - Valves






So, I keep going forward at a tortoise pace and in the back of my mind run through possible logistics of how I would pull it if I have to and when. Hopefully the mechanic can provide some guidance between the audio/video and the oil report

 

[Busterbrown]

Rob if you want to save money start taking the engine apart and make the block light as possible for removal. I am no expert but if you hire someone to do all the work 60 to 80 percent of your cost for the repair will be labor. I'm just guessing maybe Ski will chime in.

 

[Capt. Jon]

It's now been 8 months since I did the port engine rebuild on our boat. Like Ski says start by removing the heads. Really does not take that long and like said earlier they have to come off anyway. The engine will fit through a 26" passageway without the heads on but the front cover still attached. On our boat to get it out of the engine compartment it was down to the short block.

If I had to do it all over again I would not rebuild using all CAT factory parts. There are plenty of good aftermarket parts and also engine rebuilders who will supply you a short block with a warranty. The heads can be taken local for exchange or have them do the re-work. If you really try you can get this job done for a reasonable cost and have her back up and going again at least by next season.

It's a boat and $h!t happens. I feel your pain.