Perkins 4-108 vibration

So I am writing this for a friend who owns the boat.

It is on a Prairie 29.

A new Perkins 4-108 was installed in 2016, has about 150 hours on it.

On a recent trip north, the engine was using about 1/2 quart of oil per cruising day.
Then the last day of the cruise the engine began vibrating to such an extent that the owner put her in a slip to check things out.

All looks normal.
Nothing loose seemingly.
Fluids seem good.

My friend, the owner is very discouraged and either wants to sell the boat at a huge loss, or just put in a new engine (at about $20k).

These seem extreme to me.

So, not being familiar with a Perkins:

might this be a "normal" issue that some others have and simply do a fix?

Any ideas with these symptoms? (I know the symptoms are few and probably not complete).

What would you check?


I personally believe (having been around several boats and engine issues) that is a probably a simple/easy fix and does not need drastic measures.

Thanks.

Tim

Tim, you say the engine started vibrating but it is attached to the shaft and prop and may seem like it is the engine but may not be. My first thought on vibrations is did I pick up something on the prop or shaft or damage the prop. I can get a bad vibration just from weeds. Has he checked these items?

Yes, it might have been something on the prop.
It is out of the water now...and of course the prop is clear and clean.

No one is near the boat that we know (it is in GA and I am in NC and he in VA)...so cannot check the prop for any damage.

Concerned with no way to quickly check on the solution

Tim

The 4-108M ceased production some time (decades) ago. 1/2 quart per day oil is very excessive for this engine if indeed a new total rebuild. So is it a rebuild? Did he get a warranty on the rebuilt engine?

Since around 2000 all Perkins new build engines are called Perkins Sabre.

Greetings,
Mr. k. IF filled to exactly the correct level, 1/2 qt/ day does seem excessive.

I say "IF filled correctly" because I know with our Lehmans if you fill to the scribed line it will burn off that excess in short order. Meaning, it's overfilled. In our case, seems to be about a quart. IF I leave the oil 1 quart low, it remains at that level for quite some time.

Does your friend have any recourse to go back to whoever installed the "new" Perkins? 2 years old with 150 hrs is not much.

In any case, tell your friend not to fret it could easily be a variety of problems which will turn out to be quite simple to rectify. A loose motor mount, bad cutlass bearing, fouled injector, loose shaft coupling or as Mr. LaB suggested, something on the running gear which has since fallen off. Maybe a loose prop...

Before he starts throwing money at it, start with the simple and cheap things first.

I should say it was "totally rebuilt" in 2016

Thanks RT;
I agree that it is best to start with the "simple and cheap things".....I personally think it is one of those.

But right now he is scared, frustrated, too far away, and bummed out over this boat. I can understand those feelings....I have felt them over other boats...but not enough to throw a boat away and waste thousands of dollars!

We shall probably go down to GA next week and attack these issues.

Any other ideas are welcome....we can work through a list and see what happens.

Tim

I had a Perkins too and sold it for $1800. Reopwered w a S4L2 Mitsubishi. Same bore and stroke as the Perky. Just a smige more power. Mine is in a Willard 30.

Owner says “all things normal”. Has there been a compression check of any kind? Here’s my guess. Oil loss is due to lost compression. Broken ring. Pushrod bent. Oil may be sucked out through an exhaust valve guide. Have the injectors been checked? How-about exhaust gas temps at the header pipes between the head and the exhaust man. Could find one w very low temps.

This is the sort of thing I’d be looking for. Whatever it is it’s almost certainly fixable with standard shops in SE Alaska. Tim where is the boat now?

Oil loss can also be through the oil pan gaskets. We had a 4-108 and put ~4000 hours on it. I called it a “puking Perkins”. I wasn’t the first one to call it that. She always started but adding oil was a daily event. Most of our loss ended up in the bilge. The oil pan was a a 4 piece gasket set (if I remember correctly). I could never stop the leaks and learned to live with it. Imho they’re good engines, parts are still available world wide but old school.

Thanks for the input Nomad Willy
She is in Brunswick, GA...on the hard.

Larry M.....so it seems from your comment and others that the oil loss is not a vital issue....just keep a good eye on her.

RT is right about the scribed line issue...I had a Lehman once that I always overfilled until someone told me to find the factory scribe line and compare it to the tilt of the engine.

But these engines seem to be good little things and just keep on going from all I can find.

Thanks for the input. I am learning.

Tim

The 4108 normally is a good, reliable engine. I have a 1972 4108 on a generator.
Vibration can come from many things, bad motor mount, bad alignment, worn stern bearing, faulty injector, faulty injector pump, cracked injector tube, air in the fuel, loose flywheel, bad timing, crack in the crank, and combinations of them all.
1st check the motor mounts and alignment. Then do a compression test. Take the injectors out and have a injector shop check them. Injectors don't always get replaced in an overhaul.
4108s are relatively cheap to overhaul. A good gas mechanic can do it with a manual. I did mine for about $2000 including having the head done, but didn't do the injector pump or injectors.

Hi,


Maby vibration damper is broken.


http://www.trawlerforum.com/forums/s32/check-vibration-damper-29549.html


NBs

And so I finally got the full and much more complete story:

The Captain brought the boat up the ICW for two or three long days (can’t remember exactly). The next travel day he decided to go up the outside to make time. It was a hard day according to him (long day with moderate seas). He pulled into Brunswick that evening to lay over for the storm the next day. To this point there were no issues. The boat was running flawlessly. He also had not reported anything unusual with the motor and had not said anything about abnormal oil consumption. The layover day he hung out on the boat and the storm came through. High winds and rain and rapidly dropping temps. The next morning he said he could not get her to start. I don’t know how long he had been trying by the time he told me. He said she was spinning over like normal but wouldn’t fire. I told him to close the raw water intake so he wouldn’t hydro lock the engine. Through text and phone we kept trying different solutions. I read up on the 4108 and found they are cold natured since they don’t have glow plugs or heaters. Outside temp was in in low 40’s. Finally I told him to start the genny and to let it run for a while to warm the engine room. Once he did that he was able to get her started. He then texted saying she was running rough which was unusual. We let her run for an hour to see if she would warm up and clear up. She didn’t smooth out so he shut her down. He tried to restart but she wouldn’t. Same as earlier. Spun but no go. All the while I was trying to get a diesel mechanic. The next afternoon we finally got a mechanic to come over. He quickly diagnosed that the engine kill lever had malfunction and was not letting the engine get fuel. He temporarily fixed that with a zip tie and she started right up. Captain said she was still running rough. Mechanic said he has seen several 4108’s run like that and we should just run her. The Captain was nervous knowing how smoothly she ran before. Mechanic left. I got another mechanic to come out the next day and he said something is going on but he doesn’t know what. Could be head gasket or a number of things. Could be more. He didn’t want to do a “repair” and then not sure if he solved the issue. During this conversation the captain tells him he was putting 1 quart of oil in per day after each 14-16 hour day. He had never told me that and I don’t even know if it was true. The Captain also had other customers waiting and needed to get on to them. So there you have it. A lack of reliable info which I cannot confirm. A vibration which I have not seen or heard. Two supposedly reputable mechanics with different opinions and too much work.

And so with this much more complete info from my friend; what do you think?

Would you just "run it" and continue north?

Would you look deeper into the engine?

What would you look for?

Thanks.

Tim

I suspect an injector. But a compression check will show a bad head gasket, rings, valves. Good compression would mean it's probably a fuel problem.
A bad injector will make the engine vibrate excessively and can sound like a rod knocking. To isolate a bad injector, with the engine running about 1000 rpm, loosen each injector nut one at a time, only loosen enough to spill fuel. Have towels to catch fuel. Take care fuel is at very high pressure. The fuel could cut or penetrate skin. Loosening a injector nut will cause that injector to misfire. Good injectors will cause the engine to run rougher, the bad injector will have little or no effect.
Injectors have a mechanism to prevent the high pressures of combustion from forcing gases into the injector body. Long hard runs can burn a tip or cause heat damage to the internal parts.
To me, it doesn't sound like your captain has much on the ball. He should be able to do basic diagnosing. If he's in a hurry for other jobs, I would suspect he's been running the engine hard and that's the cause of the oil consumption.
Again, the 4108 is a very durable engine, but without being there it's impossible to say if the engine should be run.

Aside from a bad rebuild now rearing its head and as suggested by others, several potential issues.

Don't overlook that possibly water entered the engine from storm, bad exhaust elbow, head gasket, overheat or excessive cranking maybe? Check the oil very carefully for any sign of cloudiness or moisture.

Did we check the filters????

The guy did say he got roughed up the day before....it could simply be fuel sturred up by the rough weather and clogged the filter(s)....that would have been my first guess.

Did he reopen the raw water intake once the engine started?

When we bought Willy some 12 or so years ago she came w a Perkins. Ours was hard to start. Much cranking was required each time. Starter motors can only take so much.
I asked around and discovered a heater for starting was available but it was more of a flame thrower IMO. Didn’t like it. This was one of the big reasons we repowered. We were going to move to Alaska then and I envisioned us in a remote anchorage in the am trying to start the Perky. Not good.

I initially thought this problem was compression related but the bad injector is a very good probable as they CAN cause lots of vibration and the word vibration is in the thread title.

The basic Perky is a good engine but they are old. One skipper in our Willard Boat Owners Group had a crankshaft break while running up Chatham Strait in SE Alaska. Another “not good”. We became a beliver in newer engines. I can’t afford a newer boat but I could afford a new engine. We got one. But w/o the Alaska plans we prolly would’a stuck it out w the Perkins.

Wouldn’t advise the skipper to keep going.
Do Lepke’s drill. Removing and repairing injectors isn’t a big job.

I don’t agree w Lepke saying the skipper dosn’t have much on the ball. Most of us don’t know these things. We don’t haft-ta be engineers or mechanics to go boating. And re trawler engines most all of us have little or no experience w diesels.

Baker said:

Did we check the filters????

The guy did say he got roughed up the day before....it could simply be fuel sturred up by the rough weather and clogged the filter(s)....that would have been my first guess.

Click to expand...

+1, and the simplest to check out too.

Something changed between the long, hard, smooth run and the morning it would not start, and then ran rough once the failure to start was fixed. These are well proven, simple engines, so the list of things that could change is short.
I would not focus on the oil consumption. These are old tractor and vehicle engines, the common crankcase ventilation method was a draft tube that discharged any blow by (and the oil mist included therein) below the vehicle. This doesn’t work in a boat, so the draft tube is rerouted to the intake, and the oil mist is burned. As several have noted one of the effects of this is that above a certain oil level, which is unique to each engine and installation, the oil just blows out. Once you cure the vibration I would run it, and see if there is an oil level where the oil loss stabilizes. These engines were never intended to use zero oil as we have come to expect with modern engines.
Fuel and overheated injector tip issues would have given a hint of themselves during the hard run, or the idling that must have happened at the end of the day during harbor entrance and docking, so I don’t put them high on the list of things that might have changed.

On to what I would focus on:
The failure to start was diagnosed by the first mechanic as a stop lever problem, and fixed. No mystery on why it would not start.
One thing we know is that the captain cranked the engine for a long time before the OP told him to close the raw water intake. I assume the intake was open during all the initial cranking, or the captain would have said so. I also assume from the OP’s comments it has a water lift. Almost certainly the water lift would have filled up, allowing water to back up in the exhaust manifold. The injector check described above will identify if a cylinder is misfiring. The first thing I would do after identifying a cylinder would be to remove the rocker cover and look for a stuck valve on that cylinder. If it is a stuck valve you might get lucky and find that some tapping, wiggling and prying frees it up. If this works, I would run as is. Alternatively you could just pull the rocker cover and turn the engine over by hand two full turns verifying that all valves move appropriately, without excessive lash indicating that a valve is not fully seating.
If it is not a stuck valve I would pull the offending injector and have it checked, as well as check the compression of that cylinder to be sure it did not hydrolock and bend the rod, or break the piston.

Well between Lepke and Island Cessna I’ll bet this is solved.

But even if it’s wrong I’d be up to reading another one like I Cessna. Where do you live IC?

I thank all who responded.

Some really good ideas.

The owner (my friend) is getting a quote to drop a new beta marine 38 in her.

If it were me, I would try all these great ideas and see what happened before I spent $10k on an engine and perhaps another $10k on labor.

But it is his boat, thus far, and his worries.

I will let you know how it all goes.

Thanks.

Tim

Nomad Willy said:

But even if it’s wrong I’d be up to reading another one like I Cessna. Where do you live IC?

Click to expand...

Willy, check your PMs. Bill

If he's in a hurry for other jobs, I would suspect he's been running the engine hard and that's the cause of the oil consumption.

The Perkins is not an industrial engine , many hours at WOT or a high power setting is never acceptable.

After checking that each injector does function , and replacing the fuel filters , the EZ stuff is done.

My 108 had two problems that caused vibration and were fixed.

1) The keyway on the flywheel was wallowed out. New flywheel was not obtainable so found one in a scrap yard.

2) One motor mount failed and shifted the engine till it finally broke and dropped the engine in the bilge. Replaced it and all was well.

I don’t know if it has anything to do w it but being a three main bearing engine may. Even some engines in the 50’s and 40’s were blessed w a main bearing on each side of a crank journal. There is always more main bearings than cylinders in engines built thusly as an in-line 6cyl w a 7 main crank. This is considered “best practice” and any engineer would have it so. A three bearing crank on a 4cyl is economy of manufacture feature.

I think I’ve mentioned it but a Willard Group member had a Perkins crank break running up Catham Strait a few years ago. He went to the other extreme repowering w a Beta engine. Quite expensive. There are many less expensive engines.

Curious what happened on this?

I began this thread, so I assume you want to know what happened to my perkins.

I bought the vessel. I discovered there was nothing wrong with the engine. It seems bad advice and wrong diagnosis was given for a non-existent problem.

I have run the engine under load and toured the Neuse River for a year now and no issues have presented themselves.

That is what has happened. Very good advice was given on this forum and I appreciate all.

Tim

"Reopwered w a S4L2 Mitsubishi. Same bore and stroke as the Perky. Just a smige more power"

Who did the marinization? Asking because our old Volvo MD 3B is almost dead .

The Mitsu seems closer to industrial than the Kubota .