CAT 3208TA 375 - Runaway

On the first cruise of the season after running at 1300 rpm@ 9 knots for an hour, all temps and pressures OK. Throttled up to 2350 cruise and port engine went to 2310 and settled back to 2200. Ran both at 2200. Went below after 25 minutes. Pressures and temps OK. went in engine room to see if throttle cable had slipped. Looked OK. As soon as I closed hatch rpm dropped to 1600. Smoke started streaming from exhaust. Throttled back to neutral. Hit kill switch. Engine kept running and started to rev higher. Saw 3450 on tach before i turned key off. About ten seconds later speed gradually wound down. Other engine which was idling also stopped. Dense smoke in engine room - I think this starved both engines of air. Scared the sh-t out of me. Oil sprayed all over the place.
Severe oil dilution with diesel. Two cylinders now with minimal compression and tons of blow by. Engine still starts and stops.Yard did one hour cruise two days earlier and said boat came up to speed. Engines installed 91, reported to have about 4200 hours (hour meters not original). Satisfactory pre-purchase survey by CAT dealer.
The Question: rebuild on board as only bare block can get through window or cut hole in roof and do drop in replacement? The latter engine would come with CAT warranty. Would probably swap other engine out too if we go drop in route. Starboard engine has been trouble free to date. Port one has recent injector pump and starter.I am leaning towards drop in - want his to be a one time good deal. Thoughts? Thank you.

T&S in Crisfield Maryland have a pretty famous reputation for dealing with Cat motors...especially 3208s...


May want to call them for ideas....extraordinarily inexpensive from historical references.

Thanks. I spoke to Tim.They are measuring their slip. My beam is 15'3" and may be too wide. That may be an option.

In the last year I have had two 3208's break injector lines under the rocker cover, flooding lube sump with diesel. Both sprayed lube/diesel out of blowby tube into air intake- which can certainly cause a runaway. But in these cases, they did not. In both cases operators noted heavier than normal exhaust smoke and shut down to investigate. That's what saved them.

Good chance that is what happened with yours, but you got enough fuel through blowby to fuel the runaway. Probably burned or broken pistons.

T and S is the go to place. Ship them your whole engine and have them build it back, ready for drop in.

If you have to cut overhead to remove engine, good idea to do both.

We had a broken injector line on the same engine last year. We escaped that one without any obvious damage. No runaway then. Engine was at 2350 when it occurred. Maybe the slow cruising allowed the problem to be worse when we tried to throttle up. All pressures and temps were normal when the smoke came and rpm's dropped. I am guessing the runaway did us in. First time I though I might be abandoning ship in more than 50 years on the water.

T&S can do rebuild for about $12,000. I didn't ask, but should I expect freshly painted "like new" looking engines. Should I rebuild Twin Disc Transmissions too? They seem to function alright but pressure ran a little high when surveyed. Thanks.

Yes , they will paint engine after rebuild (most do), I would send the gearbox out at the same time if it is in the budget.
Beautiful Wilbur.

What's high pressure.
Which gear do you have?
The MINIMUM for the 502, 506, 507 is 270 psi if I recall correctly. If the gear is approaching that, as a low, then there may be a problem developing.
Mine runs [ 506] ~300-320 and has done since I bought the boat 30 yrs ago.

Some have reported up to 350.

For the final word I would not trust electric guages but rather install a good quality mechanical guage using s STEEL hydraulic tee and observe that.

A rebuild with new clutches, re/re pump and so on though might be a good idea. Discuss it and make a decision. New drive coupling would be good and it will tell you what its compatriot on the other side is like.

As for painting you should ask , which paint, whoever you get it from. Specify if needed.
And don't forget the Cat engine reman program. You will get properly updated rebuilds with a good wty.

Ski or Henry, You guys are scaring me. Is the 3208 injector line under the rocker cover that you mentioned something that should be checked or replaced at intervals ? What makes it break?

Also wondering how you stop a runaway if the kill switch doesn't stop it?

Capt K:

The only ones I've seen break the inj line are those running at high power settings. OP was running 2350, in my case it was about the same, but these were 435hp.

If you run trawler speed, nothing to worry about.

Note that if this line breaks, that cyl will stop firing. You will feel engine running a bit lumpy, and if running hard, it will smoke as the remaining 7 are then overloaded.

If in doubt, stop engine and check sump level. If the line is broken, it will be overfilled.

Only seen three cases in 15yrs. Two happened a month apart!!

Don't worry about it, just be aware of what the symptoms are.

Time for an update

This has been a long and expensive process. After having both engines and transmissions rebuilt our sea trial in October revealed a maximum RPM of 2650. The props just came back from Black Dog where they were repitched. All of the engine room hoses were replaced. All of the battery cables were replaced and numerous fuses and breakers put in to bring the boat up to current ABYC standards. The original battery cables were welding cables and had numerous bare spots. The sliding door has been dry fitted. New engine room paint and insulation. The first sliding door was not built as ordered and the replacement was a long while in coming.
We have redone the brightwork, replaced all of the electronics, put in vacuflush heads, electric davits, rebedded the stanchions, replaced all of the engine mounts, bearings and shafts, new refrigerators. New upholstery...
Hopefully it will be worth it when spring comes around.

Seems like you got a lot done fairly quickly

Sounds like a new boat, hope it all works out as planed, beautiful boat by the way.

"What makes it break?"

A "mechanic " that doesn't own a torque wrench or Da Book.

Also wondering how you stop a runaway if the kill switch doesn't stop it?[/QUOTE]


With a diesel you need fuel, heat (compression) and air to make it run. Take away any one of the 3 and it should stop. Cover the air intake with a rag being very careful to avoid moving parts like belts and you should stop most any diesel. I used to work on transit buses with Detroits and we had a couple we had to stop this way. Again, be very very very careful of moving parts around a rag - great way to loose a body part like fingers or hands

John

The only Detroit Diesels I've seen that did not have air valves shutdowns were hopped up Covingtons or J&Ts. Every other has had the "gate" on the blower. They do need to be checked occasionally for proper operation. A rag over the intake of a screaming 3208 would not be a good idea. Something more substantial, board, tool box, etc would work, and not destroy the turbo or engine by being ingested.

henrymei; said:

Hopefully it will be worth it when spring comes around.

Click to expand...

Was the mechanical not covered by insurance?

My son is a Cat diesel mechanic. I asked him about it. he says that he keeps a small piece of plywood handy to place over the air intake to cut off air when he is working around them and there is a possibility of runaway.

The runaway caused the engine room to become smoke filled. This not only extinguished the runaway, but also caused the other engine to shut down. A fair amount of hot oil sprayed around the engine room. I am not sure I could have gotten near the engine. Probably a good thing the engine room is only passively ventilated. The mechanic thought a rag over the air intake would have been ingested - he said a piece of plywood could be used if the air cleaner wasn't attached. Fortunately I did have good insurance.

henrymei said:

Fortunately I did have good insurance.

Click to expand...

That's a relief. Did they work well with you and, if you are willing to share, did they go along with all the engine repairs including re & re?

To the mechanical guys; is this more likely with the 3208 for some reason or any diesel?

They paid for the engine rebuild and the structural work to get the engine in and out as well as storage minus the deductible and depreciation. The rebuild of the second engine, both transmissions, new risers and freshening the engine room were all on me. We also put a new water heater in. Basically we replaced whatever we could get our hands on.

I should add the insurance surveyor was most helpful in providing guidance and was a great resource. He was present during the teardown of the engine and documented the mode of failure. Ended up hiring Bob Stine who used to build Wilburs to oversee what turned into a major project. We endeavored to keep the aesthetics intact and the structure sound as we updated things.

henrymei said:

I should add the insurance surveyor was most helpful in providing guidance and was a great resource. He was present during the teardown of the engine and documented the mode of failure. Ended up hiring Bob Stine who used to build Wilburs to oversee what turned into a major project. We endeavored to keep the aesthetics intact and the structure sound as we updated things.

Click to expand...

Who do you have for insurance. With mine if I suck up a Wal-Mart bag and it over heats and destroys the engine, I am covered. If the engine fails because of a broke oil line, the engine is on me......

My insurance is with ACE. I have always used Morgan Wells of the Jack Martin Insurance Agency in Annapolis as a broker except for one unfortunate experience. Another broker put me with TL Dallas who took what I thought was far too long to pay a total loss claim on a boat lost at sea on its delivery from France to Annapolis. That was a Lagoon sailing catamaran.
As far as why the claim was covered. The boat had been serviced and commissioned by a reputable yard. I had all of the receipts for service and the information from a recent engine survey. They had done a sea trial a couple of days before I picked the boat up. Maybe that had something to do with it. Obviously I was very pleased the insurance company covered a significant portion of the loss.It made sense to do all of the extra stuff to freshen the boat up and reduce the chances of anymore unpleasant surprises.

"to pay a total loss claim on a boat lost at sea on its delivery from France to Annapolis."

Whats the story?

FF said:

"to pay a total loss claim on a boat lost at sea on its delivery from France to Annapolis."

Whats the story?

Click to expand...

This article is pretty good:
Change in course proves fatal | Soundings Online