Problem with loose fuel injector / broken studs

vt97john

Well-known member
Joined
Sep 22, 2018
Messages
64
Fluid Motion Model
C-288 C
Hull Identification Number
FMLT2910J213
Vessel Name
TBD
I took a ride on my 2013 R29 a few days ago and she was running normally for a few minutes. Then something happened suddenly and there was unusual engine noise / engine rhythm and smoke started coming into the cabin. I shut it down. After getting towed back to the marina, I had a mechanic look at it and he found that the problem was that a fuel injector had broken loose (see detailed notes below). As anyone else had this occur? He said it's unusual and he can't imagine what would cause the cast iron clamp to break. He said he might contract a local Yanmar dealer to dig a little deeper. Any insight the tug nuts might have to offer would be great.

"Service call in local area, include 1st hour labor: Evaluate smoking and engine running issue.

Removed front and top covers from engine. Started engine and immediately shut down as source of smoke was obvious.

Discovered the #1 cylinder fuel injector loose, clamp block broken and laying on engine, 2 securing studs broken off. Also, #2 cylinder injector clamp block is broken, but still in place.

As a side note, 4 machine screws holding intake manifold to engine were visibly loose, tightened them up.

DO NOT RUN THIS ENGINE UNTIL THESE PROBLEMS ARES RESOLVED.

Left message for Karl's Marine Engines with details of issue. Will follow up with him to get this resolved. This may be after the new year.
"
 
John,

I haven't had this issue, but I wonder if someone stepped on the engine cover while climbing into, or out of, the engine compartment. I have a "NO STEP" sticker on mine, but I still worry that someone may do it, as it is the most convenient way in or out.
 
I do indeed step on the engine cover when I enter the engine compartment. I assumed I was stepping on a solid block.
 
BradOwens":3a41iu0n said:
John,

I haven't had this issue, but I wonder if someone stepped on the engine cover while climbing into, or out of, the engine compartment. I have a "NO STEP" sticker on mine, but I still worry that someone may do it, as it is the most convenient way in or out.

I’m also new to a R29 Classic and thought the whole idea of the engine cover was to protect the top of the engine so you could step on it. Now If the bolts holding the cover came lose, then you could have a problem with the cover impacting the top of the engine?
 
Vibration could be the culprit. If things were not properly torqued down originally, over time vibration can do a lot of damage.
 
This is the first I have read on this site about injector clamps and studs breaking. Were the injectors ever removed? Perhaps they were not tightened to specs. On the Yanmar 4BY-2 there was an injector service bulletin some years ago on some of the engines.
Stepping on the covers is not a good idea, it will eventually damage the covers. Hard to believe that doing so could break injector clamps and studs.
I remember reading on here that one owner removed the covers completely so he could see what was going on under them.

Keep us posted on the fix and what they determine to be the cause of the failure.
 
On page 6-12 of the service manual the injector nuts should be tightened to 71 inch lbs.
 
Unusual. Usually when under torqued you will notice blow by that prompts you to confirm them with a torque wrench. But this is an unusual one. Sounds like it may have been over torqued and operating conditions was the catalyst? Were your injectors recently serviced or rebuilt?
 
Broken studs are almost always due to over torquing them combined with operating stresses/vibration. What is odd is the the studs and the bracket were broken. Typically once one or the other fails tension is relieved on the remaining fastener. Unless they all suffered a transient event such as cylinder overpressure(e.g. liquid injestion). At any rate I'd say the broken fasteners/bracket and loose ones on the manifold are not mere coincidence. Sounds suspiciously like the engine was either worked on in the past or experienced a transient event.

The only thing I'd rule out is the potential of having been damaged by stepping on it. Tubing, wiring, etc, are subject to damage from stepping on the engine but not mechanical fasteners. Not a good idea to step on the engine but it's not likely to cause this type of damage.
 
Mechanic started working on the issue today. Found that multiple fuel injectors are rusted and need to come out. Looks like water somehow got to the front of the engine at some point (maybe before I owned the boat). Now the big concern is whether the mechanic will be able to get those injectors out without removing the whole engine. He said he isn't sure yet because the cabin doorway is sort of over the area where he needs to work. Anyone have any experience / thoughts with this? Tell me the engine won't have to be removed!
 
Injectors need to be serviced just like the rest of your boat and engine.
When I had our service business in Newport Beach we pop tested all injectors on an annual basis.
Injectors needs to be adjusted or replaced if you are not getting proper pop off pressures and spray patterns.

I don't know the service life on the newer engines but an injector is an injector. I would imagine maybe service every two years or more but I'd have to read up on that. I'd assume they are much better today and possibly not even serviceable.
But ALL nuts and bolts will come loose over time.

They MUST be seated properly and torqued EXACTLY to spec. Also, when tightening you tighten them evenly and at 2 to 3 steps up in torque. You don't tighten down to the required torque the first round. Slowly and evenly on each bolt. Then your final spec.... then double check.

This sounds like either the injectors have never been serviced and they came loose or someone had them out and did not correctly torque them. We also used to check these on new boats after break-in and that is what I will do on our new boat as well.
 
Our 2012 R29 has a hatch just inside the cabin door to access the front of the engine. I imagine yours is the same. Between the cockpit engine hatch and the one in the cabin, almost any part of the engine is accessible. We had our injectors serviced without difficulty.
 
Does anybody know how much it would cost to replace engine in my 2013 R29? The bill for replacing injectors and studs in head etc is approaching $9-10k and I’m just wondering if I would have been better off replacing engine!
 
vt97john":3svcrj38 said:
Does anybody know how much it would cost to replace engine in my 2013 R29? The bill for replacing injectors and studs in head etc is approaching $9-10k and I’m just wondering if I would have been better off replacing engine!
Assuming you mean replacement with a brand new engine it would likely be three to four times that cost. The comparison begins to be more favorable if the engine does have to come out of the boat. Labor for removal and installation would be roughly the same for either overhaul or replacement. So in that case the net cost differential comes down to the difference between overhaul cost vs new.
 
Sorry you have to go through this.
Hope you are able to have a positive resolution.
 
Not sure if you have the Yanmar or Volvo. The Yanmar would probably be in the neighborhood of $25,000 or so.
 
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