Mysterious ominous bolts???

[scopeusa]

Whilst replacing all of the clips under the clean out tray I came across two SS bolts lying in the bilge which I guess are 6 mm x about 125 mm that have sheared and rusted through. This did not look like good news although I could not see anything obvious. I have looked up the intermediate shaft drawings and cannot see anything. Has anyone any thoughts on this?

 

[Julian]

Owners have found all sorts of debris from the original construction in their bilges.....how about a photo of them?

 

[txav8r]

my guess is that they were dropped, replaced, and never retrieved during original assembly.

 

[RiverRat]

Are they maybe remnants of rusted out hose clamps?

 

[scopeusa]

I will take a photo tomorrow, the bolt head has the number 10 stamped on it in large digits. The bolt has a standard size washer for a 6mm bolt. The bolt is 125mm long at the point of shear.There were old corroded out SS clamps lying in the bilge, cut out bits of fiberglass and plywood and other miscellaneous junk. These bolts are nothing to do with the aforementioned clamps. The bolts could not result from earlier service as I have owned the boat from new and no one else has touched it. The question is why does the bolt evidence shearing if it has not been installed? If it had just been dropped in the bilge the end of the bolt would have a longer thread and a clean end.

 

[Julian]

Oil cooler bolt? Pretty sure that was a 2010 model year problem.

Wasn't there also a bolt on the back of the MR1s that was sheering near the oil cooler?

 

[scopeusa]

This is a 2008 model. The is no evidence of any oil leaks. I found them under the clean out tray not in the engine bay. Am I correct in thinking
the engine bay bulk head is sealed from the clean out port bilge area? If not I have another area to search for missing bolts. Cheers let me know your thoughts.

 

[itsdgm]

Wow, those are pretty big bolts. I would think that you would've noticed them missing if they weren't replaced by now. Could they be pump mount bolts? Or transom/pump plate bolts?

 

[RiverRat]

Definitely not from any clamps. Sounds like @itsdgm might be on to something.

 

[Julian]

The back of your engine compartment is connected to your bilge area. Anything that falls into the stern most section of the engine compartment will make its way back to the bilge.....so yes....you need to check the engines for missing bolts!

 

[scopeusa]

There she blows, my mistake it was an 8mm not 6mm the number 10 stamped on the head confused me until I took a closer look. According to the manual its one of six 8 x 125 mm holding the exhaust manifold to the first pipe, along with four 8 x 75 mm. The boat is at the shop so I cannot check to see if these have failed on just one manifold or whether its one on each engine. Of course the bit of thread is held in with LT. I have found my inspection camera so I will give things a good check out tomorrow. Has anyone else had manifold bolt problems. I suspect these could be over torqued at the factory, I know that upon removing bolts from brand new stuff you know darn well that the effort it took to undo that bolt was way more than the specified torque.

 

[scopeusa]

I gave up with the inspection camera, the focal length was too long so I used a friends phone that could focus. To my amazement I found all 10 bolts in place on both engines so where did these two bolts come from? The heads carry the identical stamp to the 10 exhaust to manifold ones. I could accept that they were just dropped in the engine bay but that does not account for the short thread which has sheared end. My shop manual is for a 2004 model year but I doubt much has changed in the hardware department. I have scanned it until my eyes were straining. I may well have missed something but aside of the bolts I previously mentioned I could not find another reference to 8 mm x 125mm or any other bolt that long.

 

[Julian]

The cynic in me says that they sheared off 2 while installing the manifolds and had to replace it with a new one and left their trash behind. I wonder if the dealer has the capability to look up a part and say all the locations it is used? @Williamsone46 do you know if this is possible?

 

[Williamsone46]

The cynic in me says that they sheared off 2 while installing the manifolds and had to replace it with a new one and left their trash behind. @Williamsone46 do you know if this is possible?

The engines are not assembled in the boat so if they were sheared off during assembly they wouldn't find there way into the boat.

I wonder if the dealer has the capability to look up a part and say all the locations it is used? @Williamsone46 do you know if this is possible?

That is possible, I'll check tomorrow when I'm in the office.

 

[Julian]

The engines are not assembled in the boat so if they were sheared off during assembly they wouldn't find there way into the boat.

@scopeusa said the only match he could find was on the exhaust manifold....depending on which part of the exhaust, I can easily see them leaving the manifold off until they have the assembled engine in the boat....

 

[scopeusa]

The match was between the first stage of the exhaust and the manifold. I await with interest what williamsone46 can find. I hope to have the boat back on the water by the weekend. I think that I will soon be researching FAQ's on servicing the pumps.

 

[Marshall]

they could be the mounting bolts that hold the thermostst housings to the engine housing. 2 per engine 10mm

 

[scopeusa]

I have not got the manual with me as I am travelling and way back I searched the official manual exploded views from top to bottom. There are a shed load of 10mm bolts as you would expect but unless they are 125mm long, which I doubt, then the only bolts that match this length are located on the manifold to exhaust as I said in my earlier post. If bolts had quit on the thermostats I would expect to see evidence.