Help!!! Broken rivet and possibly a washer fallen down oil filler tube into engine. Merak SS

nickb

Junior Member
Messages
40
So, I thought I'd start up the Merak tomorrow and went to add some oil. As I took off the oil filler cap, the two parts came apart and I heard something drop down the filler tube. On inspecting the two parts of the plastic filler cap, there is what looks like the remains of a broken aluminium rivet which extends through the inside part of the cap to connect the two parts. It seems to me that there must have been a washer (possibly plastic - fingers crossed - but maybe metal) on the inside. Whatever was holding the two parts together has now dropped into the engine. Not good, to say the least. I have attached a few photos.

Does anyone with a Merak know what the inside of the filler cap looks like, or can post a pic, so that at least I know what has dropped off?

Tomorrow, when I have calmed down, I will try to remove the black filler tube and hope that I can see (and retrieve) the washer and maybe a bit of broken rivet, which by some miracle may be resting on some engine part within reach of the bottom of the filler tube. What is at the bottom of the filler tube?

If I can't see it, then what are my options? I am obviously not keen to run the engine with the possibility of a washer and a bit of rivet floating around. Do I turn the engine over once, but not start it, in the hope that the items drop down to the sump, or do I get it trailered to a specialist to get the engine dismantled? Or do I just start it and use it and hope for the best.


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Oneball

Member
Messages
11,866
Looks like a Citroen one

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I’d unbolt the filled tube and get a magnet on a flexible rod. Unfortunately that tube doesn’t look like it just drops straight to the sump so I think you need to find it.
 

nickb

Junior Member
Messages
40
Thanks. That certainly looks like mine - and confirms my fear that it is a metal washer that I need to find. You are right - the tube doesn't go to straight to the sump. You can just see the bottom of the black tube here....


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Scaf

Member
Messages
7,148
What a pain in the backside for you and poor engineering on behalf of Maserati.

Hopefully you can find it
 

Oneball

Member
Messages
11,866
You might be really lucky and find there’s a flat shelf under that tube as it’s sitting above the clutch I think unfortunately it’ll go into the chamber that holds the timing gear


There’s a mk3 escort somewhere with a plate araldited onto the sump after a similar situation!
 

Diavolo Nero

Junior Member
Messages
59
Worst case.... Buy an endoscope
Take the filler tube off scope the cavity and see if you can see it. If you can make a wire hook or loop using locking wire and you can see it you may be able to recover it. I've pulled released captive nuts out of gas turbine compressors so its not impossible but it's really really hard at times. Make sure you don't drop what you are using to attempt the recovery in there the first go and make it double the job. Also check the diameter of the scope will fit the aperture.
 

allandwf

Member
Messages
11,320
Maybe just drop the sump? It's a long time since I had my Merak, but I'm sure it's reasonably accessible. Hopefully you find the washer, no more horrors, bolt it all back up and no harm done.
 
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nickb

Junior Member
Messages
40
Thank you for all the replies. I've got an endoscope camera, which has a magnet so I will certainly be giving that a go tomorrow. If I find the washer, then what about the head of the rivet? The remaining part looks to be aluminium but I may be wrong and it is quite small. If I can't find that, then do you think it'd cause a problem or just end up in the sludge at the bottom of the sump? Sleepless night awaits.
 

Oneball

Member
Messages
11,866
Thank you for all the replies. I've got an endoscope camera, which has a magnet so I will certainly be giving that a go tomorrow. If I find the washer, then what about the head of the rivet? The remaining part looks to be aluminium but I may be wrong and it is quite small. If I can't find that, then do you think it'd cause a problem or just end up in the sludge at the bottom of the sump? Sleepless night awaits.
I think you’ve just lost the washer. I think the rest of the rivet is still there looking at your pic.

You’d be amazed the stuff I’ve gotten out of engine sumps with no apparent damage. The thing that concerns me about yours it’s it might not be in the sump. I think the area the oil tube goes to is where the intermediate shaft is that drives the cams.
 

nickb

Junior Member
Messages
40
Phew! Got it.

Oneball was correct - the errant washer was sitting on a flat bit of metal just below the filler tube (I've taken a pic to show the plate). Lifted it out easily on a magnetised probe light. I had a look around with a boroscope and no sign of any other debris, so I'm confident the washer had just slipped off the mangled end of the old rivet.

Now all I need to do is to re-attach the two halves of the filler cap together. I'm not sure I trust using another rivet so I will drill out the old one and use a small bolt with a couple of nuts on it. It won't look pretty but I can't face another rivet coming loose.

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philw696

Member
Messages
28,133
Great result indeed.
It's all about being patient and working carefully Well Done.
In fairness to the rivet in question it's worked for 40 plus years so that ain't bad.
 

Diavolo Nero

Junior Member
Messages
59
Phew! Got it.

Oneball was correct - the errant washer was sitting on a flat bit of metal just below the filler tube (I've taken a pic to show the plate). Lifted it out easily on a magnetised probe light. I had a look around with a boroscope and no sign of any other debris, so I'm confident the washer had just slipped off the mangled end of the old rivet.

Now all I need to do is to re-attach the two halves of the filler cap together. I'm not sure I trust using another rivet so I will drill out the old one and use a small bolt with a couple of nuts on it. It won't look pretty but I can't face another rivet coming loose.

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Happy days glad your crisis was averted. If you are using a nut and bolt to reassemble may be an idea to use a locking method like a tab washer, spring washer or loctite on reassembly