Chain tensioner adjustment, turned in to major failure

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DanHansen
Posts: 36
Joined: Mon Apr 02, 2018 7:32 pm
Dino: No Dino (yet)

Chain tensioner adjustment, turned in to major failure

Post by DanHansen »

So....
I got this beautiful 2400 Coupé, 56.000 km on the clock since new, a rattling sound, caused by a loose chain on the right bank, adjusted both sides as described in the WM, no rattling sound...
Drove the car for 35 km and a sound, best described as a defect throw out bearing was there below 3000 rpm and disappeared just over 3100 rpm.
The sound got more superior and a rattling and a sound of metal parts breaking was the next!
Lost most of the power, but managed to limp the car 400 meter to my home, just rolling the last 8 meters, with a trail of what first seems to be hydraulic fluid, but with a closer look this evening, it is cooling water dripping from left hand manifold?
Maybe its not the chain tensioner after all, but the water pump that failed, making the head gasket to blow?
Any thoughts ?
Dario
Posts: 117
Joined: Fri Nov 29, 2013 12:18 pm
Dino: Fiat Dino 2.4 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by Dario »

Ouch, that doesn't sound good. A failing water pump usually makes a wailing noise from the bearing. On our engines, it is located in the center between the two intake manifolds, not on the left. If it was me, I would check the fluids to see if there is metal in the oil, and remove the cam covers to check. The one on the left is easy to take off since there is no heating tube running behind it. Lost power sounds like the timing chain jumped a cog. If so, the valves could be bent, etc.

A good modification that was made by Ferrari on the Dino engines is to tap a 8 mm bolt into the chain tensioner end. Once the chain was tightened according to the manual, the bolt would be tightened against the tensioner shaft and locked in place with a nut. This way, even if the chain tensioner came loose, it could not back out.

From what you describe, it seems to me that the chain tensioner was not secure, or came undone, letting the chain jump on the sprocket. This can lead to a top end failure.

Let us know what you find, and good luck...

Dario
Beanderb4
Posts: 26
Joined: Thu Dec 26, 2013 1:16 pm
Dino: Fiat Dino 2.0 Spider

Re: Chain tensioner adjustment, turned in to major failure

Post by Beanderb4 »

Dan,
Sorry to hear about your bad experience. Sounds like you may have some serious issue there. All I can do is offer some advice for the future. When you are repairing the car make sure to add a retaining bolt to the tensioner retaining caps Details are on the Dino UK.org website. See picture below which was taken from the same website.
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DanHansen
Posts: 36
Joined: Mon Apr 02, 2018 7:32 pm
Dino: No Dino (yet)

Re: Chain tensioner adjustment, turned in to major failure

Post by DanHansen »

So, with the car safely back in my garage (transported by SOS) I began the search..
First signs was not good, metal debris in the air filter box....
With the intake gone, I could now start to be really worried, what I first thought was a broken chain tensioner, showed something different.
Intake valve on 5 and 6 dropped and caused total disaster!
Next up is at engine/transmission drop, and the real tear-down begin, from there it will be decided which way to go....?
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4cambob
Posts: 111
Joined: Sat Sep 24, 2016 9:19 am
Dino: Fiat Dino 2.0 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by 4cambob »

Sorry to hear about your misfortune. If the chain did not jump a tooth then I would guess that being a low miles original car it would still have the sodium exhaust valves and these have been known to break, apparently at almost any revs. Either way its going to be quite a rebuild.
Luis A
Posts: 86
Joined: Tue Oct 31, 2017 12:35 am
Dino: Fiat Dino 2.4 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by Luis A »

Why would tightening the chains cause this? Or perhaps the rattling sound was the sign that something wasn't right, but not the chain, and it qwould have happened anyway...??
Stefan2000
Posts: 167
Joined: Sat Feb 21, 2015 8:42 am
Dino: Fiat Dino 2.0 Coupe
Location: The Netherlands
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Re: Chain tensioner adjustment, turned in to major failure

Post by Stefan2000 »

Ouch... that really really sucks big time.
The exhaust valves are 'known' for breaking but this is kind of strange because it is an intake valve and as far as my knowledge goes the intake valves are not hollow sodium filled valves.
Also a valve that breaks would not cause any noise or rattles in advance, it would just snap.
My guess would be that it did jump teeth and at some point it started to hit the valve until it broke off....but anyway at this point it wil not help you in any way, it just really f**ked up.
DanHansen
Posts: 36
Joined: Mon Apr 02, 2018 7:32 pm
Dino: No Dino (yet)

Re: Chain tensioner adjustment, turned in to major failure

Post by DanHansen »

Stefan2000
Yes, a major ouch.... Thinking of what happened, I to have come to that conclusion, that the chain have jumped...?
But for now, a tear down of the engine must show what really went wrong...
dinoverde
Posts: 330
Joined: Wed Nov 27, 2013 5:56 am
Dino: Fiat Dino 2.0 Spider

Re: Chain tensioner adjustment, turned in to major failure

Post by dinoverde »

Hi Dan
sounds like the cams got out of sync...If you are to drop the engine think about doing it from the bottom..you will have to undo part of the front suspension and the radiator fan...that is if you have a lift and an hydraulic table...
just put back mine in with the transmission attached...it is tight fit but it is less drama than over the top..
Depending how much you need to replace and depending on budget..contact me ....i have a few very good highly used engine parts that have a lot of life left in them..i will give you a killer deal..
Good luck
Hervé
DanHansen
Posts: 36
Joined: Mon Apr 02, 2018 7:32 pm
Dino: No Dino (yet)

Re: Chain tensioner adjustment, turned in to major failure

Post by DanHansen »

Hervé...
Thank you for your message... Yes it´s a major ouch... But it´s water under the bridge now.
Yes my workshop has a brand new lift, so my plan was to drop it, like you described.
When i have the engine out, I´ll decide what to do with it?
We don´t have so many workshops in Denmark that specialized in these engines, so It will probably be sent out of the country to someone who knows and works on these motors on a more daily basis.
I hope that the head which have the broken valves can be saved and restored, so the engine will stay as original as possible, but I will ask, if needed.
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