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Discussion Starter · #1 ·
Evening, I dont post on here much but follow this forum closely. i Have a stage 2 megane r26 275bhp 360ft lb and i just fort i would share this with you, i don't know if anyone else has experienced this issue before. I started my car up the other afternoon with the radio on drove about 1mile down the road to get some food. On returning to the car started it up and heard a knock from engine. opened the bonnet and there was a nasty noise from the top of the engine sounding like tappets, oil level spot on and car still drove fine with no loss of power or anything. I took the car to work and decided to take the cam cover off. Took the cam cover to find no obvious problems, so i decided to take the head of to check valves and pistons and they are all fine! So i took the sump of and well the chain that runs from the crank shaft to oil pump flapping around like a bag in the wind! Now i havnt had time to take the side of the engine of to revel what should be holding the chain tight i suspect that there should be a tensioner that is broken? can anyone confirm that there is some sort of tensioner that should be holding it tight? Below is a link to sound of my engine and the chain that is loose.



 

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Right, tht oil pump chain has no tensioner on it. That's how they are. It sounds too fast to be bottom end to me. But then it's more difficult to say when you just hear a video of it. Sounds more top end anyway IMO.
Maybe a hydraulic tappet/lifter knackered?? Have you moved all the other pulleys? Like alternator etc? Or does it sound internal to the engine??
 

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Is the video from a cold start i.e. idle at 1500 revs?

If not and it's idle is normal (less than 1k) then that's too fast to be bottom end.
 

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Discussion Starter · #4 ·
Right, tht oil pump chain has no tensioner on it. That's how they are. It sounds too fast to be bottom end to me. But then it's more difficult to say when you just hear a video of it. Sounds more top end anyway IMO.
Maybe a hydraulic tappet/lifter knackered?? Have you moved all the other pulleys? Like alternator etc? Or does it sound internal to the engine??
Thanks for the reply. Thats not wot i was hoping for. My first fort was a tappet or a lifter but theres none that are soft and all seem ok, it seems like the noise is coming from the side by the engine mount at the very top so was hoping that chain slapping about would be travelling to the top. so theres nothing that tensions that chain?

SevenC

The video isnt from cold its just at normal idle no choke. i dont think its bottom end as obviously the noise is to fast as bottom end turns slower then cams!
 

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Have you checked the idle pulley and adjuster on the cam belt?? I've seen them start to crack and make a noise.
 

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Discussion Starter · #6 ·
yes mate iv checked everything along the way and iv seen nothing wrong, its defiantly from inside the engine and sounds as you say top end. But i have checked everything and cant see nothing wrong, im a Technician for Aston Martin so i know my way around a engine, i just cant believe that the oil chain should be that loose.
 

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Stumped then mate, thought I might have nailed it with the pulleys as ive seen them crack all the way down and start to part. That gives off a right horrible noise.

I'm 100% with the oil pump chain being like that.
 

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Discussion Starter · #8 ·
Ok mate, well thanks for your help and advice! ill have to keep looking. Ill let you know what i find
 

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Discussion Starter · #10 ·
i agree topend but i have checked all tappets rockers and even removed valves from head and have found nothing wrong, thats why iv started to removed the bottom end!! ill have to do some more investigating tomorrow
 

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Discussion Starter · #11 ·
Well i decided to take the bottom end apart today and um people who think there bottom end is good for 300bhp need to think again!! 275bhp 340 ft lb had killed my rods!



 

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That's not so good fella, lucky you caught it before it went bang!!
On the plus side, forged engine it is! :)
 

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Discussion Starter · #13 ·
its good in some respect, And yeh i am gona forge it and spend some money on but im not sure i can save that block, think its skip time!
 

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Discussion Starter · #17 ·
I see, thanks for your help anyway! lets hope someone else pops up and can give me some ideas
 
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