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The mkiv Supra Owners Club

Bottom End Gone Maybe??


terribleturner

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James

 

If it was anything to do with camshafts and shims, it would make the knock at all engine speeds.

 

Unfortunately your noise sounds suspiciously like a big end :( In fact if we we running a sweepstake on it, I'd definately put my money on big end(s) :sorry:

 

Does it appear just when the engine is revved, and can you hold the revs at a point where it rattles all the time? If you rev the engine, can you rev through the noise. Does the noise appear mostly when the engine is "running light"?

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if you need a spare coil pack connector i have a few spare you can have mate.

Yes please Rob, can i nab 2 off you? :D

 

Does it appear just when the engine is revved, and can you hold the revs at a point where it rattles all the time? If you rev the engine, can you rev through the noise. Does the noise appear mostly when the engine is "running light"?

It only seems to be when the car is revved or just turned over. At one point you couldn't hear it at 2000rpm, then tried 2500 and it was there. Dropped to 1000 and then back to 2000 and it started again. Got some video of it being held at both 2000 and 2500 that i'll post later.

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It only seems to be when the car is revved or just turned over. At one point you couldn't hear it at 2000rpm, then tried 2500 and it was there. Dropped to 1000 and then back to 2000 and it started again. Got some video of it being held at both 2000 and 2500 that i'll post later.

 

I'd be interested to hear that, but I'm still 99.9% sure that its a big end. Shame CW isn't reading this thread, as I'd welcome his input as confirmation.

 

Sorry to be a bringer of doom, but better it fail now, than when you've just got the single on it ;)

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When you turn it over manually, are all the tappets coming all the way back up again? I.e when the cam is on its base circle (zero lift) are all the tappets in contact with it?

Ah, sorry i was lazy and put the cover back on and turned the engine over once with the key so didn't actually see anything moving. :(

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Honestly guys, if its a valve train problem, like a stuck valve (but it would be missfiring then anyway,) or a misplaced cam follower, it'll make the noise all the time the engine is running :banghead: :D

 

If its a bigend it'll be more noticeable when the engine is running light, or revved gently. A sort of "Burrrrrrrrrrrrrrrrrrrrup" noise IYSWIM ;) in fact JUST like the noise in the first video :cry:

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Honestly guys, if its a valve train problem, like a stuck valve (but it would be missfiring then anyway,) or a misplaced cam follower, it'll make the noise all the time the engine is running :banghead: :D

 

Actually, from the first video I do think it's noisy even at idle - albeit a different kind of noise. But I agree, its all looking like something more serious.

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Honestly guys, if its a valve train problem, like a stuck valve (but it would be missfiring then anyway,) or a misplaced cam follower, it'll make the noise all the time the engine is running :banghead: :D

 

If its a bigend it'll be more noticeable when the engine is running light, or revved gently. A sort of "Burrrrrrrrrrrrrrrrrrrrup" noise IYSWIM ;) in fact JUST like the noise in the first video :cry:

 

I'd agree, this rattle on load (change of RPM) is classic big end sound and I've had it before on an engine with a light scoring on the crank big end journal - that required a replacement crank, con rod and bearings!

 

Obviously you can't be 100% sure of anything until it is all taken appart, but I don't think it would be cam related with that sound or it would just go with the revs, not with the load too.

 

Is the spark plug idea good, anyone? i.e. remove one at a time and run on 5 to see if you can locate the cylinder / big end that may have the problem?

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Is the spark plug idea good, anyone? i.e. remove one at a time and run on 5 to see if you can locate the cylinder / big end that may have the problem?

 

It may work, but it's really a moot point.

 

The amount of aggro needed to pull the coil packs, just to tell you which bigend is knackered, when you've got to pull the engine out anyway.

 

At the end of the day, once we've agreed it's a big end knackered, which particular one, is irrelevant :(

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I can't see the video (work connection foobared) but WTF! You saying they stop turning? well if they ever slip out of position the engine would stop dead or run like a dog, so I can't see how... You sure it's not a strobing effect with the video camera, did you see it with your own eyes or just on playback?

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Guest Flat4_ire

im sick and its not even mine..worst nightmare, hope u have the money to fix her up and its not putting u under too much pressure, head up eh?

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must be strobing of the video surely? I'll have a look at the video when I get home, be amazed if they ever stop, think that is a physcal impossibility if the engine keeps running...

 

edit, ooops too slow, thought so, will take a look later though as I want to see for myself

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