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Unspecified engine knock


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#1 sheldricka

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Posted 06 July 2018 - 08:39 PM

Does anyone have a view on the source of this knock, its there from starting, quiet at low revs once started and get louder when hot and follows the engine speed. Its not coming from tappets, all set for a standard cam, oil pressure is also good, compression is also good on all cylinders. The noise is high up towards the front two cylinders. Using a stethoscope its detectable but not on any specific point. Ive recently replaced the cam followers as some were tight in the block, ive also had the first two pistons out to inspected the small ends. All thought welcome. Video attached.

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Edited by sheldricka, 06 July 2018 - 08:41 PM.

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#2 RogerH

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Posted 06 July 2018 - 08:42 PM

What was the condition on the followers faces. If anything other than perfect I would consider the cam for removal.

 

Roger


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#3 sheldricka

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Posted 06 July 2018 - 08:45 PM

They werent too bad but not perfect, a couple were mushroomed and took some persuading to get out. No2 was one of them
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#4 Waldi

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Posted 06 July 2018 - 08:55 PM

If the tappets were damaged it would be best to inspect the camshaft too.
Compare all lobes, especially those that had worn tappets with the rest.
Regards,
Waldi
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#5 sheldricka

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Posted 06 July 2018 - 09:00 PM

Thanks Waldi, Ive been suspecting the cam, just wanted some other opinions before I take on the effort to strip it all down. Alan
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#6 Mike C

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Posted 07 July 2018 - 04:28 AM

Have you tried rocking/turning the engine by hand to try and better pinpoint the source?


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#7 sheldricka

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Posted 07 July 2018 - 05:11 AM

Hi Mike, only when setting the valve clearances and its only noticeable when its running
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#8 Waldi

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Posted 07 July 2018 - 06:27 AM

Alan,
If you would have very worn lobes, you could measure the (reduced) maximum lift with a micro meter once you have removed the rockershaft.
Good luck,
Waldi
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#9 sheldricka

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Posted 07 July 2018 - 08:56 AM

Yes Ill give that a go, just mustering up the enthusiasm to take it out, I might pull the whole lot out and check it all over while Im at it. Probably easier in the end.
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#10 Steves_TR6

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Posted 07 July 2018 - 09:31 AM

Have you tried running the engine with the fan belt off to eliminate water pump and alternator from the equation?

Edited by Steves_TR6, 07 July 2018 - 09:31 AM.

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I thought TRs were meant to leak outwards!

#11 sheldricka

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Posted 07 July 2018 - 09:38 AM

Hi, yes, no change. Its definitely coming from the upper block area. Thanks for your suggestion. Alan
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#12 Waldi

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Posted 07 July 2018 - 09:59 AM

Alan,
Since a couple of tappets were mushroomed, the cam and followers are a very likely spot to look at.
Engine out makes work easier and gives a better quality, choises, choises, choises.
Waldi
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