4.2 knocking noise

Technical advice Q&A
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JD-JAG66
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Location: Italy
Italy

#1 4.2 knocking noise

Post by JD-JAG66 » Sun Sep 29, 2019 3:16 pm

Starting doing some test runs.
The 4.2 engine runs and accelerates very smoothly (originally from a 84 XJ6)with a Mangoletsi injection system. Unfortunately I have this knocking noise coming from the front of the engine, which is rather annoying.
Oil pressure is +/- 20 psi at hot idle.
I have made a short video, but can't find the youtube insert function.
I hope that the ignition light switching on and off several times during the short runs, does have nothing to do with this? Battery charge is hovering at 12V during idle.
Any idea's or suggestions would be most welcome.

Thx
Jan
Jan Deurinck
Series 1 - 1966 - 2+2 - LHD - American Import
Si vales, bene est, ego valeo

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politeperson
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#2 Re: 4.2 knocking noise

Post by politeperson » Sun Sep 29, 2019 7:29 pm

Slack timing chain?

Very easy to fix in a few minutes.
James

L.J.K. Setright was right.
"You just cant beat a good E-type"

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sk99
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#3 Re: 4.2 knocking noise

Post by sk99 » Mon Sep 30, 2019 10:10 am

Take the fan belt of and check so its not the water pump or alternator.
If upper chain is ok, maybe the lower chains hydraulic tensioner is the reason?
Is the oil pressure ok at normal running?
1967 FHC LHD
1966 OTS RHD

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JD-JAG66
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#4 Re: 4.2 knocking noise

Post by JD-JAG66 » Mon Sep 30, 2019 10:35 pm

Cheers, Will check that out this weekend!
Jan Deurinck
Series 1 - 1966 - 2+2 - LHD - American Import
Si vales, bene est, ego valeo

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