4.2 strange sound coming from engine bay

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TrevS
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#1 4.2 strange sound coming from engine bay

Post by TrevS » Sun Apr 15, 2018 9:01 am

Hi all

Had the car out for the first time yesterday and went on a good 30 minute drive. The car is driving really well after a service at XK engineering over the winter, pulling well etc. However the car has developed a strange rattling sound that's quite loud in the engine bay. It almost sounds like something is loose and the engine vibration is causing it to knock. It seems to occur mostly at slow speeds, at idle or when I hit the odd bump but at faster speeds I don't hear it so much. I've no idea if it's the engine itself or another component.

I've done a video here, if anyone can help identify what the sound might be or areas to check that would be really helpful
https://youtu.be/Q15dws5uSus

Thanks

Trevor
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Mich7920
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#2 Re: 4.2 strange sound coming from engine bay

Post by Mich7920 » Sun Apr 15, 2018 9:43 am

Did you check the screw at the bottom of the air filter ?
Michel
1965 E Type FHC - On the road / 1963 E Type OTS - on the road after Angus Restoration

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flatfloor 3.8
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#3 Re: 4.2 strange sound coming from engine bay

Post by flatfloor 3.8 » Sun Apr 15, 2018 12:53 pm

Under the carbs there are 3 metal overflow pipes these can rattle against each other and on the frame rails.
Bill S1 3.8 OTS.

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#4 Re: 4.2 strange sound coming from engine bay

Post by TrevS » Sun Apr 15, 2018 2:52 pm

flatfloor 3.8 wrote:
Sun Apr 15, 2018 12:53 pm
Under the carbs there are 3 metal overflow pipes these can rattle against each other and on the frame rails.
That’s a good call. I had an issue with one of the floats getting stuck and I had fuel leaking out of the overflow pipe before Christmas so XK serviced all the carbs during its winter service so I wonder if that’s where the noise is coming from. Will investigate this week

Trev
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#5 Re: 4.2 strange sound coming from engine bay

Post by politeperson » Sun Apr 15, 2018 3:28 pm

Another rattle could be where the top half of the air filter (the plenum) meets the bottom half (the barrel).

Although they are separated by a rubber ring, I have can them rub against each other at idle of when pulling off from stationary.

With the engine rattling away, try pushing the plenum see if it makes a difference.
Its true, but Enzo never said it
Too many E types
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#6 Re: 4.2 strange sound coming from engine bay

Post by Hugo » Fri Apr 20, 2018 1:36 am

TrevS wrote:
Sun Apr 15, 2018 9:01 am
Hi all

Had the car out for the first time yesterday and went on a good 30 minute drive. The car is driving really well after a service at XK engineering over the winter, pulling well etc. However the car has developed a strange rattling sound that's quite loud in the engine bay. It almost sounds like something is loose and the engine vibration is causing it to knock. It seems to occur mostly at slow speeds, at idle or when I hit the odd bump but at faster speeds I don't hear it so much. I've no idea if it's the engine itself or another component.

I've done a video here, if anyone can help identify what the sound might be or areas to check that would be really helpful
https://youtu.be/Q15dws5uSus

Thanks

Trevor
That's the air filter, isn't it? You can see it rattling around (unless it's the lack of a steadicam!). Not the filter - the triangular bit on top I mean.
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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#7 Re: 4.2 strange sound coming from engine bay

Post by TrevS » Fri Apr 20, 2018 5:51 am

Haven’t had proper chance to have a look but noticed that one of the aluminium floor panels looks like it might be rattling. I got XK to fit a new speed cable so maybe something got moved etc at the time which is causing the rattle. Hoping it’s nothing serious but will report back tomorrow
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#8 Re: 4.2 strange sound coming from engine bay

Post by TrevS » Thu Apr 26, 2018 5:00 pm

flatfloor 3.8 wrote:
Sun Apr 15, 2018 12:53 pm
Under the carbs there are 3 metal overflow pipes these can rattle against each other and on the frame rails.
Well done that man, spot on with where the noise is coming from. Turns out in to the overflow pipe from the centre carb. Not sure how to stop it rattling though and not sure it's completely in the right place so could some please post a picture of their centre carb showing how the overflow pipe is directed down through the engine bay.
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#9 Re: 4.2 strange sound coming from engine bay

Post by 1954Etype » Thu Apr 26, 2018 5:03 pm

There should be a flattened P clip that the pipes pass through. Held on by one of the bolts holding the oil filter base to the block (top RHS I think)
Angus 67 FHC 1E33656
61 OTS 875047

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#10 Re: 4.2 strange sound coming from engine bay

Post by TrevS » Thu Apr 26, 2018 6:44 pm

Thanks for the help everyone, problem is now sorted. Pipe just needed repositioning and after a bit of adjusting there is no more rattle.
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