Loud metallic tapping sound on start-up
Loud metallic tapping sound on start-up
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Macbags

Original Poster:

119 posts

76 months

Friday 24th January 2020
quotequote all
Just started her up for the first time in nearly a month and was alarmed by a quite loud metallic tapping/ clattering noise when she fired up which quietened down after 3 or 4 seconds, Presumably something to do with oil pressure and lubricating the tappets / valves or something but never heard the noise before. Anything to be concerned about......or do they just do that kind of thing!?!

Edited by Macbags on Friday 24th January 17:51

2 sMoKiN bArReLs

31,635 posts

256 months

Friday 24th January 2020
quotequote all
When I had this it was exhaust manifold gasket. (Although hard to say over the internet without hearing it.....)

Classic Chim

12,424 posts

170 months

Friday 24th January 2020
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What oil are you using.
Sounds like a bit of oil starvation after standing especially if it disappears moments after start up
Mine used to do this a lot on 10/40 semi from cold.
I added about 1litre of 20/50 classic oil to my mix and it’s been quiet ever since.

Macbags

Original Poster:

119 posts

76 months

Friday 24th January 2020
quotequote all
I’d be surprised if it was the manifolds as it sounds too mechanical. I remember the manifold gaskets going on my old s2 and it was a very different sound.

Oil is 20/50 mineral.


Olas

911 posts

78 months

Friday 24th January 2020
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Oil filter anti-drain-back-valve is defective. Replace with Mann or Mahle equivalent and I’ll bet you 50p the noise stops.

Classic Chim

12,424 posts

170 months

Friday 24th January 2020
quotequote all
Olas said:
Oil filter anti-drain-back-valve is defective. Replace with Mann or Mahle equivalent and I’ll bet you 50p the noise stops.
I’d agree fully use a quality filter
Note
I ran my car with too thick oil and the start up from cold was always noisy.
Drained oil as it was a 50/50 mix using semi 10/40 and 20/50 mineral so compatible with the semi.
It was just too thick.
Started again with 5.5 litres 10/40 and 1.5 litres 20/50 and it’s been right as rain ever since.
I left the car stood a good 4 months and still silent on start up. Happy Larry
For some reason manifold gaskets on my Chim and others do make what sounds like metallic tapping when bolts are loose so don’t discount it.


Edited by Classic Chim on Friday 24th January 19:04

Chimune

3,941 posts

244 months

Friday 24th January 2020
quotequote all
2 sMoKiN bArReLs said:
When I had this it was exhaust manifold gasket. (Although hard to say over the internet without hearing it.....)
I'll put 50p on this. Mani heats up quickly and seals gap in gasket.

Macbags

Original Poster:

119 posts

76 months

Friday 24th January 2020
quotequote all
I’ll be very releaved if it’s just the manifold gas gets. What I the best way to check ?


Edited by Macbags on Friday 24th January 22:50

Zener

19,286 posts

242 months

Friday 24th January 2020
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Hyd tappets can bleed down after long periods of inactivity especially a lifter on full cam lift

phazed

22,430 posts

225 months

Friday 24th January 2020
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^^^^^^^^^^^^

Boosted LS1

21,200 posts

281 months

Saturday 25th January 2020
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Lifters make a rattling noise if not primed. Metallic, a less heavy sound could be exhaust gaskets as also suggested.

Classic Chim

12,424 posts

170 months

Saturday 25th January 2020
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My 50p is on 20/50 cold oil.
My late year engine did this both times when I changed from 10/40 to thicker oils.


Olas

911 posts

78 months

Saturday 25th January 2020
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If the noise is only 3 or 4 seconds it’s oil.
The exhaust
Manifold has too much thermal mass to heat up and expand to close a gap in 3 seconds of idle, the engine simply doesn’t create that much waste heat. Double check by trying to tighten the manifold nuts/bolts/studs but I’m confident they’re tight - a blow will always blow.


A defective ADBV will allow oil to drain back to the sump and so every cold start is effectively a dry start, the noise stops when the oil reaches the valve train
A filter with an operational ADBV will NOT allow oil to drain back to the sump instead it holds oil in the galleries and bearings so there is no noise at startup.

It’s saturday - go to your local motor factor and buy a quality filter.
Fit it, run it, check the level and let it cool overnight - start it up again tomorrow and into will be smooth and silky.

I’ll actually bet you 50 English pence - if the noise stops I’ll let you off the debt. If the noise doesn’t stop I’ll PayPal you the 50pence.


PLEASE! For the sake of the your balvetrain and it’s health, fit a quality filter from Mann or Mahle

Classic Chim

12,424 posts

170 months

Saturday 25th January 2020
quotequote all
Olas said:
If the noise is only 3 or 4 seconds it’s oil.
The exhaust
Manifold has too much thermal mass to heat up and expand to close a gap in 3 seconds of idle, the engine simply doesn’t create that much waste heat. Double check by trying to tighten the manifold nuts/bolts/studs but I’m confident they’re tight - a blow will always blow.


A defective ADBV will allow oil to drain back to the sump and so every cold start is effectively a dry start, the noise stops when the oil reaches the valve train
A filter with an operational ADBV will NOT allow oil to drain back to the sump instead it holds oil in the galleries and bearings so there is no noise at startup.

It’s saturday - go to your local motor factor and buy a quality filter.
Fit it, run it, check the level and let it cool overnight - start it up again tomorrow and into will be smooth and silky.

I’ll actually bet you 50 English pence - if the noise stops I’ll let you off the debt. If the noise doesn’t stop I’ll PayPal you the 50pence.


PLEASE! For the sake of the your balvetrain and it’s health, fit a quality filter from Mann or Mahle
He should put in the correct spec oil after he’s done that as 20/50 alone is not really the oil that should be in these later built engines especially when it’s cold. My cranking speed was slower too, work that one out.


Olas

911 posts

78 months

Saturday 25th January 2020
quotequote all
Classic Chim said:
My 50p is on 20/50 cold oil.
My late year engine did this both times when I changed from 10/40 to thicker oils.
Distinct possibility - the suitability of oil viscosity is determined by climate, and quantified by the SAE. For the UK climate we have seen over the last 30 years. 10w40 is most appropriate viscosity for the UK climate, 20w50 is better suited to the Australian outback, the UK is ALWAYS to cold to use such molasses.
Assuming the OP is using a fluid with climate-appropriate viscometrics, the filter is the problem.

Olas

911 posts

78 months

Saturday 25th January 2020
quotequote all
Classic Chim said:
He should put in the correct spec oil after he’s done that as 20/50 alone is not really the oil that should be in these later built engines especially when it’s cold. My cranking speed was slower too, work that one out.
20w50 has never been appropriate for UK climates. If I missed such an obvious mistake earlier in the thread I need my eyes testing!

10w40 and a Mann or Mahle filter will stop the noise, guaranteed.

Macbags

Original Poster:

119 posts

76 months

Saturday 25th January 2020
quotequote all
Hi and thanks for your thoughts. The previous owner serviced the car at techniques in St Albans for the past 5 years and throughout has annual oil and filter changes.......20/50 mineral and Land Rover branded filters.

So .....the recommendations are slightly thinner oil say 10/40 ...... mineral, semi or fully synthetic? Oil filter...are the land rover ones pants? Never heard of Mann or Mahler filters......are they much better.

Do I change oil/ filter now or wait until she’s booked in for her next service? By the way I purchased the car last summer and haven’t yet decided where to have her serviced......topcats and Str8six are the closest. Any thoughts ?



Edited by Macbags on Saturday 25th January 22:38

J-2

35 posts

82 months

Saturday 25th January 2020
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Can someone tell me the part numbers for the Mann or Mahle oil filters.

Thanks
John