Griffith 500 engine noise

[AlfaSpider]

Good afternoon, my Griffith with the 5L serp engine has a slight engine noise which only happens when it’s hot and the revs are dropping from around 1500 down to idle.
It’s almost like a tappet noise but it’s not very noticeable, the car had a 885 cam fitted with a new chain and hydraulic lifters around 2000 miles ago before I bought the car.
It had been sat for around 12 years with very little use before I bought it.
I wasn’t sure if this could be just the different cam but this shouldn’t be the case with hydraulic lifters?
I intend to take the rocker covers off to check everything looks ok.

[Belle427]

Sounds very much like the issue these engines can suffer which is wear between the gudgeon pin and piston that can cause a rattle similar to a lifter.
Not easy to diagnose but im led to believe its not a big deal really apart from putting up with the noise.

[AlfaSpider]

Thanks thats interesting and I suppose would be possible as the pistons expand the clearance to the pin increases?
Can’t be easy to diagnose without removing a piston and measuring the parts.
I’d also read a thread on here about a similar noise being a suspected cam moving in an axial plane when then revs drop, I will try with a stethoscope to see if I can narrow it down a bit but I suspect it won t be obvious.

Edited by AlfaSpider on Sunday 16th November 15:55

Edited by AlfaSpider on Sunday 16th November 15:56

[Belle427]

Yes I have heard of maybe cam chain touching the case etc but i would have thought this would occur more often.
Exhaust manifolds would make a noise all the time but worth checking the basics.
Would expect a lifter to make a bit more noise too really.

[AlfaSpider]

I don’t think it’s noticeable enough to be a lifter but the only thing I wondered was as it was sat for a long time not being used if one may have become a little sticky, I could try some additive to the oil although I’m not sure if most of that kind of stuff is just snake oil.

[Belle427]

I would just do an oil change, some oils have been reported to make some noises worse.
What grade do you use?

[AlfaSpider]

It was serviced just before I bought it but not sure on the oil brand or grade unfortunately. I used Valvoline VR1 20w-50 in my S3 which seemed to work well, is there a particular oil recommended for the V8?

[Belle427]

Bit of a minefield to be honest, most will recommend VR1 20/50 or a quality 20/50 high zinc alternative.

[AlfaSpider]

I’ll try using some VR1, it seems from doing a bit more research this really is quite a common occurrence on the 500 engine.

[Belle427]

Yes its blamed on the design of the bottom end really and the way they chose to build it.

[macdeb]

I'd say little ends, only seems to happen on 500.