Helloo

 

Im trying to help figure this problem out.

 

from cold ONLY - so i leave it overnight and then come to start my Octavia vRS i get this aweful metallic rattle for about 2 seconds, then it simply goes away and she runs normally with no strange noises. 

 

Car is 117K and its been doing it since iv bought it. @ 114k

 

Some people say its normal but its not the usual starter noise and nothing iv ever heard a car run "Normal" with.

 

Now iv changed the oil and filter with VW spec Quantum oil and filter, she ran great for 3/4months but now this rattle is back, iv had all the timing replaced and water pump, aswell as Aux tensioner and belt.

 

My mechanic's gut feeling is its the timing CHAIN tensioner..... Ill get a video in the morning as it will not to it today now.

 

Help please!

I'd be checking the oil pick up strainer in the sump. It's very common for it to become clogged up, causing oil starvation.

Could be a worn camshaft chain tensioner/adjustment mechanism,sure they rattle when worn

It will most probably be the chain tensioner. Mines done it since I bought it 3 1/2 years ago but hasnt got any worse so iv left it. Iv replaced the pick up pipe to see if that would help but it didnt.

Iv done the pickup pipe aswell - I forgot to add that, it cured it for a while but as said its back.

 

 

It will most probably be the chain tensioner. Mines done it since I bought it 3 1/2 years ago but hasnt got any worse so iv left it. Iv replaced the pick up pipe to see if that would help but it didnt.

 

Thanks man mines never got worse i think it may be that half moon seal as its supposed to keep some oil in after engine shutdown (I think)

 

I just turn it over quickly before it starts once or twice and the noise goes away, so its clearly an oiling issue - Pickups fine, fresh oil aswell so it must be the tensioner itself not holding oil. 

 

anymore idea's guys?

Some other food for thought for you.

 

I have a sneaking suspicion that the noise you are hearing may not be the tensioner, but the hydraulic valves?

 

I've had a few cars over the years with slow / sticky hydraulic valves - my Octy VRs being one of them - basically the problem is that on cold startup, the oil pressure in the valves takes a while to build - and you get a metallic rattle until they do.

 

Caused by a multitude of reasons - most usually a lack of oil changes and poor maintenance, rubbish oil used, lots of gentle short local journeys, or possibly as posted a lack of oil pressure due to a clogged pickup pipe or oil filter.

 

And there is one other reason - the use of a crappy aftermarket oil filter. Genuine and good quality oil filters are generally designed to hold a backup of oil in the system, so that on startup the feed is quicker to the top end of the engine. I have had experience with some poor quality filters that allow all the oil to drain to the sump on shutdown, hence it takes longer for a working pressure to build.

 

 

Anyway, whatever - when I got my VRs it suffered from a similar issue to the one you describe - and it had an aftermarket filter of some description fitted, and who knows what oil.

 

I replaced it with a genuine filter from a main stealer (only 6 quid - I can't imagine why anyone would buy an oil filter from anywhere else at these low prices for a genuine unit) and Mobil 1 oil.

 

Since then, the problem disappeared. 60 odd thousand miles later (at 130k now) I get maybe a fraction of a second of noise (normal) before the engine becomes a model of quiet, 'sewing-machine' style running.