engine clatter on low revs after bets and chains changed

[Davie Bow]

Hi Guys ,

Bare with me with the following explanation , i'm listing everything we've done so as to be clear on whats happening with my car

my car was a bit noisy/ropey on start up plus i wanted to do the cam belts as a precaution , on posting on here quite a few of you mentioned the rear chain tensioners may need replacing ....which proved correct , the chain guides were all ground down . Plus issues with the SAE were mentioned so we removed them .
On replacing everything for brand new OEM parts , inc water pump , thermostat , cam belts , chain tensioners , chains etc etc we started the car and it run really sweet , slightly crap on start up due to not having the SAi mapped out yet but within 30 seconds or so running really smooth .

i then went out for a drive and after about 30 miles the oil pressure warning went off (the red one on the screen not the yellow one ) , only for a few seconds , so i pulled over checked the oil etc ....no leaks no loss of of oil , so went home with no issues or warnings sounding again.

After letting the car sit for a few hours ,I checked everything again and all was fine . next day went out in the car and then covered about 300 miles over a the weekend with no issues at all , only for the oil pressure warning light to come on again about 20 miles from home ..... so i stopped again and did the same checks , still not lost any oil or have any leaks so i set off again and over the last 20 miles it would come on intermittently i.e fine for 10 miles ,then on and off for the next 2 , then fine for the last 5 or 6.

I put it on my VCDS when i got home and I have no fault codes relating to any oil pressure sensors etc etc ????

Mentioned this to my mechanic and did a few searches on tinternet and we decided to do a engine flush this afternoon , just in case the oil pick up pipe was dirty
or something ,so we did the flush and even removed the sump and cleaned the oil pick up pipe .

Now after starting the car and letting it warm up although it seams we have cured the oil pressure problem .....but i'm guessing we won't know that fully until i drive it ....... we now have a strange rattling noise between 800 and 1200 rpm's , which becomes very prominent when you blip the throttle , we're pretty sure its coming from the top end of the engine .

Any ideas anyone because even my mechanic who has 25 years working on supercars is now scratching his head as he did everything by the book and although its ticking over sweet and sounds good when you get over 1200 rpms, on initial pressing and releasing of the throttle this rattle comes back ????

Cheers
Dave

[Nobby]

Hi Dave

Sorry to hear you are having problems. There's obviously quite a few things that could cause top end noise but you should be able to check some stuff without dismantling anything.

Have you checked the cam phasing? It could a tooth out and that would cause all sorts of problems. I assume the cam tensioner are plugged in

Did you use new cam caps bolts? They are stretch bolts and supposed to be fitted once. They aren't mega tight either but could also be stripped, snap or just come loose. Of course there could be a stray bolt loose in there too). If the cams weren't lubricated when reinstalled that could also have worn a love - I doubt that though.

Oil pressure could just be the sensor playing up. The pressure wouldn't go down that bad unless you lost a lot of oil, it got really really hot, the pump was fecked or you had a major blockage somewhere. VCDS should be able to show up any irregularities (check when it's off and fluctuation when revving)

Chris

[Davie Bow]

Hi Dave

Sorry to hear you are having problems. There's obviously quite a few things that could cause top end noise but you should be able to check some stuff without dismantling anything.

Have you checked the cam phasing? It could a tooth out and that would cause all sorts of problems. I assume the cam tensioner are plugged in

Did you use new cam caps bolts? They are stretch bolts and supposed to be fitted once. They aren't mega tight either but could also be stripped, snap or just come loose. Of course there could be a stray bolt loose in there too). If the cams weren't lubricated when reinstalled that could also have worn a love - I doubt that though.

Oil pressure could just be the sensor playing up. The pressure wouldn't go down that bad unless you lost a lot of oil, it got really really hot, the pump was fecked or you had a major blockage somewhere. VCDS should be able to show up any irregularities (check when it's off and fluctuation when revving)

Chris

Hi Chris ,
Just when I thought I was ready to bring your kit back lol
We used brand new OEM everything , bolts , parts etc , this noise only came about after the engine flush this afternoon.

I'm not sure if we've cured the oil pressure issue because I'm too scared to drive it in case I do something terminal but before that the engine was running perfect apart from on cold start .

Do you think it could be a screwed oil pump not feeding the tensioners with enough oil to operate properly , that or a major blockage seems to make the most sense as we followed everything by the book .

Where would we check for blockages ?? And how difficult is it to replace to oil pump ??

[Nobby]

Oil pump is atleast sump off. It's chain driven and there a tensioner down there too (at front of block).

Oil galleries to tensioner could get blocked. They have their own gasket and only need some liquid gasket added around the moon gaskets and outer edge.

A chap on here had a big crack in the block or something when he checked down there. I'll try find the thread. I'd have a look on elsawin but I'm away from home at the mo.

[Davie Bow]

Ok mate ,
Cheers , what's elsawin ?

[Shoppinit]

Ok mate ,
Cheers , what's elsawin ?

http://bfy.tw/D0mp

[nene]

I recently had loud tapping at idle upon starting the engine, which I had never seen before. In most cases it is just the oil being used is not RS6 engine friendly, causing a cold lifter tick.
There is a post along with the video of the sound on the engine at: http://www.rs6.com/showthread.php/33345 ... rom-engine

Upon new engine oil change the noise seems to have disappeared.
Good luck.