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D2 - Engine Bay Everything under the bonnet

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Old 2nd July 2017, 02:35 PM
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27litres 27litres is offline
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Default Oil burning smell coming through air vents in busy traffic

Hi guys.

Been tolerating this for a little while, as it's not often I'm in busy traffic these days...

The smell is almost certainly from under the bonnet and feeding into the cabin via the central air intake (I've seen better fresh air intakes in cars to be sure).

I already replaced the exhaust cam seal caps on the back of the heads about 18 months ago. I had fitment issues with them which may or may not have been caused by using RTV silicone when mounting them.
Also replaced the valve cover gaskets around the same time.
Smell was still there under the right circumstances.

So anyway, today I finally got around to changing the PCV valve (hockey puck).
I also changed the left hand cam cap again with a genuine one. However, it was in tight and not leaking. So I checked the right hand one, which was also not leaking, and left it alone.
Also checked around the valve covers. Some minor weeping around the top rear right cover (under the fuel hoses). Checked bolts which were all tight. No leaks on the left at all.

Basically there are now no leaks that would drip onto the exhaust anywhere at the top of the engine.
She's due for a visit to the hoist (ramp) soon, so I'll check for leaks below while she's up.

Is there anything I've missed?

I'm taking a peak hour drive out to the airport tomorrow (my Mum is actually on her way to London to go to her sister's funeral), so I'll give the new PCV a work out and see if the oil burning smell is still there...
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2002 Audi S8 - Project
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Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
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- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

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Old 2nd July 2017, 02:57 PM
ainarssems ainarssems is offline
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Possibly leak from gearbox rear output or one of front output seals, rear is very common, drips on cat and creates awful smell. Another thing is power steering hoses leaking and while they do not normally drip on exhaust some of the oil can be blown on exhaust by wind when at speed.
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Old 2nd July 2017, 03:02 PM
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27litres 27litres is offline
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Yeah, I know the gear oil smell. Had that when I first bought her. Was fixed for the roadworthy (MOT).
I don't think it's that (would be disappointed at it failing within 35,000km).
I'll check the output flanges on the front driveshafts though, thanks.

Power steering fluid was marginally down today. I'll check that on the hoist too.
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Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
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Old 2nd July 2017, 03:35 PM
ainarssems ainarssems is offline
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It's quite often for rear output seal to fail again soon if the flange was not replaced as well. But there are some reports with flange and seal replaced with new design and still failing. Another thing to consider is if the seal was inserted at correct depth, I know I pushed mine in too far when I was changing it and there was no way to pull it out without damaging so just left it there but i am expecting premature failure.
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Old 2nd July 2017, 09:22 PM
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27litres 27litres is offline
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I do remember checking it at recent services and seemed ok. I'll take another look though.

I do have a bit of a driveline clunk at present when switching between drive and reverse. I was thinking the front to rear driveshaft CVs (they're on the check list) might be dry/stuffed. I know Torsens are tough, but if it's low on oil...
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____________________
Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
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Old 3rd July 2017, 07:50 AM
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Ameiseuk Ameiseuk is offline
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Ive had a similar problem since engine rebuild. Noticeably worse if i use the car after its been parked uphill on the driveway.
Checked cv joints, gearbox seals, rocker gaskets etc and all seemed dry.

Happened to lift the bonnet after a long drive a couple of weeks back to check screenwash. Engine was still running, as i filled the washer bottle big puff of oily smoke from rear right side of engine. With the same smell! Looks like im getting the odd drip from rocker cover straight on to the manifold.

Did a bit of further reading, going to pull the rocker covers, thoroughly clean them and reassemble along with a taste of brush on sealing compound to see if that helps cure the problem.
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Old 3rd July 2017, 11:22 AM
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Goran Goran is offline
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There is also the big seal on the back of the engine before the transmission. This usually starts leaking at this age and rarely gets replaced as its a transmission out job.
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Old 4th July 2017, 08:19 AM
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27litres 27litres is offline
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Yes, I know the one.
I'm going to replace it on the other engine.

I'm leaning towards Ameiseuk's problem with the small amount of oil I saw on top of the right hand valve cover.

Oil smell was noticeably reduced during my drive to the airport, so I'll keep an eye on it for now...
__________________
Cheers

Marty


____________________
Current:
2001 Audi S8 - Brilliant Black with Black interior, C5 RS6 rims (whenever I actually put them on...), Solar Sunroof, Tinted side and rear glass, RNS-D, Grom, Bose, clunky old phone in arm rest!
2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
Family:
2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

Sold:
1997 Audi A4
- Hamilton's Club Sport, Achat Grey (will miss the old girl)
Reply With Quote
  #9  
Old 4th July 2017, 08:32 AM
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Ameiseuk Ameiseuk is offline
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This is the stuff I bought to do the job:

Abro Eagle Head Gasket Shellac Brush On Sealer Repair Rocker Stop Leak 59ml
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Daily drive:
2016 Infiniti QX70.....a car that's even more complicated than my last Infiniti FX to modify

Current 'Project':
VW Crafter CR50 4 berth camper van

Previous 'Projects':
2006 Subaru Legacy Spec 'B' 3.0R,
1994 Ex-MOD Land Rover Defender, now "civilianised".
2000 Audi S8 FL

www.whall.co.uk
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