Hawkeye D

Hi all,

2007 STi. (rebuilt / forged for the second time about 15k miles ago)
Still getting a burning oil smell from the driver side, driver rocker cover gasket done 2 weeks ago. Can't see any oil on the bottom seam under the rocker cover.

I'm thinking now it's the turbo oil drain pipe that leads to the bottom of the cylinder head, a leaking head gasket or a warped head. Something keeps feeding oil onto the heat shield and causing the smell. Never known such an awkward car to try and trace an oil leak and fix it.

Inner and outer OS CV boots are fine, and no PAS fluid leaks.

I just can't see enough from trying to go under the car to tell if the turbo oil drain pipe is knackered. Strong possibility it's weeping down the pipe and over the elbow / flange that goes into the cylinder head and getting to the heat shield / exhaust that way......but I just can't see anything properly, viewing it is totally blocked. I've no regrets replacing my rocker cover gasket, but I'm convinced now it was never my burning smell problem. I think the rocker cover gasket was a red herring.

I'm not getting loads of coolant pushing into the overflow tank by the radiator, and anything pushed in normal conditions is getting sucked back in overnight. So, possibly head gasket external oil leak. Would I overheat with a warped head? I could see only a small part of the bottom edge of the HG and it did look clean / dry.

Was cleaning the heat shields again with brake cleaner and found this mesh, thought it was something caught in the shield so pulled it out.
Ebay pic, what's the mesh for? You can see it in the pic below, fine mesh, can't be for acoustics can it? It's almost like a fine mesh liner, but what does / can it do? To aid any drying of any water that may get in there?

MrRtm

You can see the oil return pipe if you remove the downpipe and look up from where it was, you can also replace it with it removed. It's awkward but can be done without removing anything else. Just warm the pipe up so it's more flexible to make it easier. It could just be one of the clips on siad pipe as well. With some great difficulty you can feel said pipe without removing anything to see if its got oil on it.

The mesh originally had some horrible foam stuff all over it for heat retention, yours has disintegrated

Hawkeye D

Thank you Rtm, One for Len at Newbury to look at this one!
Once up in the air I can hopefully satisfy myself that it's not a leaking Cosworth HG (unlikely but you never know)

If it is still just oily residue from changing the rocker cover gasket, it's taking it's time / heat cycles to finally go. But best I can, I have brake cleaned the granny out of everything....twice.

I run Millers CFS 10w 60, so perhaps it can take a bit of heat and is being stubborn burning off. Perhaps it's in an area I just cannot see let alone get to.

1509joe

iTrader: (2)

Did you renew the bolt seals and washers when you did the head gasket seals.

Hawkeye D

I know the seals you mean, but my bolts don't have seals on the 2007. The bolts are shouldered and sit outside of the gasket seal. I only ordered the drivers side, and didn't need half moons as mine are bone dry on the outside. Just wish I could trace the source whilst I have time off work, but not to be!

https://www.importcarparts.co.uk/par...er&searchPart=

stamina_daddy

iTrader: (3)

I went through this madness years ago on a bug eye.
I eventually snapped a shouldered bolt after changing rocker cover 2 or 3 times and still thinking it was leaking.
I personally think on mine it was oil that had come out and leaked onto underside of engine block from when you remove rocker cover.
I also ended up putting a bead of sealant inside the rocker cover groove then squashing gasket into it.
I got really good at removing and replacing the drivers side.
I remember I could get my hand down and check for oil on bottom corner.
I kept finding oil there but I honestly think is was just where I couldn't wipe all excess off bottom of block.
Good luck.

stamina_daddy

iTrader: (3)

On mine there was some padding on the engine cover under car that was soaked in oil too

Hawkeye D

I took my undertray off to do the job, but some maybe on there from when my old gasket was possibly leaking. The smoke has greatly reduced, but it's still coming up a bit after idling for a few mins at full temp. I think hot idling is key for burning off oil as it gets heat soaked.
I need to get it onto a ramp at work, undertray off and clean everything, run without an undertray for a week or so, then re-check.
Maybe it just needs more heat cycles, but I'm not so sure. I just want to find it and fix it myself or get it fixed.

Very frustrating!

MrRtm

Try using a strong mix of foam/degreaser, you can spray down behind the power steering pump angled towards the turbo and it flows down the back and over the up pipe. That's what I did when I stupidly forgot to tighten the oil pressure adaptor and it ran down the back of the engine coating the up pipe, then just run it and let the excess burn off

Edit: Actually, are you sure it's oil? Could also be the coolant return pipe on the turbo, I only mention it as that was my other mistake, I forgot to put the bottom clip back in place and it would drip when warm, a pair of angled pliers and some patience got it in place with only removing a pipe for the fmic

Hawkeye D

Just got under it a bit. I'm happy the the drivers side HG is not leaking, looks clean (mint actually). Slipped my phone under there on a selfie stick and took videos lol.

I know the coolant hose you mean, it's a horse shoe shape and has the heat shield round it - all ok, both clips tight, no leaks and my coolant has a UV dye in it at the moment.

The smoke comes from the area before the up-pipe starts going steeply upwards, ie, near the rocker cover. It's a fine smallish cloud of grey smoke, but it's not the upper up-pipe or the turbo that's smoking.

I managed to brake clean from the underneath and aim at the drivers side exhaust manifold heat shield (right at the top and inside it the best I could) from the sump direction, in the hope that anything left on the bottom of the head near the manifold is now gone. I couldn't see anything obvious that would cause the smoke. Brake cleaner then blown away with a hoover set to blow mode.

Sump bone dry. The whole length of the bottom edge of the cambelt cover - bone dry.

I'll see how it goes now, next will be TMIC off and thorough up-pipe check from behind. There could be something on it, running to the bottom, then burning off at the lowest point.

Edit : There's no crankcase breathers down below anywhere is there?....all up top I think? Did drivers rocker breathers last week, old ones were like steel pipes. No leaks on new ones, and seated / clipped in well. Passenger side still soft.

MrRtm

Assuming it's the same as an ej20 no they are both on top of the heads, the pcv valve is however under your top mount, a leak from that could possibly work its way down the back of the block by the turbo but I'm not sure it could leak to that extent

Hawkeye D

All bone dry up top.
I so hope this is all just residue still burning off, maybe I'm not giving it enough time...
There is far less smoke for sure, fingers crossed.

Was very glad to see a clean HG, I was concerned about that. Cosworth gaskets and ARP head studs used in the build, so shouldn't lift etc. But hey, it's a 2.5 so anything can happen!

Hawkeye D

Firstly, Happy New Year to you all

Ok...spent another hour under the car tonight, couldn't see anything adrift, Frustrated, but hoped my persistence would pay off....and it did.
Undertray back up,...there has to be something.....

Ding! My standard airbox has been broken for a long time, one of the grooves on the base section had snapped off, so one of the tongues on the lid had nowhere to lock in. The two bendy clips are fine.

So, I cleaned off the airbox edges nearest the rocker cover, and duct taped the lid down to the base that end, now no smoke and no smell. Happy days. General car performance is now much much better.
Basically a big air leak, I was seeing and smelling fumes I guess, rather than smoke as it turns out.

This would also explain why the "smoke / smell" would stop once the engine was switched off. The airbox was the only unturned stone....that was when it dawned on me.
It also explains the area I was seeing the fumes, and why it would get worse whilst revving the engine - but there's so much heat there, I couldn't pinpoint where the smoke was coming from as it was going upwards so quickly. Convection effect I guess. Plus drive by wire I have no throttle cable to move / look for the source.

You could see inside the lid where the oily foam seal of the air filter had left no imprint that end, whereas the imprint was there in the other areas.

There is no oily residue in the turbo inlet pipe (Samco) nor on the topside of the air filter or on the MAF etc. The car never really burns oil, so what was I seeing and smelling exactly?

Sure, I guess my drivers side rocker cover gasket was indeed a red herring in the end, but hey ho, I learnt a lot doing it, and no harm in changing it.

Was the air leak causing a vacuum or a draw on crankcase gasses perhaps? At no point did I ever get a CEL.
I'd really like to know and understand what happened.....and fingers crossed no damage done, or do I have some serious blowby / knackered piston rings? Knackered turbo?

The smell would get worse as the engine warms up and the oil thins out.

Edit, can still smell it. I think it's serious.

Here's my YouTube vid I made....9 months ago! The smoke can be seen 30 seconds in.

MrRtm

I don't know if it's plausible/possible for oil/coolant to get in the air box (I've not had a scooby that still had it lol) but have you checked the bottom of the air box for liquid or the filter to see if its just generally full of ****? Do you have catch cans?
Having the air box I assume you still have all the standard return lines so it could be oil or fuel which I know doesn't really help but both get fed into the turbo pipe. Oil from the pcv/breathers, fuel from the charcoal canister. It shouldn't be coolant, if it is I'd personally be worried as it shouldn't be entering the air box/turbo pipe but thinking about it as I type its possible, say your throttle body is loose, it runs coolant through it, that could make its way into the inlet manifold, pool, be whipped up and make its way through the return pipes as vapor.

At this point if I were you I'd be tempted to get some oil/coolant and heat it up and get a good whiff to try and pin point the smell. You can vent both the breathers and the fuel vapor to atmosphere temporarily to try and eliminate those as smells with a bit of boost pipe and caps to avoid vacuum leaks

Hawkeye D

Airbox had a black residue in the ridges just under where the filter sits. I wondered if that was oil from the filter itself mixed with dust etc.
No signs of anything else in there. Filter is pretty clean / normal. Throttle has coolant bypass mod (coolant deleted)

I run a Mocal catch can,
Drivers side rocker breathers : The rearmost one goes into the top of the block, the smaller one goes into the metal pipe attached to the TMIC then runs to the Mocal can, the other TMIC metal pipe is capped off.

Passenger side : The rearmost breather goes to the PCV valve, and the front one goes directly to the catch can.
The top most nozzle of the PCV valve is blocked / capped off, plus a few other inlets on the turbo inlet.

Here's my set up, I've been getting this smell for ages now, but until then never used to happen. I do have a very new 12mm oil pump (not 11mm) if that has anything to possibly do with it. :

1509joe

iTrader: (2)

Have you dual avcs if not generally 12mm oil pump has too much pressure for single avcs.

Hawkeye D

No, only single AVCS I think....
The new oil pump was fitted soon after rebuild as oil pressure light was flickering for about 10 seconds on startup.
Not sure why he fitted 12mm (according to the invoice) and not 11mm.

Turns out it was the oil pickup tube in the end.
My fear is that running my fresh build with a cracked pick up tube has killed the lifespan of the engine...

Maybe it's blown some sort of oil seal somewhere, but doesn't use hardly any oil in between changes. 4k - 4.5k miles usually.

1509joe

iTrader: (2)

Fitting a 12mm pump was only a band aid for your problem. Oil switch should of been checked/replaced before going to the extent of fitting a new oil pump.
The oil pressure switches have a ridiculously low pressure point something like 8 psi iirc.
Example if I start either of my builds cold the oil light goes out instantly and if the engine is stopped straight away it is about 30 seconds before the oil light comes back on.
How long has is been built cause my first port of call would be the engine builder.
Good luck.

Hawkeye D

Tried a new pressure switch, made no difference.
This was all straight after fresh built.

If my rings were shot I'd be consuming a lot of oil which I'm not. For all I know I'm about to spin a bearing. Worrying to say the least as it's all out of warranty, but I did report the smoking to him whilst in warranty - re-sticking the rocker cover gasket did nothing.

I never used to get this smoking issue, but it has been going on a while, was thought to be rocker cover gasket, but not the case. I'm not sure if it started soon after the 12mm oil pump. But certainly wasn't before.