2G Small oil leak. What is this?

[drthorp]

I have been cleaning the engine up from old oil leaks that have since been repaired and searching for the source of one final very small leak. I believe I found it but I don’t know what it is. Anyone have some DSM knowledge they can spare me? Images show a small rubber hose just behind the turbo/intake with a wet spot. Big thanks!

 

[Vegas Smith]

There is an oil galley that runs behind one of the exhaust manifold-to-head studs in that area and can leak. I can't remember which one so do a little searching.

 

[Kryndon]

Mr. Vegas might be correct, the center stud hole is the one he's referring to which is the only stud hole that is a through hole. From the factory it comes with sealant on the threads but if you mess with the studs or have replaced them, it needs to be RTVd again. I have circled it in red. In Yellow and Green are other spots which typically could leak oil (green being the VC gasket), yellow being loose head bolts which would also cause a lot of other issues!

Honestly, though, I doubt it's the exhaust stud. I'd suggest taking a closer look at your turbo oil feed since that is also a very common leak spot. It would allow oil to run down along the coolant lines.

You must be logged in to view this image or video.

 

[Vegas Smith]

Yeah, valve cover leak is a good one too. That would be my guess.

 

[drthorp]

Mr. Vegas might be correct, the center stud hole is the one he's referring to which is the only stud hole that is a through hole. From the factory it comes with sealant on the threads but if you mess with the studs or have replaced them, it needs to be RTVd again. I have circled it in red. In Yellow and Green are other spots which typically could leak oil (green being the VC gasket), yellow being loose head bolts which would also cause a lot of other issues!

Honestly, though, I doubt it's the exhaust stud. I'd suggest taking a closer look at your turbo oil feed since that is also a very common leak spot. It would allow oil to run down along the coolant lines.

You must be logged in to view this image or video.

I have done a great deal of maintenance on this car since i got it from its original owner including the front cam seals, front crank seal, VC gasket, etc etc. so luckily this is the only engine oil leak im dealing with. From what you've shown me, that stud is still a possibility, but the oil feel and return are both dry and look alright. Is that hose of no concern in the picture? I know its not a good photo, but I noticed the seemingly fresh oil around the end of it. I just dont know what that is Thanks for the insight!

 

[Vegas Smith]

I have done a great deal of maintenance on this car since i got it from its original owner including the front cam seals, front crank seal, VC gasket, etc etc. so luckily this is the only engine oil leak im dealing with. From what you've shown me, that stud is still a possibility, but the oil feel and return are both dry and look alright. Is that hose of no concern in the picture? I know its not a good photo, but I noticed the seemingly fresh oil around the end of it. I just dont know what that is Thanks for the insight!

That appears to be a coolant line so that oil must be dropping onto it is my guess. Doubt check tightness on valve cover bolts as those loosen after initial install. Be careful not to overtighten.

 

[drthorp]

That appears to be a coolant line so that oil must be dropping onto it is my guess. Doubt check tightness on valve cover bolts as those loosen after initial install. Be careful not to overtighten.

Oh ok I was a little confused when I saw that hose there so Im just gonna roll with the idea that its coolant. If it dripping from above, it truly must be the red or yellow from the photo above... Ive already confirmed the VC gasket and turbo are both leak free so it must be? Anyway, Thanks for the help! I'll investigate further.

 

[Vegas Smith]

Surely could be coolant. These hoses are super old. Easy fix.

 

[Kryndon]

I don't mean to disrespect your maintenance or anything but parts of your engine still look messy. There's oily-looking residues around the thermostat housing as well as all around your intake snorkel and right where it clamps onto the turbo inlet. The PCV might be sending too much oil through the intake which would inevitably make its way past clamps and start to leak out. Waste a spray or two of brake cleaner all around that area and take the snorkel out to inspect if it's puddling oil.

That said, I've never seen a 100% leak free engine especially a DSM one so I wouldn't go too mad about it.

 

[EJ_GST97_JADE]

Also, it would be a good time to replace all the coolant hoses to the turbo as well. Just for peace of mind.

 

[DSMPT]

@drthorp you should also check the oil feed banjo bolt on the turbo CHRA under the exhaust manifold. When oil is leaking from there, it would be like the pics you uploaded.
@Kryndon Stefan, good write-up but sorry no offense just a little correction. In general you don't have oil leak from where you marked yellow because there is no oil passage there, the only yellow that possibly has oil leak is the left one that is close to the thermostat housing, that part has an oil passage. Other than that yellow part, what possibly would leak from yellows is coolant. Generally where would have oil leak when the head bolts/studs need to be re-torqued is where are marked green in the pic below. Also please refer the link below.
https://www.dsmtuners.com/threads/oil-leak-somewhere-between-head-and-block.437467/#post-153788601

You must be logged in to view this image or video.

 

[Mech Addict]

Even the less zoomed out photo is a bit to zoomed in for me to get a clear sense of what Im looking at. Is that the J pipe in the foreground with allen head bolts? I think the oily hose you’re indicating is the oil cooler line, which carries coolant to the oil filter, but my 90 doesn’t have that style. I am also leaning towards suspecting it is the turbo oil feed, which has banjo bolts with double copper washers at each end.

I also believe the exhaust stud protrudes into a cooling jacket, not oil gallery.

 

[drthorp]

I don't mean to disrespect your maintenance or anything but parts of your engine still look messy. There's oily-looking residues around the thermostat housing as well as all around your intake snorkel and right where it clamps onto the turbo inlet. The PCV might be sending too much oil through the intake which would inevitably make its way past clamps and start to leak out. Waste a spray or two of brake cleaner all around that area and take the snorkel out to inspect if it's puddling oil.

That said, I've never seen a 100% leak free engine especially a DSM one so I wouldn't go too mad about it.

No, its fine. My maintenance so far has just been to stop the leaks that were making such a mess on the front side of the engine (driver's side). I cleaned the timing components and everything that was soaked over there, but im just now getting the intake off to clean and inspect this side. Trust me, i have a ton of degreaser, a few brushes and a pressure washer to try and clean things up while i do some maintenance. The intake has a little bit of a blow-by issue right now, but Im working on a catch can solution for it so keep things clean under higher boost. Oh, and youre right, ive never seen a dsm completely happy at 150k miles Thanks everyone for the help!