Water in the oil
 

So i just finished a rebuild on my S5 TII. My oil pressure was low ( 20 psi ) , so i pulled the front cover suspecting the o-ring was not sealing . When i got into the tear down i saw a very ugly white froth of foammy oil. So what could cause this ? There was not alot , I'd love to beleive condecation. Any idea's thanks

It seems this catches a LOT of people off guard. I see it all the time. IT shows up a lot on fresh rebuilds when people are more worried and attentive than usual, during their first oil change. I usually attribute it to condensation and such. Some cars get it, some do not. I've also noticed that if you've run an engine recently and it's still hot, you'll see some of this, like if you drain the oil right then. Perhaps that is attributable to very small air bubbles in the oil, from being circulated under pressure.

I'd like to hear a valid explanation myself. I can say that the cars that exhibit this, never show signs of internal coolant leakage or loss, so it isn't a coolant seal issue most of the time.

My car is doing this. I'm glad its no big deal I was kind of worried.

In a small amount this is probably not a big problem. Mine did this and my local mechanic told me it was condensation. I ran half a can of sea foam in the oil for 500 miles and then changed the oil. That seemed to solve the problem. If the evidence shows a lot of foam, you might want to try to fix it because water doesn't lubricate, oil does. Moral of the story is change the oil at least every 3000 miles and use a good quality 20-50 or 10-30 like Castrol.

1500 miles... on ane engine that ingests its crankcase oil for lubrication... 1500 miles will keep oil related problems at bay for a greater length of time!!!!! Even now that I've switched to pre-mix... I still change my oil every 1500 miles, mainly because of the extreme turbo heat the oil is exposed to.

Also.... the foamy stuff can be seen a lot on turbo cars, especially if the turbo is on its way out or if someone replaces the factory return pipe with a smooth bore pipe.... the ridges in the return pipe hel separate the bubbles in the oil after it gets churned up in the turbo!

bad news , I just tore it down and a blown coolant seal is the fault. I think this is because when i had put the bridge on the port , the cut got a little to close to the seal. By looking at it i can see it looks to be torn ( BURNT ) there . I saw a write up on Nopistons about fixing the opps I got carred away with my diegrinder on my bridgeport . All my bearings are fried and my e-shaft.
Are the e-shafts enterchangable between turbo and N/A ?

So wait...it was an INNER coolant seal? It must have been a HELL of a leak to dilute the oil. Usually the only way coolant can dilute oil is if the outer seal goes, which is very rare.

there was one of each. The outer seal blew down by the exshaust port , I dont know why that one went.

nm, saw your post^

nm OK