blowing oil out exhaust!!??

[DirtyE30]

hi all,

haven't been on here for a awhile and my account got deleted...
more to the point i have a very serious problem thats really got me stuck.. i have a front sump 1uz 5 speed in a little e30 bmw.
bought the engine in mint condition and installed and got running no trouble. Was running sweet for ages untill i took it for a thrash down the road on my way to get some gas and it surged 3 or so times then suddenly dropped 2 cylinders and started smoking excessively out the exhaust. after limping home i popped the bonnet only to find oil spewing out between the head and the headers (i knew the exhaust gasket was sus). i made the asumption that i had melted 1 or more pistons so out came the motor and i pulled it right down only to find, well nothing wrong at all really apart from two leaned out cylinders (white plugs and burnt off carbon) and a slightly worn big end bearing shell. everything on the inside looks fine and i cant work out how or why oil was getting into exhuast.
just wondering if anyone has heard of something like this before or maybe could shed some light...

cheers, buck.

 

[XR8tt]

Head gasket maybe ?? Oil into cylinder on decel...
Oil surge and sucked up through PVC ??
What colour smoke ??

 

[stevechumo]

It seems like the head gasket is blown.

 

[spf_lexus]

yep, head gasket for sure. How many miles on the UZ?

 

[DirtyE30]

hey team,

big thanks for your input.
yes! it first happend on decel...
hmmm it would seem like it would be a head gasket, but how obvious is a blowin head gasket? as i already have the heads off and they both look fine.
and it was also a little low on oil.. not critical of course but down on the dipstick. what happens if it oil surges?

thanks again,
buck.

 

[XR8tt]

Any marks down the side of bores ??
Where pistons may have grabbed bore or any signs of
scratch marks where a broken ring will wear on bore ??
To have that much oil out exhaust ??..
It would have to be almost pumped there as in turbo failure
if it was turbo'd ...
So it would have to be head gasket
Recon heads, light skim, with new valve stem seals, "new"
head bolts and gaskets and your done!!!
Hopefully !!!

 

[DirtyE30]

no marks down bore, pistons and rings look fine...
well ive done a little research and down here in new zealand its cheeper to buy another long block engine than it is to just buy gaskets and bearing shells and put the old one back together so in light of that i rang a few engine importers and one of them had exactly what i wanted but they said it had been returned because the guy said he had a oil pressure gauge on it and it was reading very high oil pressure. this was also the case with my engine (not that i thought much of it). the gauge (not a cheep one either) read 2-3 bar while cranking and over 7 bar (maxed out gauge) while running even when warm. is this commen at all? or any thing to worry about? maybe to higher oil viscosity? if anyone can share there 2c on this would be very reassuring..

cheers all,
buck.

 

[XR8tt]

Sounds like oil pressure relief valve may have stuck shut..
This happened on my old B.M 318i
Blew two oil filters till I worked it out..
7 bar is just over 100Lb..
I must say most 1UZ's I see pulled apart have good bearing clearance
even on high mileage engines..
Yes I'd say a lower visc ??
5 / 35 or there abouts,,,