E34 oil in expansion tank

[ZIDSAB]

E34 535 found engine oil in coolant expansion tank half of the tank is filled with oil
Engine oil is black but not decreased
Engine head is surfaced and new gasket was installed 6 month ago
I don't know what to do now I just replaced the tranny 1 week ago
The car is working fine except for losing coolant mysteriously
What should be done right now ?

[Binjammin]

You replaced the tranny... is the car a manual or automatic?

[ross1]

E34 535 found engine oil in coolant expansion tank half of the tank is filled with oil
Engine oil is black but not decreased
Engine head is surfaced and new gasket was installed 6 month ago
I don't know what to do now I just replaced the tranny 1 week ago
The car is working fine except for losing coolant mysteriously
What should be done right now ?

Unless an automatic trans cooler in the radiator is leaking as binjammin has alluded to the above tells me the head gasket has failed again.
It could also be from the previous failure but this does not explain coolant loss.

[Binjammin]

Yep. Wondering if it's ACTUALLY engine oil, or transmission oil. After all, you lost a transmission already, it wouldn't be a great leap to realize that it died in the first place from a radiator going bad internally. The overflow half full of oil is a LOT of oil, especially from a head gasket. It's not that much from a transmission.

[ZIDSAB]

Its automatic
The shop told me that the old tranny died because I haven't changed transmission oil for a long time he said that tranny oil became like grease and filter was clogged , I couldn't find a shop where I can test the engine head for cracks where I live so I went ahead and resurfaced it but I'm still on losing coolant mysteriously since then . how to make sure that this oil is engine oil or transmission oil ? Before reopening it up

[Binjammin]

I've never, EVER seen atf turn "like grease" in any fashion. You should check your transmission fluid to make sure you aren't losing coolant into your tranny. The tranny cooler is built into the radiator, every now and then the tranny cooler will fail internally and you'll have cross contamination between the transmission and radiator.

[ross1]

I've never, EVER seen atf turn "like grease" in any fashion. You should check your transmission fluid to make sure you aren't losing coolant into your tranny. The tranny cooler is built into the radiator, every now and then the tranny cooler will fail internally and you'll have cross contamination between the transmission and radiator.
Brown, burnt tranny fluid combined with coolant churned up into a thick goo. I could see someone describing it as grease even though it would feel nothing like it.

[Binjammin]

Brown, burnt tranny fluid combined with coolant churned up into a thick goo. I could see someone describing it as grease even though it would feel nothing like it.

I can accept that theory. :shifty













:D

[ZIDSAB]

Took the expansion tank out and it was filled with brown oil ! Bled the radiator but it only flushed clear water I know that oil floats to the top but should not it contain at least some oil if the radiator was mixing tranny oil -
Another question. is there any possibility that engine head is cracked and it only mixes oil without overheating or making the oil look like milk no whitish material on engine oil cap neither oil stick
I have never had over heating problem since I have done the gasket

[sea6speed]

Presumably the transmission was filled with fresh ATF and the system flushed when replaced, no? A cheap way to test this would be to dye the transmission fluid and see if its showing up in the coolant reservoir.

[ZIDSAB]

Changed engine oil today didn't find any signs of water . does that exclude engine head troubles or not ?

[5mall5nail5]

No not necessarily - drive it a bunch and see whats up

[ross1]

Presumably the transmission was filled with fresh ATF and the system flushed when replaced, no? A cheap way to test this would be to dye the transmission fluid and see if its showing up in the coolant reservoir.
It is already dyed red

[sea6speed]

It is already dyed red If you're talking about the color it comes straight from the bottle, it doesn't seem like that would be enough dye to detect with all the other crud the OP says is in the expansion tank.

I guess now that he's changed the oil it'll be obvious if the expansion tank fills with fresh, clean engine oil...

[Tre0Tre34]

UV dye? The glowing should make it easy to spot.

[ZIDSAB]

Update !!! I guess no need to die anymore found expansion tank full of oil again the texture and color are similar to engine oil I changed couple of weeks ago
Here is a picture
Tranny oil is red http://img.tapatalk.com/d/14/08/08/a4etu6u7.jpg

Changing the tranny , differential and engine head at the same time is nightmare [emoji20]

[ZIDSAB]

Huge longitudinal crack found in the engine head . used engine head would cost 350 USD . whole used imported engine from Japan would cost 500 USD. I will try my luck and change the whole engine