[Jarninius]

(2011 335xi) After weeks, my car was finally restored to proper running condition. New plugs, nee coils, replaced a leaky injector, fixed my VANOS solenoids, and my car finally ran with no engine lights. i go down the street and back, about a 3-4 minute drive and about 1 mile, and I open my hood to see a ton of smoke coming out from what I believe to be the valve cover gasket. on top of that, i check my coolant reservoir that i had just filled, and it was completely contaminated with oil. I think it’s my head gasket, but I just have no idea what to do anymore. any help is appreciated, thanks

[3PedalJake]

Have you changed the oil filter housing gasket? That's the most likely place for oil to be infiltrating the cooling system.

[lookalikehuuh]

Yeah head gasket failures are not that common on N series engines unless the car overheated badly/continuously or something previously. It might be worth doing the OFHG since that can cause mixtures to occur due to the failure of that cheap gasket. It sounds like you are a DIYer so the cost will be super cheap to do it.

[DBShiznit]

Like everyone said OFHG is usually the culprit and while you do that, since the cooling system is already empty, replace the plastic flange that is directly below it as that is also something that is overlooked and a ticking time bomb. Literally takes an additional 5 mins to do when doing the OFHG.

[Jarninius]

Originally Posted by DBShiznit

Like everyone said OFHG is usually the culprit and while you do that, since the cooling system is already empty, replace the plastic flange that is directly below it as that is also something that is overlooked and a ticking time bomb. Literally takes an additional 5 mins to do when doing the OFHG.

fair point, i feel like the fact that it looked like that after 3-4 minutes also points towards that, because a head gasket wouldn’t do it that quickly would it? i’m taking it to a mechanic and i don’t want to spend $3000 on labor for a head gasket if it could simply just be that.

[Jarninius]

Originally Posted by DBShiznit

Like everyone said OFHG is usually the culprit and while you do that, since the cooling system is already empty, replace the plastic flange that is directly below it as that is also something that is overlooked and a ticking time bomb. Literally takes an additional 5 mins to do when doing the OFHG.

already dealt with that flange thanks for the recommendation though

[DBShiznit]

Originally Posted by Jarninius

fair point, i feel like the fact that it looked like that after 3-4 minutes also points towards that, because a head gasket wouldn’t do it that quickly would it? i’m taking it to a mechanic and i don’t want to spend $3000 on labor for a head gasket if it could simply just be that.

The job is easy and you should do it anyway. I’d start by doing that first. Bolts are one time use and cheap enough. Get all three and a gasket. Clean both services really well before putting it back together. You don’t have anything to loose by doing it and much more to gain. You’ll either fix the issue or have the piece of mind it’s done.

[Jarninius]

Originally Posted by DBShiznit

The job is easy and you should do it anyway. I’d start by doing that first. Bolts are one time use and cheap enough. Get all three and a gasket. Clean both services really well before putting it back together. You don’t have anything to loose by doing it and much more to gain. You’ll either fix the issue or have the piece of mind it’s done.

The shop ended up confirming that unfortunately my head gasket is as good as gone. They sound like they want to completely replace my engine which will run me about $7000, although i have a friend who is extremely experienced and he is offering his help. I’m planning on replacing the head gasket along with all other gaskets for any parts being removed as well as new head bolts. I think this is worth it after everything i have already replaced (plugs, coils, some injectors) and i just wanted to see if you or anyone else had any input as to anything else i should buy and replace while i have the head off. anything helps. thanks!

[Jarninius]

I also did come across a gasket/seal kit that comes with almost everything i would need on ebay, although i am very suspicious as it is only $160 for everything. wanted to know if anyone has actually used one of these kits but im probably just gonna play it safe with OE.

[lookalikehuuh]

Originally Posted by Jarninius

The shop ended up confirming that unfortunately my head gasket is as good as gone. They sound like they want to completely replace my engine which will run me about $7000, although i have a friend who is extremely experienced and he is offering his help. I’m planning on replacing the head gasket along with all other gaskets for any parts being removed as well as new head bolts. I think this is worth it after everything i have already replaced (plugs, coils, some injectors) and i just wanted to see if you or anyone else had any input as to anything else i should buy and replace while i have the head off. anything helps. thanks!

There is more to it than just a headgasket swap, you would need to straight edge both the block and the head to ensure its within limit. I would suspect there is something going on since head gaskets aren't common failures on this platform. So maybe this car overheated a bunch of times which is likely to cause warpage for sure. You could also have a cracked head or block if an overheat is the reason behind the head gasket failure.

Also DO NOT buy some shitty online kit, just buy the real OE stuff if you are going to go that deep into the engine.