Leaking engine oil cap and engine emissions light

[krx927]

Few days ago while tracking I developed a terrible oil leak from the engine oil cap. My whole engine bay was totally sprayed with oil. I also had a lot of oil in the right wheel arch, over suspension and brakes

When reading the posts I see that this is a common problem. Unfortunately I did not find any definite solution on the forum. I will try a few suggestions and hope they will help. BTW I have the new design of oil cap - 11128507153

At the same time I also got engine emissions light:


Fortunately the light went away after I started the car next time.

As my car is still under warranty I went to BMW service today. They replaced the cap and did a lousy job of cleaning the mess. I will have to do it properly myself.
They also told me that the they cannot find error code for the light as it is not on any more? I was under the impression that the car is storing error codes and you can always find them back.
Am I wrong? Or they really cannot see the error if the light is not on any more?
Does anybody know if this light is connected with my oil leak as it turned on at the same time when cap was leaking? If not what can be the cause for this light?

[thekurgan]

I believe a loose or faulty fuel cap can also trigger this light. Do you have any photos of your old cap, underneath where the seal rubber is located?

[///M Power-Belgium]

Your are not the only one with a oil cap leak =>http://www.m3post.com/forums/showthread.php?t=704497
Note ; Last year I had 3 oil caps replaced and check it now every week !
Never had a big leak,but when it starts I just replace it because I want the engine always clean !
It's realy unbelievable that this can happen on a engine like the S65 ?
Seems it's realy difficult for BMW to make a functional seal on a oil cap !
Anyway hope this one is a good one ! Let's hope...

[Saandiaago]

Had this happen within the first week of owning my car purchased as brand new. Been okay thus far since a new cap was placed. Dealer took the time to clean it all out nicely. I agree that this should not happen. Seems like a silly problem on an expensive car.

[krx927]

Originally Posted by thekurgan

I believe a loose or faulty fuel cap can also trigger this light. Do you have any photos of your old cap, underneath where the seal rubber is located?

I sincerely hope the leak and engine light are connected and I will not get it any more.

Unfortunately I do not have any photos of the cap but when I checked I saw the gasket came out of the housing... That was probably the cause for the leak.

From now on I will check the gasket every time I will put it on.

[krx927]

Originally Posted by ///M Power-Belgium

Your are not the only one with a oil cap leak =>http://www.m3post.com/forums/showthread.php?t=704497
Note ; Last year I had 3 oil caps replaced and check it now every week !
Never had a big leak,but when it starts I just replace it because I want the engine always clean !
It's realy unbelievable that this can happen on a engine like the S65 ?
Seems it's realy difficult for BMW to make a functional seal on a oil cap !
Anyway hope this one is a good one ! Let's hope...

Indeed I saw that this is quite common problem. Unfortunately there is no definite solution for this.
From now on I will thoroughly check the gasket of the cap to make sure it is seated properly before I will put the cap on.
I will also try to bend the retainer arms on my cap to put more preload on the gasket. The new one is screwed on very lightly.

Bloody 8 EUR part making so much issues.

And to top it this is my second issue with fluid leaks - already from the begining I had an issue in steering fluid leaking when driving fast. Luckily I solved that one with so called Kaiv's solution - putting extra expansion tank...

[krx927]

Originally Posted by Saandiaago

Had this happen within the first week of owning my car purchased as brand new. Been okay thus far since a new cap was placed. Dealer took the time to clean it all out nicely. I agree that this should not happen. Seems like a silly problem on an expensive car.

You were lucky that the dealer did a proper job of cleaning. My did not!

I will need to do it myself

[Minator]

There is an SB on the oil cap..it states then when the oil cap is removed it CANNOT be turned upside down....lay it right side up on a rag...if not it will cause the pesky oil leak around the head....sounds like the op had other issues with the whole engine bay covered in oil...

[thekurgan]

Originally Posted by Minator

There is an SB on the oil cap..it states then when the oil cap is removed it CANNOT be turned upside down....lay it right side up on a rag...if not it will cause the pesky oil leak around the head....sounds like the op had other issues with the whole engine bay covered in oil...

Seriously? I gotta find this SIB. I always thought it was from applying too much pressure when tightening and distorting the seal. Thanks for the info.

[Beemdog]

Originally Posted by Minator

There is an SB on the oil cap..it states then when the oil cap is removed it CANNOT be turned upside down....lay it right side up on a rag...if not it will cause the pesky oil leak around the head....sounds like the op had other issues with the whole engine bay covered in oil...

+1 on this SB. Two weeks ago I was in for my free oil change and the SA went over the oil cap and leaving it right side up always. Kind of a PITA, but that's the way it is. Obviously, this issue only causes a small amount of oil to drip down the valve cover, not a major spray-out as discussed above.

[thekurgan]

Originally Posted by Beemdog

+1 on this SB. Two weeks ago I was in for my free oil change and the SA went over the oil cap and leaving it right side up always. Kind of a PITA, but that's the way it is. Obviously, this issue only causes a small amount of oil to drip down the valve cover, not a major spray-out as discussed above.

I guess it just pools up if it's upside down, and when placed on the cover, it drips down. Agree, this is a sIB for an annoyance.

[maloo]

My old cap leaked too but the new redesigned BMW part # 11128507153 solved the problem. I think I paid around $10 for the part.

[krx927]

Originally Posted by Minator

There is an SB on the oil cap..it states then when the oil cap is removed it CANNOT be turned upside down....lay it right side up on a rag...if not it will cause the pesky oil leak around the head....sounds like the op had other issues with the whole engine bay covered in oil...

I do not really see how this will prevent the oil leak, but I will do that from now on...
When I discovered the oil spill I opened the cap and I saw that half of the gasket fell out of the housing, hence the big spill.

Does anybody know the answer to my other question: if you get the warning light that later goes out, does the car's computer remembers this and you can still find error code if you connect it to the computer?

[Flying Ace]

I have the older caps and it's never leaked, regardless how I have it sit when it's off.

[D@AP]

I'm not sure the oil cap would cause it to spray everywhere, especially the wheel arch, suspension, and brakes? Have you taken it to the dealer or any shop for a more thorough diagnosis yet?

[krx927]

Originally Posted by Dayne@AcutePerformance

I'm not sure the oil cap would cause it to spray everywhere, especially the wheel arch, suspension, and brakes? Have you taken it to the dealer or any shop for a more thorough diagnosis yet?

It really looked like just faulty oil cap. When I open the hood I saw it immediately because you could clearly see that there was the most oil around the cap. Also the bonnet is dirty only just above the oil cap.
I admit I find it strange that I saw wheel arch (right) totally dirty but you need to take into account that I was tracking when this happened, so the engine was on full load at revving to the max all the time + high G forces.
I was just lucky that I only lost 1/2l of oil and I didn't starve the engine of oil while tracking. That would be a disaster!

And yes I took the car to the dealer; they just replaced the cap and cleaned (badly!) the engine and wheel arch.