N62 head gasket oil leak

[collinja]

Hi All,

I have a 2006 X5 4.4 with 125K miles. A local independent dealer recently replaced the rear main seal and still noticed some oil leaking after the replacement. He diagnosed the oil leak as coming from the head gasket at the rear of the engine (see picture). The valve cover gaskets have already been replaced and he saw no signs of leakage from them. I'm done some searching online and haven't come across any discussion regarding this being an issue with the N62s, but perhaps most folks are just getting rid of them when this happens? Any thoughts on the head gasket leaking oil as I'm losing about a quart every 600-700 miles. Given the $5000+ estimate for replacing both head gaskets it may be time to start searching for another vehicle before the leak worsens.

[williamx5]

Good day!!

I would clean everything really really good... Almost new looking!!! Use parts cleaner, engine degreaser, or the like to make it shine! Then come back in 300-350 miles to see what it looks like... This could just be the leftovers of the old valve cover leak... I would think a quart over that short duration would cause this to look like Niagara Falls if this is where the leak was... Is there any smoke upon acceleration after sitting at a light for a minute or so?

How long has this oil leak or oil consumption been going on? Are you seeing a puddle on the garage floor? Does the interior smell of burning oil when driving? The answers here might give us some help in figuring this out... I'd rather us know the cause, than guess a $5000 repair will fix the quart of oil consumption (coming from the individual that survives off fixing leaks)... I'm in the wrong business!!! It only cost me $1475ish to REBUILD the entire motor in my 2004... All OEM BMW parts too...

Cheers!!

[collinja]

Thanks for your response. The valve covers were done over a year ago. While it doesn't look like a bunch of oil is coming out in the picture there is plenty on the belly pan/reinforcement plate directly below. It overflows on the ground enough to make a silver dollar size spot. I can't smell burning oil inside the vehicle when driving but you can smell it once you are outside. It does smoke pretty good after idling at a stop light or in stop and go traffic.

[X53Jay4.8is]

Originally Posted by collinja

Thanks for your response. The valve covers were done over a year ago. While it doesn't look like a bunch of oil is coming out in the picture there is plenty on the belly pan/reinforcement plate directly below. It overflows on the ground enough to make a silver dollar size spot. I can't smell burning oil inside the vehicle when driving but you can smell it once you are outside. It does smoke pretty good after idling at a stop light or in stop and go traffic.

Perhaps the valve cover gasket is not seated properly at the back of the engine ?

[williamx5]

Originally Posted by collinja

Thanks for your response. The valve covers were done over a year ago. While it doesn't look like a bunch of oil is coming out in the picture there is plenty on the belly pan/reinforcement plate directly below. It overflows on the ground enough to make a silver dollar size spot. I can't smell burning oil inside the vehicle when driving but you can smell it once you are outside. It does smoke pretty good after idling at a stop light or in stop and go traffic.

Good day!!

Can we clean up the area and see where the fresh oil is coming from? That could indicate a bad valve cover job as Jay suggested... The main consumption is most likely due to the smoking after idling and in stop-and-go traffic... That is the classic valve stem seal issue...

Cheers!!!

[collinja]

That was my first thought was the valve covers were leaking. However, when my local independent shop said he saw no leakage from the valve covers, I was surprised. I'll clean it up and see if I'm able to pinpoint the location better and then get a second opinion from another shop.

[X53Jay4.8is]

Originally Posted by collinja

That was my first thought was the valve covers were leaking. However, when my local independent shop said he saw no leakage from the valve covers, I was surprised. I'll clean it up and see if I'm able to pinpoint the location better and then get a second opinion from another shop.

Before you take it to another shop get one of those telescoping mirrors, clean up the area and then put the mirror behind the valve cove area to see if the gasket is pinched and seeping out. I have noticed on some of the clients that have had X5 V8 valve covers replaced a number have been pinched at the back or n to seated properly in the valley drops of the head.

[TiAgX5]

All good info above.

Worth noting; there are four spots on the rear side of each VCG that MUST have a small bead of RTV sealant applied (the corners adjacent radius areas). When this is not done, they leak.

Details like this make the VCG job a must DIY. Also the common practice of techs yanking the injector harness wires to unplug, just watch BMW VCG DIYs on Youtube.

I cringe watching them!

[X53Jay4.8is]

Originally Posted by TiAgX5

All good info above.

Worth noting; there are four spots on the rear side of each VCG that MUST have a small bead of RTV sealant applied (the corners adjacent radius areas). When this is not done, they leak.

Details like this make the VCG job a must DIY. Also the common practice of techs yanking the injector harness wires to unplug, just watch BMW VCG DIYs on Youtube.

I cringe watching them!

Agreed on the spots of the RTV in the valley/depressions. This is one area were a lot of shops miss this point. Use the RTV and no leaks.

[collinja]

Thanks for all the info. goys. Looking with a mirror, I don't see any pinches or moisture around the valve cover. Below is a picture of the rear of the valve cover. The only place which appears to be wet is the end of exhaust manifold (2nd picture).