Tips for the OFHG DIY for N55?

robthewrench · 12-11-2018, 07:21 AM

So at ~75k miles my OFHG definitely seems to be leaking. There is some oil / dirt residue on a lot of stuff just below the OFHG. Also Over the past ~8K miles I lost about 1/2-1 quart of oil. It's a 2011 N55.

So I'm planning on tackling this job soon. I've read some of the DIYs and watched a few videos, doesn't seem too bad.

If anyone has any tips for the N55, I'm happy to hear them.

I've ordered genuine BMW gaskets from FCP Euro. I also ordered the coolant return hose because many people say they crack the plastic fitting when removing the hose from the block.

I know I'll need to loosen the intake manifold. To get to that bolt under the manifold I've got a 1/4" drive E10 socket and a wobble extension. I've also got an E10 box wrench.

I plan on using some permatex ultra black on the gasket to try and get a better seal than the gasket alone.

racermp · 12-11-2018, 08:08 AM

get a small #8 wrench, it helps with the bolt closer to the fan. rachet wrench is better.

i cleaned everything with brake cleaner.

remove the oil cooler housing first, i dind't have a problem with coolant hose, gotta wiggle it a bit.

TheMidnightNarwhal · 12-11-2018, 08:22 AM

I don't think you should be adding any other additional gasket material

And a heads up for the coolant hose that cracks... if you use a 8mm or E torx wrench you can get it done without taking it off.

Personally I had issues with my 8mm so had to take it off (bolt head was stripping, probably to tight).

My issue though wasn't the plastic hose it was the O ring on the end, it had expanded and couldn't fit it back in properly. Make sure it comes with a O ring in case of that. I had to go to hardware store get a similar sized O ring, it was still leaking sligthly so I was able to drive it to the dealer to get proper O ring.

Pladi · 12-11-2018, 12:36 PM

DO NOT USE extra gasket material. That could end up in small oil channels.

With N55 you have to move the intake manifold out the way a bit. To access that 3rd bolt. I have many extensions and found that bolt impossible to get to without removing the intake a bit out the way.

Be very clean. We have heard enough engine fails after this ;procedure could be due to foreign material getting into the oil passages.

Take ur time. Its not hard at all but people who rush always fail.

neilvan · 12-11-2018, 01:39 PM

I just did 2 OHF gaskets (both 335s with oil coolers) on sunday. If you can turn a wrench its pretty easy but make sure everthing is plugged and clean surfaces. The bolt behind the intake manifold is the reason its double the work (just removing more things out of the way than you should) but atleast the intake manifold doesnt have to come off.

IMO get the E torx wrench or take the time to upgrade to the metal coolant fitting for the coolant line that has to come off. Brake clean and use a razor to clean off the mating surfaces. I dont know if Id use any gasket material. A small amount shouldnt hurt though depending what you use.

Dealer wanted $760 each plus tax. Cost me $60 for both and took a few hours maybe.

12-11-2018, 07:21 AM	#1
robthewrench Captain 266 Rep 952 Posts Drives: 11 E90 335i Join Date: Aug 2014 Location: Columbus OH iTrader: (0)	Tips for the OFHG DIY for N55? So at ~75k miles my OFHG definitely seems to be leaking. There is some oil / dirt residue on a lot of stuff just below the OFHG. Also Over the past ~8K miles I lost about 1/2-1 quart of oil. It's a 2011 N55. So I'm planning on tackling this job soon. I've read some of the DIYs and watched a few videos, doesn't seem too bad. If anyone has any tips for the N55, I'm happy to hear them. I've ordered genuine BMW gaskets from FCP Euro. I also ordered the coolant return hose because many people say they crack the plastic fitting when removing the hose from the block. I know I'll need to loosen the intake manifold. To get to that bolt under the manifold I've got a 1/4" drive E10 socket and a wobble extension. I've also got an E10 box wrench. I plan on using some permatex ultra black on the gasket to try and get a better seal than the gasket alone. __________________ bone stock
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12-11-2018, 08:08 AM	#2
racermp Major 190 Rep 937 Posts Drives: F30 330i Join Date: Apr 2013 Location: Houston, TX iTrader: (1)	get a small #8 wrench, it helps with the bolt closer to the fan. rachet wrench is better. i cleaned everything with brake cleaner. remove the oil cooler housing first, i dind't have a problem with coolant hose, gotta wiggle it a bit.
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12-11-2018, 08:22 AM	#3
TheMidnightNarwhal Major General 2657 Rep 6,290 Posts Drives: 11' 335is DCT Join Date: Jun 2015 Location: Gatineau, Quebec iTrader: (0)	I don't think you should be adding any other additional gasket material And a heads up for the coolant hose that cracks... if you use a 8mm or E torx wrench you can get it done without taking it off. Personally I had issues with my 8mm so had to take it off (bolt head was stripping, probably to tight). My issue though wasn't the plastic hose it was the O ring on the end, it had expanded and couldn't fit it back in properly. Make sure it comes with a O ring in case of that. I had to go to hardware store get a similar sized O ring, it was still leaking sligthly so I was able to drive it to the dealer to get proper O ring.
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12-11-2018, 12:36 PM	#4
Pladi Lieutenant Colonel 718 Rep 1,753 Posts Drives: 2011 335i xdrive Join Date: Nov 2017 Location: Waterloo, ON Canada iTrader: (0)	DO NOT USE extra gasket material. That could end up in small oil channels. With N55 you have to move the intake manifold out the way a bit. To access that 3rd bolt. I have many extensions and found that bolt impossible to get to without removing the intake a bit out the way. Be very clean. We have heard enough engine fails after this ;procedure could be due to foreign material getting into the oil passages. Take ur time. Its not hard at all but people who rush always fail.
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12-11-2018, 01:39 PM	#5
neilvan Major 858 Rep 1,363 Posts Drives: 09 E90 335i M-Sport 6MT RWD Join Date: Nov 2017 Location: Ontario, Canada iTrader: (0) Garage List 2007 BMW E61 530xi [0.00] 1993 Mazda Miata [0.00] 2009 BMW E90 335i [0.00]	I just did 2 OHF gaskets (both 335s with oil coolers) on sunday. If you can turn a wrench its pretty easy but make sure everthing is plugged and clean surfaces. The bolt behind the intake manifold is the reason its double the work (just removing more things out of the way than you should) but atleast the intake manifold doesnt have to come off. IMO get the E torx wrench or take the time to upgrade to the metal coolant fitting for the coolant line that has to come off. Brake clean and use a razor to clean off the mating surfaces. I dont know if Id use any gasket material. A small amount shouldnt hurt though depending what you use. Dealer wanted $760 each plus tax. Cost me $60 for both and took a few hours maybe.
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