Oil cooler/filter housing gasket replacement
 

Today I replaced the oil filter housing gaskets and the gaskets for the oil cooler. This is to try and fix an oil leak that drips down the bellhousing and looks like a rear main leak. The first picture is of a leak on a car similar to how mine looks. Previously I had replaced the valve cover and turbo oil lines.

First things first: I'm long winded, and I'm trying to put details in to help people. Sorry if this gets long.

Plan on 4-6 hours to do this, assuming that you don't have difficulties. I spent extra time because I tried to do this from the top (removed coolant tank, turbo inlet and outlet hoses). I came to the conclusion that this has to be done from under the car.

Two of the bolts holding the oil filter housing in place are under the exhaust heat shield. Therefore you need to remove the heat shields and downpipe to get to this job.

Some things to think about before you get into this:
1. If you have never removed the downpipe, plan on some time for this.
2. If the exhaust clamp has never been removed, buy another one. Don't try and save the old one, cut it off and replace it.
3. This job will expose the turbo oil lines, so it is the perfect time to replace them.
4. If you want to add a heat wrap to the turbo, this is the time to do this as well.
5. The coolant is drained, so if you think that you may have a thermostat or water pump leak, this job will save you some steps.
6. I removed the coolant tank for access, but then I saw that my tank has a small crack in the bottom of it, along with some staining that shows that it is leaking.

Parts you need:
1. Oil filter housing gasket kit
2. Oil cooler gasket kit
3. Coolant/distilled water
4. Downpipe to turbo gasket

Optional parts:
1. Oil change supplies (there is a pretty good chance that some coolant will get in the oil, but not necessarily required)
2. Turbo oil feed and drain lines
3.

Tools:
1. T25 torx bit
2. Various metric sockets, ratcheting wrenches
3. Lots of towels, cardboard, drain pan. This job is seriously messy, and I don't see any way to avoid this.
4. Brake cleaner or something to clean parts and the engine block

The second picture is the oil filter housing, the side that bolts to the block. 4 bolts connect the housing to the block.

The third picture is the other side of the oil filter housing, the side that the oil cooler bolts on.

I'm gonna do this in multiple posts since I can only put 3 pics in each post.

Mike

Ok, so start by removing the heat shields and downpipe. a 10 mm ratcheting wrench is helpful on the ones near the radiator. The one that is on the passenger side behind the radiator is a slotted hole, so you only have to loosen this bolt a few threads to remove the upper heat shield.

The first picture is the front of the engine block showing how two of the bolts are covered by the flat heat shield nearest the engine block. The second pic shows the oil filter housing with the heat shield removed.

Its also a good time to remove the bracket that attaches the auxiliary water pump to the oil filter housing. 2 bolts connect this black steel bracket to the aluminum housing. One of the hoses connects the aux water pump to the oil filter housing.

You can also remove the turbo drain hose from the turbo. One bolt holds this hose (covered in a metal foil heat wrap) into the turbo. It will take a bit of wiggling and pulling to dislodge this from the turbo.

Mike

Remove the coolant tank from the radiator support and loosen the oil filter cover (to allow some of the oil to drain back out of the oil filter). Tie the lower oxygen sensor out of the way so that it will be away from the engine block and lower radiator hose (you want to avoid getting the tip of it excessively dirty or wet). Remove the lower radiator hose and drain. Check your overflow bottle for cracks (first picture).

Remove the 4 bolts that hold the oil filter housing to the engine block. You can keep the oil cooler attached at this point. An ugly mess of oil and coolant will drain down the front of the engine. This will take a while to drain. The oil filter housing/oil cooler is now hanging by a hose connected to the aux water pump. You can stretch the hose so that you can remove the clamp and have the oil filter housing free of the MINI. Remove the oil filter and allow this unit to drain.

Separate the oil cooler from the housing, clean all mating surfaces, and replace the gaskets. Clean the front of the engine block and sealing surfaces. Now is the perfect time to replace the turbo oil line, as well as the drain line.

Inspect the oil filter housing for cracks or severe distortion. Notice that the 4 bolts that hold the housing to the engine block are biased to one side of the housing, and that the heat and pressure can warp the housing.

Reassembly is basically the reverse of these steps.

I have also included a pic to show where I had a gasket fail on the oil pump to block housing.

I also changed the oil when i completed this process. Seeing how the ports are so close to each other, I could not be positive that there was not coolant in the oil.

Good luck and let me know if this is not clear, or needs more details.

Have fun,
Mike

Nice DIY, thanks!

I forgot to add that you should disconnect the battery, your hands are in close proximity to the cooling fan for much of this work, as well as the heat shield is close to the alternator.

Mike

Awesome DIY write-up. I had mine done by an independent mechanic while the MINI was in for some other repairs. Good to know there is a good guide out there if I need to do it again and want to tackle it myself.

Nice DIY, :thumbsup: Very good. 11428643758 https://www.ecstuning.com/Search/Sit...h/11428643758/ is the part on the oil filter to engine block side and 11428643747 https://www.ecstuning.com/Search/Sit...h/11428643747/ is the part the oil filter to heat exchanger side.

I had seen expansion tank hairline cracks also and then drip leak when heated up (on bottom ), you don't know its cracked until you peek on the underside. Looks like yours was on the top side if I see the picture correctly.

Mentioned here in the thermostat thread:

https://www.northamericanmotoring.co...t-leak-or.html

Again great job.

My cracking was on the bottom of the tank. I never thought to look until I saw that thread you reference. Thanks, ECS!

Mike

Welcome, good thing you caught it. Glad I could help and great write up .

+1 for great write up. Would you recommend draining both oil and coolant from the beggining?

Definitely coolant needs to be drained. For the oil, you at least want to remove the oil filter. I don't think that there is a benefit to draining the oil first, but it probably wouldn't hurt.

Have fun,
Mike

Undertorqued
 

I just finished this task this morning, started it up, and oil gushed from the assembly, precisely from the new gaskets. Initially, I torqued the bolts to 18 N·m, but became wary of over-torquing/stripping out the housing block (catastrophic outcome) due to the small size of the bolts, so I progressively backed them out and re-torqued to 11 N·m. I forgot about the compression of the gaskets, which gave that squishy about-to-overtorque feeling. Apparently that was not the best decision, as the oil pressure bypassed the seals, and kinda ruined my morning. Caught it immediately, so it's more of a pain to re-clean and re-do this entire task.

What are the proper torque values for the filter/cooler assembly mounting bolts to engine block?

Torques
 

Okay, so I tore back into the engine (service mode - easy), and it turns out that the return oil line is actually leaking. I didn't seat it fully, and the pressure caused oil to gush out. It appears that the seals on the filter assembly are sound, but it's hard to be certain because the oil from the return line cascaded down. However, the oil seemed to be superficial, rather than coming from the seams. During the replacement, Permatex Ultra rubber was applied to the seals (to compensate for the lopsided bolt placement), the bolts were seated in a cross-wise pattern, then torqued cross-wise, so the seals are likely evenly seated.

The question regarding torques is semi-answered, as I took a pic of the bolts, and judging from the vague markings, they're probably 8.8 grade, and therefore the torque intuition was correct. The Bentley manual torque tables suggested a max of 10 N·m for M6 bolts, and I backed them down to 11 N·m. Someone suggested in another thread the 25 N·m torque that's used for the support bracket bolt, but that's much too high.

At best, if bolts are 10.9 grade, the max torque is 14 N·m (10 ft-lb); if 8.8 grade bolts, the max torque is 10 N·m (7.4 ft-lb). Suggestions and feedback are welcome!

The first pic is the bolt at the base of the turbo oil return line (lower right corner), and the second pic is the bolt next to the turbo oil feed line.

Just completed this the past weekend. It was relatively easy as I had already done the turbo oil feed and return lines, however the bracket on the aux water pump proved extremely annoying to remove. As of this morning, no leaks, however will need to watch it over the next while to check.

Thanks for the write up!

Hey Mike,

Great write up, thank you.

So about this time last year I replaced my oil supply line and return line. This year it looks like it will be the oil filter housing/cooler gaskets. But what I cannot understand right now is why the coolant must be drained. This job just seems slightly more involved than the oil supply/return lines.

While I have yet to climb under my car to view, can you tell me why the coolant has to go? I ask because I recently did my water pump/thermostat housing. Really don't want to drain :no:

The engine coolant passes through the oil filter housing to go into a small oil-to-water cooler. There is a gasket between the oil cooler and oil filter housing, and another gasket between the oil filter housing and the engine block.

If you don't drain the coolant, it will drain when you remove the oil filter housing.

If you just changed the coolant recently, drain it into a clean container and reuse it. I know it is no fun having to bleed the system again.

Have fun,
Mike

Son of a...

Fair enough. Thank you for that Mike. :-)

This is a great write-up, thank you! I'll be doing this next weekend when my parts come in. Can someone educate me a little on this exhaust clamp that should be replaced? A part number would be great. Also, the write-up mentions a "downpipe to turbo gasket" Is that this one?
http://www.ecstuning.com/Mini-2007-C...B16A/ES514883/

The exhaust clamp is a "v" style clamp. They're a PIA. Soak in WD-40 for awhile or just get another one. It connects the DP to the flex pipe/exhaust system.

The gasket you have in that link is correct.

I've got plenty of PB Blaster sitting around from working on my Jeep. This will be the first big project I'll attempt on my Mini, so I want to get it right the first time. Looks like that Exhaust V-Clamp is this one, then:
http://www.ecstuning.com/Mini-2007-C...56352/ES40513/

Is that correct?

Right you are again. PB will work great. Mine was tough but reusable. Order one just in case. Cheap insurance.

I had to do my oil supply/return lines last year. Pretty much the same job. If you get stuck let me know.

I'll be diving into this job in spring so this should go pretty quick for me. Lol

I just did this repair this weekend. I had Thursday and Friday off work so I thought I could get it done in a day. It took me three. I would highly recommend anyone attempting this to put their mini into service mode. I hadn't heard of this until after I started the job. There's a writeup on service mode here:
http://cultofmini.com/2nd-generation...-service-mode/
You don't need the special extension tools. I just used two pieces of M8 1.25 allthread. I cut them to about 11 cm and wrapped the ends in duct tape.

I had this oil housing gasket job done except for re-installing the heat shields. Couldn't for the life of me get to some of those screws. I took about 45 minutes to put the car in service mode and realized this would have made the entire job go much quicker.

I have developed a small coolant leak at the oil filter housing gasket.
After reviewing the extensive work to replace this gasket I am strongly inclined to first try K-seal to attempt to seal this gasket leak.
I installed a new thermostat 1 year ago and replaced the coolant at that time. What are your opinions on the probable success of sealing this gasket with K-seal?

That part of the engine runs very hot, and the oil/coolant are pressurized. An external chemical seal will only do so much, but it may work as a Band-aid until you can get around to a proper fix. Mine has held for months, and on the upside, you'll likely only have to do this once every 80k or so.

Considering that your vehicle is now 6 years old, and you have already replaced the thermostat, it is likely that it will need a turbo oil line replacement soon. The turbo oil line leaks at the fitting that is bolted onto the turbo housing. The fitting contains an o-ring which fails due to the heat of the turbo. That is why MINI is now installing a heat shield around this line.

To replace the turbo oil line, you need to go through the same process to fix your coolant leak.

Personally, I would keep a jug of mixed coolant in the car, and closely monitor the coolant level. I'm not a fan of stop-leak products, but I'm not familiar with the one that you specified. I would check the coolant level every few days, just to make sure that your small leak doesn't turn into a big one. I would keep topping the resevoir up until the leak gets bad enough that you need to fix it (or there is another excuse to fix it, like the turbo oil line leak).

Mike