OUZO Power

I'll try and be brief. Engine is 5.5L M273.

6 months ago I had an oil leak at the back of the engine on the passenger side. It turned out to be a leaking oil separator.

I thought lets go ahead with preventative maintenance and replace the 3 cam plugs back there. Well that was a bad idea.

Next day the oil leak on the passenger side is gone and I have a leak from the driver side.

I have replaced the small driver side plug 3 times in the last month and it still leaks. I run my hand behind the engine near the small and large plugs and only the small one has oil on it.

Last weekend I replaced the plug a 4th time. I even slathered on Ultra Black gasket maker. Let it sit for 24hrs.

Next day did a 20km drive and the leak is back. I GIVE UP.

Recommendations please.

SunnyT

Damn man, that sucks to hear. I've been putting off the connector seal replacement between the engine and transmission on mine, just because it's a $$$$ labor job and I just had the transmission serviced. Drip isn't bad, just enough to bother me ever so slightly. (My mechanic says I'm too OCD, but he gets it)

Did you add lubricant to the back of the plugs, so that they slide in completely?
DId you clean the insert and the surrounding areas with brake clean or something in case there is any gunk preventing a tight seal?
Was the cap seal clean?
Did you push in the seal when it was level? Pushing when it's at an angle can bend the plastic, or snap the teeth depending on the cap.
Did you push in with a screwdriver to remove them? Could be that it pushed/buckled the metal surround a little

Those are the "go-to" points that come to mind whenever something is leaky after I tamper with it.

I'm sure you're certain but, could the oil be coming from somewhere else?

OUZO Power

Where is the connector seal located out of curiosity? I don't think the leak is coming from anywhere else. Its driver side rear. Right in the middle of the steering wheel as you look at the car.

Every time there was oil under the small plug.

Only thing I haven't done is oil up the new plug. Every time it when in flat. Last two times I put a lot of pressure on the cap. The hole is clean, I spray it down and run my finger in it and on the lip. All looks good.

Thanks for the insight bud.

flybd5

my first gut reaction is to think that the oil is not coming from where you think it is coming. Did you steam clean the engine and then drive it to track it down?

OUZO Power

Yea I spray it down with 3 bottles of brake cleaner. Spray from the top all the way down. Same location under the car every time. Same oil behind the stupid small plug.

flybd5

Brake cleaner??? Thats not steam...

How about a picture?

SunnyT

Anthony550

Did you already replace the oil seperator? My ml550 had a bad seperator and it was building up so much pressure in the engine that it was blowing oil out of the oil cap seal.. I replaced the seperator on the back of the engine and that took care of it. I wonder if high pressure from that is blowing your plugs out?

OUZO Power

Brake cleaner does a great job at breaking down the oils and cleaning them off.

OUZO Power

Yes. I replaced the leaking Oil Centrifuge Separator and all the cam plug. And the next day the small one on the left drivers side keeps leaking. I have replaced them 4 times.

You think the new Oil Centrifuge Separator just didn't work from the get go?

Thanks for all your help guys.

SunnyT

Watch out with that brake cleaner my friend... It's not meant to be used on many different rubbers and silicones. It actually strips plastics/rubber of their embedded wax/silica properties that keep them soft/flexible. It accelerates the dry rot of hoses and housings.
If you do use it, make sure to thoroughly clean off all plastics with a strong jet of water to minimize damage from the residue. A strong, concentrated degreaser is preferred.
PM me if you want a list of great degreasers that don't damage plastics and rubber. I can also suggest some water-based products that will actually rejuvenate the plastics making them last longer if you're interested.

flybd5

No, it does NOT. That's like saying what WD-40 is a great lubricant, when it is absolutely not. WD-40 is intended to displace moisture, hence WD = Water Displacement. It also attracts a ton of dust which ruins locks, etc. Brake fluid (otherwise known as hydraulic fluid) is intended to be used in the internals of a brake system, and not for "breaking down the oils." Like has been said already, it has a bad effect on other things in your engine compartment. Like SunnyT said, I strongly suggest you go steam clean the engine to remove any trace of that fluid.

Anthony550

Maybe check to see if there is a lot of pressure when you take off the oil cap. There is also a plastic black box on the drivers side valve cover that I replaced that is part of the Oil seperator system that could be clogged or something.

SunnyT

I believe there is some confusion in the description.
Brake Cleaner ≠ Brake Fluid. Two very different fluids. Although flybd5 is correct in stating that brake fluid is used within the internals of a brake system, it is not brake cleaner as OUZO Power talked about.
Brake cleaner works wonders on metals, just not plastics or rubbers (not saying you can't use it, just saying it's not recommended). It cleans very aggressively and efficiently and therein lies the problem. It is too aggressive for most plastics and painted surfaces.

OUZO Power:
Any progress on why it is leaking?
I'm about to change the oil sensor next week. So useless, but the message is oh so annoying...

flybd5

Ah, so he is using Tetrachloroethylene? Well, isn't that precious. He should read up on what happens when you expose yourself to that, especially when it is heated.

OUZO Power

THIS IS INSANE.

So the leak stopped. The latest plug with the Ultra Black Gasket sealer worked.

But a day after another leak showed up. 1.5 foot forward near the front driver side.

Its the dreaded Rack & Pinion Leak. This one is going to cost. I hate this car.

SunnyT

Don't you mean love this car? Because it always lets you know it's there and wants your attention?

Try the refurbished market from reputable sellers. Great way to save a lot of $$$$$ on the parts, usually come with all internals replaced and have a warranty. From a quick Google, the refurbs are half the cost of new. Then only labor cost is your real enemy.
My refurb purchases/repairs have not let me down so far.

OUZO Power

Did you replace yours? Mine has the Parametric Speed Sensor. It will cost.

SunnyT

I have not replaced mine yet. So far I've been lucky. Just checking some of the websites I usually get parts from the rack with steering sensor runs under $1k (US)
If you do some searching, I'm sure you can find a well-priced one that will soften the blow.