Oil & Coolant Mixing

[fastgoat]

My wife drives a 2014 X5 35i. We’ve had the car for about 6 years now, and perform all regular maintenance. About two years ago I replaced the oil filter housing gasket (leaking) and then two months ago the valve cover gasket (leaking). At both times, I did the plugs and an oil change.

Today my wife texts me the car is giving a low coolant light. I inspected it this evening and the coolant reservoir is a chocolate milkshake. I removed the oil fill cover and there was slight milky residue on the underside. What are the odds this is a head gasket versus the OFHG or oil cooler gaskets? Car only has 73K miles on the clock. Haven’t seen much of these types of issues on an N55…

[sukhk527]

It’s your OFHG. replace that and the oil cooler gasket at the same time, flush the coolant and you should be good.

[fastgoat]

Originally Posted by sukhk527

It’s your OFHG. replace that and the oil cooler gasket at the same time, flush the coolant and you should be good.

Man, given I did this job 2 years ago, I was really hoping I didn't have to do it again...

Any specific how-to or recommendations on flushing the coolant?

[tlow98]

Originally Posted by fastgoat

Man, given I did this job 2 years ago, I was really hoping I didn't have to do it again...

Any specific how-to or recommendations on flushing the coolant?

Yeah, that’s a bummer. Sorry to hear that.

Def extremely unlikely it’s a head gasket. I don’t know that I’ve ever heard of a HG issue on a motor that wasn’t tuned within an inch of its life.

I’d say say flush the coolant with distilled water first the refill with 50/50 and you should be good to go. I second replacing both of the gaskets.

Be sure to use the oil priming procedure after the OFHG. BMW published a procedure for this.

[stocktree]

There's only a thin rubber seal between oil and coolant on that housing.
Is it possible you had oil in the coolant from previous leak? And now it's leaking elsewhere?

[Chilled]

You milkshake brings all the mechanics to your car, oh no they are looking at your car. They could fix it, but they will have to charge.




My main concern would be if it was running with the milkshake, is what condition are all the wear surfaces (bearings, cams, etc). These generally don't like milkshakes.

I personally would be looking a popping that valve cover again see what the condition the cams are in, plus can vacuum out all the milkshake thats upto.

[fastgoat]

Originally Posted by stocktree

There's only a thin rubber seal between oil and coolant on that housing.
Is it possible you had oil in the coolant from previous leak? And now it's leaking elsewhere?

I suppose it's possible that it's been leaking into the coolant since I've never checked it after these jobs. I would just change the gaskets and do an oil change. The leaks were external and those have all stopped, but suppose it's possible.

Before changing the gasket two years ago I would have oil consumption that stopped after the gasket swap. Could it be that the car ran like this for two years without issue? Maybe I'll start by flushing the coolant before I go swapping the gaskets again...

[fastgoat]

Originally Posted by Chilled

You milkshake brings all the mechanics to your car, oh no they are looking at your car. They could fix it, but they will have to charge.




My main concern would be if it was running with the milkshake, is what condition are all the wear surfaces (bearings, cams, etc). These generally don't like milkshakes.

I personally would be looking a popping that valve cover again see what the condition the cams are in, plus can vacuum out all the milkshake thats upto.

When I did the valve cover gasket a few months ago, everything was flawless. But, here we are....the car that gives me an issue on the coldest day of every year

[tlow98]

Originally Posted by fastgoat

I suppose it's possible that it's been leaking into the coolant since I've never checked it after these jobs. I would just change the gaskets and do an oil change. The leaks were external and those have all stopped, but suppose it's possible.

Before changing the gasket two years ago I would have oil consumption that stopped after the gasket swap. Could it be that the car ran like this for two years without issue? Maybe I'll start by flushing the coolant before I go swapping the gaskets again...

It seems hard to believe the car would run like that for two years and just now show signs… the only sign being low coolant. It didn’t take THAT long for two cups of coolant to boil off AND no bearings went.

I’d say do a double flush of north the oil and the coolant, swap the gaskets and move on. If the bearings are screwed, then it’s too late. I’m guessing they’re fine.

And we all know what a PIA it is to pull the valve cover on these. It’s water under the bridge at this point. If you can’t save it with fresh fluid and fresh gaskets it can’t be saved.

But I’d put my money on it’s fine, or at least not mortally wounded.

I’d disable stop/start tho. Totally unnecessary wear on the bearings for saving next to no gas…

[fastgoat]

Well, I swapped the gaskets and the oil cooler won't seem to seal properly. I torqued it down to the proper specs. It's leaking externally so not sure if it's a bad gasket or the cooler needs to be replaced at this point.

[tlow98]

Originally Posted by fastgoat

Well, I swapped the gaskets and the oil cooler won't seem to seal properly. I torqued it down to the proper specs. It's leaking externally so not sure if it's a bad gasket or the cooler needs to be replaced at this point.

Did you roll the gasket?

I’d say check the flatness of each surface and see which is the issue. I’m assuming it’s the cooler as it thin aluminum as opposed to the thick aluminum of the OFH.

[fastgoat]

Originally Posted by tlow98

Did you roll the gasket?

I’d say check the flatness of each surface and see which is the issue. I’m assuming it’s the cooler as it thin aluminum as opposed to the thick aluminum of the OFH.

I didn't roll the gasket, had no issues. It's likely the cooler as there was some pitting in the aluminum surface.

[tlow98]

Originally Posted by fastgoat

I didn't roll the gasket, had no issues. It's likely the cooler as there was some pitting in the aluminum surface.

Sounds like it. Just buy a new one. I think they’re only like $80

[suitedcboy]

The best oil cleaner for cooling systems is automatic dishwasher soap. Cascade or your brand of choice in the box, not the packets (you can cut open and dump the packets but you do not need the liquid rinse agent part in the packets). That stuff is made to attack grease and not foam up and run out of dishwasher and to rinse easily. Nothing else I ever used in my years in a workshop did it as well except for a purpose made product in a big container that was no better than dishwasher soap. I always used 2 heaping tablespoons per gallon of coolant capacity. Drain the nasty stuff out and rinse. Add the dishwasher soap and water and run it 30 minutes then drain and flush/rinse. Repeat the soap+water again for 30 min and than another rinse/flush. If no rainbow film is on the surface of water in coolant tank then flush a bit more and then put in the coolant needed and top off with water and you're done. If your water is naty tasting or known to have high chemical content then you should use distilled for a final rinse and to add to the coolant to bring up to level.

[tlow98]

Originally Posted by suitedcboy

The best oil cleaner for cooling systems is automatic dishwasher soap. Cascade or your brand of choice in the box, not the packets (you can cut open and dump the packets but you do not need the liquid rinse agent part in the packets). That stuff is made to attack grease and not foam up and run out of dishwasher and to rinse easily. Nothing else I ever used in my years in a workshop did it as well except for a purpose made product in a big container that was no better than dishwasher soap. I always used 2 heaping tablespoons per gallon of coolant capacity. Drain the nasty stuff out and rinse. Add the dishwasher soap and water and run it 30 minutes then drain and flush/rinse. Repeat the soap+water again for 30 min and than another rinse/flush. If no rainbow film is on the surface of water in coolant tank then flush a bit more and then put in the coolant needed and top off with water and your done. If your water is naty tasting or known to have high chemical content then you should use distilled for a final rinse and to add to the coolant to bring up to level.

Good tip. Thanks.

[fastgoat]

I got it all fixed up, but honestly just over the car and repeat maintenance. So I purchased a Volvo XC-90 Recharge to replace it. Picked up a 10 year warranty with it so I don’t have to deal with repairs for quite some time.

[stocktree]

Originally Posted by fastgoat

I got it all fixed up, but honestly just over the car and repeat maintenance. So I purchased a Volvo XC-90 Recharge to replace it. Picked up a 10 year warranty with it so I don’t have to deal with repairs for quite some time.

Never heard of such a long warranty. How much that cost? 😳

[tlow98]

Originally Posted by fastgoat

I got it all fixed up, but honestly just over the car and repeat maintenance. So I purchased a Volvo XC-90 Recharge to replace it. Picked up a 10 year warranty with it so I don’t have to deal with repairs for quite some time.

Smart, I have a friend that just bought one of those. They love it.

[fastgoat]

Originally Posted by stocktree

Never heard of such a long warranty. How much that cost? 😳

We picked up a CPO 2021 T8 Inscription Recharge. On the CPOs you can extend to 10 years from the in service date as an option. For just the bumper to bumper (no wheel, tire, etc.) we negotiated down to $3k. Given all of the tech and hybrid system in this car and how long my wife keeps her cars, it was worth the peace of mind.

The year and miles factored into the cost, plus the standard CPO warranty is 5 years unlimited miles from in service, so you’re really paying for an additional 5 years….versus the marketing noise of “10 years”. In this instance, we’re covered through Jan 1, 2031.

[tlow98]

Those hybrid systems are a nightmare unless it’s Toyota or Honda.

I always tell people to get a warranty as long as possible.

Bravo.

[Nate11]

Can I ask what OFHG is?

[stocktree]

Originally Posted by Nate11

Can I ask what OFHG is?

Oil filter housing gasket. Very common to leak.