Coolant Leak

[mrrsharma@yahoo.com]

Hello,

I have a '14 35D (N57)

On Friday I had the dreaded add coolant, and the. Today I had the same warning. (Took .5 gallons or so each time to top off)

While I was pulling in I saw a puddle that was coolant, front passenger side, almost where the radiator is.

I thought at first it was the EGR cooler, but looks to be an external leak. I poked around and could not see any leaks with a flashlight, (it's started to rain so I didn't poke around the bottom to search for a leak.

What are the usual suspects? Hoses and possibly the water pump? I haven't heard to many issues with the belt driven water pump on the N57.

[CatalinP]

I had a small leak and a funny noise coming from the water pump, but no major leak - not visibile, it needed refill from min to max on the expansion tank about once in 3 months.
After replacing the water pump cover, the noise disappeared and the leak stopped.

[mrrsharma@yahoo.com]

Did you replace the thermostat housing? That bolts on to the water pump. I'll see if I can see what's going on this weekend with the pump. It definitely leaks a lot more while running vs sitting over night.

[CatalinP]

I have replaced all the seals, thermostat, water pump cover. Not the thermostat housing.

[yupetc]

Use a coolant dye and wear a pair of UV glasses to look for where the leak is happening. No point just keep throwing money buying parts and roll the dice. The dye method will help you detect the leak for sure, then you'll be putting money where it belongs. Good luck.

[mrrsharma@yahoo.com]

I'll get the dye today, thanks.

[mrrsharma@yahoo.com]

What do you consider the water pump cover? There is a water pump and and thermostat cover housing that sits on the pump.

[CatalinP]

The water pump cover plate has the pulley, axle and impeller assembled and can be ordered only as 1 piece. It also comes with a rubber gasket if I recall correctly.

[mrrsharma@yahoo.com]

Leaking coolant pipe that's on the head, just below the intake. Not sure if it is a cracked pipe or leaking gasket. Will check out and report back…

[Kakalika]

I'm having the exact problem with coolant leaking. It's hard for me to see the water pump housing because mines a diesel, and I have the EGR cooler directly above the pump.

I cannot see any coolant at the frontal areas of the engine. It seems to be leaking around the oil pan area. The sound insulation material on the oil pan gets soaked with coolant.

I have ordered a water pump with a metal impeller just in case. They are not easy to find in stock at several parts outlets.

Going to remove the fan and see if I can get a better view of where the coolant is leaking from.

Does the pump housing have an emergency weep hole?

[mrrsharma@yahoo.com]

Originally Posted by Kakalika

I'm having the exact problem with coolant leaking. It's hard for me to see the water pump housing because mines a diesel, and I have the EGR cooler directly above the pump.

I cannot see any coolant at the frontal areas of the engine. It seems to be leaking around the oil pan area. The sound insulation material on the oil pan gets soaked with coolant.

I have ordered a water pump with a metal impeller just in case. They are not easy to find in stock at several parts outlets.

Going to remove the fan and see if I can get a better view of where the coolant is leaking from.

Does the pump housing have an emergency weep hole?

This is exactly what I have (diesel too). Yours is probably the coolant pipe on the drivers side just below the intake.

The best way to test it is first do a pressure test (harbor freight) has a tool that works.

If you still can not find the leak use the uv dye with the glasses and light.

The coolant tank is also something to look at.

[Kakalika]

Originally Posted by mrrsharma@yahoo.com

This is exactly what I have (diesel too). Yours is probably the coolant pipe on the drivers side just below the intake.

The best way to test it is first do a pressure test (harbor freight) has a tool that works.

If you still can not find the leak use the uv dye with the glasses and light.

The coolant tank is also something to look at.

I will pass by Harbor Freight and see if I can fine that pressure testing tool.

I did have a close look this morning, the exterior surface around the water pump is bone dry. The coolant seems to be coming from the right side of the engine, right above the turbo. There is a second EGR cooler there which connects directly to the exhaust manifold.

If it really is coming from this "Exhaust Cooler" then it's replacement will be under BMW's recall. I just have to make sure the leak is coming from there.

I hope I'm not hijacking this thread.

Sorry

[gtp900]

Originally Posted by mrrsharma@yahoo.com

Leaking coolant pipe that's on the head, just below the intake. Not sure if it is a cracked pipe or leaking gasket. Will check out and report back…

Did you figure this out? What part was needed? How did you get to it? I think I have the same issue, it's poring out very fast but I can't see where it's coming from.

[mrrsharma@yahoo.com]

Originally Posted by gtp900

Did you figure this out? What part was needed? How did you get to it? I think I have the same issue, it's poring out very fast but I can't see where it's coming from.

Yes, it was leaking from the 'coolant pipe' it's located right below the intake, by the oil filter housing. I had a hairline crack. It's a pain to replace it, the intake needs to be removed to access one of the 4 bolts holding it.

Check the coolant reservoir tank, it's know to crack too. (Much easier to replace)

The best way to find the leak is to get a pressure leak check kit( Amazon and harbor freight have them) and you should see where the leak is coming from.

[m4forum]

Hello I Have been searching for some information related to slow coolant leakage but could find anything specific so decided to write this post. This is 2014 X5 35d.

Situation : Few months ago I got an engine light due code 0C2200 "coolant temperature sensor upstream of low temperature EGR cooler". After visual inspection on coolant level realized it was low ... top if off 3/4 qtr deleted code and moved on. Back in dec/2022 the EGR was replaced under BMW recall and so far no issues.
I continue to monitor coolant level and realized was slowly going down ... no external leakages. In 1000 miles have added 1 qtr. of coolant. At this time decided to investigate it further because this is not normal.

An overview of the vehicle coolant diagram shows the following needs for coolant:
1- engine of course (coolant goes to engine block, radiator, oil cooler / transmission cooler)
2 - HVAC system (cabin heating)
3 - EGR cooling (located in front of the engine)
4 - Auxiliary exhaust cooling (exhaust manifold)
5 - DEF injector (believe or not it has cooling line)

I started going one by one to identify what could the issue.
1 - oil has 5000 miles. Replaced it and order oil analysis
2- HVAC works great no issues / no internal cabin leaks or smell
3 - code 0C2200 most likely need replacement of the changerover valve but it wont cause coolant consumption. more details later
4 - more details later
5 - was ok but decided to replace it. $180

More on items 3 / 4 below
So the big question I had was "Maybe my EGR is bad again". How can I check it out? I followed the procedure online and could not find a definitive answer.

What about the auxiliary exhaust cooler?
There is a temp sensor which I able to disconnect and visually inspect soot looking for signs of gummy soot type. Just found dry soot. But still not 100% satisfied.

So I decided to change oil and run an oil analysis. At this time I also decided to disconnect electrically the EGR valve so it would be closed no exhaust would go through it. The theory is that if there is a leakage on EGR or auxiliary exhaust cooler I would see change on coolant consumption. So I disconnected the EGR and confirmed it was fully closed by monitoring EGR exhaust temp (use Bimmerlink app). Temp dropped from ~300F to 80-90F.
Drove like that for 500 miles (engine runs fine, engine light is off of course, lacking some power as measured intake air is off). Good news ....coolant level stop going down it has stabilized. What a relieve. To fully finalize the evaluation I reconnected the EGR valve and expected the issue to come back.

Now it gets really interesting. The oil analysis came back .... found high levels of potassium and sodium what means coolant on oil. At the same time the coolant level stop dropping after the EGR was reconnected. Drove for 500 miles coolant level is stable.

For more than I can think cannot see any correlation between oil / coolant mix with EGR. Unless I am missing something. I dont see how EGR valve could fix the issue.

Next steps are to continue monitor coolant level. During spring I plan to remove oil cooler / transmission cooler ... maybe there is a crack there which could explain the coolant consumption as I want to believe head gasket is ok as car runs great, good mileage and power.

Any comments or suggestions are appreciated.