White smoke, burning water but no sign of leak

[weidgenannt]

Hi Guys!

I know, there are tons of info and threads with similar situations but please, believe me, I read almost everything and watched a lot of videos. I didn't find a logical answer to my problem.
I bought a 2004 325ci with overheated engine on purpose to learn how the engine works and how to fix it.
I did a lot of work by myself and I took the cylinder head to a specialized shop and they cleaned, re-surfaced, tested and installed new valve seals.
In my tests the block was fine, so I cleaned and put all together with new cooling parts (sensors, thermostat, water pump, hoses, etc) and also a new CCV system.
The engine started right away and had no error codes, fantastic!
But, a few seconds and I got lots of white smoke from the tailpipe.
Back to the internet to learn more stuff. I did all the tests like compression test and leak down tests and got different results like 10 to 30% leak in different cylinders and no more than 155psi average as compression.
I was disappointed.. after trying to understand the cause I find out that the engine was burning coolant, a lot, something like 500ml in 20 minutes.
I decided to check the head bolts and re-torque them... so I put to much force and stripped two of them. Too bad, I know, I also assumed that the block was warped as the cylinder head. I was probaly too exited and didn't check the block surface properly.
Not a big deal, I was learning and paying the price for it.

So, I decided to buy a new engine (used one). I was still learning but I wanted to drive the car at that point.
I swapped the engine by myself replacing only the CCV system and new parts of the cooling system I had to the original engine.
Again the engine started right away a and again.. I got white smoke from the tailpipe!
I only described the first part (with the original engine) because I thought I was doing something wrong with both engines.. same symptom?? Burning coolant again?? just bad luck and coincidence or am I doing somenthing wrong??

I reviewed everything, no leaks outside of the engine and looks pretty clear to me that I have an internal leak, the coolant is going to the combustion chamber somewhere as the coolant level is decreasing.
This time I can run the engine for about 1 hour and 30 minutes without overheat, with engine temperature around 90-92ºC but has some white smoke and the coolant level drops.

So, more tests and this time I got compression from 180 to 192psi and with the leak down test I got between 2 and 4% leak (I heard air coming out the oil cap and the oil stick). Both tests with the engine warm (80-90ºC).
I'm assuming those are really good numbers, right?
During the leak down test I didn't notice any bubbles in the coolant reservoir, no any weird noises, just a little of air coming out of the oil cap and the oil stick (wich I read is normal, specialy under 5% of leak).

I really don't know what to do next, replacing the head gasket?
The leak down test doesn't show any clear fail with the gasket but what does justify the coolant level drop?

I really don't see anywhere else I can find a coolant leak that also produce white smoke and water drops coming out of the tailpipe.

Thank you guys,
Theo.

[MarcoZandrini]

The engine is burning water. White smoke is the indication.

[jclausen]

How much white smoke for how long and how long has the new engine been in

[nonturbodan]

Hopefully you are still burning off the moisture in the exhaust system. If it's not overheating or blowing coolant out I would take it out and drive it.

I have gotten bad engines from recyclers before.

[weidgenannt]

Hi,

Thanks for all your comments!


Yes, the engine is burning water, it is pretty obvious as I have white smoke and the coolant level drops.
It is a relatively good amount of smoke and keeps making smoke as long as I let the engine running or, as long as still coolant in the system I guess.
I'll upload a video later, I see some water drops with the smoke as well.
I had the engine running for more than one hour without any problems (90-94º max engine temperature), only white smoke and the coolant level drops.


I also replaced all the CCV systems with new parts but, I have a question about it!
As I had exactly the same symptoms with the original engine it is possible that I have done something wrong with the CCV system, but, is it possible to burn or lose coolant through the CCV system?
As I understand the CCV can cause smoke but what does the CCV have to do with the coolant loss?

Thanks,
Theo W.

[weidgenannt]

Hi again,

Here is a video I made yesterday:
https://youtu.be/F6aXO_HKX68

And here is the results of the compression and leak down tests:
IMG_5784.jpg


Theo W.

[nonturbodan]

Well, if you are losing coolant with no external leakage that is a bad sign. Could be a heater core leak but that wouldn't explain steam out of the exhaust.

Compression and leak down can not rule out a head gasket leak. They will show a severely compromised head gasket but not a small leak.

The crankcase ventilation system only handles engine oil. No chance it is allowing coolant to be consumed.

[weidgenannt]

Hi Nonturbodan,

Thanks for the comment.
Yes, I agree that the crankcase ventilation doesn't handle any coolant, so it's probably fine.
If the leak down and compression test doesn't confirm 100% that the head gasket is fine would you say that the next step is replacing the gasket? there are any other tests I can make?

Theo W.

[nonturbodan]

You can test the cooling system for combustion gases. You can buy a kit that you plug into the reservoir and run the engine. If hydrocarbons are present in the cooling system the fluid changes color. This test is definitive.

Repairing these things is a questionable proposition as you know. The cylinder sleeves pop up out of the block, the head bolt threads strip. For the work involved and the expense of all the machine work it usually makes more sense to replace the whole motor. In the event that you get a bad motor, which it sounds like you did, you could contact the folks you got it from to see if they can help you out. In my case, the people I got my motor from told me to pound sand so I tried some sodium silicate to seal the leak. It has worked so far so we'll see how long it lasts.

That stuff can be your worst nightmare if used improperly. Done right it works, for how long though who knows.

[nonturbodan]

This is the tester:

https://www.napaonline.com/en/p/BK_7001006

[weidgenannt]

Thanks, I'll try that one and let you know about the results.

[jclausen]

Ya try the coolant test

[weidgenannt]

Hi!


I did the test today, four times.
I got blue fluid all the times which means no exhaust gases in the coolant and probably no head gasket fail, right?
I did the test four times because I was suspecting that I got a little of coolant in the tester, so I washed everthing, removed more coolant and tried a few more times. To make sure the tester and the fluid where working I tested with the tailpipe gases and it worked.
I spent a lot time and I'm pretty sure there was nos gases in the coolant. When I pressed the air bulb with the tester sealing the coolant reservoir, its doesn't inflate back so it's a sign that there was no gas into the coolant system, I had to lift up a little to suck some air.


Reviewing:
- Compression test (engine hot): 180-192psi
- Leak down test (engine hot): 1,5% to 4,0% of leak through the oil cap or oilstick
- Block gas tester (engine hot): no sign of exhaust gases
- No sign of coolant leak anywhere
- Engine doesn't overheat, 88-95ºC max during 1h engine idle
- Thermostat, water pump, temperature sensors, coolant reservoir: everything new.


Simptoms:
- White smoke and water drops from the tailpipe
- Coolant level drops 200 to 300ml after 1h engine idle


I really don't know what to do next, I was ready to open the cylinder head but with all those results the gasket looks fine to me.


Any ideas?
Maybe I have somenthing wrong with the CCV system that causes the smoke, but what about the coolant/water?


Thanks!
IMG_5902.jpgIMG_5904.jpg



Theo W.

[weidgenannt]

Hi!

I finally got a coolant pressure tester and tried it for the first time.
The coolant system is holding 15psi for about 2 hours now with no sign of a leak.
I probably should try with engine hot as well and will do later today but I'm pretty confident that there is no leaking which is good news (or not) but I'm out of ideas now.. what to do next with all the results I have so far?

Screen Shot 2020-05-14 at 3.56.46 PM.jpg

[MarcoZandrini]

The picture of the results of the compression test isn’t very clear. It looks like cylinder 4 is a lot lower than the other cylinders. Please confirm the reading for the cylinder.

[weidgenannt]

Hi MarcoZandrini,

I've made the tests twice but I can run all the tests again.

Compression Test Cold Engine:
1 - 197
2 - 190
3 - 205
4 - 190
5 - 198
6 - 198

Compression Test Hot Engine:
1 - 180
2 - 187
3 - 190
4 - 185
5 - 183
6 - 192

Leak Down Test Cold Engine:
1 - 2,0%
2 - 3,0%
3 - 3,0%
4 - 3,0%
5 - 2,0%
6 - 3,0%

Leak Down Test Hot Engine:
1 - 4,0%
2 - 2,0%
3 - 2,0%
4 - 4,0%
5 - 1,5%
6 - 3,0%

During the leak down test I saw/heard some air coming out of the oil cap and oil stick, I also noticed some air between cylinders 1 and 3 while injecting air through them.
I always make sure I had 100psi during the leak down tests and the valves closed.

Thanks for the help!
Theo.

[MIKYZZ4]

Your video doesn't confirm coolant leak, as that looks like plain condensation.
In all of your descriptions, the specific, distinct odor of coolant has not been mentioned,
Can you describe it?

[MarcoZandrini]

Those compression numbers are great!

[weidgenannt]

Hi!

@MIKYZZ4: Yes, I do smell a distinct odour but I have no experience with that. I would say it's coolant and I'm quite sure it is not oil, so, what else can it be, fuel?
I'm including another video showing water and smoke coming out of the exhaust pipe.


@MarcoZandrini: Yes! That's the reason I'm trying so hard to fix it


I've made another coolant pressure test with the engine hot and didn't notice any leak. The pressure dropped from 18psi to 14psi in about 5 minutes and stoped there. I'm assuming the system was cooling down and losing some pressure. I also removed all the sparks plugs but didn't notice anything inside the cylinders or loss of pressure.


I just have one question: there is no way for a head gasket to fail without an overheat situation? I mean, having a head gasket fail is always proof that something worse happened or is kind normal just to replace the gasket from time to time?
Another video:


Thanks!

[MarcoZandrini]

Well, a head gasket can have a production flaw that wasn’t caught by the manufacturer’s QA folks. Also, the gasket could have been nicked or dinged during assembly. But knowing how highly automated BMW factories are, I doubt it could be an assembly issue. Plus, the car has gone a bunch of miles without issue. You might see if you can add a dye to the coolant. I know shops put a UV dye in cars’ ac system to find leaks. Perhaps there’s a dye for the coolant.

[MIKYZZ4]

Are you checking the coolant level every morning, before engine startup, to take note of coolant level?
This will determine the amount of daily coolant loss, that you can report back to us.

[nonturbodan]

I just have one question: there is no way for a head gasket to fail without an overheat situation? I mean, having a head gasket fail is always proof that something worse happened or is kind normal just to replace the gasket from time to time?

The head gasket itself isn't the failure despite this problem typically being described as a blown head gasket. The head warps due to overheating which relieves clamping force on portions of the head gasket. If the gasket is not properly compressed between the head and block it cannot seal. These motors use a multi layered steel gasket which does not corrode or deteriorate in any way. Provided that the head and block are flat and the head bolts are intact and properly torqued, it will never require replacement.

Overheating is the cause of the failure, the cause of the overheating could be many things. Thermostat or water pump failure, resulting in loss of coolant circulation can do it. Expansion tanks or radiators can crack causing rapid coolant loss, that can do it. Failure of the cooling fan or fan clutch can do it. In some cases such as coolant loss the engine can overheat before the gauge indicates a problem. Since the thermostat is electronically controlled on the M52TU and M54 the gauge does not correspond to actual engine temperature. It tolerates a range of temperatures before the needle moves off of the middle of the gauge. This masks the raising and lowering of the coolant temp under normal operation and also masks the early stages of overheating.

The odor of burning coolant is very much like buttery, syrup coated pancakes. Distinctively sweet. It can be hard to tell the difference between that and the typical smell of catalytic converters warming up on a cold start but once you know it you know it.

[weidgenannt]

Hi,


I'm sorry, I had a busy weekend and I didn't have the chance to check the messages.
Thank you all for the comments.

@MarcoZandrini: I never heard about dye in the coolant but I'll do some research, thanks.


@MIKYZZ4: I don't drive the car every day as it still a project car. Every time I leave the engine running for about 40-60 minutes in idle I see about 300ml of coolant loss, I normally check with the engine cold.


@nonturbodan: Thank you for the detailed explanation and I have another question: an overheating episode will always warp the head or it is possible to have just a blown head gasket and in this case a gasket replacement will fix it?


I was thinking about it and remembered that before installing the new engine in the car I replaced some parts with new ones and also some parts from the original engine.
New parts:
- Valve cover gasket
- Intake manifold gasket
- Exhaust manifold gasket
- Oil filter housing gasket (and filter, of course)
- Thermostat
- Water pump
- Coolant sensors


Some parts I used from the original engine:
- Intake manifold
- Fuel injectors
- Ignition coils
- Spark plugs (were new but used int the original engine after I replaced the head gasket)
- CCV system, complete with all the pipes (were new but used int the original engine after I replaced the head gasket)


I'm saying that because I should be tested the new engine before replacing any parts, I know.
I decided to put the intake manifold, injectors and also the CCV system that came with the new engine back to see if makes any difference, I just removed the intake manifold and notice some milky oil in the CCV pipes, pictures below:


The first picture is the vent pipe connection on the valve cover to the CVV and the second is the vent hose from the CCV to the dipstick tube.
I don't see any signal of milky oil in the oil cap but it is clearly oil with water, right? any chance to know where the water mixes with the oil?


IMG_6401.jpg IMG_6402.jpg IMG_6404.jpg IMG_6411.jpg

Thank you!
Theo.

[LeverThis]

Have you checked oil level? In case some of the missing coolant is ending up in the crankcase.