Cyclone Valve and Head Gasket Repair - Yikes It's A BMW!


Here’s My Problem In Detail:

Last Week:

Got a “Check Engine: Increased Emissions” fault. Dealership replaced the CCV (Cyclone Valve) and 4 associated hoses, including the vent pipe, connecting line, vent hose, and return pipe. Oil change was completed two days before. I should note that there were no external leaks, misfires, or overheating. The car would “shake” a little when at a red light. But otherwise ran fine.

After The Cyclone Valve & Hoses Was Replaced:

Car runs fine, no shaking at red lights. No auburn lights on the dash.

5 Days After The Repair:

Got a “Coolant Level Low” fault. Topped it off with BMW coolant only to reveal brown liquid as the sensor stick rose. Took it immediately back to dealership.

The dealership has completed the following:

Pulled the car records, and the car never heated above 178 degrees.

Leak Down Test (Hot)

#1 Cylinder - 30

#2-6 Cylinder - 15

Leak Down Test (Cool)

#1-6 Cylinder - 15

Service Manager advised that it is possible that oil is passing through a crack in cylinder #1, allowing oil to shoot in the coolent passage. Also, the coolent/oil was not emusulfied and there is no water in the oil.

Service Manager Recommendation:

Pull head and see if there is a crack. Service Manager said he has never seen a case like this before in his 20+ years of being in the business, whereby the engine does not overheat, no smoke, runs fine, but leads to a cracked head. He advised that it could be a manufacturers defect. I’ve done alot of research online so far, and I’m wondering is it possible that the newly installed CCV/PCV/Oil Separator failed causing oil to shoot into the cylinders, leading to a possible cracked head or blown head gasket?

My car has 85K miles, purchased CPO with a little over 8K in 2005.

Does this “brown liquid” appear anywhere else (like in valve train area?) Please list more specific symptons you are seeing.

Thank you for your quick reply. That a great question, but I’m not certain. The car is sitting at the dealership now, and the head will be pulled and inspected on Monday/Tuesday. Is this something that I should inquire about, as well? If there is brown liquid in the valve train or other areas what does that indicate?

If the oil/coolant mix is present in areas such as the valve train it confirms that some type of defect exists (in a major form). If the only place you see this mix is on the sensor stick the mix may be misidentified.

I would suggest a plan to pull only the valve cover and judge the level of contamination from how the mechanical valve train pieces look in regards to being covered with a oil/coolant mix.

You could end up with the head off and still without a reason for the sensor being coated with a ‘brown mix’. Then the Dealer is going to insist on replacing the head “just to be sure”. Inspect the valve train area first before deciding to remove the head.

Well, I received a response from the dealership today…and the verdict is a broken head. I have a crack between cyclinders 1 and 2. The problem is that they still have no earthly idea how this could have happened. I should also note that the car was also inspected by the Head of Service by BMW NA today, and still no answer. So for this “manufacturer’s defect” BMW NA will cover the cost of the part, which is $3000. The labor from the dealership will be an additional $3000 - down from the original $3500 quote, which includes labor and gaskets, and tax. I’m VERY grateful that BMW NA will cover the cost of the part. It is a huge savings. Especially since I’m a year out of warranty.

But, I’m still concerned that they were unable to identify how the head became cracked in the first place. With no other plausible explanation, I’m inclined to believe that the service that they performed, less than one week prior, is directly related to this issue. It has to be related to either the oil change or the cyclone valve replacement - something obviously went wrong! Engines just don’t break!

So, now knowing that it is a cracked head, I need your expert advice on the following:

  1. What other parts should I ask them to inspect to ensure that they too have not been damaged?

For questions 2-4, keep in mind that the head was not cracked before they did the following service:

  1. Can a bad oil change cause a head to crack? If so, how?

  2. Can a bad cyclove valve cause a head to crack? If so, how?

  3. Can a vent pipe, connecting line, vent hose, or return pipe cause a head to crack? If so, how?

  4. The Service Manager advised that I will still need to have my radiator flushed 2-3 over the next year, because it takes time for the brown liquid to expel itself. Is there something that can be done now to prevent this? If it means asking for additional parts, well I will certainly do that. So advise away.

  5. Finally, should I re-negotiate the costs of the labor with BMW NA and/or the dealership, as well?

All I can say is I have put these cyclone valves (also know a crankcase vent valve, BMW’s version of a PCV system) on before and there is no reason to suspect that the vent valve job cracked the head,unless… for some reason they drained the coolant (some people pull the intake on V-8’s to do this job) but I have never removed the intake to do this job a a 6cyl.

This reply is out of order cronologicaly.

Contact says there must be a overheat situation involved somewhere,sometime, and no one drains coolant to do this job… I was also told you are overpaying by about 2000.00 if you pay 3000.00 for the labor. The job pays 12hrslabor by the book.

If they drained the coolant and drove before refilling or did not bleed,then you get a crack.

Let me talk to someone first and see if anyone is starting to remove intakes to do this job. I will get back to you promptly so don’t make the drained coolant accusation yet.

What you need to do is see the crack with your own eyes…Until then, you have no way of knowing if there IS a crack…$3000 labor to replace the head?? Not even if they charge $400 an hour is this true. $3000 is the total cost of the repair which you may or may not have needed…The entire drama is based on brown anti-freeze. Half the cars on the road have brown anti-freeze.

Thank you for your reply. I will make that request. Is there a way to verify that a cracked head is the actual head that came out of my vehicle? I’ve read so much lately on all related topics, that I recall seeing that the VIN # is located on some parts. Is this true for heads as well? I just wanna make sure that they don’t show me some drag racers engine head instead - I’m not saying that they would lie, but…

Walk in unannounced and ask to see the head off your car. It should be on a bench near your car. Ask the mechanic assigned to work on your car: “Could you please show me the crack in the head?” If you are satisfied with what you see, fine. If not, take the head with you to an automotive machine shop and get a second opinion about the “crack”. That’s your right. Armed with your new knowledge, you can make an informed decision about spending your 3 grand…

It is unlikely they will have a cracked head identical to yours lying around…Your head is not uniquely marked and can not be positively identified.

You do have a another option. Install a salvage yard head.

There are heads and then there are heads…Most heads come complete with valves installed…But in your case, they may be talking about a bare casting in which they will install all your old parts. That would explain the $3K labor…This job becomes a cash-cow for them…