Mbsti

My 2009 e63 has 72000 miles. car is completely stock. In the past month the low coolant warning was displayed twice. Each time I had to add almost 1 liter diluted zerex. No smoke, no leaks, engine is running well. over the 3 years of ownership I intermittently added coolant in small amounts to top it off but not the volume I needed in the past month. I hope this is not the head bolt problem. I have not checked for codes. I called a service advicer, she told me to top off the coolant or they could do it for me. she said this is because the motor is high compression. is it safe to keep driving if driven carefully?
I'm not sure what to do next.

Thanks

WideLowandFast

You need to have it looked at ASAP. Engines do not 'normally' consume coolant. I'd perform a coolant system pressure test, at the least. Hope it's not a head bolt issue.

RZT5

"She said this is because the motor is high compression." How do these people get hired and how do they keep their jobs?

Unfortunately, unless you notice coolant leaking onto the ground it's probably head bolts. Search for leaks and hope you find something. A coolant system pressure test like WideLowandFast recommended would be helpful too.

If it were my car I'd only drive it to the place where it was going to get fixed and no more. But it's probably not going to catastrophically explode if you keep driving it.

Mbsti

I forgot to mention if this helps, there seems to be air pressure in the coolant reservoir when I open the cap even after a few hours after the motor has cooled down some.
I am just trying to get as much information before I bring it to the mechanic. can independent shops fix it is indeed head bolts?

Thanks for the advice

RVAE34

Pressure in the reservoir is another sign of a failed HG (which is likely the head bolts). I say have it towed to the mechanic you prefer to use. You might be able to save the bottom end.

Dublinoh

Op....this would really get my attention, hope for the best but these symptoms are common to the engines that subsequently hydro lock. Catastrophic damage, need new engine is what you are risking by driving the car. Don't drive it, you can only dodge so many bullets.

Hotsauce55

You are so lucky, quit while ahead. Take car in & have head bolt job done.
Cars don't lose coolant. Its a closed system. Find a good indy, they can do it.

Maybe there is a shop within a reasonable tow truck ride? Where are you located?

Rocman8

check your oil level as well to confirm. as the coolant level goes down the engine oil level goes up in this head bolt situation.

Ls1toAMG

Yes do your self a favor and drain your oil asap. Look at it closely. If it has a milky look it's going into the oil. Also your oil cap filler may have a foamy milk like sludge on the bottom. Tell tail sign of head bolt/gasket/ cracked head.

Mbsti

I'm located in Memhis TN
the oil is not milky, the oil level did not increase, no coolant in the garage floor, no coolant burning smell. The air pressuure sound is a very faint swoosh.
There are 2 dealers here, If the price is reasonable I'll go to them but but
I'll check an independent shop that fix mercedes and porches.
I will not drive the car until this is resolved.

thanks again for your replies.

Elhonaz

sorry to hear, sure sounds like a headbolt/gasket issue :/

2000UZJ

Coolant level sensor perhaps?

Hotsauce55

He said he filled coolant twice and it took 1 whole liter.

Mbsti

I Talked to a mechanic of an independent shop, I did not take my car. He said he can do a pressure test but since I thought it may be a head bolt issue he immediately said take it to the dealer. I have not driven it since last week. My beeper and emergencies pretty much controls my schedule.i will very likely flatbed it and bring it to where they will fix it as another member suggested.
Again I dropped some oil on a clear plastic and looked against the light.It was clear and smells like normal motor which I changed 2000 miles ago. Not milky, the oil level did not increase.
It may be 2 weeks before I can take my car to the dealer.

WideLowandFast

It sounds like you caught it in time and saved yourself THOUSANDS! It's still a pricey job to replace the head gaskets but a lot less than replacing a grenaded engine.

Hotsauce55

If the car is sitting anyways why not try a compression test? Maybe check for bubbles in coolant?

trackjunky

iTrader: (1)

if you don't have the time to take it to a dealer/shop right now and you are able to do an oil change yourself at where the car sits right now, why not do an oil analysis? Send it to Blackstone labs and they will tell you whether or not there's any trace of coolant (parts per million measurement) in your oil sample. Smelling the oil or holding it to the light is still just a guess game. At least with this you can find out for sure whether coolant has been entering the engine without taking your car anywhere. This will cost you an oil change + $25 for the analysis.

JayE63

****, I've been having the same problem with mine, glad I finally looked at the forum! Better take it in. How much does the head bolt/gasket fix run?

layzie12g

If you car is not leaking coolant, you need to take it to the dealer ASAP. Pay the cost to have the head bolts done. Also keep in the back of your mind the cams, lifters, and adjusters... Its an expensive road to go down.

Dublinoh

Mbsti have you had this diagnosed/repaired yet?

hachiroku

sadly most shops will not touch the M156 engine as they are not qualified to do the work or have the cam locking fixture required to do a head gasket job.

if you're in ontario, ca i'd recommend either going to your local MBZ dealer or Weistec in Anaheim. there is also Benzworks in Huntington Beach who I'd assume should be able to do the job as well. All of the GOOD Mercedes tuner shops in California are located in Orange County. Unless the shop specifically does engine work, most private Mercedes service specific shops don't touch the internals of the M156.

a couple of grand now can save you from double that in the future. i know after i've done a few more things to my car i'm gonna have one of the shops mentioned replace my head gaskets and head bolts in the near future for preventive maintenance.

Mbsti

The service advicer called within one hour the svc dept opened.He said head bolts need replacement. This will take 4 to 5 days. They will also replace the plugs and I added to replace the crankshaft position sensor also. Apparently no other damage although they did not mention the cam shafts and lifters. I did not ask if they removed the cylinder head cover.
I have been having cel 0171 before this which is lean condition left bank, this went away intermittently without clearing the code myself. Is this related to head bolt issue too?
It's a relief that no other damage was seen ,they have not called me yet today if they found other things. If they see camshaft and lifter damage this should add another couple thousands. I have read in other forums that their repair was $10,000.
I do not have an extended warranty, I was quoted $5000.00 then and today the quote was a couple hundred more than the extended warranty 4 years ago

Thanks to everybody's recommendations
I will update you on the progress and I hope this also helps those who have the same issues or concerns.

Dryfly

Left bank lean condition is probably an intake manifold gasket leak. This should be remedied incidentally in the process of performing the work currently commissioned. If they aren't planning to do it already, have them replace the PCV tube/valve. They are known to fail causing lean conditions, relatively cheap, and they'll have it torn down to the point that it can be easily swapped out.

Mbsti

I did not ask what they did to diagnose head bolt failure. I was actually surprised that they called me in one hour after the service department opened on Monday. The SA said part of the repair is replace the spark plugs also. I wonder if they did a compression test to diagnose the problem quickly. Therefore I wonder if other 156 owners should get the compression test to get an early diagnosis and not wait for coolant loss like I experienced. If the engine is not stressed will the loss of compression not show up?

rapidoxidation

Compression test? Or cooling system pressure test? I'd think the pressure test would indicate HG problems.