THE M3 IS GETTING THE ANRI BUILD TREATMENT - Blown headgasket to build thread

[sapote]

The car however is not fixed - I didn't have them do the headgasket as I can't throw $6k at the car right now (that was their quote to me for doing just the top end) - so although it seems like it's driving totally OK, 1. it's still driving on 120psi in both 5 and 6 apparently, and so for the time being I'm parking it and not driving it until I can get it fixed - I don't want to keep driving it and have it get worse if that makes sense
2. Something just doesn't add up to me of why 3,4, and 5 would be misfiring if the break in the HG is indicated between 5 and 6 - if anyone knows the answer of why this is occurring, that would help settle my mind.

1. Yes, try not to run the engine until it's fixed, as the leaking hot combustion gas can eat through the metal more (head and block if leaking between 5 and 6 thin wall).
2. When the 5 and 6 misfired, this could affected the crank rotational speed and many times caused the incorrect misfire detection on the other normal cylinders.
3. All of the plugs look the same and not too bad. I would have a second shop to check.

[cobra]

I would do a leakdown for my own peace of mind.

If it's driving fine then I wouldn't worry and just keep driving it.

[George Hill]

They also drove it about 45 miles in total apparently to check for misfires coming back and in general to feel the car out. 45 miles seems excessive though, don't you think?

45 miles is nothing in my shop, just a fyi. I had a car come in that was misdiagnosed as needing a headgasket (M54) and the client had already approved and engine replacement but I was skeptical of the failure so I probably drove it 40 miles on the diagnosis to find out it had a bad crank case vent valve. After fixing it I put another 45 on it to verify. It then came right back with a bad brake pressure sensor (previously replaced URO brand, not by me) and I put another 40 on it just making sure it was truly good to go. If you trust your shop don't sweat the miles they are sorting your car. If you don't trust them, then maybe they are going to lunch, lol.

Honestly from everything you had stated I would get a second opinion and not tell the 2nd shop anything that the first shop told you. Go in and tell them what you observed like you did the first shop and see what they say. IF the come to the same conclusion you have your answer.

Anri what is your method for test a fan clutch operation?

[ChapterM3]

45 miles is an extended test drive. They were making sure if something went wrong, it'd be with them, not you. That's not an abnormal thing to do, especially with a very specific issue like yours. There's also the cascade effect where just because one problem caused a misfire doesn't mean there cant be more. Misfires will throw off the balance of the engine and cause other cylinders to misfire. You have to think, the misfire detection is based on the sensor data. With a leaking headgasket, there is a leak in two cylinders the entire four stroke cycle. It can't always detect the misfire accurately. The fuel trims are also trying to adjust for the leaks and that can also screw up other cylinders. Your DME didn't know your headgasket was blown, it just knows what the sensors tell it. It sounds like your car is fixed and I wouldn't stress until there's a problem. Breathe easy and enjoy your car.

Thank you for this, I needed to hear that, and it makes sense. The car however is not fixed - I didn't have them do the headgasket as I can't throw $6k at the car right now (that was their quote to me for doing just the top end) - so although it seems like it's driving totally OK, it's still driving on 120psi in both 5 and 6 apparently, and so for the time being I'm parking it and not driving it until I can get it fixed - I don't want to keep driving it and have it get worse if that makes sense

[Arith2]

45 miles is an extended test drive. They were making sure if something went wrong, it'd be with them, not you. That's not an abnormal thing to do, especially with a very specific issue like yours. There's also the cascade effect where just because one problem caused a misfire doesn't mean there cant be more. Misfires will throw off the balance of the engine and cause other cylinders to misfire. You have to think, the misfire detection is based on the sensor data. With a leaking headgasket, there is a leak in two cylinders the entire four stroke cycle. It can't always detect the misfire accurately. The fuel trims are also trying to adjust for the leaks and that can also screw up other cylinders. Your DME didn't know your headgasket was blown, it just knows what the sensors tell it. It sounds like your car is fixed and I wouldn't stress until there's a problem. Breathe easy and enjoy your car.

[ChapterM3]

Short update - I got the car back yesterday evening. Drives fine, except for the misfires at idle on startup. Car idles just at or above 1k for a few minutes after being started, then settles at its normal 750rpm. Drives super smooth and no other indications of a 50 psi difference in those 2 cylinders, but I have to believe what that shop told me. They also drove it about 45 miles in total apparently to check for misfires coming back and in general to feel the car out. 45 miles seems excessive though, don't you think? Overall I'm super down about the whole thing as I really had no idea this was about to come up.

Something just doesn't add up to me of why 3,4, and 5 would be misfiring if the break in the HG is indicated between 5 and 6 - if anyone knows the answer of why this is occurring, that would help settle my mind. That or do another leakdown to see if its actually the right numbers?

Here are some photos of the plugs that they pulled and a short video of it driving - they all have oil on the threads, but all look to be worn the same - I have no idea which ones are 5 and 6 as they're not labeled, but from what I can tell they all have the same wear on them. For now it'll be parked under its cover until I can get this thing worked on.

[ZiMMie]

Hi - what temperature does the e36m3 fan clutch engage at?

90 degrees.

[nyc951]

Hi,

Tricks how to improve the system in every area is something I usually
don't like to share online but in the name to help the community here we go.
The Fan clutch I use is from E36M3 which fits all M50 engine family
and the brand is Sachs part number 11 52 7 505 302. (I have another
more aggressive custom option but will shorten the life span of the water pump
by a bit but that is for heavy duty applications).


The Sachs engages right above the thermostat means the second the
T stat opens at 80C and pushes the water circle inline the fan clutch engages
immediately and keeps the engine from heat soaking and will shut down
aprox ~68C, and the cycle continues.



Regards,
Anri

Hi - what temperature does the e36m3 fan clutch engage at?

[Anri]

Hi,

A well maintained S54 with OE parts will work better than what you are suggestion

I believe you..

Regards,
Anri

[ZiMMie]

Hi,

Tricks how to improve the system in every area is something I usually
don't like to share online but in the name to help the community here we go.
The Fan clutch I use is from E36M3 which fits all M50 engine family
and the brand is Sachs part number 11 52 7 505 302. (I have another
more aggressive custom option but will shorten the life span of the water pump
by a bit but that is for heavy duty applications).


The Sachs engages right above the thermostat means the second the
T stat opens at 80C and pushes the water circle inline the fan clutch engages
immediately and keeps the engine from heat soaking and will shut down
aprox ~68C, and the cycle continues.

Behr fan clutch will engage at around ~93-98C and will shut around at ~85-88..
The vario electrical fan engage earlier and this make the system to work
reverse which is terrible idea!

The reason why it works reverse is because Owners don't like the noise
can you believe this? but its the reality...and I will example. On E34M5 the
system works reverse as on the E46M3 The system is designed to work
only on the fan clutch cycles. The E.Fan has 2 speed low and hi. Low speed
engages at 91C and the hi speed engages at 99C.

The E34M5 owners do complain all the time from this very loud and pronounce
noise. Every generation BMW do improve in noise and why BMW decided to
do reverse and if the fan goes bad because works all the time Buy New one.

The E.Fan DB is more quiet than the 420mm fan deep blade. BMW 420mm Fan
was first introduced in E32/E34 chassis and used till the last car rolled out with mechanical
fan from the factory. (V8 engines same design but its 460mm instead of 420mm).

A very important note I want to make here: installing this Sachs will increase the
cycles and the Fan Blade must be replaced with Brand New Factory Part never
ever use Febi or any other brand. I even can smell the plastic and define which
one is which !!!!
You don't want to be one of those owners who are "if aint broken dont fix it" and one
day under hard driving conditions the 20years old Cooked-Plastic one of the
blades will let go and your aluminum hood will see a hole! Replace per my suggestion
and you are good for another 100k.

Yes on the track/street. If you are very aggressive driver on the track race agains
the clock as I do personally then it will be a point were the system will max out due
other factors which is for another chapter/subject.

Regards,
Anri

Its a 2 degree difference between the 2 clutch couplings.

92 vs 90(S54). Thermostat Openings are 88-97 (M5x->M54) vs 80(S54).

Clutch fans do not operate above 4,500rpm. It has no benefit on the race track.
Your are better of opening your engine bay letting the motor cool after you session than running a lower locking clutch fan.

A well maintained S54 with OE parts will work better than what you are suggestion.

[Anri]

What is the part no. for the upgraded fan clutch that you replace it with? And do you use it regardless of application (street/track)?

Hi,

Tricks how to improve the system in every area is something I usually
don't like to share online but in the name to help the community here we go.
The Fan clutch I use is from E36M3 which fits all M50 engine family
and the brand is Sachs part number 11 52 7 505 302. (I have another
more aggressive custom option but will shorten the life span of the water pump
by a bit but that is for heavy duty applications).


The Sachs engages right above the thermostat means the second the
T stat opens at 80C and pushes the water circle inline the fan clutch engages
immediately and keeps the engine from heat soaking and will shut down
aprox ~68C, and the cycle continues.

Behr fan clutch will engage at around ~93-98C and will shut around at ~85-88..
The vario electrical fan engage earlier and this make the system to work
reverse which is terrible idea!

The reason why it works reverse is because Owners don't like the noise
can you believe this? but its the reality...and I will example. On E34M5 the
system works reverse as on the E46M3 The system is designed to work
only on the fan clutch cycles. The E.Fan has 2 speed low and hi. Low speed
engages at 91C and the hi speed engages at 99C.

The E34M5 owners do complain all the time from this very loud and pronounce
noise. Every generation BMW do improve in noise and why BMW decided to
do reverse and if the fan goes bad because works all the time Buy New one.

The E.Fan DB is more quiet than the 420mm fan deep blade. BMW 420mm Fan
was first introduced in E32/E34 chassis and used till the last car rolled out with mechanical
fan from the factory. (V8 engines same design but its 460mm instead of 420mm).

A very important note I want to make here: installing this Sachs will increase the
cycles and the Fan Blade must be replaced with Brand New Factory Part never
ever use Febi or any other brand. I even can smell the plastic and define which
one is which !!!!
You don't want to be one of those owners who are "if aint broken dont fix it" and one
day under hard driving conditions the 20years old Cooked-Plastic one of the
blades will let go and your aluminum hood will see a hole! Replace per my suggestion
and you are good for another 100k.

Yes on the track/street. If you are very aggressive driver on the track race agains
the clock as I do personally then it will be a point were the system will max out due
other factors which is for another chapter/subject.

Regards,
Anri

[sapote]

It's unclear to me if BMW designed the system as e-fan-first, with the clutch as the failsafe, or the other way around. It sounds as if you think the e-fan is the failsafe.

Engine needs both. The clutch fan is to off load the efan which is the primary unit if the twos - without the efan engine will overheat; without the clutch fan, the efan should keep the engine alive in most situation but might need to turn off AC in a very hot day and high load. Also, without the clutch fan the efan works in high duty cycle and dies earlier.

[Pklauser]

Very interesting to hear your take on the Behr clutch Anri. I recently replaced mine with a brand new Behr, and it actually does seem a little lazy to me. My electric fan runs much more now than it did before. It's unclear to me if BMW designed the system as e-fan-first, with the clutch as the failsafe, or the other way around. It sounds as if you think the e-fan is the failsafe.

[ChapterM3]

Anri thank you for the call today! I so appreciate the conversation - I'll be following up with you later today.

One question that popped into my mind - why would I have codes pop up for cylinder 3,4 and 5, when 5 and 6 came back with the issue? Could this be a stuck valve? or perhaps the leak down was performed incorrectly on 5 and 6?

[dukeofchen]

On all of my customers cars I have updated flan clutch which engages
earlier. Behr fan engages way to late and the AC fan is the one to cool
down, you dont want that. You want the Fan clutch to engage and
cool the engine down...AC fan is to help only in emergency with AC
on and you are stuck in traffic...One of my tricks I used at our track
M3 I had 460mm fan blade from S62/M60 adapted...with another
trick fan clutch (not Behr) and the AC fan will barely move here and
there.....

What is the part no. for the upgraded fan clutch that you replace it with? And do you use it regardless of application (street/track)?