Not really sure where to go with this next... (intermittent no start/power loss)

[sapote]

Update...

it’s currently 75° here. Car has been sitting all night. Checked temps before startup and notice the following;

coolant temp engine 25°c
oil temp engine 25°c
coolant temp radiator outlet 23°c
intake air temp ((( 37°)))
ambient temp 23°c

Pull the IAT sensor connector off and check if the brass female pin sockets too loose then tighten them a little bit and connect/disconnect couple times to clean up the conductive surface. Try next day same cool morning and if not change them get a new sensor. This sensor sure will affect the mixture and ignition timing. I'm sure it is one of the index to look for the map lookup table in DME mapping memory.

[Redline]

cleaned connections and pins. Unchanged.

have it idling now and checked the following and saw;

Fuel readings

mix adapt, idle speed, additive bank 1 -0.13 ms
mix adapt, multiplicative, part load bank 1 5.98%

mix adapt, idle speed, additive bank 2. -0.18 ms
mix adapt, multiplicative, part load bank 2 5.95%

smells rich as hell like I’m catless. (Stock headers/cats)

[maw1124]

How's Cylinder 4 doing? If having switched the coils around there's still a problem there, you might have to get into that head gasket to make sure you don't have fuel leaking right there. Only because at this mileage if it hasn't been done it's probably "due" anyway so you're not wasting anything. Other than that, you're sort of down to the DME, although I would suspect "hardware" more than "software", as the computers seem to be the most consistent part of this story (assuming they are consistently pointing to C4). I still cannot figure out a connection between that cylinder and differences in temperature though (other than fuel cools slower than empty space -- and that's a reach).

maw

[sapote]

about 2k miles after this i go out to my car after work and go to start it, just a click and gauge cluster starts buzzing (battery dead) jump started it and it fired right up, drove it to a friends shop to replace the battery...after this even is when sh!t started rolling down hill and components have been dying off here and there. idk if it was a voltage spike or what have you but ive replaced the following components to make a long story short....

Any chances that the event caused by a loose battery connection and not a dead battery? If it was a loose connection and then jump started, this could fry many electronic parts, as without a good battery connection to have the battery serving as a capacity/reservoir to filter absorb the spike voltage (generated by equipment turned ON/OFF, i.e. AC clutch, fans, lights...and the alternator itself) the spike voltage was high enough to cause damages. This is why the book says never run engine with not battery or disconnecting the battery while running. This spike is called load dump in electronics. The spikes could be over 30 volts.

You might start thinking about a another DME if #4 misfire persist.

[Redline]

How's Cylinder 4 doing? If having switched the coils around there's still a problem there, you might have to get into that head gasket to make sure you don't have fuel leaking right there. Only because at this mileage if it hasn't been done it's probably "due" anyway so you're not wasting anything. Other than that, you're sort of down to the DME, although I would suspect "hardware" more than "software", as the computers seem to be the most consistent part of this story (assuming they are consistently pointing to C4). I still cannot figure out a connection between that cylinder and differences in temperature though (other than fuel cools slower than empty space -- and that's a reach).

maw

Head Gasket is already in the works for near future I know they fail between 1-2 and 5-6 more so in Europe but have seen it here but compression is consistent across the board but no doubt it’s tired/wouldn’t hurt to refresh the head after these years, would have done it sooner but in the middle of renovating a property I just purchased which has consumed most of my free time.

Haven’t had a cylinder 4 misfire or any codes return in months. Until last week when starting vehicle it chugged then died, restarted fine 2nd time and finally the CEL came on!

only code I’ve had for months was the engine temp plausibility no other codes, finally got some more again after months.

car idles and drives fine actually get 20.2 MPG and I drive it hard in city/lots of highway too.

just hard start and feels like it has heat soak/sluggish at times. Doesn’t throw you back in the seat sometimes and others it shreds tires.

codes I got were

active:

69 [105] Signal engine temp implausible.

shadow:

3x of 8F [143] Electronics Box Fan
3x of 10 [016] Signal Crankshaft Sensor
2x of 32 [050] Ignition Coil Cylinder 4

thats why I started prodding around again to see if I could find anything new.

[Redline]

Any chances that the event caused by a loose battery connection and not a dead battery? If it was a loose connection and then jump started, this could fry many electronic parts, as without a good battery connection to have the battery serving as a capacity/reservoir to filter absorb the spike voltage (generated by equipment turned ON/OFF, i.e. AC clutch, fans, lights...and the alternator itself) the spike voltage was high enough to cause damages. This is why the book says never run engine with not battery or disconnecting the battery while running. This spike is called load dump in electronics. The spikes could be over 30 volts.

You might start thinking about a another DME if #4 misfire persist.

I think this very well might be what caused all of this. Car was fine until the dead battery/jump start ordeal. All grounds are good and no corrosion.

sucks I have an early 03 SMG m3 sitting right next to this one just don’t want to start hacking apart a perfect garage queen to test my daily beater lol.

the 03 feels wayyyyy faster than my 02 off idle it pulls hard as hell. Have to rev out my 02 to get it going...

[maw1124]

Did you or did you not switch coils around?

Did you or did you not reflash the DME to stock (or is that not a thing)?

I hear you about compression test and head gasket. At these miles, makes sense if never been done just to rule out leaks.

I’m thinking (1) bad coil, which switching them around may flesh out; (2) leaky injector at cylinder 4, if you move the coils and the problem remains at C4... if the problem moves with the coil then it’s obvious; (3) IAT sensor, which I’d probably throw at it anyway unless it’s new; and (4) DME. I wouldn’t assume new coils means none of them are bad.

In that order.

Other than that, I’ve got nothing. It’s just hard for me to tell from here whether the poor mechanical performance (gasket, coils, injector, sensor) is giving your computer fits... or whether a fuss bucket computer is causing the poor mechanical performance. But I suspect the former over the latter.

maw

[Redline]

Did you or did you not switch coils around?

Did you or did you not reflash the DME to stock (or is that not a thing)?

I hear you about compression test and head gasket. At these miles, makes sense if never been done just to rule out leaks.

I’m thinking (1) bad coil, which switching them around may flesh out; (2) leaky injector at cylinder 4, if you move the coils and the problem remains at C4... if the problem moves with the coil then it’s obvious; (3) IAT sensor, which I’d probably throw at it anyway unless it’s new; and (4) DME. I wouldn’t assume new coils means none of them are bad.

In that order.

Other than that, I’ve got nothing. It’s just hard for me to tell from here whether the poor mechanical performance (gasket, coils, injector, sensor) is giving your computer fits... or whether a fuss bucket computer is causing the poor mechanical performance. But I suspect the former over the latter.

maw

I think I swapped coils around but I’ll do it again as well as plugs to see what happens again.

coils are new eldor
plugs are new ngk
injectors are new bosch

IAT sensor is part of the 5 wire maf sensor. Cleaned pins and hit it with contact cleaner. Nothing. Maf is new. Test the old one I had laying around and gave the same 10-15°c higher reading for the IAT so it’s not the sensor or normal it seems.

tried hitting/moving around harness at idle, spraying brake cleaner around at idle. No change.

software it stock for DME but could try a reflash. Hate to buy and install an easy deleted DME but if I have to I guess I have no choice. And what’s to say the old one isn’t shot.

[Redline]

Update CEL light on tonight. No misfire. Still does the beard starting per usual.

codes are:

69 [105] signal, engine temperature, implausible

AF [175] Fuel-System Diagnosis bank 2 (cylinder 4-6)

Never got that AF code before. Always have that temp code lol.

no misfires detected.

[Redline]

So now getting fuel related codes no more misfire codes. Cylinder 4 misfire hasn’t returned. Coils swapped.

just that engine temp plausible and AF 175 bank 2 fuel system diag code...

[maw1124]

Reflash? It may be time to start thinking about DME... I know they’re on eBay... but before I did that, I’d disconnect my battery for a day or so... and or have the dealer reset mine... that’s a simple and direct enough ask of a dealer that they can’t make $1k worth of work out of it... they might force you to change that sensor though... the consistency of that temp code tells me the DME might be working just fine... if you get that same code after a reflash you will have run out of questions.

My $.02 is you’re in danger of making more work out of this than necessary.

maw

[Redline]

Reflash? It may be time to start thinking about DME... I know they’re on eBay... but before I did that, I’d disconnect my battery for a day or so... and or have the dealer reset mine... that’s a simple and direct enough ask of a dealer that they can’t make $1k worth of work out of it... they might force you to change that sensor though... the consistency of that temp code tells me the DME might be working just fine... if you get that same code after a reflash you will have run out of questions.

My $.02 is you’re in danger of making more work out of this than necessary.

maw

I’ll try the reflash and go from there.

every sensor on the engine is new lol. Replaced the ect 2 times and thermostat is brand new. Wiring is good to these sensors as well.

appreciate the help! I’ll report back what happens next with the reflash.

ive heard of/seen some instances the 69 temp plausible code can be tripped from other faults unrelated...like Vanos. Seen it more on the m5’s rather than the e46 m3. Idk lol.

I’ll shut up now and just try the reflash.

[maw1124]

Ha! Funny. But I also don't know the difference between OE and non-OE sensors, etc. Trying to avoid that rabbit hole.

Also keep in mind there’s a DME recall on ‘02 cars... not sure if yours has had this work done yet. I'm not sure if they're related by I'm sure you should be sure...

maw

[Redline]

Ha! Funny. But I also don't know the difference between OE and non-OE sensors, etc. Trying to avoid that rabbit hole.

Also keep in mind there’s a DME recall on ‘02 cars... not sure if yours has had this work done yet. I'm not sure if they're related by I'm sure you should be sure...

maw

I always go genuine bmw for cam/crank sensors. OE manufacturer for everything else. Can literally see the bmw logo ground off on them.

replaced so far:

intake/exhaust cam sensors (oil leaking, not part of this issue)
crank sensor (faults present for it)
EGT sensor (was open circuit, been failed for a minute)
pre cat a/f sensors (oxygen sensors) (parts cannon)
maf sensor (parts cannon)
Throttle position sensors (failed, erratic reading)
injectors (injector driver fault cyl 1, leaking, erratic flow all 6)
fuel pressure regulator (parts cannon)
fuel filter (maintenance)
fuel pressure regulator vacuum lines (dry rot)
cleaned ICV (no issue, just while I was in there)
Vanos seals/cam bolts
timimg chain guides
repaired Vanos solenoid (inlet Vanos retard fault, bad connection at connector, cut open, soldered, besian fix essentially)
cleaned Vanos solenoid valve
starter (failed on me)
battery (bad cell, jumpstart, most likely cause of all this)
thermostat (sticking open)
fan clutch (free wheeling, shot)
ECT sensor (temp plausible code, still returns)
Fan control sensor (lower radiator hose) (why not)
Valve adjustment
constant pressure valve
rod bearings
cleaned throttle bodies and intake ports in head
plugs
coils

things I haven’t replaced:

money lost throwing parts at it
time

Head gasket
DME...
throttle actuator/bodies

and obviously valvetrain and main bearings, pistons, rods. Might as well and have a new s54 at this point....

[maw1124]

https://www.e46fanatics.com/threads/another-p0113-error-thread.1287868/

posting this here in the off chance it’s helpful... maybe check the wiring to make sure someone’s previous mod isn’t your current problem.

maw