[Skrrtt335]

I drove the car for about 1 hour straight car was running fine , i then stopped and to get food . when i went back to start the car it only cranked(almost turning on) but did not start. got the car towed home & had 2 mechanics come look at it . the first mechanic tested fuel pumps and they both seem to be working . Checked all fuses too . He did a spark test to the coils and they were not getting spark he said it might be the crankshaft sensor . BOTH MECHANICS SAID NO CODES SHOW UP , i also checked codes with bm3 and only code i get is

- 21a023 combustion engine : false start or engine stopped without driver influence

2nd mechanic said there was spark and did compression test and all cylinders came back to 60PSI and that i need a new engine

i'm confused from both answers and my questions are would no spark cause engine to have low compression ? The car was driving fine before it wouldn't start . where else should i look or what other tests should i run before getting into buying a new motor .

[thejeremyman9]

I dont see how the engine would be toast if it ran when parked. My guess based on the limited information (not starting and low compression assuming thats true) is a valve/tronic issue

[Slumped335]

Sorry i don’t have a direct answer. Mainly just questions.

-What is ur current mileage?
-What Maintenance have you done?
-When was the last time you changed Spark Plugs / Coils?
-Did you take it to a dealer or an indie shop?

Anymore info would help narrow down things.

Hopefully someone will be able to give you an answer.

[Skrrtt335]

Originally Posted by thejeremyman9

I dont see how the engine would be toast if it ran when parked. My guess based on the limited information (not starting and low compression assuming thats true) is a valve/tronic issue

yeah the i drove the car an hour and a half with no issues and soon as i turned it off to walk in the store for 10 mins came back out and it just cranked . thats true tho 2nd mechanic told me the same

[Skrrtt335]

Originally Posted by Slumped335

Sorry i don’t have a direct answer. Mainly just questions.

-What is ur current mileage?
-What Maintenance have you done?
-When was the last time you changed Spark Plugs / Coils?
-Did you take it to a dealer or an indie shop?

Anymore info would help narrow down things.

Hopefully someone will be able to give you an answer.

Current miles : 134k bought at 75k was told they did maintenace on the car ( water pump ) i changed spark plugs & coils when i got the car , just changed spark plugs today to see if it would change anything . waiting on coils to come in . car also has new battery i put in after the day it wouldnt turn back on. mechanic 1 came to me since he works as a mechanic for autozone off the books & mechanic 2 was the indie shop . oil changes every 5k miles

car is also on bm3 stage 2 tune fbo running 93

had some issues of the engine stalling out like 3 times in the past 3 years while cruising on the highway bout 80mph sometimes coming back on as im still on the gas pedal ( seemed like fuel pump but they both seem fine ) car always started back up , i can post bm3 logs of fuel pumps psi i have while cranking the car if that helps in any way . car takes a while to turn on sometimes in cold weather and has small valve cover leak

https://youtube.com/shorts/VxVy4_sO0UQ?feature=share

video of how it sounds when cranking

[BeastMode335i]

Bro weirdest shit ever, my F30 just did this same exact thing almost yesterday. I pulled in to get food and as I was driving away it turned off. I pulled codes and had 21A023, and I cleared it with MHD. Car started up and drove home about 4 miles w/o issue after that..... Strange...

[Slumped335]

For what it’s worth i don’t think your engine is toast. It sounds potentially electrical? Cam Sensor losing signal or something.

IMO it might be worth taking it over to a BMW dealer and seeing what they say. $250~ in Diagnostics is way better peace of mind than a autozone mechanic and a indie mechanic.

Sorry i’m not more help. I personally take my car to a indie shop for all my work.

Good luck man!

[Skrrtt335]

thanks for all the advice guys , i have it at a bmw specialist rn he thinks its valvetronic issue . He said hes taking the valvecover off tmr . i did get valvetronic motor code when i checked for codes when car didnt start but i cleared it and never came back . He also said car was showing low compression on all cylinders . could that be bc of valvetronic stuck or not working ? car has spark / fuel .

[thejeremyman9]

Originally Posted by Skrrtt335

thanks for all the advice guys , i have it at a bmw specialist rn he thinks its valvetronic issue . He said hes taking the valvecover off tmr . i did get valvetronic motor code when i checked for codes when car didnt start but i cleared it and never came back . He also said car was showing low compression on all cylinders . could that be bc of valvetronic stuck or not working ? car has spark / fuel .

If the valves are not opening/closed when they are supposed to, yes, that can cause low compression. Seems far more likely than a catastrophic failure on all cylinders at the same time when the car ran when parked...

[Skrrtt335]

Originally Posted by thejeremyman9

If the valves are not opening/closed when they are supposed to, yes, that can cause low compression. Seems far more likely than a catastrophic failure on all cylinders at the same time when the car ran when parked...

yeah the mechanic just got back to me & said my eccentric shaft had all my valves closed & the valvetronic motor blew . Going to replace the valve cover aswell cause i had a leak

[Slumped335]

Originally Posted by Skrrtt335

yeah the mechanic just got back to me & said my eccentric shaft had all my valves closed & the valvetronic motor blew . Going to replace the valve cover aswell cause i had a leak

Well at least its not an entire engine. Glad to see that you at least came out on top. Good luck! Hopefully it wont be too much by the end.