A what tf! 5 codes and no symptoms to show for it

[spyderg0d]

Only useing rtv until parts come in friday to monday, more of a tool to really spot the leaks. I kinda am a hack i guess. Not paying $40 for a smoke test to probably not spot smoke from small cracks spray wont enter, or spots i wont be able to see smoke come from because its innecessible.
The sensors are my last thing to get to, not juat because they are $120 a piece,but because i see they oscillate as they should, in the right scale that they should without any problem. I guess they could be soft failing, but still, last step. And indeed if i spent $220 on 02 sensors and it wasnt it, i would pretty much be calling you some names you dont want to be called. So, il take it step by step if you dont mind.

[whiskychaser]

You can make a smoke tester for the price of a cigar. In fact, the cigar was the most expensive bit of mine But I do agree that finding wisps of smoke is not the easiest thing in the world. Did you check if your STFTs are high at idle and go down when you rev the engine? If they don't, you may not even have a vacuum leak.

You might also want to check your MAF. So if you are bored, you could try checking the airflow when stationery. Just run the engine at say, idle 750,1000,1250 rpm etc and see what g/sec you get in each case. Plot rpm and g/sec in a graph and you should get a straight line. Mine came out like a dog's hind leg so I suspect it is on its way out

[dhurley34]

I would focus on the MAF. A rule of thumb on a MAF’s air flow rate at 500 rpm is 1 gram per second per liter of engine displacement. Your data shows 7.0grams @ 2krpms. With the engines 2.5L displacement, the reading should be around 10grams/sec.

[spyderg0d]

My monitors set ok. Pending lean codes from before the last intake exstravaganza. I think my maf is right at 3g at about 650rpm. I think ait and elevation have alot to do with it. So 7seems about right on the scale.

[spyderg0d]

P2237 i think came on just a few minutes ago after a 45 minute drive. Before i turned the car off i looked at the live data to see the stft were unresponsive on both banks but the ltft were fluctuating. The code is posative circuit open for 02 sensors. Bank 2 is pending for the same fault. After starting the car 20minutes later i see the 02 sensors working fine. Wtf?
Do bad sensors stop working when they get hot? Doesnt make much sense to me. My trims are under 8 all the way when the cars running.

[harrier]

Only useing rtv until parts come in friday to monday, more of a tool to really spot the leaks. I kinda am a hack i guess. Not paying $40 for a smoke test to probably not spot smoke from small cracks spray wont enter, or spots i wont be able to see smoke come from because its innecessible.
The sensors are my last thing to get to, not juat because they are $120 a piece,but because i see they oscillate as they should, in the right scale that they should without any problem. I guess they could be soft failing, but still, last step. And indeed if i spent $220 on 02 sensors and it wasnt it, i would pretty much be calling you some names you dont want to be called. So, il take it step by step if you dont mind.

It is your car, so if you want to use gorilla glue then I support you 100%

However what you are going through others have gone through hundreds of and hundreds of times, so in this case simple institutional knowledge has value against traditional tools.

A few things that have been demonstrated by practice over and over again:

1. The rubber is all gone by now, and gluing won’t fix it. You need to replace literally all of it. It is not expensive. Remember the SAP vacuum line and the dipstick oring. You can “fix what you find” just like with the cooling system, but you will end up replacing it all.
2. It is almost certain that part of the issue is the MAF. It always is. It is almost impossible
To test in the garage unless you have access to a known good one.
3. MAF won’t get better with MAF cleaner
4. Spraying for leaks doesn’t catch them on this engine. Perfectly legit on others. You have to smoke test
5. It is unclear which O2 sensors you have replaced, pre or post cat. Pre-cat are done at 100-125. They soft fail so it is not an issue of codes
6. Fuel pump and filter often play a role. If you can’t reach and maintain 50psi then that is a part of the issue
7. The brake booster can leak without obvious symptoms and can’t be diagnosed with smoke test because of valve. You can detach the hose and plug/unplug while watching fuel trims.

You don’t have to follow any of this, and I suspect you know way more about auto mechanics than I do, but this issue is so well-trodden that it makes sense to just follow the path of everyone before you

[harrier]

As an aside, oscillation only demonstrates they have not outright failed. If you log the sensor values and compare against new sensors you will likely see they are soft falling which is giving bad data to the ecm.

For my part, they are past their stated lifespan, but if you want more deterministic proof, log using OBDFusion and post on e46fanatics. JFOJ will compare your sensor values against expected and chart it.

Good luck

[spyderg0d]

I replaced the boots, the plastic bits, the small vacuum line intake gaskets, ect. Discovered a valve cover leak in the usual spot. Sighhhhhh. Il have to order 02 sensors. So.. Ive pretty mich got a brand new bmw out of the deal. Haha. Oh well. Atleast its almost over and i wont have to worry about maintenance besides tires and oil changes until the car hits 210k or so.

[harrier]

Don’t get me started on how many parts I have bought for this car!!!

But I don’t want a different car, so this is my fate!

Good luck

[spyderg0d]

Eh. I got mine for 1grand with 111k on it. Crank bearings were bad. At the time bmws were a rare thing in the ahit hole that cny is. So a junkyard was happy to sell me a good 66k engine that had been bearing serviced before removal for $240. It was untouched for 2 years after it got together and on the road. Then, front fenders, windsheild, brakes, tires, converters, crank amd cam sensors, fuel pump (yet to change the sending unit that screws up my gas guage), battery, post cat 02 sensors, driver seat material, side marker lights, brake lines, rtabs, front control arms and bushings, motor mount, longer transmission line, radiator, coolant hoses and pipes, .... Im probably forgetting a few things... Fronts sway bar and endlinks... Rear shocks... Uhmmm.