BMW E46 Fanatics Forum banner

41 - 60 of 80 Posts

·
Premium Member
2003 330cic, 2003 325iT
Joined
·
4,696 Posts
Very true! As you suggested, I’ll definitely be using silicone hoses. Great suggestion!

I’ve been working on this car myself for the past year and it’s almost there! Cant wait until I make full circle (OFHG replacement was the first item).
My first repair was replacing an awful console. My first "real" repair was replacing the fuel pump, which I did with a full tank of gas and made an unholy mess! That was 7 years ago, and since then I have learned a TON!
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #42
My first repair was replacing an awful console. My first "real" repair was replacing the fuel pump, which I did with a full tank of gas and made an unholy mess! That was 7 years ago, and since then I have learned a TON!
I did the same (tank full of gas)... wow... the mess... and the headache that followed...

I have learned a lot thanks to you and others on here. I know I still have a long way to go with learning though.

I’m going on 2 years with this car, and loving every repair!
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #43
Another quick update, I decided to change the MAF side intake boot, this is one of the things I replaced when I got the car and did not think an after market cheap one would be a problem.

Well, with the knowledge I have now, especially after inspecting the cheapo boot... I know getting cheap parts is bad... got a reinz intake boot, feels and fits amazingly. The cheapo intake boot had the nipple blocked off completely, where the 2 hoses with the F fitting go...

I don’t know if this caused my CEL P0174 code or not, but an issue resolved none the less! - I don’t feel any difference with the car and the brakes perform the same, one big difference is that the SAP is a lot quieter, probably because the valve opens correctly now....

I will be checking the intake manifold nipple caps and small vacuum hoses this weekend. More updates to come!
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #44
Big update: replaced those hoses and nipple caps. No change in idle, but they were crusty and fell apart. I replaced the hoses with silicone ones as advised. Terrible job while intake manifold is still on the engine... but it’s done, thank you!!!!

I did get the SES light again, same p0174, so the leak has not been found, next on the list is fuel pressure test and if that is good, onto taking off the intake manifold...

Archbid, you are a champion. Thank you again!

EDIT: I thought I replaced those hoses for the check valve, but I apparently did not. So it’s a really good thing that was advised!
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #49
Hmmm, so got the P0174 again, I will post a full log and code/s that I got using fusion later today when I am not working.

Interestingly, after the crusty nipple caps and small vacuum hoses on the back of the intake manifold were replaced, the SES light is coming on more frequently. This has to mean that I did something wrong...

I think I may have botched up that job, unfortunately I cannot check it until the weekend... I did make sure to have the right orientation of the check valve and all the lines were replaced individually, so I didn’t mess up the trail. Could be the caps that may be loose or something. And the small silicone hose I used was really tight. So I doubt it’s the hose. (I used thicker vacuum rated hose to make sure it doesn’t collapse)

Maybe I should put some silicone or rtv in the caps to seal it off completely? (I would hate to do that though...)

I will check those caps this coming weekend and do a fuel pressure test. I may just end up doing a whole intake manifold job, replacing the coolant hardline, starter and seal up those tiny vacuum passages for good.
 

·
Premium Member
2003 330cic, 2003 325iT
Joined
·
4,696 Posts
Don’t do silicon or rtv. It is a hack.

mans ignore the light and the lean codes. Focus on the fuel trims right now. You need to get the LTFTs down to below 6 or so (ideally +/- 2, but that is for another day).

what are the LTFTs at idle and 3k rpm now?
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #51
Idle Bank 1 LTFT: ~1.5
Idle Bank 2 LTFT: ~2.3

3k Bank1 LTFT: ~1.5625
3k Bank2 LTFT: ~3.125


This is before the cap/hose replacement. I will have to do some logging a little later today.
 

·
Premium Member
2003 330cic, 2003 325iT
Joined
·
4,696 Posts
Idle Bank 1 LTFT: ~1.5
Idle Bank 2 LTFT: ~2.3

3k Bank1 LTFT: ~1.5625
3k Bank2 LTFT: ~3.125


This is before the cap/hose replacement. I will have to do some logging a little later today.
Those are perfectly good. Exactly what code are you getting?
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #54
The code p0174 is specifically high fuel trims, and yours are not high - again you could have miss connected the solenoid or left something disconnected

Just did a quick log, here are the freeze frame screenshots too:


Just did a quick log. Bank2 fuel trim being 0 ? Must not be logging correctly...
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #55
I will do a full log of about 10 minutes for my drive back from work, it’s mainly a 6 minute highway drive and 4 minute stop/go, back roads drive. That should give enough time to trigger the SES again.

Thanks again Arch, I really appreciate your guide here. I am still at a loss with this, I don’t see why the short trims on bank 2 would be so high while long trim is 0% on bank 2, faulty O2 sensor? I hope not since they are less than 5k miles old and Bosch.... so rather pricey

I still have to do a fuel pressure test, could still be an injector on bank2 or maybe the caps are leaking. (Just making a laundry list, out loud, of what to check)
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #56 (Edited)
Okay, did logging for a while, the last log includes + 27% STFT, this is causing my SES to trigger on bank 2. Please note my WiFi kept disconnecting, that’s why there are 5 files, sorry about that!


I did check fuel pressure, 50psi at idle and ~40psi after turning off and waiting 10 minutes as shown by pics below; (that’s within spec as far as I remember)

After car is off for 10 minutes.


Car at idle and warm:
 

·
Registered
2000 E46 323i, 3.0L and 2.0L Z3's
Joined
·
571 Posts
Hi

I haven't been following your thread very much, so have just done a skim read and a quick look at your after cap/hose replacement logs.

The Bank 2 long term fuel trim is always 0. The Bank 2 short term fuel trim appears to be trying to do the full fuel correction of both the short term and long term trims. The two fuel trims have different PID characteristics. The long term having a bigger influence and the short term being a fine tune PID.

Just ran my eye down the Bank 1 long term fuel trims and they are pegged/always at -0.78125. Something is very wrong with your long term fuel trims as they do not vary.

You have new pre-cat O2's. If you had swapped the O2 connections when you had replaced the pre-cat O2's, then one bank would go full lean and the other full rich. The DME is seeing the pre-cat O2's and the voltages are varying. The short term trims are varying in time with the O2 voltages.

I'm stumped. What have I missed?

Can't think of any other fix/test than trying another DME.
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #58
Hi

I haven't been following your thread very much, so have just done a skim read and a quick look at your after cap/hose replacement logs.

The Bank 2 long term fuel trim is always 0. The Bank 2 short term fuel trim appears to be trying to do the full fuel correction of both the short term and long term trims. The two fuel trims have different PID characteristics. The long term having a bigger influence and the short term being a fine tune PID.

Just ran my eye down the Bank 1 long term fuel trims and they are pegged/always at -0.78125. Something is very wrong with your long term fuel trims as they do not vary.

You have new pre-cat O2's. If you had swapped the O2 connections when you had replaced the pre-cat O2's, then one bank would go full lean and the other full rich. The DME is seeing the pre-cat O2's and the voltages are varying. The short term trims are varying in time with the O2 voltages.

I'm stumped. What have I missed?

Can't think of any other fix/test than trying another DME.
Thanks for the input!!

I am stumped too, I changed all of the O2 sensors not long ago. Not just pre-cat sensors.

I have a ms45 dme on hand, my current ms43. I don’t know how to code it though. (Apart from bmw scanner and using INPA to make it manual).

Personally, I think that would be taking a shark to a gun fight. I will leave that on the back burner and use it if no one else chimes in.

Could it possibly be O2 sensor defects? I mean, since both trims are weird and not coherent at all.
(No rough idle, no weird sluggish acceleration, the car has never driven this good before).
 

·
Registered
BMW 325i 2001 Manual
Joined
·
346 Posts
Discussion Starter #59
Hi

I haven't been following your thread very much, so have just done a skim read and a quick look at your after cap/hose replacement logs.

The Bank 2 long term fuel trim is always 0. The Bank 2 short term fuel trim appears to be trying to do the full fuel correction of both the short term and long term trims. The two fuel trims have different PID characteristics. The long term having a bigger influence and the short term being a fine tune PID.

Just ran my eye down the Bank 1 long term fuel trims and they are pegged/always at -0.78125. Something is very wrong with your long term fuel trims as they do not vary.

You have new pre-cat O2's. If you had swapped the O2 connections when you had replaced the pre-cat O2's, then one bank would go full lean and the other full rich. The DME is seeing the pre-cat O2's and the voltages are varying. The short term trims are varying in time with the O2 voltages.

I'm stumped. What have I missed?

Can't think of any other fix/test than trying another DME.
I just had a thought, I did replace my cats not too long ago, what if I swapped both O2’s on both banks?

So basically both O2’s on bank 1 are reading bank 2 and vice versa? - I did make sure I used the rope trick and made sure that they plugged in the same way, but I could have made a mistake...

Is there an easy way to check this?
 

·
Here to serve y’all
2004 330Ci 85k miles
Joined
·
13,095 Posts
We just updated the DME software on OP’s car to the latest. Then started the engine and let it come up to full temperature. Here is what I saw using INPA:
  • pre-cat O2 sensors were very responsive at cold start
  • idle was rock solid at 700 RPM
  • both STFTs were excellent (staying between -1% and +2%)
  • MAF value was correct at 11.5 kg/hr (3.2 g/s)
I verified the AT->MT coding was correct (his 2001 325i has ZCS) by making sure both IKE and EWS had modified GM part of the ZCS.

He later verified the pre-cat O2 sensors are not crossed-connected.

I’d like to see an OBD Fusion Diagnostic Report at hot idle after a few days of driving it normally.
 
41 - 60 of 80 Posts
Top