Please search, theres about 5 million threads about what vanos is.Originally Posted by 318is4life
I just got the exhaust air pressure tester from pelican parts to test out the exhaust flow pressure through the cats. It was $30, and in fact the pressure is elevated, so a used set of OBD2 cats and O2 sensors are on the way. I definitely think your problem (and mine as well,) is the cats: our old ceramic matrix is simply not made to last more than 10yrs/100k miles. Do you notice how this problem almost never happens on the 328s?
I'll post the results in a few days.
I'm still failing to understand how the cats could cause this...
im with him i believe its something with fuel deliveryOriginally Posted by Spood
I think it could be a combination of both, but am leaning towards cats. How elevated was the pressure? Great results, please keep us all posted! This is the only thread that keeps me coming back to bimmerforums.
I'm not saying it couldn't be the cats, but I haven't heard and solid logic to explain the idea.
Very interesting. How "elevated" was it? Also, how do you plan on making the OBDII cats fit in with the OBDI headers?Originally Posted by calves2997
Dan
Dan
what would happen with a test pipe in an obd1 car...even if you made new spots for the o2 sensors? I have a bogging problem, but have had cars with race cats aka straight nice replacement, that ran awesome. would the o2 sensor freak out and make things worse in our cars?
I'm not sure that the cat being the culprit is making sense.. like sdotlalond said
What exactly does the clamping of the return line do? just raise the pressure of the fuel supply? will this cause the motor to run rich or will the computer lower the fuel mix automatically? if it does run rich does that cause other problems?
Do any of you have check engine lights?
I have 1262 Idle Speed Control This shows up if the idle speed actuator shows a ground fault, or if the car stalls from an idle above 600 RPM.
not sure if thats a related problem or not..
similar to alot of your symptoms, mine idles fine when its cold and first starts. does so until it warms up (maybe like 1/4 of the temp gauge) from the left
then it starts revving up and down anywhere from 600-1500 rpm. it seems to vary every time. It may even start at a small fluctuation then get larger as the engine gets warmer. I was thinking it was my ICV like the code said but now I'm thinking that may be a different problem altogether, or else the computer is just confused. Similar again I'm getting the bogging or hesitating thing at 3k rpm when accelerating quickly, as if I were taking my foot off the pedal then going back on really fast. Seems only to happen when the motor is warm again, and it does fine when its cold.. called the dealer today and its $100/hr for diagnostics, they dont know how long it takes to diagnose..
like i said before, i'm not a career mechanic,
but i do understand the logic of systems.
reading all of this leads me to this conclusion; if it is a post combustion problem, then it must be a feedback issue with precombustion. in other words, something postcombustion is telling precombustion [or combustion] to fuck up somewhere.
i say this because the known direct postcombustion problems have been addressed. thus, maybe there's a funky feedback loop in the pre-combustion area?
i sure hope ya'll figure this shit out. i, for one, am not capable.
oh yeah; i just took up golf too.
cheers,
sv-
sidvicious
97 BMW 328i Convertable [My first BMW]
60k miles
Automatic
99 New Beetle TDI
Blown engine [through negligence]
Under self repair [oh hell!]
2004 Toyota Sequoia
2003 Buick Rendezvous
Honestly, no one knows for certain right now. No reason to go shooting down people's ideas if we haven't tried it first. The quickest answer would probably be to take our cars to the dealer, but that's not what we're doing, we're experimenting. So let's give each idea a thought and not cross it off right away...
Sidvicious - I'm hesitant to think that the computer KNOWS about whatever is causing this issue, as I think it would cause a major CEL if it was something it could monitor. Instead, I think it's something the computer can't (or for some reason isn't able to) monitor.
Prophecy - I think you need to clean your ICV. Sounds like that's it for you...
Dan
Dan
I took video too dan, but I can't find my damn firewire cable!
Mine (and a few others on this thread) is strictly ambient temperature, or as I said earlier engine bay temperature not engine temperature.Originally Posted by dmurray14
For example sit in traffic (in cool weather) engine bay heats up, it bogs down. Drive for a couple of minutes and (whatever it is) cools down and everything is fine again.
dmurray
i'm with you on the computer thing. what i mean is, from the totality of what i've read, the fault seems to be on the intake or combustion side.
if it is a computer feedback loop problem, then the problem could be that the computer is sending the incorrect readings back into the intake/combustion system.
the engine temperature variance seems to confirm this. when the engine is warmer the intake air is warmer, etc.
it reminds me of the old "high" altitude days with carburators. if the intake jets weren't adjusted, when the car warmed you wouldn't move.
i'm sortof like a parrot here, mostly repeating what i've heard. but i do listen well. too, i remember flipping the breather cover on many a colorado rental car to get more air into the system, and it did work.
it seems to me that something is leading the system to conclude that too much 02 is in the front end of the system. thus, the sluggish and erratic burn.
everyone seems to have done all the timing and spark plug stuff. this is hardware. software, however, is much more creepy and full of gremlins.
on the other hand, something in the hardware could be forcing the software to an inappropriate conclusion.
i know a couple of experts. i'll ask around and see what i can come up with.
sidvicious
97 BMW 328i Convertable [My first BMW]
60k miles
Automatic
99 New Beetle TDI
Blown engine [through negligence]
Under self repair [oh hell!]
2004 Toyota Sequoia
2003 Buick Rendezvous
In relation to fuel pressure and injection requirements, I ordered a new fuel pressure regulator to see if maybe I am running lean in the rail. It came in today and when I went to install it the darndest thing happened........the original one is not there. There is not a place for it on the rail nor anywhere else. I have an exploded diagram and it just is not there. So, does anyone know why some would have one on the rail and some not? Also if not on the rail, where the h l is it? 95 E36 Auto
Jerry
95' 325i
Very interesting...I know I have been an annoyance and maybe my lack of posts has led me to the 'Dunce' chair but I have heard three other people say the same thing...one guy I believe even on this thread made mention that he called a BMW recycler and they said all of them were "missing"...very peculiar. At the same time another gentleman on Pelican talked to different service techs and two said it didn't have one...BMW said it did but that it wasnt shown in the parts schematic of his service program....and somehow knowone is able to locate it??? Is this part of the technology to incorporate the check valve in the intake line to be pumped out on the return line? Not experinced with FI systems or anything for that matter related to this problem - all I know is I am buying a .99 cent for sale sign and buying an M3, hopefully I will not have the same problem with it
According to the Bentley, on 92-95 6cyl cars, it should be on the fuel rail. On 96+ cars, it should be underneath the car. Dunno if that helps at all. Just a thought, but maybe it's either a misprint or yours was manufactured late in 95 and it is under the car. If it is under the car, it will be under a protective cover on the left side.Originally Posted by jperry58
The Bentley manual says it could be in two places. Either on the fuel rail or under the car. The picture looks like it is next to the fuel filter under the car, driver's side. There is supposed to be a cover over it, about under the driver's seat that contains the filter and regulator.Originally Posted by jperry58
1995 325I, tinted windows, K&N, debaffled airbox, Nighthawk low beams, BMW style #104 wheels, smoked corners, smoked sidemarkers, smoked taillights, M3 style heated mirrors, various interior bits, Bosal cat-back.
Ha! Beat you to it! ^^
this thread has crazy amounts of info in it. I'm just waiting for the person to cure their hesitation. I'll try clamping the return line when I get home this weekend.
murray14
Ill be checking my CAt's at the weekend and if i suspect they are faulty ill be taking them out
prophecy
<!-- / message --> Your pronblem sounds very similar to what my engine does im going to try cleaning my ICV this weekend too and see if it makes much diffrence<!-- controls -->
Yep, you win this roundOriginally Posted by Spood
1995 325I, tinted windows, K&N, debaffled airbox, Nighthawk low beams, BMW style #104 wheels, smoked corners, smoked sidemarkers, smoked taillights, M3 style heated mirrors, various interior bits, Bosal cat-back.
its definitely not it. I cleaned it throughly when it was all apart during the HG job. I even reached under the intake and took it out the other day to inspect. still clean. so maybe the unit has somehow gone bad and is throwing the code.. i think i may have a combination of problems here, with the same symptoms you all seem to be havingOriginally Posted by dmurray14
Oh and another thing I found out.. After doing a compression test lastnight I put it backtogether and started it up.. I then turned the headlights on for some more light. I noticed a small decrease in RPM. I thought that was strange, so I turned the headlights off. RPM's go back up. I mess around with this for a little while and the RPM's fluctuate with the headlights being on or off. It was cold out and the motor still hadn't heated up. It was still below 1/4 on the temp gauge. The idle was normal. Then I turned the lights on again (i'm pretty sure it was on, but could have been off) and it induced a premature surging idling (since the engine was still cold and it only ever happens after it warms up). Turned the lights off (or vise versa) and it went back to normal idle. I continued to do this for a few minutes until the motor warmed up and it was surging no matter what position the lightswitch was in.
This seems very bizarre? an electrical problem ?
Last edited by prophecy; 02-08-2006 at 10:42 AM.
Originally Posted by prophecy
An alternator problem. I have the same thing. Know how I know? My PS pump squeels like a little shit sometimes, and when I turn on the headlights, the tone of the squeel really changes. Of course, you can see the change in RPMs too. Don't know if this would relate to our problems, though I guess it could if the alternator was seizing up? I woudl think the belts would be getting worn though, but who knows...
OK, great. Very interested to see what the cats do.Originally Posted by Tim Poole
Yep. I don't know whether it's a sensor or what, but I'm convinced that the ECU doesn't think it's doing anything wrong, though it should be. Maybe we have a sensor that's on the verge of going, but not bad enough to trigger a warning...Originally Posted by sidvicious
I can't be 100% certain, but I'm fairly sure mine is engine-temp related. When the needle just about hits 12 o'clock, that's about when it starts to run like crap. I guess it could be engine bay temp too (assuming the temperatures rise similarly), but I still have a gut feeling mine's engine-temp related. I also don't think mine recovers after driving down the freeway for example, but I'm not sure as I haven't been on it for a while.Originally Posted by shortly99
Just an idea, but maybe we could make a list of sensors/parts that we suspect, and have people each try one or two? This way we can all minimize our losses...
Also proposing a "my car doesn't suck anymore" party when/if this is all figured out
Dan
Last edited by dmurray14; 02-08-2006 at 11:21 AM.
Dan
There is a technical bullitin for the E36 but dont recall the exact years or models, but there is a issue with the DME programming and required a "patch" be installed to fix this issue. Ill try to look into it
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