Milky330ci Posted January 3, 2012 Report Share Posted January 3, 2012 Hi Guys, Im hoping someone out there can cast some light on a problem that apears very common, with lots of posts across the web, but with very few answers. 2003 330ci vert auto 75000miles. Bought the car at the end of the autumn, drove for 2 months with no issues except the exhaust emissions light came on from time to time. It showed up as the lamber sensors when i scanned it but turned out to be ripped air hoses. As a precaution I did a oil and filter change as i do with all my new cars and replaced the torn air pipes at the same time and cleared the 2 fault codes both related to the hoses. No other codes were logged. This completly cured the Exhaust emissions light issue and the car continues to show no fault codes. After about a week of changing the oil, the red oil pressure light started to flicker on when the car was warmed up, reversing the car up my drive using the 'creep'. it flashed up so quick it took me a while to work out if it was the oil light or battery light. The red oil light then began to flicker when the car was warmed up and coming to a stop, just as the revs dropped before the car 'dipped the clutch' at about 500rpm and then as it sat in drive at idle. Shifting to N or P or blipping the throttle clears it instantly. After looking about online i decided as i had used 0w40 oil (as recomended by my local parts place) it may be causing a low pressure at idle so i dropped it out and replaced the oil with 5w30 and a new filter... Same problem. Replaced the oil pressure switch... Same problem. So I then thought it may be a ploblem with the idle speed 550rpm at idle in drive or reverse 700rpm in park or neutral when warm. I cleaned the ICV and Throttle body and replaced the plugs and air filter as a precaution ... Revs stayed the same and the light continues to flicker but hasnt got anyworse. I've not cleaned the AFM as i had the cleaning go wrong on my E36 328i Sport and had to buy a new AFM. Spoke to my local BMW garage who say they have never heard of it, but as it seems so common across the web im hoping someone has had and actually sorted it. The only thing the BMW techs could come up with was perhaps there were cracked CCV hoses as that would cause a slight drop in the oil pressure which may be enough to trigger the light as the factory oil pressure at idle is close to the minimum needed to trigger the light. Having searched about under bonnet there is a small oil leak coming from around the manifold cover which hides the CCV hoses so will strip it off this weekend to investigate. The only other thing i though of was uping the revs via the engine management (if possible), I would rather cure the problem than mask it though. Anyone whos had this problem and has actually cured it's input would be really apreciated as its spoiling what is a lovely car! Chris. Quote Link to comment Share on other sites More sharing options...
DJ Syxx Posted January 3, 2012 Report Share Posted January 3, 2012 Red oil light is pressure so its losing pressure somewhere. You've replaced the switch so thats eliminated, if you got a leak then that could causing the light to come when warm. Does it flicker when cold and when you start up does the red oil light go out straight away from start up? Be worth testing the oil pressure to see if it holds well. Quote Link to comment Share on other sites More sharing options...
marc l Posted January 3, 2012 Report Share Posted January 3, 2012 Never heard of this problem before! I think 550rpm at idle is low? What do the other auto owners think? It's funny how it has only started happening after the oil change, when I've changed the filter on my 1.9 I also changed the rubber seals (these come in the Mann filter box) did u change them? That's a good shout getting an oil pressure gauge they aren't that expensive to buy so if u asked a garage to do it for you it wouldn't be much Quote Link to comment Share on other sites More sharing options...
Milky330ci Posted January 4, 2012 Author Report Share Posted January 4, 2012 Hey, Its absolutly perfect when cold, goes out as soon as the engine fires as it should. Its only after ive been driving it for a good while. I replaced the filter and the 2 seals twice now, I didnt notice a change... Its going in to have the pressure checked on Monday, Im going to replace the pressure sensor with a BMW one at the same time as i could only get my hands on a pattern one when i had it all apart, i doubt this is the cause though. I do agree the idle seems low, it drops when you select drive as all autos do but im wondering if the idle speed needs upping by maybe 50rpm, I understand this can be done with the GT1 software. Has anyone tried this?? Thanks for the input. Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 26, 2013 Report Share Posted January 26, 2013 My car is e46 320i year 2003 with M54B22 engine 170 HP and I'm have the same problem. The oil pressure sensor is the first thing that I replaced than the oil pump, pressure relief valve of oil pump, than all the bearings and squirters(machined the crank), oil filter housin, oil filter, oil(original BMW LL 5w30) and yes, the light in dash board still comes on at hot idle. The presure readings are 0.5 bar at hot idle and at higher rpm reaces 4 bar. The idle is about 700 rpm and the car does not overheat. The car runs fine, the idle is normal (no variations) and the throtle is very responsive.There are no external oil leaks and all the redings of oil pressure where made with a mechanical gauge. I also did the VANOS unit with the kit from beysand systems. I'm loosing my mind head.....please if you guys have some sugestion....help Quote Link to comment Share on other sites More sharing options...
marc l Posted January 26, 2013 Report Share Posted January 26, 2013 You've been busy with your car! I don't really know what to suggest I'd prob let an engine specialist have a look at it tbh. A company that rebuilds them Quote Link to comment Share on other sites More sharing options...
quackers Posted January 26, 2013 Report Share Posted January 26, 2013 0.5 bar at hot idle is low, I'd have thought. That's only about 7 psi - not much (although maybe that's 0.5 bar above atmospheric pressure, which would make it about 21 psi). Obviously as you've changed the oil pump it can't be that, assuming it was a new BMW item. These engine sensors seem somewhat flaky - even BMW ones at times. Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 27, 2013 Report Share Posted January 27, 2013 All the work to my car was made by an engine specialist, i even went to my local BMW and talked to the BMW in Germany but nobody can't fint the devil inside my car. Also all the parts changed are original. I am thinking now at the CCV valve that i changed 2 years back....but that will be odd couse the car is runing fine. Posibilities are the non return valve in cylinder head(the o-ring is bad letting oil pass) or maybe the pressure reliefe valve from my new oil pump was defective from factory. What do you guys think of that? Quote Link to comment Share on other sites More sharing options...
Rich_D Posted January 27, 2013 Report Share Posted January 27, 2013 I had this on a car a few years ago, it was the bottom end, it started knocking eventually. Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 27, 2013 Report Share Posted January 27, 2013 I forgot to mention how this flicker started. When it first started to flicked it happen randomly...where some days when the light wont come on. That was the moment i started investigating, but after some months the problem got worst untill one day at a stop the oil pressure light started to flicker faster until it stayed on. I stoped the car fast, checked the oil level which was low and put some oil to get the normal level(not much was missing). Started the car again and the light stayd on only at idle. If i slightly tap the throttle the light will go of and since i was not far from a friend of mine(mechanic engineer), i talked to him and decided to take it to his shop but, on my way, at stops, sometimes the engine tended stall if i wold take my foot of the gas. That's how my nightmare begins (. Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 27, 2013 Report Share Posted January 27, 2013 I had this on a car a few years ago, it was the bottom end, it started knocking eventually. After all the major work was done to it(bearings, oil pump....) i never drove the car again since the problem still persist. The car is in the shop for the past 3 months and i'm trying to get to the bottom of this. There must be a solution to this. Quote Link to comment Share on other sites More sharing options...
marc l Posted January 27, 2013 Report Share Posted January 27, 2013 I know this is a big idea but if you've run out of options you could replace the engine? They are about £500 on the bay when I checked a while ago. I don't know how much labour a garage would charge to fit Quote Link to comment Share on other sites More sharing options...
Webby Posted January 27, 2013 Report Share Posted January 27, 2013 Does this engine have a oil pump? What about gaskets for the bottom end? If you cant find the problem soon you should sell it on before your buying used engines at around £1000 and paying someone a bomb to fit it. I know it sounds harsh but it will be someone elses problem. You can always go buy another e46! Quote Link to comment Share on other sites More sharing options...
Webby Posted January 27, 2013 Report Share Posted January 27, 2013 Just seen marcs post so change my quote of a used engine price to that! Haha Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 28, 2013 Report Share Posted January 28, 2013 I don't want to offend you but how would you feel if you where the buyer of a car that has a hiden problem like this? Sure thing, I can pull the light from the dash or put diesel oil in it and sell it but I don't like to be that guy.Sorry Blair and B0B 2 Quote Link to comment Share on other sites More sharing options...
marc l Posted January 28, 2013 Report Share Posted January 28, 2013 I'm the same mate I couldn't sell a car with a problem like that Quote Link to comment Share on other sites More sharing options...
Webby Posted January 28, 2013 Report Share Posted January 28, 2013 I don't want to offend you but how would you feel if you where the buyer of a car that has a hiden problem like this? Sure thing, I can pull the light from the dash or put diesel oil in it and sell it but I don't like to be that guy.Sorry Well the OP was sold the car with the same problem, at the minute its just a flickering red light on the dash... Its not 100% going to die of oil starvation its fine as it is as the guy has been using it for 6 months without a problem. After all it could be a dodgy sensor connection?! Quote Link to comment Share on other sites More sharing options...
Webby Posted January 28, 2013 Report Share Posted January 28, 2013 I don't want to offend you but how would you feel if you where the buyer of a car that has a hiden problem like this? Sure thing, I can pull the light from the dash or put diesel oil in it and sell it but I don't like to be that guy.Sorry Well the OP was sold the car with the same problem, at the minute its just a flickering red light on the dash... Its not 100% going to die of oil starvation its fine as it is as the guy has been using it for 6 months without a problem. After all it could be a dodgy sensor connection?! Quote Link to comment Share on other sites More sharing options...
Ginger Posted January 28, 2013 Report Share Posted January 28, 2013 This fault is normally due to a poor contact somewhere in the harness between the oil pressure sensor and the instrument cluster. I've found replacing the engine wiring harness cures this fault. Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 29, 2013 Report Share Posted January 29, 2013 This fault is normally due to a poor contact somewhere in the harness between the oil pressure sensor and the instrument cluster. I've found replacing the engine wiring harness cures this fault. This is what I was thinking last night. But in my case it means that the gauge I am using is not calibrated right. I will try using another gauge and se whats happening. I found also a post where someone cure this changing the oil level sensor that at high temp was messing up the ECU. Quote Link to comment Share on other sites More sharing options...
Blair Posted January 29, 2013 Report Share Posted January 29, 2013 This fault is normally due to a poor contact somewhere in the harness between the oil pressure sensor and the instrument cluster. I've found replacing the engine wiring harness cures this fault. You'd replace the engine harness because one wire may have a high resistance joint? That's the reason I'd never let a car go to a main dealer or let 'trained technician' near one! This is what I was thinking last night. But in my case it means that the gauge I am using is not calibrated right. I will try using another gauge and se whats happening. I found also a post where someone cure this changing the oil level sensor that at high temp was messing up the ECU. The oil level sensor can be coded out . Quote Link to comment Share on other sites More sharing options...
Ginger Posted January 29, 2013 Report Share Posted January 29, 2013 Oil pressure sensors are basic. They only have one wire going to them. If you've replaced... Oil filter, oil pump, pressure sensor, checked for blockages in the oil filter housing unit (housing removal needed for this) and made sure the oil level and grade is correct, I'd say a loom is your next best/cheapest option. Quote Link to comment Share on other sites More sharing options...
Ginger Posted January 29, 2013 Report Share Posted January 29, 2013 Bashing a tech who's trying to help isn't exactly friendly, or polite. Paying someone to sift through the wiring to find a break, will be more expensive than putting a new/good used quality loom in. What professional occupation do you have blair? And would you like me to insult your knowledge in it??? john.med 1 Quote Link to comment Share on other sites More sharing options...
co2_121 Posted January 29, 2013 Report Share Posted January 29, 2013 I don't know what you mean by "a loom". Could you please elaborate? Quote Link to comment Share on other sites More sharing options...
Ginger Posted January 29, 2013 Report Share Posted January 29, 2013 Plus were talking about a pressure sensor, you should never code out a pressure sensor!!! Common sense please. Quote Link to comment Share on other sites More sharing options...
