Is PCV valve save to replace without any extra precautions, meaning battery disconnect,adding fluids after or simply covering button with fluid absorbing mat?
I recently drained coolant , replaced all rubber hoses, well almost all, with exemption of small hose , that comes out of left side of T bleeder valve and disappears down into the engine bay.I just simply did not wanted to look hard enough where it ends, with this thicker part of it.
I can replace things in my car comfortably, but just need to know before hand , what is involved in particular application.Also noticed , that i still have a old capacitor, so it would be wise to replace it as well, I think.Thanks

 

R-n-R of the PCV is straight forward. Remove the box covering it by loosening the hose clamps on either side (1 to MAF 1 to TB). Squeeze the connector coupler to remove it from the PCV. Remove the 2 screws using a #20 torx. Replace it by lubricating the O rings of the new PCV with some motor oil and inserting. Don't over tighten the torx screws.

 

I was doing some searching on the web for the 3 and I came across a thread about an info/diagnostics feature on my touch screen. I had it on the 'vehicle info' screen so I can see the voltage as I drive. I started the day fluctuating between 13.5-14.0 volts running 12.0v engine off. I checked the battery with a multimeter and it was reading 14.26v running 12.5v off. Now let me say after I replaced the PCV valve I did a hard reset just for the hell of it and the 3 was running like a dream. As I was taking my wife shopping the idle started to get rough and the display was reading 13.0v and as time passed (about 1 hour of drive time stop and start in and out of stores) I was down to 12.5-12.0v and the idle and performance degraded even more. By this time I was home and shut the 3 down to get my multimeter when I tried to restart she caught for a second and sputtered out. Took the key out of the ignition and check the battery voltage and it was 12.3. After 2 minutes she started just fine and the display read 12.5-13.0v and I got 14.26v off the battery. Did a hard reset again and got 13.5 on the display (idling real good by the way) and 14.24v off the battery. Any thoughts? Side note tried to do some remembering and as far as I can recall just about every time the 3 died it was after 45 minutes or so of cumulative run time without much time down.

 

Did the hazard lights come on. When it died. Would indicate a med speed can bus issue. This is a good start

 

My understanding of the hard reset is that it generally just erases minor codes. I use it when my BlueTooth or radio, that sort of thing starts to act up. I recall that when I replaced my alternator, the radio would not function and the display was all messed up - a hard reset resolved the issue.

In your case, if the engine runs OK after a hard reset and then later starts to act up, the problem and solution is computer related. By that I mean some signal the engine computer is receiving is perhaps false or the regulator within the alternator is sick - well it could be alot of other stuff but I see the problem as a sensor problem not a mechanical problem.

Also as I understand the engine computer and these sensor systems, (particularily the air suspension), is that for many of the systems, a great number of errors messages have to be sent to the computer before it acts on them. This is so spurious errors do not shut the vehicle down - most often you need the same error signal a number of times before the computer software regards the signals as valid. This is why your 3 will run well for some time before it again acts up.

The bad news codes, (high temperature, low pressures etc), do not generally get erased via a hard reset, just minor ones such as emissions and the entertainment systems, or the brake light / tail light caused problems.

I doubt this response helps much but somehow the problem seems to me to be something to do with the hard reset related systems.

 

So if the regulator and the computer are not playing nice is it more probable that the alternator is the culprit? I've heard of the alternators being kind of wonky on the 3. Is there any way to test the regulator? And, what component is the display reading from? I'm guessing the computer rather than the alternator or the battery.

 

Rover2013, no hazard lights or any other signals.

 

There is some sort of regulator tester device out there somewhere but it is rare.

The regulator is what Denso calls a smart regulator and I call a dumb regulator. In older vehicles, the regulator used to look at the battery and tell the alternator what to do. With the newer PWM design, (Pulse Width Modulated) on the 3, the engine computer looks at a number of sensors and then tells the regulator what to tell the alternator.

The regulator when sick, has some default setting that seems to tell the alternator to make enough electricity to the headlights etc, but will not actually properly charge the battery; as such, the 3 is always slightly electrically power deficient, and hence runs badly. That is how it seems to me anyway.

Also the voltage readings off the NAV display are I think not representative of what the alternator and battery see - they are reading from within the NAV itself and it probably has internal circuity to smooth out voltage changes - its own filtering so to speak.

 

Now that I'm starting to understand the regulator better I think it is note worthy that when I engage the A/C I get a fluctuation in RPM from 1000 all the way to 1700 or occasionally it will stay around 700-800 (normal idling) but still blow really cold. In any other car I've owned the RPM's increase slightly to compensate for increased power draw. If I take it to the dealer will they be able or willing to check the regulator? I have a feeling this was going on before I owned the 3 because according to the service records the starter, battery and alternator were replaced about a year before it was traded in starting at about 70,000 miles. I now have 93,000.

 

There are five files related to the alternator and regulator per the link below. The files are towards the bottom of the page that opens.

DISCO3.CO.UK Photo Gallery - LR3 miscellaneous

I doubt anyone can check the regulator - normal test procedures show all to be OK.

Most shops, including alternator shops, do not understand PWM regulators as they are just starting to be installed in domestic production. Chrysler and Ford are just starting to use them in some vehicles; GM, I do not know about.

Also the ground cable off the battery, a short thing about a foot long can be internally corroded and cause problems. I put a new one on my 3 when I was trying to figure out the problem. As it turned out, the ground cable was OK; installing a new alternator cured the problem but there was no real indication of the alternator being "bad". Actually I had to install two as the first replacement did sort of quit.

Also if you are replacing your alternator, count the number of grooves in the pulley; there seems to be two pulleys out there - five and six groove. The first replacement alternator had the correct pulley, the second, not! That meant a new fan belt as well once that was discovered. - and then the hard reset to get the radio going again.

And yes, a year later, all is good again - well I did have to put a new starter motor in and that was again a can't diagnose it kind of probem, but may as well just put one in and see if the intermittent starting concern resolves itself. It did.

Throughout it all, I was never actually stranded.

One thing I did do was put my 3 on a CTEK US3300 charger pretty much every night for a year - fully charged battery, no problems for most of the day.