e46 n42 head gasket

So, as I mentioned earlier I replaced my expansion tank due to it emptying itself at a rate of knots as I thought it was probably the well documented problem of a cracked expansion tank.

Unfortunately I could not see a crack in the old tank and upon refilling I found out what the real culprit was. When I started the engine with the expansion cap off I noticed that there were a lot of bubbles in the coolant, it was almost frothy. Furthermore, it didn't seem to matter how many times I ran the engine and bled the system there was always more air coming out.

I went for a drive and came back to find that there was coolant all down the outside of the expansion tank, just as there had been with the old tank.

I found that if I revved the car past 3000rpm at idle coolant would exit the tank via the expansion cap. The expansion cap of course is also a one-way valve so that coolant can exit if the pressure in the cooling system gets too high.

Having seen almost identical symptoms on a VW Polo, I decided the most logical conclusion was the head gasket. Everyone thinks about oil in the water or vice versa when it comes to head gasket failure. However, it is also possible for a gasket to blow between the cylinder and the cooling jacket. This lets exhaust gases into the cooling system, which subsequently pressurises it and forces coolant out of the expansion cap. It is also possible for it to go the other way and for coolant to be burnt in the cylinders, but this was not my problem.

Bizarrely, I wasn't experiencing any overheating and it seemed to leak more when the engine was started and stopped so I actually made it to my brothers in the South of France. This was a slightly nerve racking experience as the coolant light was permanently on. I simply stopped every couple of hours, let some air out, put some coolant in and then carried on.

I covered 1500 miles and used ten litres of coolant on that journey.

I didn't have an in-car heater for most of it either, so it wasn't the most comfortable of journeys!

I have always fancied a 6 cylinder engine and with a newborn around I didn't want to be faffing around with a head gasket change, so I decided to use this as an excuse. I sold my trusty 318i touring for a e46 330i touring.

So it was a fond-farewell to our trusty 318i SE ...

And I warm welcome to our new 330i M Sport:

e46 n42 Bottom Hose Confusion

So I was about a week away from visiting my brother in the South of France when I got in my touring to find the coolant light was on. I lift the bonnet and unscrew the expansion cap to discover an empty header tank.

It had been a slight loss of coolant over time since I got the car which I hadn't been able to trace so I just put it down to that, filled it up and forgot about. A couple of short journeys later she was empty again.

There was a lot of coolant on the outside of the expansion tank so I assumed I had fallen victim to the well known cracked expansion tank issue. I ordered up a replacement expansion tank and fitted it.

However, when I filled it back up with coolant my original top and bottom hoses leaked, it seems the o-rings that seal them don't like to be disturbed. Unfortunately BMW don't sell them separately and you have to fork out for the full pipe. I am sure I could've found o-rings to fit, but I was in a rush as I was about to drive to France so I wanted a permanent reliable solution.

However, getting the pipes from BMW was harder than expected, the BMW diagrams are not 100% clear and the car differs quite a lot from the six cylinders. I needed to replace the top hose and the pipe which attaches to the middle of the expansion tank.

So, originally the technician ordered completely the wrong pipe. I had to take pictures to get him to believe me that it was the wrong part. So I will try and describe the problem as best I can just in case it helps someone else:

The problem is this parts diagram which I've taken from realoem.com (the dealer's was identical) ... According to this diagram the large pipe (no 4) that runs underneath the radiator from the thermostat/water pump attaches to the middle of the expansion tank:

I thought the pipe was incredibly expensive when I ordered it (even for BMW) because the pipe I actually wanted is this one (no 7):

No 7 runs from the middle of the expansion tank to the heater matrix and is quite short, and has one of BMW's plastic attachments at one end and a jubilee clip at the other...

However, the dealer looked at the first picture first and it took quite alot of too-ing and fro-ing to get the correct pipe.

The large pipe actually attached to the bottom of plastic bracket that holds the expansion tank to the radiator (no10):

This is a different set up to the six cylinders which don't have anything going into the bottom of that bracket. You can see in this picture that there is a connector for a pipe sticking out of the bracket, this is where that long bottom hose attaches...

Hopefully that makes sense and saves somebody some time with the dealer! Unfortunately, after all that, the car still had a serious cooling problem... check my next post to find out why.

BMW 3 series 318i e46 n42 Sump Gasket Replacement DIY

My N42 engine, like every other N42 engine has so far leaked from all the known trouble spots and the sump gasket was no exception. It wasn't serious enough to be leaving oil on the ground, but I found I was getting quite a lot of clutch judder when the car had been left standing for a while and I was concerned that the oil was leaking backwards on to the clutch.

There don't seem to be many DIY's around for this job as people seem to be put off by the prospect of lowering the sub-frame  I've done a few big jobs on various vehicles so I felt up for the challenge, but I did arrange for a friend to help me just in case it turned out to be a real pig.

However, on my car I didn't find it to be too difficult at all and with an extra pair hands we had the job done in one Saturday. Due to the lack of DIY's I thought I would write one up as it may help somebody else do theirs.

I followed the procedure detailed in the Haynes manual, although I found it to be incorrect in a number of places. For starters it says you need to drop the anti-roll bar and the lower auxiliary belt pulley.  This is odd because Haynes tells you to maneuver the sump out towards the rear of the car and we couldn't see how either of those items were obstructing it! I did drop the ARB anyway as I had bought new bushes for it, but I am not convinced it was necessary.

Haynes says you need to replace the reinforcement plate bolts, the sub-frame bolts and the engine mounting nuts.  When I spoke to BMW they said this is not the case, they said that there is nothing special about any of those bolts and they don't replace them.  I did buy the full twenty sump bolts as they have a dry thread locking compound on them and considering the effort required to get to the sump I thought I would err on the side of caution. I also bought a replacement rubber O-ring for the bottom of the dipstick tube, this turned out to be a good call!

This guide mostly follows the Haynes manual, so if I have missed anything it will probably be in there! I am assuming you have drained all your oil before you have started this job!!! :)

There are some photos missing, I plan adding a few extra soon when I jack her up to see if she is now oil-tight! :)

Start by jacking up the car and supporting it on axle stands.

Next, remove the large piece of air-intake that also exists to try and make things prettier.

Next, you want to get the air-box out of the way, start by removing these two bolts.

The air-box is also held in place by a Jubilee clip on the air-hose and a rubber grommet thing on a plastic box beneath it, both circled in this pic.  Once the bolts are out and the Jubilee clip is undone, you should be able to just pull it apart from the other plastic box.

Next, remove the engine under-tray   This is held in place mostly be screws, but at the front it is held in place by some awkward plastic pop rivet thingies.  You need to negotiate the middle part out and then it will be loose enough to remove the whole thing!

Next the lower re-reinforcement plate needs to come out (I believe that on older cars this is some sort of cross brace rather than a plate).  There are eight bolts that are probably quite stiff, but nothing a drop of WD40 and a breaker bar couldn't handle.

The reinforcement plate off the car.

Before you go any further, now is the time to set up your support beam and make sure it is secure.

I had a question about how the beam attaches, so I've added the following photos which are hopefully helpful. My beam had two feet, one at each end which were braced against the edges of the engine bay... At the front of the engine a bit of metal sticks out with a hole in it, this is where you hook in the chain...

The feet of the beam.

The hook for the chain.

Next, we the undid the two nuts on each anti-roll bar collar and dropped it down.  We couldn't really see why this was necessary and wouldn't have bothered at all if I hadn't have already bought some replacement poly-bushes to do while we were there. :)

Haynes also talks about removing the lower auxiliary drive-belt pulley, but we couldn't see why this need removing either so we left in place. (A good thing really as the bolts looked very rusty!)

Next, was the steering rack pinch bolt, this was an E10 spline bolt that was fairly easy to shift.  However, to get at it the steering had to turned. Once the bolt was removed, we turned the steering back and engaged the steering lock before removing the steering UJ, this is easy enough, just requires some pulling and wiggling.

Next, remove the bolts holding the wishbone bush 'lollipops' to the chassis.

Next, we removed the engine mount nuts. (Viewed here through one of the holes in the wishbone) Double check the engine support is ok.

Next, we supported the sub-frame on a jack and removed the sub-frame bolts. There are two on each side, they were relatively stiff, but again nothing a breaker bar couldn't deal with! ;)

You can now slowly lower the sub-frame until you have good access to the sump.  Haynes says to be careful not put any strain on the power steering hoses.  That's true, but in reality we found that the hoses were quite long and we had ample room without being close to straining them.

One last component to undo:

This is a push-fit plastic breather hose (goes back to the crankcase breather valve) which attaches to the oil dipstick tube. Mine didn't want to play ball and was a little awkward to get off. I think I managed it with a screwdriver by inserting it inside the collar and pushing/wiggling something.

You might not have any trouble with yours, but if yours is stubborn like mine, here is a pic that proves it does come off!

Next we had to unbolt the oil dipstick at the top of the engine and then wiggle it out (we did try without removing it, but found the sump just got stuck.

Next, we undid the twenty bolts holding the sump in place and maneuvered it out towards the back of the vehicle.

Sadly, this is the only shot I took of the sump removed, but plenty of the engine internals!

There is a small rubber o-ring that sits at the end of the dipstick tube, I bought a new one of these and I was glad I did because the old one was incredibly brittle. The old one was stuck to the sump, however I fitted the new one to the end of the tube to try to ensure it didn't fall in to the sump (you'll see what I mean).

We cleaned it up, fitted the new gasket and then maneuvered it back in to position.  You need to guide the dipstick into the sump when maneuvering the sump into position. We found it impossible to get the dipstick in once the sump was bolted in!

Refitting as they say is a reversal of the removal.

BMW e46 Touring Rear Speaker Replacement DIY

I decided to write this DIY about replacing the rear speakers in my e46 318i Touring because there seems to be a certain amount of misinformation (or just a plain lack of information) on how to do it.

Haynes doesn't cover the rear boot trim in the e46 Touring and most of the forum posts I came across about the matter talked about how hard it is to do and you shouldn't bother.  However, most of these posters were happy to take their front door cards off to replace their speakers.

If you are reading this post then you are probably aware that the standard sound system in the e46 Touring leaves a lot to be desired and I was determined mine would have a sound system that was worthy of an otherwise great car.

I started by replacing the Head Unit, this was relatively straightforward.  I fitted one with a rear USB input, the cable for which runs into the glove-box and is attached to 16GB USB stick with a very large number of albums on it.  So I also removed the 6 disc multi-changer from the boot, I sold the Head Unit and Multi-changer over eBay and the combined price covered the majority of the price of the new stereo install! :)

However, the new head unit only showed up quite how terrible the original speakers are.  There is plenty of information on the internet about doing the front speakers.  I followed BSW's youtube video for removing the door cards and a separate DIY for the tweeter.

The sound was noticeably better, but was lacking bass so next I bought a small sub which wouldn't impede too much on boot space.  I fitted this sub with a plug for easy removal.  If I was going to do it again I may well do something like this: (especially since I have removed the multi-changer).

But I still wasn't happy with the sound.  So I then tried to find out how to do the rear speakers and this is where things became problematic.  Haynes doesn't cover the rear boot trim in the touring.  No problem I thought, there is a wealth of information on enthusiast's forums about various jobs for the e46.  But, unfortunately most people on said forums seem to think the rear speakers are too difficult and must involve some sort of black magic to get at.

Admittedly this put me off for a while, but I already had some speakers which I wanted to put in and eventually I bit the bullet.  It was looking at the data sheet on realoem.com that gave me the confidence, since it showed that the offending panel is only held in place by a few screws.

http://www.realoem.com/bmw/showparts.do?model=AX52&mospid=47662&btnr=51_3949&hg=51&fg=65

Despite what the forums say I found this job to be fairly easy and straightforward, I certainly didn't think it was more difficult than a door card.  And if you have any experience with removing trim panels you shouldn't either.  Just take your time and think logically and methodically and it should be easy enough.  It took me roughly two hours per speaker, but as always I reckon I could do it quicker now I know how to do it.

The following is a guide only and applies to a late model UK spec e46 with standard speakers, I can't help it if yours is different, but I doubt it is!

In my car the speakers were exactly the same as the front... which in my car meant I could fit 17cm component speakers with the relevant adaptor plates which you can get from eBay.

First things first, this is the panel we are ultimately aiming to remove (I will refer to this as the main speaker panel):

So, we start by removing the panel next to it which allows access to either the battery or the multi-changer (depending on which side you are working on).  The first trim panel we want to remove is the one by the boot opening which has an interior light in it, it is held in place by two screws in these locations:

With the two screws out the panel is still held in place with two plastic clips (the same type that hold the door cards on).  These clips are at the top where the panel meets the carpet, wiggle it a bit and then pull or pry it off and the panel should come off fairly easily.  You will either need to unplug the light or pop the light assembly out of the panel (I found the plug very stiff and found it easier to just pop the assembly out).  The next photo shows the panel removed and the clips I am referring to:

Next we want to remove the piece of air vent trim.

It is held in place by two more bolts, the first of which is just visible in the next picture (it also holds the main speaker trim panel in place).

Remove this nut now.

It is also held in place by a nut which is hidden under the piece of trim highlighted in the next picture.

To access it, we must first remove the two bolts that hold the roller blind clip in place:  

Once we have done that and the roller blind clip is loose we can lever up the plastic trim which surrounds it, it is held in place only by plastic clips.  It does not need to be removed, it only  needs to raised up to allow access underneath it.  Once you have raised it up, you will be able to remove the roller blind clip.

This is what you should see once you have done that:

In the highlighted area is a nut which secures the air vent trim, a piece of plastic trim which we are not going to fully remove and the main trim panel which we are trying to remove.

Undo that nut.

Now, you should be able to lift the top piece of plastic trim high enough to remove the air vent trim.

The air vent removed:

Once you have removed the air vent trim, you may as well free the top of the main speaker trim.

The next thing to remove is some sort of plastic rivet and they can be a complete pig.  Of the four two of mine came out relatively easily, and two were absolute swines, in fact I broke the one in the following picture and had to replace it with a good old fashioned nut and bolt! The idea is that you remove the middle part of the clip and then the whole thing will come out, hopefully yours are not as stubborn as mine.  If you have removed your engine undertray before then this is not the first time you have encountered these... except these ones have probably not been removed since your car left the factory!

 Next you can remove the piece of plastic which surrounds the metal clamp for the rear seats.  This should be fairly easy, the clips at the top of it are designed to come away first.

Next, you need to remove the two bolts behind the luggage strap clamp.  These came out easily enough, but I had trouble lining them back up on one side... re-fit them sooner rather than later.

And finally, there is another of those annoying plastic pop rivet thingies at the bottom of the panel.  Remove your boot floor and you should see it.

Once you have removed that the panel should be free... just remember that on one side there is a 12volt socket which needs to be unplugged before you can fully remove the panel! :)

And there it is the offending rear speaker:

Fit your new speakers and then refitting the panels is a reversal of the removal as they say.

Personally it makes a difference and I am now pretty happy with the overall sound of my system and it is a million miles from the tinny rubbish that used to be in the car.