E46 318i Touring: New front drop-link for MOT

The 318i Touring was up for MOT this week and failed only on the O/S front anti roll-bar link. Normally I would replace these as a pair, which would have been more cost effective as you can get a set of two from eBay for under £15. Time was an issue and I wanted to get it back for a re-test so had to buy one from Euro Car Parts for the same price, around £15. Annoyingly, the eBay pair were Lemforder and the single piece from ECP is Starline, but needs must.

The car has only just passed 104k miles, so this could well have been the original anti-roll bar linkage and boy was it seized on. I only got a couple of turns on the top nut before the 5mm Allen-key in the stud stripped and rounded, so had to cut the rubber boot off to get a 17mm spanner on to the flats at the back. Even so, progress was painstakingly slow. Couldn’t even get a grinder in there as things are surprisingly tightly packed on E46. This made an otherwise quick and easy job last a bit longer, but it is nearly 20 years old.

F10 530d: N57 EGR / Cooler related fault-code scan results

 Been getting the 'Drivetrain' malfunction message on my F10 530d iDrive and figured it likely to be EGR (exhaust-gas-recirculator) related, so plugged in a Snap-On Modis scanner and these are the codes I got, which are what I suspected to be honest. The EGR and EGR-cooler are known to pack in on the N57 series of engine, the latter of which can leak coolant into the inlet causing a bit of smoke on startup. 

28E200 - Exhaust Gas Temperature sensor before Cat, open circuit

255C00 - EGR Controller, Position Control, Valve open too far

190900 - EGR Mass Air Flow, measured plausibility calculated too high

240400 - EGR Control, control deviation air mass too low

272F09 - EGR, mechanically faulty close to open position

272E00 - EGR, mechanically faulty close to closed position

So, I have the classic two codes of the EGR failing close to open and closed position, which denotes a stuck EGR valve, which is quite common on all diesel engines, along with the EGR mass-air codes where values are higher and lower than they should be, which clearly ties in to the valve sticking in the open and closed position. Faults for the EGR control-module show that it is struggling to position the EGR correctly and this all points to one stuck EGR valve.

I also notice that I am getting a bit of smoke on startup sometimes which I have never noticed before. This also points to a faulty EGR-valve, or rather the cooler itself. The EGR-cooler is fed with coolant to reduce the operating temperature of the EGR-valve itself and these are known to have problems with leaking after time. They crack inside after prolonged use and start to leak coolant into the EGR and thereafter the air-intake, which causes a bit of white smoke on startup, which I have been experiencing the last few weeks and so it looks like this is the culprit and I will be replacing the EGR / cooler unit at some point I would imagine... watch this space.

E46 318i: Front-of-cat o2 / Lambda sensor replacement [Fault Code 271D, 271A, 271B] [Rear-of-cat 271C, 271F]

E46 failed its MOT on the O/S rear tyre and O2 emissions too high. I duly replaced both rear tyres with a new pair sourced through work for just £23 each and they are V-rated so should be ok for the Touring. As for the O2 level being too high, I was told this was a fault with an O2 / Lambda sensor so I plugged in a Snap On Modis scanner to see if this was right.

The code I got back was 271D, as in pic above, which is the up-stream or 'front-of-cat' sensor heating. Codes 271A and 271B show fault at the same sensor, but are labelled directly 'front-ofcat-sensor' with no heating suffix. This sensor is located slightly forward of the catalytic-convert mounted about halfway down the car's underside, as in the diagram below. The one shown to the rear of the cat is the down-stream or 'rear-of-cat' sensor. Code 271C applies to this rear sensor, along with 271E for Rear O2 sensor-heating. The two sensors, though essentially the same, are different parts and part numbers due to the rear sensor having a longer wire. [List of emission based fault-codes here.]

I got hold of a used sensor taken from another E46 318i from www.marobmwspares.co.uk for £18. I prefer used OWM BMW parts that come with a warranty / guarantee over cheap spurious items. The least expensive spurious items start at about £20 for a sensor that can be used for either front or rear of cat, having a long wire than can be cut to length with two bare wire or universal wire-terminal ends that require the original plug to be soldered on from the broken sensor. On the other end of the spurious price range was Euro Car Parts, who offer an OEM-quality sensor for £68, which is pricey but comes with the correct wire-length and plug fitted.

My old sensor proved very tricky to remove with the car on fixed-ramps and I would not like to attempt it with jack and axle-stands. I was unable to crack the sensor off and unscrew it even with the use of special Lambda-sensor sockets and it began to round so I ended up booking ramp-time in the workshop of the company where I work and lifted the E46 Touring on a 2-post ramp to give loads of access underneath. To avoid the risk of breaking the Lambda-sockets or further rounding the sensor itself, I decided to cut about half of the sensor off using a 3.5" cutting-disc and used a 22mm deep impact-socket with a long breaker-bar to finally crack the sensor off. It was pretty seized on, but once cracked just unscrewed by hand. The replacement sensor screwed straight in and swapping / mounting the plug was easy to make for a 5-10-minute job once the car was positioned on the ramp legs.

RESULTS:

The emission test result went from 2.2, with a maximum of 2.0 allowed, down to just 1.0 with the faulty sensor replaced. There is also a significant drop in neat-petrol smell emitting from the rear of the car when it is started from cold, so I'm glad this problem showed itself and got fixed.

Article on /BMWTech subreddit: https://www.reddit.com/r/BmwTech/comments/d5v30t/271d_lambda_sensor_front_of_cat_which_one_there/

E60: Opening Stuck Bonnet.

PROBLEM:
The annoying turbo whine from my previous post can only be heard while underway and not while stationary, so the bonnet is up and down for every bit of work and test drive. After several such runs, the O/S (driver's side) bonnet latch refused to open. Nearly an hour was spent with a helper pulling the bonnet-lever while I tried to push / pull / wiggle the O/S bonnet up, but it was stuck solid. The front bonnet lip on the E60 (and all modern BMWs) extends right down over the slam-panel / grille and the latches are a good 6 inches up inside it. It's impossible to slide something up through the gap between the rubber seal and pop the latch from outside, as you can with older cars, so I turned to the internet and eventually found a superb solution.

CAUSE:
Yes, this is quite a common problem with the E60, especially when you are working on it at home. The cable splits in two and a separate one runs to each latch. The end of the cable fits through an eyelet on the 'release-switch' and is kept under tension by a plastic collar that fits into a notch in the latch-frame. If the plastic collar pops out of the notch, cable tension is lost and the bonnet-lever simply will not pull the release-switch far enough. Removing the bonnet-lever reveals a plastic-cage with the cable housed deep inside, so yanking that further with a pair of grips won't do either. If you've been working on the front-end of the car and changed the location of the bonnet-latches / slam-panel, even slightly, then there's a high chance the collar will start popping out.

SOLUTION:
There are a few forum threads saying the latch can easily be opened from underneath the car, with the front under-tray removed. This is true, but the E60 engine-bay is so tightly packed there is a bit more to it than that. I have to give props to Kilty1 on forum.BMW5.co.uk, for his amazing guide, linked below:

http://forum.bmw5.co.uk/topic/87159-bonnet-release-not-working/

Getting to the latch requires removal on the front under-tray, both pieces of the O/S brake air-duct and the plastic inlet-pipe that runs to the air-filter. These can all be removed from underneath the car, as shown in Kilty1's guide. He used ramps, though I managed to open mine with the car raised a few inches on an axle-stand. Looking up with a torch, you will just see the latch next to the inner corner of the headlight.

Luckily, my brake duct, inlet pipe and tray were already off as I was working on the car, so I could get straight to the latch and will just show a couple of steps and pics from Kilty1's guide:

1. Reach up and slide a steel-rule or similar slim/flat object into the bottom of the latch, just to the inside of the right-hand spring-wheel [shown on the left in the pic, looking from front]. When the steel-rule is far enough in there should be a small clunk. Now slide the steel-rule quickly out and the bonnet latch should release on the O/S. 

2. The collar doesn't take much to pop out, so to stop it from happening again as soon as you shut the bonnet, wrap a cable-tie round the back of the collar and round through the gap in the steel-frame. It will be solid.

E60: Snapped Head-Bolts! No progress.

Well this has been the most fruitless weekend to date. First I discover the simple sump cannot be removed without lifting the engine and lowering the subframe. I am now the owner of a Clarke engine-crane, not cheap at £179.99, but it moved the job along. Next I find that to lower the subframe, almost everything must be unbolted from it - anti-roll bar, steering-rack etc. - and, once the mounts are unbolted, there is nothing stopping the engine from dropping straight onto you if something fails. I figured if I'm having the engine suspended freely above me while I work then it's best to get as much weight off it as possible, so began removing the head. The camshafts etc. came out in record time, but when I got to the head-bolts at about 12.30pm, the whole weekend's work ground to a halt.

Magnet to catch metal swarf from the drill.

Ok, it happens to us all from time to time, but I didn't expect snapped head-bolts as an added problem with the 530d rebuild. First my E14 torx-socket burst open, causing a trip to Halfords for two new ones, then 4 of the bolts snapped. Four! What a pointless setback. I did the correct removal sequence, so I must have over-tightened the head or they're just not ready to come back out after only 2 weeks, but as I got down to the last two head-bolts one of them snapped in the most awkward way imaginable - just the top of the head, leaving the giant collar and washer still incredibly tight against the head. All the other bolts did crack off slightly, the almighty creaking sound, but after that a further 3 of them stuck solid and the heads duly snapped off one by one, despite re-tightening the surrounding bolts. This hasn't half messed up the un-tightening sequence and has put the rebuild completely on hold.

Determined not to be drilled off, the head was finally
cracked off with a chisel and screwed out by hand.

I battled away until 3pm with the drill-bits I had available to me, before caving in and rushing to B&Q to buy a new 8 and 10mm titanium, again not cheap at nearly £17! I placed a large block-magnet in the head next to where I was drilling and held a smaller one to the other side in order to catch as much swarf as possible, but I will still have to give the cyl.-head and rockers a good blast in the parts-cleaner at work. The plan was to drill down the centre of the bolt head, boring it out gradually wider until the head broke away from the washer. Life is never so simple. The hole was slightly off-centre, so part of the shank was still attached even though I'd drilled well down it, so I began reaming the hole around the bolt head as much as possible. It was still stuck solid, so as a final shot in the dark I drilled a smaller hole in the rim of the bolt head and hit it with a chisel. To my amazement it cracked off and I was able to drift it round enough to become loose. I tried repeating the chisel process off the bat with the other 3 bolts, but they're having none of it, so I will have to bear out the drilling and reaming again. This is not going to be a quick thing, let alone getting that subframe down. Ah well, another week passes.

Problems to overcome:

• Drilling out stuck head-bolts.
• Getting the subframe down.
• Identifying the correct piston type.
• Clearing the head of any drilling debris.
• Identifying main source of oil leak.