E30 318i M40: Camshaft and valve condition

I whipped the rocker cover off to check if there was a dropped valve or broken spring that might be contributing to the poorly idle, but no such defect found. In fact, this has to be one of the cleanest top ends I have ever seen. Nice!

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.

BMW M54 Engine Wiring Harness Diagram Illustration

Illustrated diagram showing the engine wiring-harness configuration on BMWs with the M54 6-cylinder petrol/gasoline engine family, showing connections to the Vanos, GCV, DISA Valve, etc.

“TIP: Ensure your CCV system is properly connected to the underside of the intake-manifold (and it is not damaged) before connecting all of these harnesses. It’s a huge pain trying to reach through all the wires to adjust or properly connect it.”

A different take on a wiring-harness diagram done in a hand-drawn artwork style, but useful none-the-less, so it had to get catalogued. Originally posted by u/feedthedonkey on the r/BMW Tech subReddit, who claims credit for the artwork.

E60: New engine tune-up Part 4 - Waste-gate + Pressure-converter.

After the last tune-up [here] the stifled boost remained. Up to about 2000rpm the power was ok, but after that, when the real boost is expected to come in, it wouldn't. Rev and noise would rise with no acceleration. All that exhaust gas was just escaping through an open waste-gate, signified by a constant 'dump-valve' style hiss. At this point i really got my head around the vacuum-actuated turbo setup and tested the vacuum-tank [3 in diagram] and each hose individually for leaks, finding nothing. In a last ditch attempt to try and get the E60 boosting again I replaced both the waste-gate [with the slightly shinier one from my old turbo] and the electronic pressure-converter that controls it [1 in diagram].

This finally gave some results. Boost is now back and the long drawn-out hissing has gone, though there is still a short gap in between low and high boost. If you are rolling slowly in 2nd or 3rd gear and plant the throttle, the car surges forward then hesitates with a hiss for a moment before full boost comes in and the hiss stops abruptly, however this is only noticeable when accelerating in this way. A slower rate of acceleration gives an almost unnoticeable transition to the point where full boost can be applied and the car pulls away. This is also true when cruising a bit faster in 2nd or 3rd, where the waste-gate has had time to shut and full boost acceleration is instant. This to me suggests there is still a vacuum problem and I will have to re-check the hoses going under the steering to the engine-mounts, as they're the only bits I haven't been over a dozen times. The car is useable at full boost now, so I know the new engine is running as it should and capable of giving the power I was used to before the troubles, but pulling away fast in 2nd from traffic lights is a bit long-winded and I find myself changing up to 4th pretty sharpish before I feel confident enough to grill it. Really though, how often do I need to pull away fast without waiting in gear for a second before doing so? Perhaps I'm asking too much...

The next engine jobs will be focused on smoothing the rough idle, though in the meantime I threw in a mixture of Cataclean and Wynn's Injector Cleaner to see if that helped - half of each bottle added to 30 litres of diesel twice. I'm sure it did some good to the engine, but apart from making it a bit peppier for a couple of weeks there was no improvement to the idling situation. If the vacuum problem is not to blame then one or more injectors could be failing. There may even be a problem with the DDE controller, though this is extremely unlikely.

Next jobs:

• Redo smooth-running measurement.
• Replace / recode injectors if necessary.
• Check oil on rocker-cover. Is it leaking from 10mm injector-studs to head?
• Re-check all vacuum-tubing and replace where possible.

Future things to do / buy:

• Rear ball-joints / ball-joint tool. [Advisory on last MOT].
• Swap glow-plug module.
• Intake manifold ring profile-gaskets.
• Rubber rear exhaust-hanger.

E60: Split Vac-line, some boost, weird noises.

The turbo whine and lack of boost has persisted, so I took off the inlet-manifold again to check the vacuum-lines and found one has snapped off. Luckily, there was plenty of hose left to cut it down and push it back onto the T-piece. I re-checked every line twice against the diagrams on RealOEM.com and refitted the manifold, making sure the seals were super flush. Now when I fired up the turbo started making a ridiculous whoosh and dump-valve style hiss, as in the vid below. Some boost had returned too, though not as much as there should be and certainly nothing like the turbo sounded. Still, the vac-line repair did get a result, so it looks there could be life in the turbo yet.

There was nothing else I could do other than pore over the vac-line configuration, so I made this quick one-piece diagram to show the route of the four coming off the servo-pipe to save switching between several diagrams on RealOEM. I then started pulling vac-lines off in order to find the faulty area and, amazingly, managed to get rid of the whoosh/hiss and still have some boost. The turbo is still whistling though and there is not enough pull as you get over 2k rpm, so something is still amiss.

• Split vac-line to swirl-flaps - Low boost, quiet turbo-whistle higher up.
• Repaired vac-line - Some boost low down, cuts out higher up. Loud whoosh and hiss noise, turbo-whistle constantly.
• Vac-hose removed from wastegate - Low boost, quiet turbo-whistle higher up.
• Swirl-flaps and engine-mount vac-lines switched round - Some boost, no whoosh/hiss, constant turbo whistle, less engine vibration.

The diagrams do not make clear the route of the red/black striped hose on the right of mine. This turned out to be the N/S engine-mount and another scan of RealOEM.com revealed how they work in the pic below. I had wondered about a problem with the engine-mounts anyway, as there seems to be a lot more engine vibration than before, especially on tickover, so my next job will be to find the pipes that link the mounts together and check their condition. They all run through the subframe next to the steering-rack. M57N is a complicated vacuum arrangement.

E46: Inlet full of oil! Re-con time.

Removed the inlet-manifold to check the CCV [crankcase-ventilator], crankshaft-sensor and main wiring-loom / connections. It didn't look too bad underneath, though there are some signs of a stuck CCV valve. I put the manifold down next to the car while I was working and after 5 minutes I noticed a large pool of dirty oil had run out of the throttle-body, so I placed that end in a bowl, jammed the butterfly open and leant the manifold on its end. Another 1/4 pint of oil ran out of it and today I removed the throttle-body entirely and managed to get about half as much again. More is coming, so I've blasted carb-cleaner back through the inlet-ports and left it to run down.

So either the piston-rings are completely shot and are leaking that much oil back up into the inlet, in which case the engine wouldn't run... or it's one heck of a stuck CCV. In this case, it would appear the crankcase-vent valve has stuck closed, which is allowing pressure to build up and pump oil back through the clean side of the CCV-system, dumping it right into the top of the throttle-body! Rather than creating a vacuum in the air-inlet that keeps the car at a decent idle, the CCV is pumping combustion pressure instead and covering all the sensors with hot oil. Not good. This is the most poorly engine I've ever seen.

While the throttle-body is off I may as well give it a good clean, along with all the sensors that had filled up to the wiring-connector with the pressurised oil. Even if this doesn't completely clear the rough running faults, it has certainly given the engine a new lease of like and it never does any harm to flush everything out and eliminate any further problems in the inlet.

E21 316: M10 Distributor/Ignition Timing: Strobe Light Ahoy!

So my adventures into re-timing the spark-plugs continue with the purchase of a Gunson Xenon timing strobe-light! I went for the cheapest kit in Halfords, but it was still a slight pain at £45, considering it's in addition to a new dizzy-cap and rotor-arm, set of spark-plugs, compression-test kit, gasket-set, oil, coolant and a 30mm socket to turn the engine from the crank, but as I just can't seem to get the old M10 engine running happily I guess it's just as vital and at least we can use it to time in our old MGA engine this summer (hopefully).

Before I start to moan again about the intricacies of re-timing the distributor I should say that I know there is no need to remove it in order to get the cylinder-head off and the dizzy should really be left in place to save all this trouble, but the diaphragm on mine was blocking one of the head-bolts so that wasn't an option for me.

The timing light works by flashing every time your 1st-cylinder spark-plug fires. There is a timing-mark on the spinning crank-pulley or flywheel that passes a stationary mark on the block at the exact point the 1st spark-plug should be firing. When the flashing light from plug 1 is aimed at the spinning pulley it shows the timing-mark in a fixed position in relation to the stationary mark and allows you to gauge how how many degrees before or after the correct point the spark is. Clever stuff.

On the BMW M10 engine, there are two timing-marks on the flywheel, one for top dead-centre [TDC] and another, called Z, that corresponds to the right point before TDC that the 1st spark-plug should be firing. The marks are visible with the flashing light through a small oblong hole at the back of the crankcase. It's easy enough to find the hole, but seeing into it with the timing-light is a challenge in itself, let alone trying to adjust it or move the dizzy-cap and I ended up having to stand over it with my feet on the strut-tops to steady myself enough without leaning in from the side and crushing the wheel arches. There is another TDC timing-mark on the rearmost rim of the front crank-pulley, which is a lot easier to see with the timing-strobe from the n/s of the engine-bay, but the mark is tiny so when you do find it it's best to file a larger notch across the whole pulley - mine had this done already and it makes things a lot clearer.

It's best to first time your engine to Z on the flywheel, at 2200rpm, using 0 degrees of advance on the timing-light gun - just shine it into the oblong hole and rotate the distributor-cap until the large pointer is lined up with the silver ball, not the TDC line. Now check the front crank-pulley for reference by shining the light at it with 0 degrees advance. The groove for TDC should appear around 25 degrees before the stud on the engine-block. Rotate the dial on the timing gun slowly to 25 degrees and the groove should move in line with the pin. Simples.

Ignition timing isn't too much of a fine art, so as long as the rotor-arm contact is roughly on point no.1 on the dizzy with the engine at top dead-centre then it should fire right up and not need much adjustment to find Z. Mine was still making the god awful noise after repeatedly timing to Z, but this turned out to be a badly positioned exhaust-manifold gasket [in this post] so, obviously, check everything else isn't amiss before starting to mess with ignition timing.

E21 316: M10 Misfire Woes:

Went on a Maccies run with some work colleagues on New Year's Eve and I may have been pushing the old girl a bit hard, when a horrible clanging noise began from the engine and got worse quickly. Some of the guys at work suggested the first stop should be the rotor-arm and dizzy-cap so we managed to get some delivered through the parts dept. that afternoon, but it was still chugging on a mixture of cylinders and it limped home for me then refused to start again. When it eventually did the old M10 barely managed to fire 3 cylinders.

My list of diagnostic checks was:

Replaced distributor-cap and rotor-arm.

Tested all 4 plug-leads.

Replaced all 4 spark-plugs.

Removed, cleaned and rebuilt Weber carb.

Checked valve-clearances and confirmed all valves appear to be moving correctly, turning the engine by hand.

Finally diagnosed cylinder 4 as no firing.

Plug and lead tested again, this time sparking against the suspension turret.

Compression test revealed Cyl. 1 and 2 @ 150psi, 3 @ 45psi and 4 @ 25psi.


This all seems to point to a bust head-gasket between the 3 and 4 cylinders. It is unlikely the valves for 2 cylinders would have bent or suddenly need adjusting at the same time, so off with its head and lets look at that gasket.

*UPDATE: The head came off pretty quickly and revealed one seriously blown head-gasket right between the 3rd and 4th cylinders [detailed pics in this post]. Diagnosis spot on, but the culprit may be a slight warping at that end of the alloy-head - not very much at all, but still a worry considering it looks to have been skimmed before. Either way, the new head-gasket is on [I went for a full head set off eBay for £27.99, which includes the manifold gaskets etc.] and the car is running on all four cylinders again, though not as happily as it could be. I was forced to remove the distributor and seem to be having some issues with ignition timing since putting it back [in this post], and the carb. still hasn't been tuned properly since the rebuild, so a range of fettling awaits before I can drive it for the first time in 2013.