BMW E30 323i Spec Comparison to contemporary early-80s rivals...

How does the E30 stack up next to its five most common early 1980s stablemates, the MG Montego Turbo, Peugeot 505 GTi, Renault 25 GTX, Saab 900 Turbo and Subaru RX Turbo?

Great review from MOTOR Magazine, November 1985.

BMW M20 Engine: Front Timing Marks [Front Timing Cover]

Here is a great diagram someone (not me) has made to show the front timing marks for the M20 engine series. Handy. 

M40 engine timing marks HERE.

E30 318i: Speedometer / Odometer faults + check list

If your E30 speedometer is broken, your odometer isn't turning or both, then here is a troubleshoot check list to find and fix the fault. Doing the work yourself is a bit fiddly, but totally doable if you are handy with a soldering-iron.

** A more detailed guide / thread all about E30 speedometer / odometer faults by 03IRM3 on r3vLimited.com is here - https://www.r3vlimited.com/board/forum/e30-technical-forums/general-technical/59019-e30-speedometer-repairs-failure-modes, which was a great help. **

NOTE: If your speedometer is not reading, before starting to diagnose the instrument the first thing to check should be if there is a pulse being generated by the speed-sensor in the differential, see E30Zone Wiki here.

Broken Odometer drive gear.

This is the most common problem when the odometer has stopped turning. The drive gear from the stepper motor that turns the larger cogs tends to split on higher mileage cars causing it to skip teeth and not turn the odometer gearing. Replacement gear sets can be bought from eBay for a few quid.

Burnt out resistor.

This is the main power resistor on the 12v + input to the PCB and it's never usually failure of this component that causes it to burn out. Instead, failure of a component further upstream is usually the culprit by drawing way too much current, causing the resistor to work double-time and overheat. This one was still working amazingly, given the heat it had been producing that charred everything around it, but I threw a new one in anyway. The value was about 150 ohms, so that's what I went with.

Blown capacitor.

Sudden failure of both speedo and odometer can often be down to the main power capacitor blowing. This is visible in the above pic to the right of (and next in sequence to) the burnt out resistor. It's a basic 220uF electrolytic capacitor and is very simple to replace with only two pins needing de-soldering, so should be the first step in troubleshooting a dead unit, even if the cap itself doesn't appear blown. Mine had been scorched by the overheating resistor, but seemed ok. I replaced it anyway, but it did not help with mine.

Snapped wire on Odometer stepper-motor coil.

This is rare, but does happen as 03IRM3 has seen one and mine had this too so I guess it does happen, where one of the single strands of copper coil for the stepper-motor snaps off its pin on the PCB. It’s possible that this happens due to time/age and vibration in the vehicle, but could likely be due to manhandling the unit while it is out for other repair work. Either way, it’s an easy fix to just solder it back in place and will be stronger than it was before at least.

UAF chip blown.

If none of the above fixes have worked and both speedo and odo are still not working, the likely culprit is that the UAF I/C chip has malfunctioned and is not processing inputs and outputs correctly, which leads to the resistor burning out, caps blowing and the odometer coil overheating. These UAF2115 chips are common, used in many speedo/odo units, taxi-meters, tachographs etc., so replacements can be found on eBay or electronic component sites for a few £/$, but this is probably the most advanced fix needed for these units and the question at this point is whether it's worthwhile. 03IRM3 has replaced chips as a last resort only to find the unit still won't work, so I decided that with all other fixes not working and my odometer still needing new drive gears that it was time to junk it and seek a replacement unit... [THIS POST].

BMW M40 Engine - how to check timing, where the marks are located

This must be one of the hardest bits of info to find in the whole world of BMW, but there is a great post on BMW Werks on how to do it [https://www.bimmerwerkz.com/threads/m40-motor-timing-info.59059/].

QUICK TIMING CHECK GUIDE:

** Only if crank pulley has NOT been separated from crankshaft! **

1. Remove the distributor / timing cover at the front of the engine.

2. Check the timing mark on the crank pulley. This is an arrow cast into the block which should line up with the sprocket tooth to the right of the gap in the teeth, as in pic below.

3. Check the timing mark on the camshaft pulley. This is a notch/line mark in the pulley and should line up with the right-angle notch in the cylinder head, as in pic below. If this looks good, your timing is fine.

Thanks again to xdrian on BMW Works for making these pics and sharing this secret!

E60: 530d Replacement Engine - the time has come!

Im not a fan of engine swaps, they never go perfectly, but with the amount of effort and cost required to fix my original lump, I've decided to bite the bullet and spend the money. After all, I bought the engine-crane... it was as if I knew what was coming.

Here is my new donkey, cheaper than the going rate at £900, but still on the pricey side. Even if I remove my broken engine and put it on a stand to rebuild, the minimum cost will be about £400 for the new piston / timing-case and it will take a lot of evenings work. On top of that, my current engine, the one that was strong as an ox and never had a major problem until that swirl-flap fell in, still has nearly 140k miles under its belt. This new one has just 78k - nothing for one of these, so I guess the extra spend will be worth it and I am absolutely assured that this one has never had swirl-flap damage. It'll arrive on Monday, so it's high-time I booked some holidays from work and fixed the mothership! Oh, and er, continue renovating my new house... Jeez, maybe a month off work would be in order!