Cheap and mostly cheerful BMW i3

[IainWhy]

I will update on the Mclaren in a bit but thought some of this may be useful into the public domain.

So, in brief, we have had this for a few years, its basically my wifes car. Her previous car was a fiat 500 abarth, this was a fantastic car but with two growing teenagers, a dog and occasionally me it was a cramped affair. it was also starting to get a little leggy.

Being that the reality is that she just drives whatever is supplied my default state is something turns up on the drive and she either likes it or doesnt, if its a thumbs down then its lifespan is very limited.

Living where we do i was "electrically curious", I felt I had a decent understanding of the physics of it and i understood the efficiency opportunity, however, i didn't want to spend a load of money on something that could be poorly received, alse i would sooner spend money on pointless things like the Mclaren.
and
I settled fairly quickly on a bmw i3 as it was small, but bigger than the abarth and (consider this was a few years back) comparatively cheap.

A mooch on ebay turned up a can that had problems, mainly that the Rex, was not Rexing, the engine would run very briefly and then shut off and throw a red drivetrain error and misfire codes, the car had had a larger screen fitted, been lowered and had some spacers and some uprated speakers

I had a chat with the seller who was a master mechanic and had owned the car for a long time but had ultimately lost interest in it, he concurred that most probably the rex would need to come out as probably the timing chain had stretched. I was ok with this (i had never driven or worked on one but ignorance is bliss)

We agreed on £3600 for the car as it stood and i went down with my long suffering mate and collected it with a trailer.

It had had a life, the interior was a bit minging but it moved about on its own and had an mot.

I got it back to my mates and cleaned the living st out of the inside, then we dragged it a bit closer to the Liverpool ferry port before kicking me out of the trailer and tlling me to ps off.

So i pissed off with 40 miles of range and a broken range extender in my first EV drive

it was fine



Having got it back i cleaning the living st out of it and gave it a hard polishing, taking the external condition from poor, to ok






Having sanitised it it was just driven about for a while using just the battery, in all honesty this was fine, it s (and is) doing about 70 miles on a charge in summer, 60ish in winter and the reality is for local duties your rarely doing more than 40 miles in a sitting on a day to day basis.

Nero gave the car a provisional thumbs up on the basis it was nt constantly coming up with drivetrain faults.

I figured i may as well get after it.

Long story short, i pulled the top off the engine and it looked absolutely mint inside, having eventually rotated it the timing marks on the sprockets looked ok, and the chain didnt actually seem slack, soooooo.

I decided to give the cam timing block a wiggle big block on the (end of the cam)



And found it was loose, that would be the misfire issue then....

Problem was i had no idea where it should be, and it needed to be absolutely correct, not kind of correct. The engine is a 2 cylinder 650cc scooter motor, so i went hunting for pictures of scooter camshafts and eventually got lucky with one that was at a usable angle to calculate the position relative to another fixed point, the lobe.

so i mapped this into fusion360 and then scaled the measurements from the image back onto the timing gear.



I now had a good idea where it should be, but i needed to remove it and stop it flapping about.

Removing it was not too bad, manifolds off etc etc cover off, cam ladder off and i could then tilt the cams upwards and drive it off with a spanner and hammer.



however the reluctor ring was some sort of insanely hard and very heavy sintered material. It laughed off all efforts to drill it



We eventually got into it with a carbide milling bit but it was a pain. i have some really nice taps that i managed to use to cut a thread in it, but one of them has never been the same after the experience, and to add insult to injury the bd thing cracked while tapping it.

Being sintered it was full of old engine oil making it unweldable or so i initially thought, however a caveman solution came to mind, set it on fire and burn the oil out!



You can see the old dirty engine oil running out of it as it burns.

With that sage over i managed to tig it and get a grub screw in the fking thing



With that done i scribed in an alignment line so i could align it with the cam lobs and smacked it onto the end of the camshaft, and locktited the grubscrew in



With it all back together and all the engine codes cleared, it ran like a top, all be it it sounds like a bloke on a scooter is following you about but otherwise mint.

Its now covered 20k miles with no rex issues since the repair (and subsequent service)

Next up (when i can be arsed)
Air con pump failure
Traction battery failure
Bit of the roof falls off
and engine mounts

Oooh the excitement

[macron]

fking good effort to fix that!!!!

[E-numbers]

Excited!

Interesting to hear the rest when you can be bothered.

[tgr]

That is top level commitment!

Great little cars, would love one but have no home charging

[Mad Maximus]

That’s some top tinkering, always liked these. What’s your background if you don’t mind me asking?

[Hoofy]

Bloody hell. Good work.

[POIDH]

I really like these cars.
I wish BMW and others would look at these, or Honda e, and see the market potential for a small, light EV with a nice interior...

[Gad-Westy]

Great effort there OP! Inspiring.

I'm quite tempted by a cheap REX at the moment. They escape the higher tax of the BEV (and will be lower tax if pay per mile comes in too) and I think at the cheaper end of the i3 market, i.e the small battery cars, the REX seems a more usable prospect.

I presume you cannot buy a new camshaft with the reluctor ring in situ? I wonder how it is held on when new.
I assume the car could still be driven as a regular BEV while the engine was out of action?

What's the deal with the failing traction battery? Ouch!

[Hoofy]

Gad-Westy said:

Great effort there OP! Inspiring.

I'm quite tempted by a cheap REX at the moment. They escape the higher tax of the BEV (and will be lower tax if pay per mile comes in too) and I think at the cheaper end of the i3 market, i.e the small battery cars, the REX seems a more usable prospect.

If you want it for the REX functionality, you might be better off with a cheap "normal" PHEV. The REX function is limited to filling up something like 10 litres of petrol which gives you 80 miles of range. I guess it depends on your usage as the EV range is pretty good as a PHEV (200+ miles?).

[SJfW]

IainWhy said:

With it all back together and all the engine codes cleared, it ran like a top, all be it it sounds like a bloke on a scooter is following you about but otherwise mint.

Its now covered 20k miles with no rex issues since the repair (and subsequent service)

Next up (when i can be arsed)
Air con pump failure
Traction battery failure
Bit of the roof falls off
and engine mounts

Oooh the excitement

If this counts as "mostly cheerful" I would hate to see what you consider miserable!!

[Shaoxter]

Good job saving it, that would have been an uneconomical repair for most people.

[IainWhy]

macron said:

fking good effort to fix that!!!!

I did feel smug for about 2 minutes, but it passed quickly when i noticed the rocker cover had a weep.

E-numbers said:

Excited!

Interesting to hear the rest when you can be bothered.

Will do one tonight so i dont have to do something more productive

tgr said:

That is top level commitment!

Great little cars, would love one but have no home charging

Its a shame that all the providers of public charging seem so hell bent on fleecing the absolute st out of everyone, feels like something that should be regulated i.e. no more than x price over cost.

Mad Maximus said:

That s some top tinkering, always liked these. What s your background if you don t mind me asking?

Much like my school report, "a lifetime of unfulfilled potential" I was an apprentice greaseball briefly, then went to work in telecoms, then went to work for a private bank.

Hoofy said:

Bloody hell. Good work.

POIDH said:

I really like these cars.
I wish BMW and others would look at these, or Honda e, and see the market potential for a small, light EV with a nice interior...

There is a spurious argument that weight in EV's is less important as your recovering it, however its apocryphal as your recovery rate is so much lower than your consumption, its a bit bizarre that no one has really done anything like the i3 since it went into production as with modern battery densities i think it would have incredible range, or be even lighter. I can only put it down to a combination of production cost and the range fixation that means people will only consider an EV if it can cover their annual milage in one charge.

Gad-Westy said:

Great effort there OP! Inspiring.

I'm quite tempted by a cheap REX at the moment. They escape the higher tax of the BEV (and will be lower tax if pay per mile comes in too) and I think at the cheaper end of the i3 market, i.e the small battery cars, the REX seems a more usable prospect.

I presume you cannot buy a new camshaft with the reluctor ring in situ? I wonder how it is held on when new.
I assume the car could still be driven as a regular BEV while the engine was out of action?

What's the deal with the failing traction battery? Ouch!

They are great cars and i thing generally highly reliable, buying the worst one available obviously has resulted in a higher instance of issues than would be normal but its only failed to move once, and that was at home, so in terms of outright failure, not too bad. I would go for the 94 ah rex as you will get a really usable EV range with the petrol backup. in reality we very very rarely use the Rex, but its a great tool to have in the kit as it just takes all the stress out and as you can turn it on and off as you choose (under75% charge) you can use it to stretch the battery say if you have a long persistent climb to help take the load.

Ours in theory has the least favoured battery being a 2014 60ah, but it will hit 100k miles in a week or so and its still doing about 70 on a charge, with a full tank in the rex adding a further 90 if you really needed it.

You could replace the cam but the timing gear is a friction fit, so you would need to drop the drive unit at the least as the chain tensioner is on the back of the assembly, the reductor ring is also a press fit, but due to its weight and the, er, "character" of the 2 cyl lawn mower engine had worked loose. I think its quite a common issue as I have seen a few owners reporting flames out of the exhaust which i would say is 99% due to failed ignition timing.

When the rex stopped working the car still worked fine on battery, just you had no backup and some warnings.

Will write up the traction battery issue, but basically it cost about £35 to fix it with a 50 Eur donation to a guy in the CZ for some pointers as to the underlying issue. the battery in the car is the same one was born with, just with a replacement module, all the cells are as was.

Hoofy said:

Gad-Westy said:

Great effort there OP! Inspiring.

I'm quite tempted by a cheap REX at the moment. They escape the higher tax of the BEV (and will be lower tax if pay per mile comes in too) and I think at the cheaper end of the i3 market, i.e the small battery cars, the REX seems a more usable prospect.

If you want it for the REX functionality, you might be better off with a cheap "normal" PHEV. The REX function is limited to filling up something like 10 litres of petrol which gives you 80 miles of range. I guess it depends on your usage as the EV range is pretty good as a PHEV (200+ miles?).

Kind of disagree, the rex is a different thing, its not linked to the wheels in any way, as such while its considerably more complex than a BEV its less complex than a full PHEV a decent 94AH Rex should give a combined range of close to 200 miles.

[IainWhy]

SJfW said:

If this counts as "mostly cheerful" I would hate to see what you consider miserable!!

Well its always cheerful if it doesn't leave you at the side of the road (its not done that yet) and the cost to fix it is low.

off the top of my head
Fix rex - essentially - £0
fix Ac compressor - £160
traction battery - £90
engine mounts both sides with the bracket replaced - £180
bit of roof (this was a pain in the arse tbh) - £150
replaced all brakes - £160
Some tyres (these are unreasonably expensive) say £300

its done about 18k in our ownership so that's about a grand in total repairs and maintenance over that time, but its now got a lot of the common issues (engine mounts being a big one) sorted out, so its kind of tricky to calculate, i would hope that its got a reasonably long period of minimal problems, though that said i do need to do a CV boot.....

Buying a good one would definitely allow you to dodge some of these costs, but likely not all of them

[Hoofy]

IainWhy said:

If you want it for the REX functionality, you might be better off with a cheap "normal" PHEV. The REX function is limited to filling up something like 10 litres of petrol which gives you 80 miles of range. I guess it depends on your usage as the EV range is pretty good as a PHEV (200+ miles?).

Kind of disagree, the rex is a different thing, its not linked to the wheels in any way, as such while its considerably more complex than a BEV its less complex than a full PHEV a decent 94AH Rex should give a combined range of close to 200 miles.

Yeah, I know, it just charges the battery, which is why I said he might be better off with a "normal" PHEV. I thought the combined would be higher ie closer to 300 miles for the REX?

[IainWhy]

Hoofy said:

Yeah, I know, it just charges the battery, which is why I said he might be better off with a "normal" PHEV. I thought the combined would be higher ie closer to 300 miles for the REX?

I think if you could find a 120ah rex you would be closer to the 300, but likely still not quite there, the 94 would be about 200 ish and the 60 more like 170ish. the most i have ever seen on a "guess the range today" display showed 100 miles on the Rex

All that said i think it depends if this is your only car, it would not be my choice for doing bit miles, over 85mph its a bit wobbly and tends to follow ruts in the road due to the narrow tyre at 95 its a bit white knuckle and would be very tiring over an extended duration. these things are absolutely mega for the 20/40 mile daily grind are incredibly cheap to operate (particularly if you can sneak in a charge at work). but it wouldn't be my choice for daily distance if that was my requirement.

The fiat was the same really, you could if you had to, but it wouldn't be a preferred option

[Gad-Westy]

Hoofy said:

Gad-Westy said:

Great effort there OP! Inspiring.

I'm quite tempted by a cheap REX at the moment. They escape the higher tax of the BEV (and will be lower tax if pay per mile comes in too) and I think at the cheaper end of the i3 market, i.e the small battery cars, the REX seems a more usable prospect.

If you want it for the REX functionality, you might be better off with a cheap "normal" PHEV. The REX function is limited to filling up something like 10 litres of petrol which gives you 80 miles of range. I guess it depends on your usage as the EV range is pretty good as a PHEV (200+ miles?).

Not so much the rex functionality, more just an insurance policy because the 60ah battery range is pretty small but theoretically would be fine for us. Just good to know there is an engine there if caught out. The lower tax costs are a nice bonus but I suspect could easily be outweighed by higher maintenance costs. A bigger battery version would be nice but at the very bottom end of the i3 market, it's 60ah BEV vs. 60ah REX only.

[IainWhy]

Gad-Westy said:

Hoofy said:

Gad-Westy said:

Great effort there OP! Inspiring.

I'm quite tempted by a cheap REX at the moment. They escape the higher tax of the BEV (and will be lower tax if pay per mile comes in too) and I think at the cheaper end of the i3 market, i.e the small battery cars, the REX seems a more usable prospect.

If you want it for the REX functionality, you might be better off with a cheap "normal" PHEV. The REX function is limited to filling up something like 10 litres of petrol which gives you 80 miles of range. I guess it depends on your usage as the EV range is pretty good as a PHEV (200+ miles?).

Not so much the rex functionality, more just an insurance policy because the 60ah battery range is pretty small but theoretically would be fine for us. Just good to know there is an engine there if caught out. The lower tax costs are a nice bonus but I suspect could easily be outweighed by higher maintenance costs. A bigger battery version would be nice but at the very bottom end of the i3 market, it's 60ah BEV vs. 60ah REX only.

I would take the rex every time, works very well, only in very cold situations does it run a bit short in term of output, and even them i don't believe we have ever seen the available power curve be restricted

[Hoofy]

IainWhy said:

Hoofy said:

Yeah, I know, it just charges the battery, which is why I said he might be better off with a "normal" PHEV. I thought the combined would be higher ie closer to 300 miles for the REX?

I think if you could find a 120ah rex you would be closer to the 300, but likely still not quite there, the 94 would be about 200 ish and the 60 more like 170ish. the most i have ever seen on a "guess the range today" display showed 100 miles on the Rex

All that said i think it depends if this is your only car, it would not be my choice for doing bit miles, over 85mph its a bit wobbly and tends to follow ruts in the road due to the narrow tyre at 95 its a bit white knuckle and would be very tiring over an extended duration. these things are absolutely mega for the 20/40 mile daily grind are incredibly cheap to operate (particularly if you can sneak in a charge at work). but it wouldn't be my choice for daily distance if that was my requirement.

The fiat was the same really, you could if you had to, but it wouldn't be a preferred option

Interesting stuff. I definitely see the Rex as a city car. Perfect for popping to the shops, doing the school run or the commute to work on the other side of town. It's what I use my PHEV for (with its paltry 30 mile range (no heating or A/C!)). The advantage of my Golf is that for a longer run or a country lane, you're basically in a slightly heavier GTI. I did consider a Rex - wondered how useful it would be to carry two 5L cans of petrol in the froot for more mileage on a longer run. Park up at the side of the road or a motorway services car park to fuel up rather than be at the mercy of their prices.

[Dog Biscuit]

An absolute Billy bargain now you've fixed it.

Fab work

[biggbn]

Brilliant. My dad just bought one. Not cheap but I'm hoping it brings him great cheer. He's 80 years young, first ever, hope it sees him out!!