Removing Toyota Sera engine.
Removing and replacing a Sera engine is something that can be tackled by an amateur mechanic & assistance with a moderately comprehensive toolkit. The only specialist equipment needed is an engine crane – these can sometimes be borrowed or rented or a block and tackle can be used on a sturdy beam. You may need to borrow a larger socket for the front hub nuts.
Rather than a step by step guide, I’m covering the major areas. Make your own notes, take drawings and photos as you go. Whilst I don’t think you can get the wiring wrong, referring to photos for routing is helpful.
The way I do it is to remove engine and gearbox as one unit, lowering them to the ground, then lifting body and sliding engine out from underneath.
Depending on your working area you may find it advantageous to remove the bonnet. 4 bolts and split the screen washer hose. That parts really a two person job. Store safely on something soft so you don’t damage the paint. However, it can be done without.
Position the car into the working area. Disconnect battery. Apply handbrake. Drain coolant (tap on drivers side lower tank) and once drained, dispose or store coolant and remove radiator. Two water hoses – top and bottom and if automatic two oil cooler to gearbox pipes, all held with spring loaded clips. Radiator fan will unplug and the top radiator support clamps can be undone and the radiator lifted out.
The next job is to remove the front section of exhaust. There is a clamp on the downpipe to remove, and you have two bolts to separate the downpipe from the catalyst. These may be difficult to undo. I would use a 6 point socket to reduce chance of rounding. I’ve not known one shear, but they can be bl**dy difficult to undo. At the other end you can either remove exhaust at the manifold to head joint or between manifold and downpipe. If you remove at the cylinder head you have to remove the heat shield – there are 4 10mm bolts which often shear off – penetrating fluid such as WD40 may help. Whilst you are underneath undo some wiring – knock sensor on rear of block, as well as starter motor and alternator wiring.
There are some trims to undo – a LH and RH undertray.
Remove each wheel and remove the hubnuts. There should be a split pin to remove, with a castellated cover. Then you need to undo the hub nut, but you may find it useful to have someone one the brake pedal to offer resistance. Once that is undone you can undo the two bolts holding the upright to the shock absorber, and then you should be able to knock the driveshaft out of the front hub. Reassemble damper, but don’t fully tighten.
I would then slacken the belt that drives the power steering pump and the air conditioning compressor, and then unbolt both pumps. The Power steering pump will sit on the inner wing area quite happily (assuming the car doesn’t have ABS), and the air conditioning compressor will unbolt from the block. Tie up securely in such a way that strain isn’t on the hoses.
Now the jobs are to disconnect wiring and hoses. The is a fuel supply and a fuel return hose to undo, cable tie up so they don’t drain. You can take off the flexible hose between airbox and inlet manifold. You have already removed half the cooling system, the other section is the two pipes from the engine to the heater matrix on the bulkhead. Most of the wiring has unique plugs so it’s a question of systematically unplugging things. There should be no need to In some places the loom is clipped to the engine or gearbox, and the clips have a tine which releases the clip from its metal mounting tag. The hardest to get at is the knock sensor which is best accessed whilst doing the exhaust. The throttle cable can be loosened and unclipped, and there are some thin vacuum piping going from inlet manifold to bulkhead, and from inlet manifold to power steering rack. These should easily pull off.
The clutch hydraulics can be unbolted from gearbox (if manual). If automatic, there is a selector cable to unbolt and a couple of electrical connectors.
You should now be in a position to lower the engine and gearbox. Put something on the ground – a small trolley, some matting, sheet of plastic to make it easier to drag the engine out with. Attach the engine crane to the engine using the hooks on the engine in such a way that there is sufficient downwards travel. The top engine mount splits in two, and there is a hidden bolt underneath to get at. You don’t need to dismantle the rubber section from the car. The gearbox mount unbolts easily and the rear gearbox mount should undo. The engine and gearbox can not be lowered to the ground, the crane reslung and used to raise body fairly high and the engine and gearbox can be slid out.
The gearbox can be separated from the engine, and the replacement engine attached. Whilst out its an opportunity to wash down components and the engine bay or fit new water pump / timing belt / clutch kit.
Reassembly is really just the reverse of dismantling.
This job is the sort of job one person or two people can achieve over a weekend.
As usual, take precautions – don’t rely on jacks when working underneath a car – use axle stands.
Tools – most of the smaller fasteners will use a 10mm, 12mm or 14mm spanner / socket. 13mm were not used by Toyota, but if the car has been in Europe for some time, you may find one or two have been fitted.
Some wide pliers are useful for some radiator hoses, and needle nose pliers are handy for the smaller clips.
The most difficult item will be splitting the exhaust due to age / rust.
The fiddliest thing to do is removing the knock sensor wiring.
Everything else just requires a methodical approach.