This order of events makes no sense to me, I'm hoping someone here can see some possible link between them that I can't. Car is a 1998 Toyota RAV4 automatic, FWD:
- I had a car-not-starting problem (clicking, no starter) which I fixed which turned out to be electrical, I recharged the battery, changed fuses and taped over a section of wire that had become exposed, and the car started fine.
- A mechanic I'd booked to look at the electrics before I realised I'd fixed it myself did some work on a leak in the transmission fluid gasket, which involved replacing the pan and emptying then refilling the transmission fluid.
- The car started fine after this, and we kept it running to check for problems. There weren't any, the engine ran happily, and I checked the voltage which was over 14V which I believe means the alternator was happily charging the battery as normal.
- Ten minutes later, after the mechanic had gone, I started the car again and drove it a few meters, to reposition it in the driveway. Everything still worked perfectly.
- 30 minutes later, with the car having done nothing but sat parked for those 30 minutes, I tried to start the car to go somewhere, but while the starter motor and fan start fine (so the electrics seem good still unlike the previous problem), the engine doesn't join in - the starter cranks and makes the normal whup-whup-whup sound, the fan whirs until I release the ignition, but no gas ignition.
Normally I'd suspect low fuel or bad spark plugs based on those symptoms, but the spark plugs are new changed just a few weeks ago, and the tank has plenty of fuel. The battery is fine and near fully charged.
I don't understand what could have happened in those 30 minutes to cause the engine to fail. The only think I can think of that could have happened in that time is the recently re-poured transmission fluid settling and any spillage dripping, which seems unrelated to the fuel and spark plugs which appears to be where the problem is.
My best idea was spilt transmission fluid getting between two electrical connections. I found a plug that had got dripped on a little, cleaned it up until all the metal was shiny, but it made no difference.
How could this problem follow from these events?
The spark plugs themselves are deep set and difficult to reach, taking them out to inspect would be a tricky job requiring tools I don't have access to currently. They're less than a couple of months old and weren't touched as part of this work, and I checked that no fluids of any kind had got near them.
The only other possible link between transmission fluid and engine firing I can think of is safety switches preventing starting the engine when in the wrong gear, but I think those work in this car by preventing the key physically turning to the start position, which isn't what's happening here.