Sorry for joining up and immediately asking a question but I'm stumped with my old Corolla.
I haven't had it very long, only doing about 1500 miles, but I've got a couple of niggling issues that have got me stuck.
The first is something I'm hoping isn't detonation. I've recorded a clip here that demonstrates the noise I'm getting. Corolla Noise
This only really happens in 4th and 5th gear between 2000-2500 RPM with load on the engine, sometimes a little in 3rd and 6th gear.
The second issue that may be related is that at around 1800-2000 RPM mark at constant speed with very low throttle input, the car jerks slightly, almost like a very light misfire/surging. If you give it more gas, it carries on. Ocassionally it will hesitate a tiny bit doing so.
After only a couple of hundred miles of me having the car, I had to change the head gasket as it blew between a coolant channel and atmosphere, so was pushing coolant out of the side of the engine. Sadly it wasn't doing this when I bought it, or for the first few hundred miles. I managed to catch it and get it done before it overheated, and both of the above issues were present before it was fixed. The car does have a full service history.
Since then I've done over 1000 miles no problem, car runs great besides those 2 issues. Returning 42 imperial MPG which is about what I'd expect and passed emissions shortly before I bought it. It has done 96k miles.
So far I've tried:
- New Denso K16TR11 plugs
- Tested the TPS, this seems OK and is working correctly.
- Oil and filter changed.
- Ran a few tanks of Shell V-Power to see if it helped, nothing really changed.
- Briefly checked for vacuum leaks and can't find any other than the first stages of the PCV return hose perishing, but didn't seem to leak.
- Checked for fault codes, nothing stored.
This engine was the latest revision of the 4E-FE we had in the UK, so it uses a crank sensor and wasted spark with ECU controlled ignition timing rather than the distributor setup on other models, so I can't adjust/check the timing.
My initial thought is that the MAP sensor is slightly out, but hopefully I'm being a little paranoid with the above noise being detonation.
Any help is gratefully appreciated, I'm a massive Toyota nut and like this car a lot, so I'd like it to last a while.