The battery went flat through not being used for a number of days and being old. It needs replacing. Not totally flat though, juts not enough to start to turn over the starter motor. I had a jump start and after the oil light stays on. The oil level is fine. When turned off and restarted the light still stays on. Anyone have any ideas why?
If the oil light is the only warning indicator that is illuminated on the instrument cluster, then the good news is that it probably has nothing to do with the bad battery.
The bad news is that the oil light can be an indication of a serious problem. The first thing to do is to check the oil pressure sender to make sure it is functioning properly. If it is, then remove the oil pressure sender and install an oil pressure gauge in the sender opening and measure oil pressure. If oil pressure is below specifications, remove the valve cover and inspect the valvetrain and remove the oil pan to inspect the contents of the oil pan. If the nothing looks amiss, remove the oil pump and check the oil pump clearances in accordance to the factory repair manual.
It happened at the same time as the jump start when the battery went very dead - may be below what was acceptable to some components.
Ray, thanks. The car has had Mobil 1 in at service from new. I will look into the sender, however I doubt if it is a major mechanic problem - unless it is a co-incidence that the oil problem came along when the battery went very low. The light came on after the jump start.
I cannot imagine how a dead battery or a jump start can damage the oil pressure sender without other symptoms appearing first, so I think it is just a coincidence.
If you have been diligent in getting oil changes done on a timely basis, then the risk of a problem with the oil pump or internal engine components is low.
Hopefully, the problem is something as simple as a loose wire to the oil pressure sender.
I hope so. The oil is changed every 9,000 miles using Mobil 1. Also Mobil
1 can go many 1000s of miles over the change interval without any adverse affects to the engine. Any idea where the sender is on this car, before I do an oil search and hope to strike oil?
Sorry, I am not really familiar with the Avensis since it is not sold in the U.S. Likely places for the oil pressure sender on Toyota engines are the front of the engine and the rear behind the exhaust manifold.
The engine is the 7A-FE 1.8 litre. I have bought a Haynes Manual and it doesn't even mention the oil pressure sensor. Anyone know exactly where it is on this engine? There are many electrical connections on the engine and I'm not too sure what is what.
Search google images for "toyota oil pressure sender" (not a "sensor) for photos of what typical Toyota oil pressure senders look like. It will most likely be located on the block and not the head. As you are facing the engine compartment, look to the right of the exhaust manifold first.
Ray, thanks. The engine is transverse. As you look at the engine bay the exhaust on the front of the engine. There appears to be nothing there with an electrical connection apart from the alternator. At the rear is the inlet manifold and there is a large plastic canister under the manifold on the block with two rubber tubes coming off it. On the right of the engine when looking into the bay there is a lot of plumbing and there appears two sensors - I assume for water temperature purposes.
The oil pressure sender appears elusive. It want to check this first before looking at the oil pressure regulating valve which is a part of the oil filter assembly. This is just a piston and spring.
BTW, the engine has an oil cooler.
Normal convention for determining sides of a vehicle are from the perspective of the passenger compartment.
On a Toyota with a transverse-mounted engine, the front of the engine is on the right hand side of the car. When standing in front of the vehicle, the front of the engine will be to the left. The back of the engine is what is connected to the transmission and will be to the right when standing in front of the car looking into the engine compartment.
For simplicity's sake, I will refer to "left" and "right" from the perspective of standing in front of the car, looking into the engine compartment, and front means towards the front of the car and rear means towards the back of the car.
Likely places for the oil pressure sender are: - to the right of the exhaust manifold on the front of the block; - near the oil filter; - on the front of the engine, (left side of the engine compartment).
On the 7A-FE in my Corona the sender unit is hiding behind the alternator, nearly straight down from the end stud of the exhaust manifold.
Thanks. Found it hidden away. To get at it the alternator has to come out. Duh! The car runs OK the oil level is fine too.
Anyone know the symptoms if the oil pressure regulating valve is stuck:
a) open? b) closed?
The car has had fully synthetic oil in from 1000 miles and came with a semi-synthetic. The likelihood of sludge in anyway is virtually nil. I believe sludge can affect the oil pressure regulating valve.
The oil pressure sender. It is OK to wrap PTFE tape aroud the threads rather than use a liquid sealing compound? I don't like the idea of liquid entering the oil galleries..
If you are talking about the bypass valve in the oil filter, it does not normally open and close. If the filtering media is clogged, it the oil will bypass the media and circulate unfiltered though the engine. There are no real symptoms.
I would not use plastic tape around the threads for the oil pressure sender because I don't know if it can handle the heat or not.
I would use 1 drop of the blue Permatex thread locker instead.
Quick question. With the oil pressure sender disconnected does your light come on?
I pulled an in-line plug and it was still on. I assume this sender has the contacts closed when no pressure and open when pressure opens the switch.
I just read what I wrote. If that is the case then disconnecting the wire should open the circuit and the light should be off, and the problem is not the sender it is elsewhere. Anyone agree?
Without looking at a wiring diagram, I can't say for sure, but if the oil pressure sender has only 1 wire going to it, the sender may be completing the circuit to ground. When the circuit is open, the low oil pressure warning light is not grounded, but when the circuit is closed, then the circuit is grounded to the block (another reason you don't want to use tape on the threads).
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