What 0w16 are you using in your newer toyota?

[Elmo Howe]

The diesel-like clattering is the direct injectors clicking away (A25A-FKS engine). They are active when the RAV4 first starts, then shut off after the engine has idled for a short while. I was surprised at the noise as well until I saw a few YouTube videos describing how the engine switches between the port and direct fuel injectors.

That's interesting information. I had seen information that said that the direct injectors don't come into operation until the middle rpm range and do so in unison with the port injectors. The higher rpm range is when the direct injectors are solely providing fuel to the engine. I will have to look on YouTube for the videos that you are referring to.
But the noise that I am hearing sounds more like it is coming from the area across the entire valve cover, not just in the mechanical fuel pump area. I may have to just learn to live with it and wear earplugs during the engine warmup phase on each " first time " start of the day.
Thanks for your input.

 

[Elmo Howe]

That's interesting information. I had seen information that said that the direct injectors don't come into operation until the middle rpm range and do so in unison with the port injectors. The higher rpm range is when the direct injectors are solely providing fuel to the engine. I will have to look on YouTube for the videos that you are referring to.
But the noise that I am hearing sounds more like it is coming from the area across the entire valve cover, not just in the mechanical fuel pump area. I may have to just learn to live with it and wear earplugs during the engine warmup phase on each " first time " start of the day.
Thanks for your input.

The diesel-like clattering is the direct injectors clicking away (A25A-FKS engine). They are active when the RAV4 first starts, then shut off after the engine has idled for a short while. I was surprised at the noise as well until I saw a few YouTube videos describing how the engine switches between the port and direct fuel injectors.

" Upon further review" via the Toyota technical information from their website, the D4S fuel injection system uses both port and direct injectors to supply fuel to the cylinders under low to medium laod conditions. Under high load conditions - pulling a heavy load, going up a steep hill or " heavy " acceleration - the direct injectors only are utilized. The more that I investigate the " clattering at cold start up " , I am pretty sure that I am hearing valve train noise, from the top of the engine, that goes away once the engine is up to operating temperature or at least 100 degrees fahrenheit. That temperature is what I am seeing when monitoring the engine at startup with a good scan tool . It usually takes about 7 minutes of warning up, cycling through the engine rpm changes, for my engine to get to 100 F. And the " clattering" goes away.

 

[tolian21]

"Lack of or improper maintenance including use of fluids and fuel other than those specified in the owners manual".

Correct, but viscosity is recommended and not specified.

 

[ATex7239]

" Upon further review" via the Toyota technical information from their website, the D4S fuel injection system uses both port and direct injectors to supply fuel to the cylinders under low to medium laod conditions. Under high load conditions - pulling a heavy load, going up a steep hill or " heavy " acceleration - the direct injectors only are utilized. The more that I investigate the " clattering at cold start up " , I am pretty sure that I am hearing valve train noise, from the top of the engine, that goes away once the engine is up to operating temperature or at least 100 degrees fahrenheit. That temperature is what I am seeing when monitoring the engine at startup with a good scan tool . It usually takes about 7 minutes of warning up, cycling through the engine rpm changes, for my engine to get to 100 F. And the " clattering" goes away.

Fuel system (D-4S)

1 - ECM, 2 - fuel pressure sensor (high), 3 - fuel rail (high pressure), 4 - direct fuel injector, 5 - fuel delivery pipe with sensor (low pressure), 6 - port fuel injector, 7 - fuel pump ECU, 8 - fuel tank, 9 - fuel main valve (high pressure), 10 - fuel main valve assembly (low pressure), 11 - fuel filter, 12 - fuel pump (low pressure), 13 - fuel suction filter, 14 - fuel pump (high pressure), 15 - fuel sus filter, 16 - fuel pressure pulsation damper, 17 - spill control valve, 18 - check valve (60 kpa), 19 - fuel relief valve (26.4 MPa), 20 - exhaust camshaft.​

Fuel injection - combined: directly in the combustion chamber and multipoint in the inlet ports. At low to medium loads - combined injection is applied - homogeneous mixture increases the stability of the combustion process and reduces emissions. Under a heavy load use direct fuel injection - the evaporation of the fuel in the cylinder filling mass improves and reduces the tendency to knock.

1 - injection in port, 2 - injection in cylinder + port, 3 - injection in cylinder.​

- Stratified combustion mode. Fuel is supplied in the intake ports on the exhaust stroke. On the intake stroke after the opening of the valves in the cylinder receives a homogeneous lean mixture. At the end of the compression stroke, additional fuel is injected directly into the cylinder, allowing to enrich the mixture near the spark plug. This facilitates the initial ignition, is then distributed on the all lean mixture charge in the remaining volume of the combustion chamber. This mode is applied after a cold start to retard ignition timing and to increase the exhaust gas temperature for accelerate catalyst warming up.

- Homogenous mixture mode. Fuel is supplied in the intake ports on the expansion, exhaust and intake strokes. At the beginning of the intake stroke, additional fuel is injected directly into the cylinder and evenly mixed with the incoming charge. Homogeneous air-fuel mixture is compressed and then ignited. Due to the evaporation of injected fuel, air charge in the cylinder is cooled improves cylinder filling.

Toyota engines - A25·M20 - Dynamic Force series (R4)

Review of Toyota Dynamic Force engines design and components - inline-4 (M20A, A25A)

toyota-club.net

 

[Elmo Howe]

Fuel system (D-4S)

​

​

1 - ECM, 2 - fuel pressure sensor (high), 3 - fuel rail (high pressure), 4 - direct fuel injector, 5 - fuel delivery pipe with sensor (low pressure), 6 - port fuel injector, 7 - fuel pump ECU, 8 - fuel tank, 9 - fuel main valve (high pressure), 10 - fuel main valve assembly (low pressure), 11 - fuel filter, 12 - fuel pump (low pressure), 13 - fuel suction filter, 14 - fuel pump (high pressure), 15 - fuel sus filter, 16 - fuel pressure pulsation damper, 17 - spill control valve, 18 - check valve (60 kpa), 19 - fuel relief valve (26.4 MPa), 20 - exhaust camshaft.​

Fuel injection - combined: directly in the combustion chamber and multipoint in the inlet ports. At low to medium loads - combined injection is applied - homogeneous mixture increases the stability of the combustion process and reduces emissions. Under a heavy load use direct fuel injection - the evaporation of the fuel in the cylinder filling mass improves and reduces the tendency to knock.

​

​

1 - injection in port, 2 - injection in cylinder + port, 3 - injection in cylinder.​

- Stratified combustion mode. Fuel is supplied in the intake ports on the exhaust stroke. On the intake stroke after the opening of the valves in the cylinder receives a homogeneous lean mixture. At the end of the compression stroke, additional fuel is injected directly into the cylinder, allowing to enrich the mixture near the spark plug. This facilitates the initial ignition, is then distributed on the all lean mixture charge in the remaining volume of the combustion chamber. This mode is applied after a cold start to retard ignition timing and to increase the exhaust gas temperature for accelerate catalyst warming up.

- Homogenous mixture mode. Fuel is supplied in the intake ports on the expansion, exhaust and intake strokes. At the beginning of the intake stroke, additional fuel is injected directly into the cylinder and evenly mixed with the incoming charge. Homogeneous air-fuel mixture is compressed and then ignited. Due to the evaporation of injected fuel, air charge in the cylinder is cooled improves cylinder filling.

Toyota engines - A25·M20 - Dynamic Force series (R4)

Review of Toyota Dynamic Force engines design and components - inline-4 (M20A, A25A)

toyota-club.net

Thank you for the additional data and charts. They are helpful in understanding the Toyota A25A-FKS fuel injection system operation.

 

[Nesterenko]

GTMO

TGMO

 

[Elmo Howe]

TGMO

Correct. I was extremely tired from a long day and long week when I posted that. Had a " flashback" to the U.S Marine base in Cuba, I guess.

 

[Ride_Red]

" Upon further review" via the Toyota technical information from their website, the D4S fuel injection system uses both port and direct injectors to supply fuel to the cylinders under low to medium laod conditions. Under high load conditions - pulling a heavy load, going up a steep hill or " heavy " acceleration - the direct injectors only are utilized. The more that I investigate the " clattering at cold start up " , I am pretty sure that I am hearing valve train noise, from the top of the engine, that goes away once the engine is up to operating temperature or at least 100 degrees fahrenheit. That temperature is what I am seeing when monitoring the engine at startup with a good scan tool . It usually takes about 7 minutes of warning up, cycling through the engine rpm changes, for my engine to get to 100 F. And the " clattering" goes away.

Right, it switches between the injectors based on load, RPM, etc. But... the sound I am describing relates to startup, the direct injectors are active for about 10-20 seconds or so and then they turn off. When I was changing my oil, I could hear them clacking away and then abruptly go silent, every time I started the engine moving the car on and off the ramps, etc. Most oil related startup clacking/clicking I have heard would tend to taper off quickly as the oil pressure would rise, not abruptly stop like flipping a switch. I'm guessing the engine ECU exercises them as a diagnostic during startup or something. Or maybe it help with quick starts as this vehicle has the auto start/stop fuel saving mode.

After two weeks of ownership and 1000 miles or mixed city/highway, I haven't heard any other strange noises from the engine yet.