Looking at replacing pistons and rings in a 2007 rav4 with the i4 engine that's using oil. There are three part numbers listed for the pistons. They are listed as MarkA, MarkB and MarkC with part# ending in -A0, -B0, -C0. Is there any way to determine which is needed or are the original pistons stamped so that the engine would have to come apart to determine the correct parts?
Piston/ring replacement (which pistons needed)
grizztracks
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Looking at replacing pistons and rings in a 2007 rav4 with the i4 engine that's using oil. There are three part numbers listed for the pistons. They are listed as MarkA, MarkB and MarkC with part# ending in -A0, -B0, -C0. Is there any way to determine which is needed or are the original pistons stamped so that the engine would have to come apart to determine the correct parts?
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Sounds like each one is for a different overbore?
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I don't believe the piston options are for over bore. It appears it has something to do with the piston pins. You would think that the engine number or VIN would indicate what pistons are installed. I've worked on a lot of engines over the year and never ran into anything like this. I wanted to order parts before I tore it down but it looks like I'll need to measure the pins to determine which pistons to order.
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Maybe toyota used piston matching to better fit the bores in this engine? They didn't do it in the V6 2GR-FE engine and people ended up with weird engine noises.
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It appears that the piston, pin and rod are matched. I'm not sure why they would change rods and pins from engine to engine. The rings are all the same for the different pistons so better cylinder fit doesn't make sense. Someone must know the reason for this.
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I fully read the TSB several times and I'm aware of the crosshatching and Toyota's recommendations. I'm thinking about just sticking a new set of rings and rod bearings in the engine and running it for another year or so before replacement. Once I get it apart I'll make my final decision on how far to go with this. I'm still interested in knowing why so many piston and rod options for this engine.
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Rings are compressible, pistons are not.
But, I'm guessing as I never rebuilt engine myself.
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I've rebuilt many engines over the past 40 years. Everything from diesel trucks to powersports. I'm very familiar with the internal components of combustion engines. I'm just looking for some clearification on why Toyota has these variations. It's not a common thing that I've seen in the past.
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