Lwerewolf

Shocks' performance deteriorates with time. Not as noticeable on shocks which solely rely on shims for damping force generation, but it's still there. What is unfortunate is that (almost all) OEM units are not serviceable at all. Other than that - stock shocks are monotubes with an adjustable (by AVS motor action) orifice.

Shocks are consumables. Better replace early due to misting than have them looking good at 150k with performance degraded to nothing. edit: ...or rebuild/refurb but that's not an option for OEM parts nowadays... for... some... stupid... reason...

https://www.toyota-tech.eu/HYBRID/HVDM/EN/RAV4_AXAH52 hvdm.pdf [quote]The HV battery pack consists of 34 low voltage (7.2 Volts) NiMH battery modules connected in series to produce approximately 244.8 Volts. Each NiMH battery module is non-spillable and sealed in a metal case.[/quote] Quoted NiMH nominal voltage is 1.2v 7.2/1.2=6 >> should be, unless the rav4 & NX hybrids use unique 6-cell modules for themselves. Also - 244.8/1.2 = 204, 204/6 = 34 (the quoted number of batteries). To my knowledge, there are (were?) 4 generations of the 6-cell modules that are used in every NiMH toyota hybrid battery other than the RX & LS600h ones. All of them are compatible - I have gen4 modules in my 3rd gen GS (originally with gen2 modules, I believe). The RX/Highlander (perhaps not the new highlander, I don't know) uses the 9-cell modules, the LS600h uses the 12-cell modules. You can guess why an ls600h is an expensive proposition to own, compared to the ls460 😄 Anyways, can't confirm, can just deduce. Good luck!

Had a similar thing. For the record - our brake systems are the same (other than the hybrid having regen, but that's just an addition). My handbrake/e-brake/whatever-brake light started popping up from time to time - after driving for a short while (i.e. the fluid warming up, I guess) it'd disappear. A techstream check didn't note anything out of the ordinary. A few days later, the car went in panic mode ("check VSC check this check that" i.e. the usual check everything) - pulled over, tried panic braking a few times - everything was working as normal. Turned around to go home and pick up the laptop - the lights disappeared. Got the laptop, drove around actuating the brakes hard at mostly every opportunity - nothing. The next day, after a night's rest, it did the same - and the lights and warnings went out just as I was turning on the diagnostics. No "history" codes whatsoever. I put the car on stands, inspected the brakes physically, and... the front pads were, shall we say, very close to the wear indicators. Had no time to wait for OEM ones so I ordered ATE pads & discs (discs were vibrating during winter for a period, it cured itself with the "wear down the pad deposits by braking when the rotors are cold" technique but I didn't want to risk it) - problem solved. Now, on to the weirdness: The car warns you on the little LCD in the instrument cluster for: -Low windshield washer fluid -Low tyre pressures -All kinds of system problems The car also has a low level sensor for the oil and the brake fluid. Yet it won't straight up tell you that brake fluid is running low... ...doesn't have a low coolant indicator either, for whatever reason.

I just want to emphasize this. A cat either gets poisoned, or gets physically damaged - melted, broken down, etc. Poison primarily comes from certain components in motor oil - the oil's SAPS (low/mid/high) rating generally tells you how "safe" it is for converters - if the particular components end up burning through the combustion chamber. Coolant and leaded fuel also poison cats. Destruction can happen in many ways. Misfires or bad combustion get unburned fuel into the cats, igniting it there and causing pressure damage. A rich mixture typically cools cats down, unless it's caused by an air leak in the exhaust system before or near the air/fuel sensors - then it can heat them up rapidly. A lean mixture generally causes cats (and engine components near the combustion chamber - pistons, valves) to overheat, melt and so on. Make absolutely sure that there are no exhaust leaks before or anywhere near the (front and rear) O2 sensors. This is usually checked with a smoke machine. This generation of GS's typically have pinhole leaks after the secondary O2s and before the secondary cats - right underneath the shielded section of the exhaust pipes there. Make sure that the O2s work. The upstream ones are wideband (AFR), the downstream ones are the regular type. The car can be told (via techstream or anything else that offers similar utility) to run rich (up to +25% fueling) or lean (up to -12.5%) to confirm proper operation of the O2 sensors. If you decide to go for new OEM units, as getting good aftermarket cats appears to be a problem, make sure that you've resolved any such issues. In summary - fix any kind of oil/coolant loss, make sure that there are no intake or exhaust leaks, make sure that the O2s work properly. Might wanna replace the primary O2s regardless.

Inverters don't blow up on these, so unless the water pump gives... only the hybrid battery should be a potential concern 🙂

Most trouble-free - 2012+ non-F-sport. Worry about: -The hybrid battery - probably a nonissue given the warranty on these -The electronic brake module - the brushed DC motor may wear through its commutator eventually, causing a nonstart issue and the famous (albeit very rare),sudden "no brakes" event, also the hydraulic accumulator sphere is non-replaceable... or at least not sold as a spare -The transmission's auxiliary oil pump bearings (annoying disassembly of the wire harness, cheap parts-wise) -The hybrid inverter if it's a 3rd gen (2006-2011) - RHD inverters are still plentyful, but there isn't much that you can do to prevent IPM solder layers degradation. 4th gen uses a different design. 2012+ f-sport uses front rotors with alu hats. The rotors are not sold separately from the hats, and the whole assembly is very pricey, compared to the non-F-sport version. Might also not fit 17''s (not sure about this). On the other hand, lighter rotating mass = better... Suspension - AVS shocks tend to leak and are relatively expensive (not really IMO, but still) to replace. I view this as a benefit - you replace shocks before they're still "working" with severely degraded damping characteristics. Everything else is very sturdy, but expensive to replace if it goes wrong. No bushings sold separately (very few exceptions), alloy control arms, alloy knuckles (with pressed in bushings & heim joints at the rear)... No good aftermarket "OEM replacement" parts whatsoever - it's either polyurethane or "sports" stuff (adjustable length control arms with uniballs - I'd avoid). Overall - VERY reliable vehicles, but can get very expensive if they go wrong. Don't buy one thinking it'll be cheap to run and/or maintain properly... or fix, if need be. Same goes for every car in this segment. Mods, I think we need a master thread, given the amount of threads popping up on the subject(s).

Shocks do leak, but they're consumables anyway - might want to replace all four regardless. Oil leaks - mine had apparently started fuming around the lower external banjo bolt for the VVT-I oil line (for bank 1 - i.e. right side)... that's my anecdotal evidence. Replaced crush washers and VVT-I filters while it was in for an oil change. Nothing in particular that is a mass defect on these comes to mind. No measurable oil consumption whatsoever, 330000km on the clock.

Indeed, my fault. I was thinking of the 2UR-GSE as the recent exception. Re: radiator - mine did "blow up" (well, started leaking under high pressure) a few weeks ago, had to wait 10 days for a new OEM one. Car is 08/2008. About time 🙂

VVT-i hydraulic variable valve timing actuators not locking up when stopping and/or not holding oil at startup, or at least that's the first thing that comes to mind, given what it sounds like. The engine is also direct-injected, and it DOES run in "stratified combustion" mode while warming up the catalytic converters - i.e. right at the start. It makes a lean mixture with the port injectors and makes a "rich" pocket with the direct injectors in order to ignite it. This leads to higher exhaust gas temperatures and quicker catalytic converter lightoff. https://toyota-club.net/files/faq/13-11-10_faq_gr-engine_eng.htm I wouldn't run 0w20 in an engine that was originally specified for 5w30. I also probably just stirred up a hornet's nest. Re: random warm air - get the t-stat open, put heater on HIGH, rev the engine for awhile in D-mode (easiest way to maintain ~2500-3000rpm), see if that helps. Re: potential head gasket failure - check the cooling system for leaks (pressurize via a special cap & check whether it holds pressure, check where it leaks if it does - could be a cylinder), check the cylinders with a good borescope (clean usually means "vapour cleaning" i.e. eating water/coolant), check the old plugs for any indication of running lean/burning coolant/etc, check the system with a "block tester" (an "exhaust in the cooling system" test)... If it is, it won't be easy and/or cheap, but... IMO tear it down and do the whole thing proper. @Mihanicos every engine in the 3rd gen GS lineup has hydraulic valve clearance adjusters.

It also has (afaik, at least in the US) bigger front discs (same calipers and pads, supposedly) that also happen to be two-piece (alu hat, cast rotor)... with no option to buy the rotor without the hat. Quite expensive to replace. I thought that all 450h's had VGRS? On that note - the true F cars have no VGRS, no rear-wheel steering and (afaik) no adaptive suspension... 🙂 You can do a lot to the chassis to "improve" the handling. Mine (3rd gen but still) has GS-F front LCA bushings (the big ones at the rear of the LCA that basically control dynamic toe-out/in on braking/acceleration), IS-F rear subframe bushings and poly everything else at the rear-end (OEM pillowball in the knuckle still not destroyed somehow). Similar mods started being applied to all IS/GS cars after the... 2011 (I think?) version of the IS (250/350) - retuned rear bushings directional/twisting stiffness, IS-F subframe bushes, adjusted power steering ECU calibration and so on.

One is a Camry. The other is a Crown. The GS is way more of a driver's car, but I'd seriously look for a 450h. The ES is more utilitarian.

There are the formations, then there is the subsequent rise in internal resistance and resp. waste heat production, leading to accelerated fluid evaporation, leading to... it's a devilish circle. As stated, not as simple.

The engine and hybrid system coolant loops share the overflow/reserve tank on the 3rd gen gs450h. Other than that, they are separate.

Environmental temperature? (shock oil temperature matters) Tyre pressures? Under-inflation can also make the car "seem" stiffer in some situations.

As opposed to, electrically? For context, the post above that one does mention that you can't "lock" mg1 without powering it, so unless you meant some third (non-electrical and non-mechanical) way... 🙂 If you look at just about any ORNL publication re: Toyota hybrid systems, you might notice that the efficiency chart for the motors is not exactly "best at 0rpm, progressively worse above". Sample below: ...taken from https://www.osti.gov/servlets/purl/928684 Also the GS (well, the LS, but it's the same motor): ...taken from https://www.osti.gov/servlets/purl/947393 As for Tesla's (and other EVs) top speed - I was under the impression that it's more of a case of battery pack voltage sag. You can always overgear the motor and use multiple gears to maintain off-the-line performance (taycan, gs450h/ls600h, ls/lc500h/s220) Blanket statements are all over the place in auto manufacturers' literature, especially when it comes to articles detailing specific "realizations" - cars, engines, transmissions, suspensions, brakes, whatever. Everything is appropriate, everything is optimised, everything is... insert good adjective here. Quite a few of these don't hold up to scrutiny. As for why I posted that link - it has quite a few specific and concrete implementation details. "Heretical" mode is any condition in which MG2 generates and MG1 consumes. I've yet to see MG1 stay locked at 0 RPM, other than when the car is stationary and the engine is not running. Don't think I've managed to get it to cruise below +-150rpm at the minimum. Not sure how I'd even try to make the system do that. I've yet to see actual data that indicates that THS cars are locking MG1 at precisely 0rpm during cruise - i.e. executing "geared neutral ratio" via the PSD.

You didn't catch my drift again. Let me rephrase: A CVT (whatever the implementation) is used to be able to keep the engine at its optimal running condition (with regards to BSFC = brake-specific fuel consumption) for whatever load is required of it. If you lock up the sun gear mechanically (somehow) and disconnect MG2 (again, somehow), you have a direct gear to the wheels. This linearly maps engine RPM to road speed. This is about the worst thing that you can do in terms of overall efficiency, unless all you do is drive at a constant speed on a constant incline with constant everything else that may affect engine load requirements. I've reread the thread (for some weird reason) and I think you might want to read up on how the eCVT works. Preferably not from marketing material and without focusing on generalizations----I mean, blanket statements such as "The power split device distributes the engine power as appropriate to directly drive the vehicle as well as the generator."

"Heretical" mode. MG2 generating, MG1 "motoring". Overdrive. Mentioned several times during the past few hours. I'm really having trouble maintaining a decent tone. Anyways. Lock the sun gear, disconnect MG2 (not that it matters much) and now you have a direct gear to the wheels. The whole point of the CVT is for the engine to be able to operate with optimal BSFC at all times.

So which one is it? You can lock the ring gear with the parking pawl. You can obviously lock some gears in the 2-speed gearbox for MG2 via the two clutch packs. There is no way to mechanically lock the sun gear. What you're trying to say (the "engine" being the only thing sending motive power to the wheels) can only happen if mg2 is generating just enough power to keep the 12v system on, and if that much "push back" from regeneration is enough for the PSD to send everything else coming from the engine to the wheels. Doesn't really happen under "normal" driving conditions - the car would rather keep the engine "off" during such low loads, for efficiency purposes.

As for: Notice that both mg1 and mg2 torques are "positive" or "negative" at the same time. Goes hand in hand with my comment re: looking at what torque commands it takes for the inverter to drive both motors in such a way as for the car to move forward without engine power - assuming that the planets fork (i.e. the engine) is welded to the transmission chassis. In other words - you can probably think as "all positive" - non-overdrive, "all negative" - overdrive ("heretical").

How do you lock the sun gear?

That statement is the same statement like: ...from the "new car features" section on the monotubes. What does it tell you? Practically nothing - "we're using a monotube, we're super duper cool". Later on it does show a digressive tune and the bleed port setup (and the double pistons acting as a "main piston", but it doesn't say why they're used). Anyways, look for the "how", which leads me to: Power figures in the tables are absolute. Look at the torque - negative in the "cruise" scenario. Would it theoretically be possible for MG2 to regen and for MG1 to push? http://prius.ecrostech.com/original/PriusFrames.htm How the ECU reports "positive" or "negative" torque numbers is another story - you might want to look here: https://openinverter.org/forum/viewforum.php?f=14&sid=1e7a76c446e71061f34dc8cb44526c2b Several mentions in the gs450h vcu discussions regarding how you give "negative" torque requests to mg1 to get it to move forwards with mg2. Finally: It's KPH, the limit on the road is 140KPH if you're wondering. You're referring to this: Frame 2 > 3, in particular. The car is trying to raise the revs from ~1550 to ~1850, which means that the motor has to let off for a bit. How exactly have you told the car what your "uprated" battery is uprated too? Have you also "uprated" the buck/boost converter? How have you measured the "a bit quicker" part? Google "AC-DC-AC converter" and then "AC-DC-AC inverter" and tell me which term should I use. Two inverters sharing the capacitor bank, that can also get power from the battery via a buck-boost converter. There's also the DC-DC (HV->12V) converter next to the battery, the AC drive, the power steering drive, the auxiliary oil pump drive, potentially the active stabilizer inverters... anyways. The ORNL article that I linked previously also goes into how the "inverter" (PCU) is arranged. The GS450h one is almost the same as the "camry" one (investigated in an earlier ORNL article - https://www.osti.gov/biblio/928684-evaluation-toyota-camry-hybrid-synergy-drive-system), filling the missing transistor slots.

1) Bold claim 🙂 2) You can see a whole lot of nothing from the console. Get hybridassistant if you want useful live system information and very good logging to boot. 3/4/5) Read up on how this car works. https://slideplayer.com/slide/14432904/ Same transmission, without the LF1A transfer case. Certainly the same ratios - the "new car features" for the gs450h service manual is wrong in some places on sun/planet/ring gear teeth - basically states an impossible arrangement, conveniently the digits were just swapped or something. The EU-spec 450h has 245/40/18 tyres and a 3.266 diff. This is enough info for you to plot the RPM relationships between the motors and the engine at different speeds. The prius and pretty much every single toyota hybrid is almost the same. The GS has a 2-stage auto for MG2 and an FR drivetrain. Pretty much all serious discussions re: the prius apply. The inverter is actually an AC-DC-AC converter with an additional buck-boost converter that is connected to the battery. The converter is rated at 35kw. The AC-DC-AC converter handles the electrical (i.e. "series hybrid") path for the engine's power, and can use the battery to boost to or regen from the AC motors. Some data (the mg2 rpm column is way to the left, sorry): Sample acceleration data, with the gear shift visible (look for the mg2 rpm switch at ~12k, gps speed is lagging badly): Sample cruising data, with SOC<60%: Sample cruising data, with SoC at 60%: Don't remember the details, probably with AC on, low beams (it's a highway), music, potentially cruise control. The ICE is RPM-limited (and respectively, somewhat power-limited, but not too much) by the max RPM of MG1 at certain speeds - it takes approximately 140kph before MG1's top speed (12.5k rpm) stops limiting the engine. The ICE is also power-limited by MG2's powerband. A good analysis of the motors can be found here: https://www.osti.gov/biblio/947393 The motors are the same (ignore the stated RPM limit on MG2). Anyways, @Thackeray is on to something 😉

Any aftermarket midpipe is going to increase noise. I'd "rebuild" the midpipe, using the factory resonator and catalytic converters. You won't like the price of a new OEM midpipe - the converters add a significant amount to the price, and it's VERY unlikely that your secondary catalytic converters are compromised - the primaries (the ones near the manifold that are measured) are meant to 1) warm up faster, 2) light up the secondaries faster, and 3) "soak up" contaminants/poisons/etc that would ruin the secondaries. Aftermarket midpipes tend to come with... sub-par converters. I've replaced my catback with a new OEM unit, it's holding up but there are already rust spots. I still have my old one so next time I'll just tear it down and have a shop remake it in stainless. The new OEM catback cost me 500eur locally. The old one had plenty of holes but sound was not really affected, at least to my (and others') perception.

Would also love to know which OEM torsen cassette fits the F21SF differential casting... actually, a lot of people would love to know 😄