Hi All.

I'm a new owner of a 2006 GS 430, picked it up on Thursday, working out the bugs.

The car is in wonderful shape, 122,000 KM's (76,000 mi) Premium Package etc.
The car has only had 7,000 km's put on it since 2015. In theory came from a collection of Lexi (plural?)
so has been driven very little and sitting around a lot.
When I bought it it had the codes PO 751 and 761 (shift solenoid A & C performance or stuck off) and a weep coming from the pan and an o-ring on the drivers side.
I had the car checked by a Lexus dealer and of course quoted Lexus pricing to re-seal and replace the solenoids, but besides that green checks everywhere, did notice after the fact transmission fluid level wasn't one of the things checked.
After, it also threw a PO 174 code (bank 2 lean) so I thought I would take it for an Italian tune up up the side of a local mountain.
The codes were cleared by the alignment tech before I did the mountain tune up.
When I got back it did a shudder in reverse up the incline of my driveway.
I checked for new codes and didn't see any. In theory my scan software in my phone can check for them. There is no check engine light on.
Anyway took it to a transmission shop this morning and the tech noticed a noise in reverse, said it was the pump, don't think it slipped for him.
Anyway he proceeds to saying pump is probably shot, new valve bodies yady yada, Said $5, 500 for a rebuilt.
So the dude never checked the codes, checked fluid level or much less dropped the pan to see what was going on.
Said the trans could have been abused etc, the car looks like brand new, all green checks from the Lexus dealer, has the OEM electronic shocks on it, they look original, so I'm guessing it's not likely.
So I do hear some noise in reverse, but none in drive.
No shudder in reverse today up the driveway.
I noticed no bad things heading up the mountain, I had it going over 100 MPH, that car is fast!
And once again to does not appear that the car has thrown any of the original or new codes.
I'm thinking new fluid (who knows how old it is) and reseal and then take it for a good long drive on the highway. I'd do the pan myself except don't know
what the o-ring piece adjusts or is attached to, it's on the drivers side of the transmission, I have a vid of it if anyone wants to see it.
And for the fluid change would just the 4-5 litres do or a complete change of the 10 + litres recommended?
I'm located in Vancouver BC if anyone has a recommendation for a good transmission shop.
My 2005 Highlander was diagnosed with a bad valve body 4 years ago (shifts like crap) but it's still on the road with 250,000 km's on it, so far so good.
Any thoughts are appreciated and thanks in advance!

John

 

Welcome to the world of transmission issues, where every shop’s answer is simply “let’s rebuild/replace.”

- Is the fluid the correct type and level?

From your account it does not look like this has been done. Do it yourself if you want it done correctly, not any more technically challenging than an oil change. The fluid level is checked running - even shops mess this simple detail up and leave it low. MaxLife is an excellent fluid for these, better than WS/3324 and especially in high horsepower/heavier/harder use applications.

 

Thanks for the reply.

The transmission is of the variety with no dipstick so not easy to check. Getting it up off the ground level would be some work but not impossible. As it's 4 litres at a time would have to do it 2 or 3 times. I'm inclined to go for doing it myself, just have to figure out what the leaking grommet is, perhaps the check or fill hole. haven't gotten that far yet. Curious that the pump makes noise in reverse and not drive. Hope someone could shed some light on that.

 

Transmission fluid check temperature

 

Thanks skur, I'll refer to this when I change the fluid.

 

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I doubt it does, as that’s not how transmission oil pumps work. No competent person has looked at it from what I could tell, so I discount the very unlikely at this point. There can be noise, but not likely related to the pump itself. Placing the unit in reverse gear has zero effect on the oil pump or oil circulation pathway.

I would lift it and do the fluid, remove and clean the output speed shaft sensor at the rear of the unit at the time as in the past, that has led to codes like you reported. Do it while there. The temperature of the fluid at check is unimportant; it just needs to be running and not fully hot. Don’t waste much time on that, or at all.

 

Absolutely please do get the transmission oil checked for any signs of metal, burnt oil or water. If it's old you can get a full flush through but if it's ok get the level checked.

I recently bought a GS430 with a few different transmission misbehaviours and three solenoid performance issues. After a few recommendations for a rebuild I got a shop to actually look and it was under half full. Topped up with the correct ATF it's been driving perfectly ever since.

Shop told me Toyota and Lexus solenoids almost never fail. Makes you wonder how many unnecessary rebuilds get done?

 

Thanks guys. Yeah my BS detector was at full alert with the pump nonsense and lack of troubleshooting. This was at a well rated shop but I noticed sitting there all of the service discussed were transmission replacements.
I might just bite the bullet and take it to Lexus to quote on fluid & filter change and reseal the pan and the leak above the oil pan. The leak appears to be coming from the connector on the drivers side middle and I don't know if the hold down screw just needs a new grommet or if a gasket up there is required. At least the correct fluid will be used, the parts are the real deal and the tech's will be working from the real manual and service bulletins. My work space outside isn't ideal and I can only easily get the car a foot off the ground, which isn't completely level. So not Ideal for the pan off work. After I can do the subsequent transmission oil changes as the fluid "change" isn't complete.
I'll post the results whether I DIY or get Lexu$ to do it.
Thanks for all the advise!

 

Hi folks,
Here's my update. Took it to Regency Lexus here in Vancouver.
Apparently one of their master mechanics from Japan, spent quite a bit of time road testing, ran the scanner road test etc.
The verdict, nothing wrong with the transmission.
The original solenoid codes haven't come back.
The tech showed me where he thinks the leak is coming from,
doesn't think it's the pan or the harness plug on the left side, figures it's the vent at the top.
As far as the issues I've experienced, he agrees it could be low fluid and/or from sitting for so many years.
So as it is a pita to check might as well change the fluid, clean up the transmission and watch for the leak to pop up.
The only thing I need to decide is just change the pan fluid or change out the full 11 liters. Not much difference in price
as it's close to the same about of time and the Toyota WS fluid isn't very costly. The service rep says they've never had problems
with the full replacement and mentioned they have the techs and the correct equipment to perform the full change.
The quoted price isn't much more than the quote I got from a near by transmission shop to do a pan drain and fill on my daughters 2000 Camry XLE,
which I will do myself, eventually.
Anyone have a bad experience doing a full change on a A761E? Apparently last done by Lexus (in their system) in 2010 at 99,000KM now 122k.
Don't know if a flush or just a change.
As I was leaving one of the employees there came out to drool on the car, remarked what awesome shape it's in. Figured I will get notes on my windshield asking if I want to sell it. Kinda nice considering it threw PO171 and PO174 codes on the way home. Never when the tech is driving it!
So probably not the last bit of cash I will have to throw at it this summer.
I think I will just clear the codes, throw some Lucas fuel system cleaner, top it off with Chevron 94 and take it for a burn to whistler after the transmission is serviced. Failing that hopefully it's something I can take care of.

 

If it’s only got 23k km on it since a fluid service, just drain the pan, refill, and check level correctly. Or just check the level - fluid age/condition is not the problem. It does not degrade from sitting.

Those two codes in tandem suggest an air leak past the maf sensor - unmetered air is likely leaning the mixture. For example, a crack in the hoses around the throttle body or bad seal, etc.

 

True enough on the fluid. It's not like engine oil.
On the codes it's interesting it's throwing them after a few short drives in the day, then after less than 5 minutes after a start.
That makes sense. Tomorrow I'm planning on popping the cover and poke around, check clamps etc. I'll clear the codes and take it for a nice high speed run after the fluid change and push some fuel and air through her. Failing that I have a can of MAF cleaner kicking around I can try, check resistance etc. The saga continues...

 

This is not about the trans codes, but since this car is new to you I’ll mention a routine I do on new-to-me cars. It works well and has been refined and proven. Things I’ve picked up over years and found to work well.

- Clean the TB by hand w/solvent, MAF sensor if needed
- Run SeaFoam or B-12 (preferred) through hoses in induction for cleaning. Enjoy the smoke show.
- Drive a tank of Gumout Regane HM or Techron through the tank.
- Make sure pcv valve is very clean or replace
- Drive the car hard a bit - redlining it aggressively. On-ramps or other roads in lower gear is fine, not suggesting MadMax death-runs .

You would be surprised what this can do - particularly some hard red-line pulls, and PEA cleaner (techron, gumout) through the fuel. Those particularly can help decarb the combustion chamber, loosen sticking rings, and improve fuel injection pattern and metering/delivery accuracy. It’s all simple, direct, effective, and cheap ways to address typical issues.

 

So I popped the engine cover yesterday to find a loose clamp on a1/2 inch hose on the air induction system by the cover bolt on the passenger side. Used a flashlight to peer down at the other end to find the other end completely disconnected. As I'm heading to Lexus tomorrow it looks like a 15 minute job for someone that knows what they're doing, I need to get my hands on a factory service manual, I see they're not cheap for a set, guess I'll get the engine and suspension to start. I was going to throw some Lucas fuel system cleaner in the tank as I have a jug of it around. Good advise on the TB cleaning and the neighborhood smoke show. Looking forward to setting the switches to sport and power and going for a burn on Wednesday

 

Do you know if he removed the overflow plug to see the oil level or condition? I'd suggest you go incrementally as the above doesn't confirm it's even at the right level. Start with a top-up by any transmission shop that knows the process. If it's just low on oil that might be enough. Then try the pan, filter and oil swap if you still have issues. After that you only have the full flush which does indeed get expensive and wastes lots of ATF. It can be done at home but it's messy and needs lots of lifting and lots of time. It's a last resort. I'm hoping just the top up will see improvements for you.

 

Hi all.
So an update on my issues. Had Lexus do an oil change but not a full flush, 4 litres in. Had them reconnect the hose that was off. The service advisor said it was the evap system and likely the cause of my p 174 code. Did some city driving and a 160k of highway driving and the result is no codes. The noise the pump was making in reverse is now gone. Transmission is shifting just fine, I suspect a low fluid level. So happy camper! Thanks for all who took the time to give me some guidance.