Russell Wheeler

12v battery, or water ingress - its a 2008 RX400h (ie seive)

£276 for my 2006 RX400h with 1st Central

Never heard of leaks, like they have never heard of the small starter battery causing a problem in a RX400h. Liars. They do leak especially as they get older, seals drying out, poor welds.

Water leaks on an 18 year old car. Not uncommon. Just needs time and patience to trace/seal them.

My 2006 RX400h - looks like it needs a cambelt - the sticker says it was changed 2014. Any idea of costs. Also it is on it's original battery pack (seems to be working fine) - any idea how long it can last, and how much to change. Car has done 140k and runs fine. I am concious of pouring lots of money into a 2006 car, although as a family we have owned it since 2009, it's going to need some serious maintenance this year. It's been 2 years since it's last service. Also I had a service plan with Lexus and the spark plugs are supposed to be changed every 60k. I can't find any evidence it was done at 120k. Apparently they are a pig to do.

Yep, used it and it does seem to work - It's a liquid when you pour it and it creeps and then sets. Will only work on tiny cracks.

Mine is the same, and I do live by the seaside. 2020 was the 1st mention of corrosion underneath on mine. Removed the spare wheel, cleaned and used hammerite on both subframes, then waxoyl all areas I could find. Seems to be keeping the worst of it at bay. Doing nothing means it will eventually rust away. The subframes should not rust out from the inside, if they have then it would have failed the MOT. The advisory must be for rust they can see (ie on the outside of the subframes). At 17/18 years old, you do need to expect they will be rusting underneath. Some older RX300 owners have had to have new subframes (or scrap the car)

Take out the boot liners and the back seats, see if the hybrid battery is submerged

Check for water leaks, if water gets in to the hybrid system it causes all sorts of problems. There are lots of posts about leaks and how to cure

True - I knew about headlight washers - which it may have as standard - Self leveling, my car has conventional springs and shocks.

You are correct, it should fail the MOT by converting to HID, however as the RX400h was also available with HID (Mine is) then the MOT inspector is not going to know.

I purchased an blank OBD port, and soldered the connections from the solar panel to the positive and negative points in the OBD, so the solar panel connects directly into this. Your battery should not discharge overnight. Mine takes about a week - which is not ok for me - as sometimes the car does not get used from Month to Month. I have heard of a solution where a larger battery is located in the boot - however this requires significant changes to the wiring as you need to get the power from the boot to under the bonnet.

When it warms up I will go underneath and have a look.

I use one of these in the winter. It's not a very elegant solution but does work. https://www.amazon.co.uk/Battery-Isolator-Switch-Power-Leakage/dp/B07J34S5DH/ref=asc_df_B07J34S5DH/?tag=googshopuk-21&linkCode=df0&hvadid=224431698442&hvpos=&hvnetw=g&hvrand=16332938530141334352&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1007098&hvtargid=pla-757317365237&psc=1&mcid=3f6a06c2dbf432e1a17c232a91df02e9

You can jump the 12v starter battery from a 12v source. Just don't jump anyone elses car from yours. And like you I have looked for a larger capacity one, there isn't space under the bonnet - hence all the problems. I believe they fixed it in 2009 with the next generation by putting a normal sized battery in - which is no help to anyone with an earlier 400h

Yep, it's a pain, mine is exactly the same. I use a solar panel in summer and a battery disconnect in winter. I also carry a jump pack in the glove box, so have never been let down.

Another pass this year. Again another advisory for rust. I rubbed down and hammerited both subframes the other year, but the advisory is for general underbody corrosion. Anyone used lanoguard - my regime of hammerite and wayoil doens't seem to be working (or it's just the car getting older). On top it looks perfect, not a spot of rust.

I have the same problem, as the car is only used a few times a month. In the summer I have a solar panel that keeps it topped up. In winter I have a battery disconnect, so pop the bonnet and lock the car - then disconnect the battery. It's a pain but has been like that since I inherited the car. My Dad used it a few times weekly so the problem didn't occur for him.

15 years old, the underside of these cars does not seem very well rustproofed. I have been out with a wire brush, hammerite and waxyoil with mine - and it was quite rusty - commented on the MOT

It is hidden under the cover sills, so weld plates on, then put the cover sill back on. You won't see it. Is the otherside similar ? - Might be worth rust proofing it (unless it's already too late)

I used a 55mm flexy pipe in the end, angle ground off the old exhaust then put this in the middle. Had to reduce one side a little by cutting down the edges a little, so it squashed down. Repair complete and working fine.

It's been in the family since 2009 - my Dad purchased it at 3 years old with 90k on the Clock for 15K. Seems like a bargain now. I inherited it 3 years ago

Mine's 17 years old, never any problems. Always starts and runs. Yes MOT time can get expensive with worn rubber components - but it is 100% dependable

The bluetooth is more annoying. I can't play music though it !

Yep, that's where mne has developed a hole - it just needs sleeving as the rest of the exhaust isn't bad