Tyrosman

I can't understand the reason for taking all the trouble to
change the rear lamps as they will only be viewed by following vehicles and not
be seen by the owner??

Possibly a partial blocked heater matrix. When idling the (engine driven) coolant pump is operating at a low speed therefore the pumping action is at reduced pressure.

Under this condition a partially blocked matrix may not be receiving sufficient heated coolant flow.

At normal running speed the pumping pressure is increased, thereby forcing sufficient coolant through the matrix to produce heat.

This may not be the cause but is, at least, a line of thought to follow.

Let us know if you do discover the fault and also the remedy.

Good luck

Barrie

Bit of a side issue. I had a door mirror vandalised, cost of replacement unit from Lexus £518, fitting extra! How do they justify their prices?

My local independent service technician employed a very powerful 2 part adhesive to repair the damage, cost £40 for labour.

I have now bought and installed a professional high tech night/day security camera system. Cost of parts including camera, digital recording system, 100m special cable, extra strong mounting pole and anchors, power units, accessories etc. Cost £506.

Barrie

My wife has a VW Passat and I have the RX300 both cars a similar age (10years) and mileage circa 73,000miles. The Passat has been the most reliable and least expensive to repair just two faults, a leaking radiator cost £280 replaced and fitted and front driveshaft gaiters supplied and fitted for £230.

The RX300 had a power steering pump leak (Lexus replacement part circa £900 plus fitting). Passenger heater servo failed cost £200 fitted and now the heater matrix faulty, cost unknown. Not a fault but the offside door mirror was vandalised. Door mirror unit replacement part £518 plus fitting.

Fuel consumption for the passat diesel - 45+mpg. For the Rx300 - around 20-23mpg.

I am not damning the Lexus one bit the car is excellent, only the ridiculous cost of spare parts. Therefore the cost of ownership must be a leading factor re. VW as opposed to Lexus.

I believe the RX models are quite reliable, but not invincible, as the many posts both here and in the USA have found.

In my case I have had a leaking steering pump. Never experienced this problem in any other vehicle I (or my family) have owned.

Other problems being a leaking rear axle propshaft seal followed by a passenger side heater servo failure and now the heater matrix fails to heat, just lukewarm airflow.

I agree in most other aspects it is a great car to own, quiet, comfortable, a useful all-rounder.

Many years ago I had the same problem with my (then) Ford Granada automatic. I was informed that the problem was due to the rubber seals within the gearbox shrinking when cold but expanding when the transmission fluid warmed up slightly. Used to take around 2 minutes or so before being ready to drive off, more in the winter months.

I found an automatic transmission fluid additive advertised in a motor magazine (no web google in those days!) that would cure the problem. After adding the fluid the gearbox worked perfectly ever after.

I would be very wary about using such a treatment in the Lexus transmssion as the unit sees to be very picky about its food. There again, if it means a new transmssion unit is required, then why not? Could save a lot of expense.

Barrie

I agree with Stu. My RX has been outside for 10 years - no problem.

Barrie

Good for you John, that's exactly how I would have proceeded.

Barrie

Strange, I am fairly sure my 2003 (2004 model) RX300 SE-L is fitted with a metal radiator, not plastic. I know that VW cars have plastic radiators which have a known failure problem.

My suggestion would be to find an independent radiator specialist if you do not want to DIY, they would be far less expensive than Lexus rip-off charges.

I would not recommend the Radwell route as it may cause heater matrix blockages.

Good luck.

Maybe part exchange the Rx for a LS430.

The LS430 looks a very luxious large car, quite tempting!

Barrie

My 03 Mk2 RX300 with 74,000+ miles on the clock has smooth gear shifts during heavy, or light footed, driving. There is sometimes a slight surge from taking off from stationary, this could be caused by my lack of throttle control!

The Battery (new in 05/2012) was fully charged using a Battery charger before going on holiday. 20 days later the Battery voltage measured 12.31 volts (Digital voltmeter) ,which I would estimate as holding up to a 60% charge level.

Maybe Lexus could, in future, convert the hybrid's sun roof into a solar panel?

A fair proportion of the chassis underside appears to be protected by (plastic/fibre?) underbody shields. Whether it is worth removing these shields to spray underneath is debateable. Many years ago I used to spray the undersides of my cars with waxoil using a pump up garden sprayer, a messy job but quite effective. At least it will do no harm and waxoil is not bad stuff to handle. I don't think it contains harmfull chemicals but I would recommend using a facemask & goggles when spraying.

Hi Roy, those older Mercs seem to go on forever. I friend of mine has a P reg. C series which he is still clocking up the miles. It has been just about fault free all the time he has had it. According to reports the modern versions are not so reliable. Same appears to go for BMWs, I kept a 1990 5 series model that was fault free for 16 years and only really let it go as I was bored with it. Again the modern equivalents appear not to be so reliable. I part exchanged the BMW for a Jeep Grand Cherokee, I liked the vehicle, except for the sloppy steering, but the reliability was a disaster.

Reading through the RX postings on various pages it does appear that there are more problems associated with the hybrid versions as opposed to the petrol engine only models. Maybe it is because of the complexity i.e. more components that could fail. I find it hard to accept that if one of the hybrid components fail (such as the inverter) the vehicle comes to a halt. Although there is a perfectly willing V6 engine sitting under the bonnet which is unable to, or prevented from, powering the vehicle. Sounds like the well known phrase 'The computer says NO'.

I visited a local Toyota/Lexus independent specialist to have my transmission and coolant fluids changed. When I asked the owner regarding RX300 reliability he said that they were very reliable. I then asked him about the hybrid version reliability, his eyes went skywards and said 'that's another story'.

Fine for you Paul but traversing the M3/M4/M5 with windows etc., tightly closed, ear defenders on (only kidding). Not only that but navigating urban roads could be a danger to pedestrians as they may not hear me approaching. Alright let me be honest, I am just envious of you being in Corwall! Just a word of warning, keep a lookout for those pesky seagulls if you happen to walk around Padstow (or is it Padstein?) with a bag of chips in your hand.

For some unknown reason the link I posted on my previous post became distorted. I will now try again, if it does not work the I apologise.

http://batteryuniversity.com/learn/article/sulfation_and_how_to_prevent_it/

Nope, still didn't work. Ok when I typed it but corrupted when posted, any ideas why?

There should not be a problem to leave a lead acid Battery connected to a charger, provided it is a voltage/current regulated (intelligent) device, most modern Battery charges are. What you are effectively achieving is a 'float charged Battery system' whereby the current requirements of your onboard electronics are provided by the mains powered charger with the vehicle Battery just sitting there, maintained in a fully charged state.

This is common practice in industrial/commercial situations to provide emergency power when required. Where I used to work they had a large lead acid Battery float charging system to provide power if the mains supply failed. When the system was decommissioned, after 30 years, the batteries where still in perfect condition. NEVER leave a lead acid Battery in a discharged

state, the plates will suffer from sulfation.

See link http://batteryuniversity.com/learn/article/sulfation_and_how_to_prevent_it

I may be missing something here, but it does seem that most problems appearing in posts on this forum concern the RX Hybrid models. I think I will stay with my RX300.

I would try to find out the Battery life expectancy and cost of replacements.

Did you get the job finished OK?

I haven't a clue re. the mechanics of a hybrid but should't the petrol engine take over in the event of an electric drive system failure?

My existing pump was removed and sent away for remanufacturing and has now been refitted and the fluid flushed and refilled. The rear diff. was also checked and topped up as there is a small leak from the oil seal . The whole job including labour charge totalled £410. I am not sure how much Lexus would have charged but, considering the pump price, well in excess of £1,000.

Many thanks for the for your reply.

I was quoted £715 + vat from lexus just for a replacement pump. I went to my local technician who has removed the original pump and sent it to be remanufactured. Not sure how much it will cost but should know quite soon.

Kind regards

Barrie

My 2004 RX300 SE-L has developed a power steering pump fluid leak. It appears that the leak is coming from just behind the pump pulley wheel, probably the shaft oil seal. I had to top up the fluid reservoir as the level was well below the fill level.

Has anyone had a similar experience, if so, what was the repair/ replacement cost?

It maybe that the sockets are only live with the key in the ignition/accessory position. Not sure about the Lexus but this was the case with my Grand Cherokee..

Thanks Bobby

Barrie