Mihanicos

Thank you very much indeed for sharing your knowledge and experience with me. Your threads were very enlightening and the videos explained very clearly in detail how everything works. I knew that the braking was regenerative through the motors but I did not have a full drawing of the car's gearbox to understand how everything works. I bought viewing time from Lexus website to look up relevant information but all I could access was how to change gearbox oil. I will check the car's behaviour in the next few days and I will know if it is back to normal. I take this opportunity to thank you for your help and the Lexus owners club of uk for hosting me. Chris.

Recently when going down mountain roads with gradients in excess of 10% I noticed that the engine braking when in 5th, 4th and 3rd gears was much less than before. The difference in braking between these gears was also very small. The car displayed no trouble codes and neither the Techstream. There has been no loss of transmission fluid. The 12v battery has gone flat a couple of occasions due to absence abroad but the car was ok after recharging the battery. The only items to initialize after reconnecting the battery was the steering by turning it fully in both directions and the tyre pressure sensors. I would be grateful if anybody can give any advise as to the cause of the problem. Chris.

Make certain that you have no ignition issue. If you have HT leads to the spark plugs, check their insulation. An easy way is to look at them at night with the engine running. If you see flashing from any HT cable to anything that is grounded then the insulation is poor. If you have a fuel filter, replace it. Check that you have no damaged vacuum tubes on the engine. Move them and bend them a little and listen for any effect while the engine is running. Failing all the foregoing, rough idling is a clear sign that you have burnt valves or sealing problems with the combustion chamber of any cylinder. You have to remove the cylinder head to find out the cause. If you need any further help, contact me. Regards, Chris.

Fit the new bushes, preferably original or by an original equipment manufacturer and leave the anti roll bar free to move within them. Lower the car to stand free on its wheels and then tighten the bushes. Clean the anti roll bar from any grease or old rubber. God luck!

All the steering geometry parameters, toe in or toe out, camber and caster angles, are progressively altered to their pre determined limits to increase the rolling resistance of the front wheels, hence increase braking and reduce braking distance. Any deviation from the design values of the steering geometry will impair road holding but when braking hard to avoid danger or an impact, safety becomes first priority and under these circumstances, road holding does not matter much since it is only temporary for a very short distance or time. Any grease other than silicon will damage the rubber and cause further deterioration. This will increase the gap around the anti roll bar and make things worse. Regards, Chris

The rubber bushes fitted to the anti roll bar are designed to be in continuous stationary contact with the bar and the bush holder/cradle. As the bar moves about its axes due to the road surface, the bush inner mass is continuously forced by the bar to follow these fluctuations while the bush's surface in contact with the bar and the holder/cradle are in stationary contact. When you brake, certain rubber suspension bushes, including the ones in question, are progressively deformed to their design parameters to alter the steering geometry thereby increasing braking and simultaneously reducing the braking distance. Worn bushes, including the ones in question, alter the steering geometry thereby causing poor road holding and accelerate front tire wear and tear. The only grease that preserves rubber, is silicon grease. [ Application on constant velocity joints, brake calliper dust seals etc. ] However, in this instance, using grease, is simply against the design principle! I hope the foregoing is of help to you. Kindest regards, Chris.

You should replace the bushes and never use any grease of any kind. Clean the anti roll bar area where the bushes fit. For some cars you can get bushes made from a different material that is harder and last a lot longer than the original.

The efficiency and the power any engine produces is directly proportional to the compression ratio of the cylinders. Worn piston rings and cylinder head valves will reduce compression ratio. Worn valve guides will allow the valve to change seat position every time it closes. A compression test will verify the condition of each cylinder. Excessive oil consumption will be noticed. A clocked or bad exhaust with worn silencer tubes will increase back pressure and this will cause the engine aspiration to drop, the cylinders will not be emptied of exhaust gases, thereby reducing the amount of fresh air and fuel into the cylinders, hence a drop in power. The ignition timing is critical. The manufacturer gives a way of checking the ignition timing of the engine at idle speed and higher. The engine timing is critical as well. I would check all the timing marks of the engine. The air to fuel ratio is also critical for optimum performance. Inlet manifold vacuum should be as specified to indicate any air drawn in due to a leak. I would check the lambda sensors to be within limits. I would also check the ECU against a reference to confirm that it is functioning correctly and controls the engine correctly. I hope the forgoing is of some help. Kindest regards, Chris.

Drain completely the automatic transmission fluid and replace the ATF filter with another original. Use only original ATF fluid or another approved by Toyota. Make sure that you follow the correct procedure to fill and check that the fluid is at the correct level. Nearly all problems with automatic transmissions are down to a clogged filter and fluid needing replacement. This is the first step I would do before looking any further.

A leak is developed when the bore of the brake master cylinder is scratched, scored or not having a perfect smooth mirror surface. The brake fluid is hygroscopic and absorbs water moisture from the air every time you brake. This in turn causes corrosion which damages the seals of the piston thereby allowing brake fluid to be drawn into the brake servo operated by the vacuum of the inlet manifold. Examine the bore of the brake master cylinder and polish it with very fine wet sand paper like P 5000 or finer. A lapping compound will give the mirror surface. The corrosion I can see is not within the operating range of the piston seals and you should have no problem. Remove the corrosion in the photo and polish the surface as above. Be very careful as you slide in the piston with the new seals not to damage or scratch them. Use brake fluid to lubricate the bore of the brake master cylinder and the seals. Push them in the bore with a smooth instrument. If you need further help, do not hesitate to contact me. Kindest regards, Chris. PS The best thing to do is to get a good used brake master cylinder if you can and replace the seals. Bleeding the whole system is a lot of trouble and work to risk for a poor repair.

I would certainly attempt the same. The only think to consider, is the maximum charging current to be the same and the ampere hours [capacity ] of the replacement batteries to be the same. The internal resistance of the replacement batteries should be the same or lower.

Whenever you drain the coolant for any reason, you should bleed the system so no air is left in. Some manufacturers have a drain plug and others do not. Remove the radiator cap with the engine cold and check that the thermostat opens, the hose from the engine cylinder head to the radiator gets hot. Rev the engine a little and you should see the water circulating. Indication that the water pump is ok. Now, with the heating fully on and the radiator cap removed, you must find the heater hoses and squeeze the heater intake hose first and then the heater outlet hose. As you squeeze, observe the water level in the radiator rise. with the heater fan on high, feel the air temperature coming out of the heater. When really hot, the system has been bled and there is no air in the coolant. Never mind about the water overflowing due to expansion as the temperature rises. Hope this is the cause of your overheating. Another reason that causes overheating are worn piston rings but with this engine is highly unlikely. Always start from the inexpensive and simple causes and leave the expensive solutions last. Good luck.

Ευχαριστώ πάρα πολύ! Thank you very much indeed for your advise, mine was made late 2010 and registered in May 2011. I got no alarms yet but I will have the ECU checked and updated as soon as possible. I am still looking for a Techstream to buy.

The power battery consists of some 40 cells connected in series to produce some 280 volts dc. The charging current is in series too, so any resistance in any single connection , just only one, will reduce the charging current going through the battery. Hence the battery will never have its full power. Simultaneously when the battery is called upon to deliver power to the converter and then to the inverter, will not be able to deliver the full current possible and available. The fact that you get the alarms when it rains or when there is humidity in the air, indicates bad contacts on the battery connections, power cable connections etc. I would strongly recommend that you access the power battery, check for any signs of corrosion on all the terminals and disconnect each cell, measure the voltage across each one and record it. You should also check the current delivered through a resistance to limit the maximum current delivered during the check. To do this work you must have the knowledge to work on medium voltage circuits. If you do not have this knowledge, it is very dangerous and it can be lethal if you touch the dc battery terminals. There are special insulated gloves you wear for this purpose. The Techstream diagnostic scanner would be a great help in pin pointing the problem. I would be very interested to do this work for nothing but I do not live in uk. If you look at a similar topic you will find a contribution made by Richard. He repaired the power battery for somebody and the problem was corrosion on the connectors of the battery cells. He has the experience the knowledge and the equipment to help you. Wishing you the very best of luck, Chris.

Warped brake rotors will give a judder on the brake pedal every time you brake. At about 50 mph, usually, indicates an imbalance on the front rotating wheels. Jack up the front wheels and check that the tyres are fairly round when freely rotating. Look for any bulges indicating that the steel belt of the tyre has failed. Check the bearings for any play. There must be no play at all. Rebalance all wheels dynamically.

I got a quote from Lexus Cyprus for the timing chain of a Lexus GS 450H 2011. I could not get it for your car because they need the VIN number of the car. The cost is just over 100 Euro!!! Lexus Cyprus spare parts tel No.: 00357 22 400001. I have replaced the timing chain on other cars and it is possible if the replacement chain is with a removable link. The timing marks of the engine must be accessible and visible before attempting the replacement. You need a replacement compressible link which can be compressed by a special tool so the new chain is endless like the original. Never ever attempt to run the engine with the removable link, it may snap or come off. If you are interested, I can tell you every detail step by step. My number is : 00357 99 671096 [Cyprus] . Hope to have been helpful. regards, Chris.

Lexus Europe has the original manuals on CD. Visit lexus-tech.eu get an account and you choose the repair manual you want to buy. Manualsoft.com also have repair manuals on CD too. These are very good, I have one for a Toyota Cynos and it is really very good. They are cheaper than the original. The problem with both is that they are supported by Windows XP. You need a laptop with Windows XP. Another alternative is Alldata.com but their manuals are for North America and Canada. These manuals are supported by all Windows. I have a year's subscription for my car, it is only $25 a year and if you get a repair manual for another car you pay something like $17 but there are differences with the maintenance of the owner's manual I have. In Alldata.diy.com the rear differential oil for a Lexus GS 450H 2011 is never replaced at all, only inspected every so many miles. In the Lexus owner's manual, the rear differential oil must be replaced every two years or 20000 miles whichever comes first. Hope to have been helpful. Regards, Chris.

If your brakes have a vacuum servo to assist the brake master cylinder, then the brake fluid is sucked in the servo due to the vacuum created by the engine. Check the brake master cylinder seals or replace them. Good luck Mihanicos