Mihanicos

Recently I had my tyres replaced and at the same time I removed all Tpms sensors, despite all functioning. I could not find batteries witth terminals connected to them so I could replace the existing ones who were about to die. Having tried a few pressurised box ideas, I ended up getting a very small tubeless moped bike tyre, about 10 inch diameter and put them there. All sensors were connected to a 3v alkaline battery and the tyre was inflated to 3 bar. The low air pressure light went out! In my car's manual, it says that if the tpms monitors are removed or seize functioning, after some time, the system will be self disabled. If the tpms monitors are re energised, the system will self enable itself. I had the car running for more than one month without the tpms monitors and the annoying light never went out. Chris.

Before you do any adjustments on the steering geometry, you should make sure that all suspension and steering members and joints have no play. Also all wheel bearings should have no play at all either. Use a small crowbar to check them. The alignment shop should tell you to have the foregoing checked before you go for alighnment. Chris.

Always and before you remove a timimg belt or chain, you need to verify the engine's timing marks and align the engine to them. With the crankshaft at TDC, both intake and exhaust valves are closed. If you have a distributor, the pointer should be pointing at No1 cylinder ignition cable. If they are not, rotate the crankshaft one more revolution and bring it to the TDC mark. All camshafts should align with their respective fixed marks on the cylinder head of each vee. Make sure that the engine timing is correct and turn the engine two revolutions and verify it rotates freely. If you have an interference valve timing and your timing is off, the pistons may hit the valves with catastrophic consequences. Emanuals have repair manuals for lexus and they are about 25 euro each. Chris.

Check all ground points of the car. Also check that all ground pins on the OBD socket are good. Chris.

When you use washable filters which need to be sprayed with some kind of oil every time, there is a possibility that this oil forms a film on the mass air flow sensor, thereby causing it to read wrongly the amount of air entering the engine. It is worth checking and cleaning the maf more often for peak engine performance and fuel economy. I use Vic air filters, OEM to japanese cars and change it at the annual service, about 5000 miles. I live abroad and there is a lot of dust especially in the summer. Chris.

The difference of one tooth off is very small. Usually the engine would start but not sharply as before and a slight hick up occurs about mid range. A loss of power and fuel consumptiom increase is a result. If the engine check light does not come on then they would investigate. Chris.

Before condemming the starter motor verify the fault. Disconnect the solenoid supply and connect a 12v supply from the battery to it. It may be the starter relay faulty, easily replaced or put a jumper on the power contacts of the relay. Last, it may be the ignition switch contacts or the ignition barrel not completing a full travel. Chris.

Check the engine timing. Often they miss a tooth and the engine runs erratically. Chris.

Always before you attempt to remove a timing chain, verify the engine's timing. The coloured links on the timing chains are to help their correct fitting. Rotate the engine from the cranksfaft pulley clockwise until the TDC timing mark is aligned with the pointer. The 10 mark is the cranksfaft position 10 degrees before the Top Dead Centre. Turn clockwise past this 10 degree mark and you should be at the TDC. The TDC mark on the crankshaft pulley should opposite the pointer. The camshaft marks should align with the fixed marks opposite them. If not, rotate the engine another 360 degrees to align the camshaft marks. All inlet and exhaust valves on No1 cylinder should be closed. If all the camshaft marks do not align with the reference marks on the engine, relevant to the TDC, then you have to replace the timing chain. An easy way to verify the TDC of any engine is to remove the spark plug of No1 cylinder and put a long screwdriver in until it rests on the piston. As you rotate the engine, you will see the screwdriver reach a highest point and then it will begin to go down. The TDC mark on the crankshaft should be very close opposite the pointer. From my experience, the tensioner and the guides of the chain should be good until an engine overhaul. But there are always exceptions. If you opt out to change the timing chain, I agree with the recommendations of the other learned members. I would recommend a compressed link to close the chain instead of a clip. Clips run the risk of failing or coming off and that would mean another engine alltogether. You need a special tool to do this. Chris.

Check the fuel pump delivery pressure. Then check the fuel pressure to the injectors. If they are ok, have the injectors checked by a specialist. Chris.

Refer them to the maintenance schedule of their cars. For my car which is " sealed for life " it is specified that the transmission oil should be changed every 6 years or 54000 miles. For severe service conditions the time is reduced to 3 years and I cannot remember off hand the mileage. Chris.

Most people do not dare to even remove the oil pan of an automatic transmission. If you inderstand the principles of its operation, it is not difficult to repair it. For this you need the repair manual which will guide you step by step to disassemble it, check each component and reassemble it. The valve body controls the flow of oil to the various pistons to operate the right combination of clutches so the right gear is employed according to the prevailing driving conditions. The solenoids are operated by the transmission ECU to control their respective valves which in turn control the flow of oil to the various clutches. If the valves are stuck you get a code for the respective solenoid but the solenoid may be ok. Sometimes the spring return of the valves breaks. Bebris inhibits the smooth operation of the valves causing malfunction. So replacing a solenoid unless it is not working, it will not cure the fault. In the valve body there are check valves made of stainless steel. Also there are more very small oil filters. If any of those check valves has got as much as a single hair in it, it will not function correctly causing clutch slipping and delay gear engagement. So the conclusion is that you should disassemble the entire valve body and check it thoroughly. There are repair kits with all the o rings, seals, clutch assemblies, pistons, valves etc. It is worth disassembling the entire transmission to check the various components, wear of bushes, planetary gears and above all the rubber seals of the pistons. Heat turns them into solid rubber causing oil leaks and pressure loss resulting in clutch slipping. If you need any special tools, there are available. You can use compressed air to check the operation of the various clutches. Toyota automatic transmissions are very reliable if they are serviced and looked after regularly. All the information is in Lexus-tech.doc. Chris.

I agree with everything the learned members have already stressed in detail. The problem is that the compressor oil is carried by the refrigetant in every part and pocket within the system's equipment . Even with systems incorporating an oil separator an oil film is still left everywhere. Verifying that every trace of the oil has been removed from the system prior to charging in view of the work involved, equipment and time needed and the fact that bad workmanship will not be obvious immediately, I would say that it would take a very dedicated professional, perfectionist from another world to do the job right. Chris.

According to the Lexus Maintenance schedule, for the GS 450h GWS 191, the transmission fluid, for normal conditions, must be changed at 54000 miles or 72 months whichever comes first. For severe conditions, it must be changed every 36 months. It is of critical importance to change the transmission fluid strictly in accordance with the maintenance schedule because its purpose is to lubricate and cool the moving parts but at the same it must insulate the windings of the motors within it. As the fluid quality deteriorates with time and use, a high voltage flashover within the motors and the transmission case cannot be excluded rendering the transmission useless. Mechanics in general simply cannot see, understand or appreciate the electrical side of these transmissions and the consequences thereto. Chris.

Switch the radio on to the FM. At the bottom of the screen, below the cd slot, press TA button to go to TP, again to go to TA and again to go to OFF. TP, the system switches to traffic information when a broadcast with traffic information signal is received. TA, traffic information can be heard only when a signal is received. Chris.

Most likely is the oil pressure sensor. It is usually on the cylinder head. The symptoms you describe usually point to bad contacts of the oil pressure sensor. Chris.

Assuming that there is no major oil leak check the oil level. If no oil has been consumed, you may have a faulty oil pressure sensor. If your oil level is via a sensor and not a dipstick, then this sensor may be faulty. If indeed the sensors are ok, you may have faulty inlet valve seals or worn piston rings. A diesel engine with worn piston rings has a low compression and it will not start. Worn inlet valve seals would not burn so much oil in such a very short time. Chris.

I missed out recommending a drain and filter change, like another member has already mentioned. Fill the transmission with new oil, use the recommended by the factory, do not try anything better cheaper, synthetic..... There is a high possibility that the transmission will recover. Chris

The humming noise could be caused by the final drive pinion. I had the same problem with my prevous car, a Mercedes 280CE. I put 80W140 GL 5 oil and it stopped. There was never any problem after that. This is cheaper and within specs than opening the final drive and adjusting the ring gear postion by changing the shims on eithet side of the pinion. In your case use the same low viscosity number as the one specified in the manual. It could be 70W..... or 75W.... Chris.

Select the lowest Ohm range and remove the ABS connector from the car's wiring connector. Measure the resistance between each pin and its respective wire. You should get 0 Ohms. Chris.

Just clean the contacts in the connectors so they are free of any rust or dirt. This should be enough for this case. To measure a resistance with a volt meter, you need to measure the current as well through the circuit to determine the resistance in question. Much simpler with an Ohm meter. Chris.

Check for clean contact connections of the wiring from the ABS sensors to the ABS ECU. If you have contact resistance in the connectors due to dirt or corrosion, that could trigger ABS operation. Usually bad connections you find in the connectors from the ABS sensors to the car's wiring. Chris.

Hi, P0751 refers to Shift solenoid A performance or stuck P0761 " " C " P2714 refers to pressure control solenoid D or stuck It seems that you may have debris in the valve body which inhibits the solenoid operation and the oil filter may be clogged The first thing I would do is to change the transmission oil filter and the oil. They are recommended to be changed according to a maintenance schedule, depending on the service conditions the car is operated under. The solenoids are mounted on the valve body and they operate to give the right combination of various clutches so the right gear is selected according to the transmission ECU commands. Under normal circumstances a good cleaning of the solenoid plungers and the channels they operate through, should restore a seamless gear shifting throughout the range. Normally, the valve body is removable having removed the oil pan first. Chris.

Get a good scanner, preferably Techstream, set up and read any codes displayed. If the engine is running fine, then the injectors are working. If only one injector is not working, the engine is shaking. Chris.

Very unlikely the injectors are responsible for so much unburnt fuel through the exhaust pipe. It would have ignited and the exhaust pipe would push flames through. Extreamly rich fuel mixture would result in a very rough idling and cause the engine to stall. Look for a fuel leak. Chris.