WadeLovell

Update: The "OEM" fitment Asin water pump I bought from AutoPartsWarehouse {NOT recommended} was not an OEM fitment water pump. If you buy a real OEM fitment pump you will be able to separate the front half (which has moving parts) from the back half (which has no moving parts) and dramatically reduce the time required to replace the water pump. If, on the other hand, you do as I did and buy one where the entire unit is the same size and shape but the casting itself is different, you will have to figure out you have a problem when the replacement gasket you ordered fits the old pump but not the new pump, remove the heat shield on the passenger's side, disconnect additional couplings, and replace additional o-rings. O-rings not included with the pump were over $17 at the dealer. The one leak I had afterward could have been avoided but I had to disconnect the back half of the water pump {where I tried to reuse an o-ring}. Ideal world: Buy an OEM pump or a precise replica of the OEM pump. Spend $3 on a replacement gasket which you probably won't need. Save some money on o-rings. Save some money on coolant. Save an hour or so on disassembly and reassembly.

Amazingly helpful write-up. Thank you. Please send holder details to SC300@ceoathome dot com (I hate bots!). Thank you in advance. I need to torque mine back down properly before driving it. My air impact wrench is rated high enough, barely, and supposedly set to the proper torque based on the PSI setting on the air pressure regulator but I would feel better if I could use a torque wrench. BTW - If you use an air impact wrench to remove or install the bolt on the harmonic balancer you will probably have to remove the radiator, as I did, to allow room for the tool. Since I was doing the water pump at the same time, I drained the entire cooling system and recovered the coolant. It wasn't that much more work, maybe 15 minutes. NOTE: If you are replacing the timing belt you should consider replacing the water pump at the same time. It is the same tear down. I last replaced the timing belt at 145,000 miles and foolishly did not replace the water pump. I got 15,000 miles out of this timing belt before the water pump died. This is a needless duplication of effort! WARNING: Be very careful about the replacement water pump you order. I purchased the Aisin OEM Fitment water pump from Autopartswarehouse (16100-49837-83 / W0133-1600218). This is NOT an OEM Fitment unit. To use this pump one must replace the back half of the pump housing which comes with it but which has no moving parts. Their gasket (16124-46041 / W0133-1738759) would fit the original pump but does not fit their "OEM Fitment" pump listed above. If you remove the rear half of the pump housing you will have to replace the o-ring behind it, the gasket on the inlet tube, and the three o-rings on the water by-pass tube. The last three o-rings are dealer parts. I paid over $17 today at Kearny Mesa Lexus for them. If you can find a real OEM water pump you will save at least an hour of work and a trip to the dealer. (Please post the source and cost along with the part number for everyone's benefit.) FOLLOW DIRECTIONS (Do as he said, not as I did.) I would like to emphasize the importance of step 24. Remove the 1.5mm hex wrench at this point. If you install the harmonic balancer first it makes it hard to grip the 1.5mm hex wrench. It is not a simple matter to pull the wrench out once the tube is properly torqued even without the harmonic balancer in the way. I had to use a pair of Vise Grip pliers and plenty of elbow grease. The wrench looked like a nail by the time I got it out. You need the stiffness of the tool steel but plan on sacrificing the wrench to this installation. Make it a great one!

So far, it amounts to following the directions for replacing the timing belt. I had to pull the radiator in order to fit the air impact wrench onto the large bolt for the harmonic balancer. That actually did not do it (600 ft/lbs at 90PSI using 4.8 CFM). I attached a four foot long cheater bar to a 1/2" drive bar and an air impact six sided 22mm socket, had the assistant crank the starter and forced up hard on the cheater bar to free the nut. Next time I will remember to either disconnect the spark plug wires or connect an oil cooler to avoid the mess I created this time. I am replacing the timing belt as well even though this timing belt only has 15,000 miles on it. It is a quarter of its way through its life and this will buy a full 60,000.

Back for another issue and saw I never received a response to this one. I called AAA and had them come on a lock-out call. They were able to open the door. Then I removed the interior panel per directions in this Forum and replaced the broken $2 plastic bit that holds the door rod in the door handle assembly. Buy the Lexus part from the dealer. The one out of the plastic bits kit from Napa lasted a week. Calling AAA or a locksmith certainly beats tearing up the interior door panel.

Failed to replace water pump when timing belt was done by mechanic last year. Is there a good write-up on doing just the water pump for the SC300? I see a lot of information on the timing belt. Is it just the same job over again with a different objective? I hate to drop another $1k to have the mechanic do it if I can handle the work. Thanks in advance.

Salvation! Thanks to a slim jim and a little patience the door is open. Slim jim and related tools available online for about $25 including shipping. That is about $700 cheaper than replacing the inner door panel at the dealer. Once the door is open follow the steps on this forum to remove the inner door panel. Wade

Has anyone succeeded opening an SC300/400 door with a slim jim or other tool? My outer handle failed. Then the mechanic couldn't open the driver's door from the inside so he yanked on it and broke the handle. The broken handle is an irritant but the mechanism is actually stuck and attaching the missing portion with super glue has not accomplished much (looks better but still does not open the door). Suggestions? Thanks, Wade P.S. I am absolutely not interested in busting up the inner door panel.

Now I am in the same boat. I had been unable to open the driver's door from the outside for awhile but it had not inched up my to do list since all I had to do was reach over from the passenger side. I took the car in for its smog test today (passed easily, thank you) and the diagnostician apparently could not open the door from the inside. He tugged on the inside door handle hard enough to snap it. Previously, all I had to do was take the door panel off. As everyone knows, however, once a diagnostician broke it so I could not open the door at all, the challenge became much greater. How do I get my hands in the right place to release the emergency latch without destroying my interior door panel? Thanks, Wade

When I first received this code I cleaned and tested my EGR Valve. The movement was correct except the diaphram leaked down slowly under vacuum. Then I started getting too rich and too lean conditions (Error 25 and Error 26) instead of EGR System Error 71. Not wanting to take a chance, I replaced the EGR valve (along with a bunch of other components - see my post under Rough Idle for a full confession.). That seemed to do the trick for a couple of hours. Then the Error code 71 reappeared, disappeaered, and reappeared again. The only thing left I can think of is the EGR Temperature Sensor (a special order part at $164 plus tax and shipping). Is there anything else I should be testing? What are the specs for the EGR temperature sensor? Seems it should be about 2 k ohms at room temp (68 degrees F, 20 degrees C) and drop to about 0.2 k ohms at 212 degree F (100 degrees C). But does anyone have the actual spec? Thanks, Wade

OUCH! I got VERY Lucky. I finally pulled the throttle body to change out the #3 and #4 plugs and wires. Both cylinders had great compression. I thought one of them was certainly going to have low compression. When I put it all back together with new Bosch wires and platinum plugs it ran like it was NEW! It did finally throw a #71 EGR code after two hours on the freeway. Then the check engine light went dark again shortly thereafter. I will check the wiring one more time on the EGR temp sensor while my new sensor is in transit. If I don't cure the problem before the new sensor arrives, I will be forced to add it to the list of recently replaced parts. Still, the overall damage including the new timing belt (professionally installed) was just this side of $1,000. Now, if I can just get to 215,000 like you have without blowing the head gasket. Wade

Thanks, Tom, I am a Mobil 1 synthetic man myself. There is not any evidence of a white film under the oil fill cap. As I mentioned, I recently added Slick 50's high mileage formulation to the crankcase. As soon as I have 500 miles on that I will replace the oil and send a sample to Blackstone Labs for evaluation. Wade

:cries: I am having a similar problem on my 1993 SC300. I suspect the head gasket since mine overheated. During the last 1,000 miles I have done the following maintenance on the Lexus SC300: At about 146,500 we began experiencing an overheating problem. There were three incidents. 1. The first was the plastic top of the radiator cracked. • Replaced the radiator with a new all metal radiator. 2. The second was the upper radiator hose burst. • Replaced upper radiator hose and radiator cap. 3. The heater hose that connects at the back of the block burst. • Replaced the lower radiator hose, thermostat, and heater hose. There have not been any more overheating incidents. After the third overheating related repair, the engine idled roughly when warm and threw EGR code #71. • Replaced EGR vacuum lines. • Cleaned and tested EGR valve. Seemed good but I replaced it anyway. • Replaced the oxygen sensors. • Replaced the coolant temperature sensor – the one the ECU uses. Continued idling roughly and began throwing #25 Lean and #26 Rich error codes. • Replaced distributor cap and rotor, spark plugs, and ignition wires. • Ran a tank with injector cleaner. • Added Slick 50 engine treatment for high mileage vehicles to crankcase. Threw a #71 EGR code. The only remaining components there are the wiring and the EGR Gas Temperature Sensor. I accidentally disconnected the hose to the vacuum diaphram for the EGR when changing the PCV today. The #71 EGR code was a red herring (unless of course it reappears later). What’s next? • Run a compression test on all six cylinders. (140 to 160. I wish it were better.) • May want to replace the fuel filter to rule it out. Do I have a fuel line pressure tester? • Want to test the EGR Gas Temperature Sensor or replace it. • Want to test the injectors and inspect the injector wiring. Symptoms: • Rough idle. • Low power. Suspect: • Damage related to overheating once too often or for a little too long. • Burned valve(s) from one of the overheating episodes. • Bad head gasket from one of the overheating episodes (I have not noticed any white smoke or seen any loss of coolant.) What did your head gasket and valve job cost? Does anyone have any other ideas? Thanks, Wade

Hi Sam, I don't know if it's the same for 1993 but in my 1992-SC400 book it says this; CODE 14 : NO IGF1 SIGNAL FROM IGNITOR NO.1 - IGNITION CODE 41 : OPEN OR SHORT IN CIRCUIT FOR MORE THAN 0.5 SECOND - THROTTLE POSITION SENSOR. If you wish I can email you the 2 complete pdf files for my 1992 manual. Cheers! ← ← Hey Guys, I have a problem also. I don't know what the codes would be but my 1997 SC300 runs and cranks beautifully unless I let the car sit for more than 3 days. Then the battery dies and I have to jump it off. Yes, I have replaced the battery and was told the alternator is OK. Do you think I could have a short circuit somewhere? All the interior lights, radio and everthing works unless I let it sit for 3 or more days??? Any suggestions? Your 1997 is OBDII compliant. Purchase a scanner, e.g. actron CP9175 from Amazon for $145 plus $21 for the computer cable and you will be able to diagnose just about any problem with your car. With our 1993 SC300s we seem to be in the transition period and just missed getting OBDII. The OBDI is not nearly as easy to work with. BTW - I am looking for a copy of the error codes for our vehicles. Maybe the Mitchell CDs I ordered will have them. Anyone have a list in an email format?

Take it BacK! White smoke is typically the byproduct of COOLANT which means you have a blown head gasket. $$$$