K9crew

I recently bought a '99 LS400 and I'm embarrassed to say that I thought the car had factory rims. When I had the rims balanced the other day the shop informed me that the symbol in the center is a V and not the Lexus logo that I thought it was. Other than feeling a little stupid I'm not disappointed with the revelation but I am curious as to what I have on the car. The shop (a performance rim/tire shop) had no idea as to the rim manufacturer. Can anyone point me in the right direction? The rim is a 16" and sits WAY too close to the brake caliper in the front!! The other question that I have concerns the compatibility of LS400 and SC400 rims. My wife's '95 SC400 has factory rims but she is hoping that the rims on the LS will fit the SC. If they do I plan on buying some 17" or 18" rims for the LS. I checked on www.tirerack.com and noticed that different rims are listed for our two cars which leads me to think that the back-spacing is different. Thanks, :)

A few weeks ago I changed the distributor caps, rotors, wires, fuel filter, oil etc and I was pleased with the results since the miss at idle and under load disappeared and generally the car was running very well. The only problem was that the engine would stall at idle in N or P. It got so bad that the engine was stalling EVERY time I put the shifter in P. On Sunday morning I decided to check all of the vacuum hoses, wiring harnesses etc that I had messed with during the previous maintenance ... everything looked ok. AWJ had suggested checking the fuel pump ECM so I followed the link that he posted and did some reading in the factory repair manual. I wasn't optimistic since the car wasn't exhibiting the typical symptoms that precede a failed ECM but then I noticed a reference to the Volume Airflow Sensor (VAF) ... "The ECM determines airflow volume by applying a reference voltage to the VAF sensor, which contains a Karman-Vortex unit. The ECM uses a signal to control fuel injection duration and spark advance". As part of the distributor installation I had to remove the air filter, MAF sensor housing and associated ducting. I happened to notice a metal honeycomb screen after the air filter but before the MAF. I decided to remove it at the time to improve air flow since I thought the mesh was merely a coarse screen to catch debris that made it past the filter. To cut a long story short I reinstalled the screen on Sunday and the car hasn't stalled once since then. :) So now to my question ... has anyone else removed that screen and experienced drivability problems afterwards? Is that mesh the Karman-Vortex unit that is mentioned in the manual? It will certainly diffuse and straighten the incoming air but I was amazed that its removal would have such an effect.

AWJ, Thanks for the suggestions. I'll do the test tomorrow. I read the link that you posted and the author mentioned that it's not a good idea to run the fuel pump on 12V for long (I think this was based on his intuition rather than on something that he read in the manual). Anyway, it'd be nice to set the pump at 12V and then drive like that for a day or two to see if the idle problem goes away. :)

I had my charging system checked this morning and according to the tech everything's ok. I was surprised that he simply connected a meter of some type to the battery terminals and checked the system at idle. The factory manual mentions testing the alternator output at 2000rpm ... but I guess his meter is a lot smarter than a standard volt meter! I think I've narrowed down the intermittent stalling-at-idle problem enough to say that it only happens when the transmission is in neutral and when the engine is hot. Usually when I'm waiting at a light I put the trans in N to reduce trans temps but I noticed that the rpm drops slightly in N compared to D. When the engine's cold the rpm are higher so that could explain why the engine doesn't stall in N when cold. I'd better take a look at "adjusting the idle" in the factory manual to see how the ECU controls idle speed. :(

kvh73, Thanks for the information. I don't know if the previous owner had a PS pump leak or had the unit replaced but I did notice oil/dirt all over the PS pump body. I sprayed it with Brake Clean (the alternator was covered with rags at the time) and it's remained clean for a few weeks now so I don't think the pump is leaking. I have an appointment this morning with a local electrical shop that specializes in charging systems. They can tell me if the alternator is defective. :)

I've never been a fan of the plastic/aluminum radiators that come in many import and domestic vehicles since a common problem is that coolant seeps out at the interface between the plastic tanks and the aluminum core. I had that problem with my '98 Jeep Wrangler so I installed a three-row copper/steel unit from radiators.com. Now I have no coolant leaks and no coolant smell when the engine gets hot. Anyway, that could be the source of the leak. Other causes of coolant loss include a failed head gasket, a cracked head or block or anything that causes the coolant to get too hot e.g. a lack of sufficient pressure in the cooling system, debris on the front of the condenser blocking air flow to the radiator, a water pump failure etc. As for the oil consumption ... 1/3 QT in 1500 miles doesn't sound that bad for a six cylinder engine although I just changed my oil (Mobil 1 10W-30) and I didn't have to add any in 4900 miles ( the engine has 51K on it now). Do you always check the oil when the engine is cold and in the same place each time such as your garage or driveway? These may sound like simple questions but it's important to compare apples to apples. If the conditions under which you check the oil each time are the same then we can assume that your engine is consuming or losing oil. The oil could be leaking out somewhere but you already checked for external leaks and didn't find any so it's probably getting past the rings and being burned with the fuel. I don't know if the repair manual provides oil consumption specs (I doubt they do) but you could perform a compression test to see if one or more of your cylinders are out of spec. :)

AWJ, I didn't check out the fuel pump ECM yet but I did manage to flush and the replace the fluid for the hydraulic engine fan this morning. The oil in the reservoir is supposed to be DEXRON II but it looked and smelled like brake fluid. I filled it with Mobil 1 synthetic ATF (nice red color now). I followed the bleeding procedure outlined in the manual. The car is running very well (VERY smooth) except on occasion it still stalls at idle. It died this morning when I hopped out to check the fluid level (HOT) in the hydraulic fan reservoir. Just before I got out I noticed the battery light come on for a second or so then it went out. I'm wondering about the alternator now since that could be the cause of the noise/vibration that I'm feeling. I'll take the alternator apart this weekend to see what's going on. Bad input shaft bearings could be felt in the cabin as a low frequency vibration. Despite the two main problems that I'm experiencing I'm still impressed with this car. :)

Thanks!! :)

AWJ, Thanks for the information. Yes, I'd appreciate the test procedure for the fuel pump/ecu. I had wondered if fuel delivery was the problem but there are so many complex systems on these cars that I was at a loss for where to begin. There is no doubt that the plugs, wires etc made a difference to overall performance but the engine dying at a light was quite alarming. I just put it down to the computer relearning since I'd disconnected the battery. The repair manual mentions "drivability problems after battery disconnect ... “ but I didn't expect that to include the engine stalling.

I had the same problem on my '95 with 51K miles on it. After changing the plugs, plug wires, distributor caps, rotors and fuel filter the engine is very smooth. Since I had to disconnect the battery the car is in the "relearn" stages at the moment so I've experienced an erratic idle at times (the engine actually stalled at a light yesterday!). However, the "miss" that I was getting at idle and the stuttering that you mention have both gone away. I would advise you to buy the ignition wires from Lexus. They're more expensive but worth it since they come preconfigured i.e. the wires are routed in the plastic guides that bolt to the heads. The Bosch wires that I bought from thepartsbin.com were the wrong length ... I had to return them. The rest of the items are worth buying online since they're quite a bit cheaper. :)

Here are the compression specs for a '95 SC300. :)

I have two changers at the moment. The original one that causes the ERR message to be displayed and the one that I bought on eBay. The 12-disc changers are made by Pioneer (I think) so I'm fairly confident that they have oil-filled dampers or something similar. I did notice that CDR's skip less than "real" CD's which is counter intuitive since CDR's are less reflective. Anyway, I plan on disassembling the original changer to see what's going on inside. I may be able to scavenge some parts or at least determine why the other changer skips so much. I remember a trick that involved sucking out the old oil and injecting new oil in the dampers ... I'll try to find the exact process. :)

Marty, Did your changer "skip" a lot as well before you sent it out? If so, did Ken fix that problem too? When I bought my '95 the seller told me that the changer didn't work (ERR messages displayed) so I bought a used changer on eBay for $200. It works well except that it skips fairly regularly. I remember a pioneer changer that I had years ago that had oil-filled vibration dampers in it. I also remember something about the oil "gelling" over time reducing the effectiveness of the dampers. :)

CODE 31 OR 41 - AIR MIX DOOR POSITION SENSOR CIRCUIT NOTE: For Code 41, also see CODE 41 - AIR MIX DOOR SERVOMOTOR CIRCUIT for additional trouble shooting procedures. Voltage Check 1) Remove A/C-heater control panel, leaving harness connectors attached. See A/C-HEATER CONTROL PANEL under REMOVAL & INSTALLATION. 2) Turn ignition on. Backprobe between terminals A12-22 (Green/White 6wire) and A12-20 (Brown wire) of A/C-heater control panel connector. See Fig. 5. 3) Measure voltage while changing set temperature to activate air mix 6door. See AIR MIX DOOR POSITION SENSOR CIRCUIT VOLTAGE SPECIFICATIONS table. 4) If voltage is as specified, temporarily substitute a known-good 6A/C-heater control panel, then retest system. If voltage is not as specified, measure sensor resistance. See SENSOR RESISTANCE TEST. AIR MIX DOOR POSITION SENSOR CIRCUIT VOLTAGE SPECIFICATIONS TABLE Set Temperature (1) Volts Maximum Cool ................................... 3.70-4.27 Maximum Hot .................................... 0.88-1.16 (1) - As set temperature increases, voltage should gradually decrease. CODE 41 - AIR MIX DOOR SERVOMOTOR CIRCUIT NOTE: Also see CODE 31 OR 41 - AIR MIX DOOR POSITION SENSOR CIRCUIT for additional trouble shooting procedures. Actuator Test 1) Warm the engine to normal operating temperature. Perform step 1) under RETRIEVING CODES. After system enters diagnostic code check mode, perform actuator check. See ACTUATOR CHECK under TROUBLE SHOOTING. Observe air mix door operation. See appropriate AIR MIX DOOR AIRFLOW table. 2) If air mix door functions as specified, no problem is indicated at this time. If air mix door does not function as specified, test air mix door servomotor. See AIR MIX DOOR SERVOMOTOR TEST heading below. AIR MIX DOOR AIRFLOW TABLE (1995) Display Code Door Position Condition 20-22 ..... Fully Closed ............ Cool Air Comes Out 23-24 ...... Half Open ... Blend (Cool/Hot) Air Comes Out 25-27 ...... Fully Open .............. Hot Air Comes Out AIR MIX DOOR AIRFLOW TABLE (1996) Display Code Door Position Condition 0-2 ........ Fully Closed ........... Cool Air Comes Out 3-4 ......... Half Open ... Blend (Cool/Hot) Air Comes Out 5-7 ......... Fully Open ............. Hot Air Comes Out Air Mix Door Servomotor Test 1) Remove air mix door servomotor. Refer to AIR MIX DOOR SERVOMOTOR R & I under REMOVAL & INSTALLATION. Unplug air mix door servomotor connector. 2) Connect battery voltage to air mix door servomotor connector terminal No. 5 (Violet wire). Connect terminal No. 4 (Red/Yellow wire) to ground. See Fig. 8. Air mix door servomotor lever should move to cool air position. Transpose battery and ground leads. Servomotor lever should move to hot air position. 3) Replace air mix door servomotor if it does not function as described. If servomotor functions correctly, inspect wiring harness and connectors between servomotor and A/C-heater control panel. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute a known-good A/C-heater control panel, then retest system. :)

Marty, Here's some information on diagnosing faulty actuators. ACTUATOR CHECK 1) Perform step 1) of RETRIEVING CODES. When system enters self-diagnostic mode, press recirculated air button. Each mode door, motor, and relay will operate at one-second intervals. Press fresh air button to display codes one at a time, and perform step-by-step actuator check. 2) Check airflow and temperature by hand. Tone will sound each time display code changes. Each display code is associated with a system operating condition. See Fig. 3 or 4. Press OFF button to cancel actuator check mode. I hope this helps. :)

... no comment! :D Marty, I'll check the manual today. I've been so busy trying to solve my own SC400 problems that I haven't checked the board in a few days ... sorry about that. I'll try to make a post around 1:00pm (PST). That A/C heater diagnostic feature is excellent!! I've yet to try it but the 41 code that you received does make sense. If the air mix door isn't opening then you won't be getting any heat. :)

The 7.3L is a turbo charged diesel engine. 275HP and 525lb-ft (@1600rpm). I have a 65:1 crawl ratio, a 6spd manual trans and a 4.11 rear end ... anyway, there are other boards to discuss my F-350 (excellent fit/finish by the way) ... I won't mention it again ....

Since the gauge "swings all over the place" it's unlikely that it is accurately representing the temperature of the coolant since the engine coolant temp doesn't "swing all over the place". The heat capacity of the coolant is such that it heats up and stays hot and then cools down slowly i.e. the temperature doesn't increase/decrease/increase rapidly. I would hope that you have a failed coolant temperature sensor since that would be the easiest thing to fix. :) I copied an A/C heater system test procedure from the factory manual under another topic so you might want to try that to determine why you're not getting any heat in the cabin.

SK, I happen to own a '02 Ford F-350 7.3L dually and it's AWESOME. No creaks, rattles, leaks or problems of any kind in almost two years!! I also have a '98 Jeep Wrangler that I abuse on weekends on some tough trails. That vehicle has 42K trouble-free miles on it. I'm not one of those that subscribes to the theory that Japanese vehicles are perfect and American vehicles are a POS. This '95 SC400 is fun but it ain't no PSD!!! :)

AWJ and SK, I just copied the information from the '95 SC400 repair manual that I bought on eBay. I think it's amazing that the A/C controller has a built in diagnostic tool ... very cool!! :) I'm learning about these cars along with everyone else.

I just wanted to add that replacing the heater core would be a royal PITA and that's why shops charge an arm and a leg to do that since it often requires dismantling or removing the dash. If the car was used in a temperate climate like Hawaii, Florida, South Texas etc then it's possible that the coolant in the heater core never got circulated which could lead to a heater core failure. If the heater was run on any kind of the regular basis AND the coolant was flushed every year or two then I seriously doubt that the heater core is the problem. I would guess that it's a stuck door or a failed door actuator. If you run through the test procedures that I listed you might get lucky and find the problem. Good luck. :)

Marty, You may already have the factory repair manual but if not this might help. There are numerous possible explanations as to why you're not getting any heat. A plugged heater core is certainly one of them but you could easily verify if coolant is flowing in and out of the heater just by grabbing the return hose. You'll feel the coolant in the hose if you squeeze it enough to provide a restriction. Other explanations include a failed actuator, a failed interior temperature sensor or maybe a failed coolant temperature sensor. TROUBLE SHOOTING SELF-DIAGNOSTICS An Electronic Control Unit (ECU) within A/C-heater control panel monitors system circuits and stores trouble codes in memory if problems are detected. All codes, except Codes 22 and 23, are stored in memory. Malfunction is current if Code 22 or 23 is displayed. To retrieve stored codes, see RETRIEVING CODES. Codes are displayed at temperature display. See Fig. 2. RETRIEVING CODES 1) Simultaneously press and hold AUTO and recirculated air switches. See Fig. 2. Turn ignition on. All indicators will flash 4 times, at one-second intervals. Tone will sound when indicators flash. 2) A/C system will enter self-diagnostic mode. To end indicator check, press and release OFF switch. Read codes at temperature display. 3) If trouble code is displayed, proceed to appropriate trouble shooting procedure. See DIAGNOSTIC CODE IDENTIFICATION table. Codes are displayed in ascending order. To slow rate at which codes are displayed, press fresh air button to change display to step operation. Each time fresh air button is pressed, display changes by one step. 4) If tone sounds as code is displayed, problem currently exists. If tone does not sound as code is displayed, problem occurred in past and does not presently exist. Code Diagnosis 00 ................................................ Normal 11 (1) ............. In-Vehicle Temperature Sensor Circuit 12 (2) ................ Ambient Temperature Sensor Circuit 13 ................. Evaporator Temperature Sensor Circuit 14 .................... Coolant Temperature Sensor Circuit 21 (3) .............................. Solar Sensor Circuit 22 (4) .................... Compressor Lock Sensor Circuit 23 (4) ........................... Pressure Switch Circuit 31 .................. Air Mix Door Position Sensor Circuit 32 ................ Air Inlet Door Position Sensor Circuit 33 ............... Air Outlet Door Position Sensor Circuit 41 ....................... Air Mix Door Servomotor Circuit 42 ..................... Air Inlet Door Servomotor Circuit 43 .................... Air Outlet Door Servomotor Circuit (1) - If in-vehicle temperature is -4 F (-20 C) or less, Code 11 may set even though system is normal. (2) - If outside air temperature is -58 F (-50 C) or less, Code 12 may occur set though system is normal. (3) - If testing is done in a dark area, Code 21 may set even though system is normal. Shine a light at solar sensor and recheck codes. (4) - Malfunction is current. Code is not stored in memory. ACTUATOR CHECK 1) Perform step 1) of RETRIEVING CODES. When system enters self-diagnostic mode, press recirculated air button. Each mode door, motor, and relay will operate at one-second intervals. Press fresh air button to display codes one at a time, and perform step-by-step actuator check. 2) Check airflow and temperature by hand. Tone will sound each time display code changes. Each display code is associated with a system operating condition. See Fig. 3 or 4. Press OFF button to cancel actuator check mode. :) Let me know if you need more information. I can send you a link to the factory repair manual for a '95 SC400.

AWJ, At this point I don't think the cooling system is the problem, well at least I don't think it's anything that has coolant flowing through it. I've been reading up on the hydraulic fan arrangement including the hydraulic pump, hydraulic motor on the fan, the fluid reservoir, ECU etc. I was pleased to learn that the hydraulic assembly uses plain old Dexron II ATF which is a good thing. I wasn't happy to learn that the hydraulic fan, pump, ECU etc comprise a relatively complex system. What was Lexus thinking? I don't see the benefit of an hydraulic fan vs. an electric one at all. The system is CONSIDERABLY more complex and WAY more expensive in addition to not being able to run unless the engine is running. I'd be interested in hearing the reasons for the hydraulic set up if anyone is privy to that information. Anyway, I digress ... I plan on flushing the ATF out of the lines, pump, reservoir, cooler etc and refilling the system with Mobil 1 synthetic ATF. The manual lists a procedure for "bleeding" the system so I'll do that to make sure there's no air in the lines. After that I'll have to follow the manual's numerous inspection/repair procedures. I think you may be right about the fan being out of balance since it appears to oscillate in and out of the plane of rotation ... not by much but enough to be noticeable. Thanks for your help and your willingness to bounce ideas around. :)

A bad thermostat perhaps? If the thermostat is a "fail-safe" type then it can stick open i.e. coolant is constantly circulating through the radiator. Is your coolant temp gauge in the normal range? At idle the coolant would warm up providing some heat but once you start driving the temp could drop well below 195F to the point where you don't get much heat from the vents. Anyway, a new thermostat is cheap and it's easy to check if the thermostat is stuck open. Start the engine when it's cold and squeeze the hose that supplies the radiator ... if the thermostat is working properly you shouldn't be able to feel any pressure build up in the hose as you're constricting it. :)

Well, I think the noise that I'm hearing/feeling is the hydraulic fan coming on. I doubt that what I'm feeling is normal so either the hydraulic pump is getting ready to quit or the fan bearing is in bad shape. With my hand holding the hydraulic line from the pump to the fan I can feel the fluid flowing in the hose almost like there's air in the line. As the fan cycles on/off I can feel the change in the hose and a change in the vibration. I need to read the repair manual to see if there are any diagnosis/repair procedures for the hydraulic fan.