Illunic Posted February 8, 2009 Share Posted February 8, 2009 Hello, I am new to this form (but already gotten a lot of useful information here). I own a used 1990 LS400 with ~160,000 miles on it. It runs well for its age and gives nothing to really complain about. But I do have a few questions about some minor issues I have. My cabin had a tendency to fog up along the windows for a long time, I am not sure what was causing this but it seemed to be related to the coolant used in the AC, when it ran out the fogging up started so I didn't get it recharged. Any ideas what may be causing this and/or a way to fix it? The passenger seat's motor appears to have been shot and I can't seem to find a place (or site) that has had one available. Know of a place to get one or of a compatible motor that is currently around? The biggest one is that when I let off the gas to coast the engines rpm will drop too low and will start to feel like its pulling on the car (almost like you are lightly pressing on the break) any idea what is causing that and how damaging it is? (This problem goes away if I run it in O/D) And lastly my dipstick for my power steering reservoir has snapped off the cap and I don't have an accurate way of measuring the amount in the system, anyone know of an aftermarket item that would have the same measurements as the original, hell even telling me the length of it from the cap and the distances of the marks would allow me to make a temporary one. Thanks for the help in advance, this site is really helpful. I'm not even sure how I did but it sure did answer a lot of my questions before asking them (went to page 30) Quote Link to comment Share on other sites More sharing options...
Threadcutter Posted February 8, 2009 Share Posted February 8, 2009 Hello, I am new to this form (but already gotten a lot of useful information here). I own a used 1990 LS400 with ~160,000 miles on it. It runs well for its age and gives nothing to really complain about. But I do have a few questions about some minor issues I have. My cabin had a tendency to fog up along the windows for a long time, I am not sure what was causing this but it seemed to be related to the coolant used in the AC, when it ran out the fogging up started so I didn't get it recharged. Any ideas what may be causing this and/or a way to fix it? The passenger seat's motor appears to have been shot and I can't seem to find a place (or site) that has had one available. Know of a place to get one or of a compatible motor that is currently around? The biggest one is that when I let off the gas to coast the engines rpm will drop too low and will start to feel like its pulling on the car (almost like you are lightly pressing on the break) any idea what is causing that and how damaging it is? (This problem goes away if I run it in O/D) And lastly my dipstick for my power steering reservoir has snapped off the cap and I don't have an accurate way of measuring the amount in the system, anyone know of an aftermarket item that would have the same measurements as the original, hell even telling me the length of it from the cap and the distances of the marks would allow me to make a temporary one. Thanks for the help in advance, this site is really helpful. I'm not even sure how I did but it sure did answer a lot of my questions before asking them (went to page 30) Illunic; I'll comment on the engine idle dropping/shifting/OD. You probably need a new Idle Air Control Valve (IAC or IACV). Other posters here have cleaned them (by what method, I am not sure) with success. The IAC valve is on the side of your Power Steering pump and has two rubber vacuum hoses attached to it. Also, if you haven't flushed and replaced the tranny fluid in some time, doing so will help quite a bit. It doesn't do much for the RPM dropping issue, but will in most cases, work wonders for the smoothness of shifting. I have also used a tranny additive called "Dr. Tranny". It comes in a small red tube & will set you back about $ 7.00 large. Works wonders. Quote Link to comment Share on other sites More sharing options...
landar Posted February 8, 2009 Share Posted February 8, 2009 My cabin had a tendency to fog up along the windows for a long time, I am not sure what was causing this but it seemed to be related to the coolant used in the AC, when it ran out the fogging up started so I didn't get it recharged. Any ideas what may be causing this and/or a way to fix it? The fogging up is pretty simple. If you lose the charge in your AC system, the AC function tends not to work. Unbeknownst to some, the AC kicks in to dry the air when defrost mode is selected . No AC, no dry air, hence foggy windows. Fix the AC and the fogging should go away. Quote Link to comment Share on other sites More sharing options...
Illunic Posted February 9, 2009 Author Share Posted February 9, 2009 My cabin had a tendency to fog up along the windows for a long time, I am not sure what was causing this but it seemed to be related to the coolant used in the AC, when it ran out the fogging up started so I didn't get it recharged. Any ideas what may be causing this and/or a way to fix it? The fogging up is pretty simple. If you lose the charge in your AC system, the AC function tends not to work. Unbeknownst to some, the AC kicks in to dry the air when defrost mode is selected . No AC, no dry air, hence foggy windows. Fix the AC and the fogging should go away. Actually the situation was reverse for my case, when the AC system was charged the windows would fog up and the cabin would have a light must smell to it. I am not to savvy in automotive terminology but from what I read it may have something to do with a leak in the heating system. I have no idea if this is correct or not can anyone confirm or deny? In regards to the IAC/IACV I found this http://us.lexusownersclub.com/forums/index...723&hl=IACV regarding cleaning the valve, aside from the fact that its location is probably different in my '90 LS, it should still be able to apply to my car in terms of what to remove from it and what not, right? And thanks for the quick replies. Quote Link to comment Share on other sites More sharing options...
amcdonal86 Posted February 9, 2009 Share Posted February 9, 2009 If the foggy windows are accompanied by a musty smell, it's possible that one of your door/window seals is leaking and is allowing water to accumulate somewhere in the interior. Quote Link to comment Share on other sites More sharing options...
Threadcutter Posted February 9, 2009 Share Posted February 9, 2009 My cabin had a tendency to fog up along the windows for a long time, I am not sure what was causing this but it seemed to be related to the coolant used in the AC, when it ran out the fogging up started so I didn't get it recharged. Any ideas what may be causing this and/or a way to fix it? The fogging up is pretty simple. If you lose the charge in your AC system, the AC function tends not to work. Unbeknownst to some, the AC kicks in to dry the air when defrost mode is selected . No AC, no dry air, hence foggy windows. Fix the AC and the fogging should go away. Actually the situation was reverse for my case, when the AC system was charged the windows would fog up and the cabin would have a light must smell to it. I am not to savvy in automotive terminology but from what I read it may have something to do with a leak in the heating system. I have no idea if this is correct or not can anyone confirm or deny? In regards to the IAC/IACV I found this http://us.lexusownersclub.com/forums/index...723&hl=IACV regarding cleaning the valve, aside from the fact that its location is probably different in my '90 LS, it should still be able to apply to my car in terms of what to remove from it and what not, right? And thanks for the quick replies. Illunic; Hmmm......now I have some homework to do. That was a very good, very high quality writeup. However, I think it may erroneously refer to the IAC Motor as the IAC Valve. The valve I have been referring to is the black plastic bodied, dual barbed fitting device that screws into the side of the Power Steering Pump. If I've got it wrong, my apologies......not trying to confuse anyone. Having said that, it appears that quite a few people have cleaned the "device" using the method outlined in that post with great results. I have not had this "device" apart on my '95 or my '04, but I have on my Suburban. If they serve the same purpose, it is the recirculating exhaust gases (EGR System) that fouls them. Provided my assumption is correct, then it makes perfect sense to me why it would cause rough idle, why it would need cleaning and why cleaning makes such a big improvement. Quote Link to comment Share on other sites More sharing options...
oldskewel Posted February 9, 2009 Share Posted February 9, 2009 Here's an easy thing to try that may fix the window fogging problem: run with the AC turned off and the heat set on max for as long as you can stand it. My 1991 LS used to have that problem as well as a weird smell. Running on full heat seems to have burned all the extra moisture out of there. No tools required. Good luck. Quote Link to comment Share on other sites More sharing options...
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