Engine Heat At Feet

[CJG53]

I was going to say that I just got a 1992 SC400 but the truth is I just got a girlfriend w/ an SC400. It was her dad's and was well maintained. The problem she's having (and I'm hearing about often so I have to fix it) is that after the car's been running for a 1/2 hour or more hot air begins blowing at the driver's feet.

What i found was that it took me 2 different test trips to replicate the situation but that it is real and it is a PITA. THe heat is not coming from the vent below the steering wheel. It appears to be coming through the firewall, specifically from the slotted plastic sheath that surrounds the steering column.

Now if that's the case, why wouldn't it be doing that all the time? As it is, it takes quite awhile to start spewing this dragon's breath. (No, it doesn't smell, it's just HOT.) THe new girlfriend thought it happened after the A/C had been on for 1/2 but I was able ot feel it come on when I started the car cold w/out ever runing the A/C.

Is it possible that there's a component that just happens to be located near the steering column that may be overheating or be exhibiting some other such behavior and it isn't engine heat at all?

As I live in Los Angeles and wouldn't trust a dealer here as far as I could throw him so I figured I'd turn to a group like you guys. (I belong to several for both my 1992 Nissan 300ZX and my 2000 Triumph Speed Triple motorcycle and can't sing the praises of these internet groups loudly enough!)

Also, some joker clipped her driver's side mirror; any good, local leads on a reputable used parts dealer for the Lexus? Or even a reputable Internet used parts supplier? Plus, where can I find a color code for her year and model -- it's a '92 in a deep green. Pretty car and fun to drive!

I thank you all in advance for your help and advice.

CJ Green

Los Angeles, Ca.

[SKperformance]

check the diagnostic codes that are in the general maintance section.

[joedoc]

try this link for used parts:

http://taprecycling.com/inv-lexus/sc.html

i assume the coolant temp stays normal while this heat pours out--is that correct?

have you looked to make sure there is not a red hot exhaust manifold when this happens? i'm thinking that the heat must be from the exhaust.

does the interior heat work when you switch it on?

[CJG53]

check the diagnostic codes that are in the general maintance section.

SK --

I checked the Gen Maintenence section but the codes you listed say they are "a lexus standard since 94". This SC400 is a '92. Also, wouldn't I need a reader to see the codes anyway or are they available elsewhere like the a/c codes you listed which are retreivable via the a/c unit? (A buddy once owned a Fiero which spit out all the codes on the radio face.)

CJ

[CJG53]

Yep, temp stays normal, heat and a/c work like champs.

I'll test again this weekend and see if the a header is acting funny. If so, other than a malfunctioning piston, what might cause that? And if it is a bum piston, what specifically w/in the cylinder would cause the excess heat?

Oh, and I just read a post about a hot ignition key which is another symptom this girl's car is experiencing!

Thanks,

CJ

[SKperformance]

A/c Codes, what they mean,and how to get them

http://us.lexusownersclub.com/forums/index...showtopic=3794&

not the obd2 codes

[CJG53]

Thanks, SK. I'll check the A/C codes this weekend.

CJ

[SPORTcoupe300]

I noticed that area heating up one time.(Everything was off but my temp was set to max because I last used the heater)

All I did was turn the temp to Minimum and the heat went away.

It's not rushing out of the vents to the point where you feel it coming out, but while your car is in motion, it slowly comes out and over a period of time, makes that area really hot.

[lexxus]

Hi, I'm the guy with the hot key. Yeah, I did notice heat under the steering as well. I took it to my mechanic yesterday, and he just got a funny look on his face and shrugged. He said that he didn't want to change the ignition switch, because that might not be the problem(he's very honest and tries to save me money.) I definitely do not have the heat on in this weather! I guess I'll just have to watch it. He didn't seem too concerned.

[Alex-us]

Paint codes for a whole lotta cars can be found here:

http://www.autocolorlibrary.com/

[SKperformance]

might be a vacume problem if it gets better as you speed up or a voltage one.

[luther414]

I am having the same problem too. I tried to ignore the heat from comming up from the footpedals, or the hot keys. My center console (the radio and the climate control) also gets hot. Its nearing winter and one day it droped below 65 degrees. I turned the temp in my car up to 79 degrees--nothing. I then turned it up to hot max--nothing. I need to get this fixed soon I live in New York City and it can get very cold in the winters. I drive a 92 sc400. If anyone has any ideas it would be greatly appreciated.

[boobstar]

I experienced the same thing yesterday while driving home from Pembroke (about 1.5 hour drive). I had the AC set to about 74-76 the whole time and I could swear the intermittenly the air would blow warm for a second. When I got into town I turned the AC off and rolled the windows down and I started to feel that same heat problem that everyone above is mentioning.

[Sadistic]

I had the same problem with a friend's 300 A/T. We did a tranny service and the problem went away. We thought maybe the tranny was getting hot from never being serviced. Problem solved. His heat was coming from the Center console/floor area.

[boobstar]

When you say tranny service, do you mean having it flushed and the fluids changed???

[Sadistic]

When you say tranny service, do you mean having it flushed and the fluids changed???

←

Of course.

[boobstar]

well i assumed at least that but i wanted to make sure you didnt mean having it rebuilt or anything.

[SirSam]

I have the same problem with my 92 SC400. With more posts regarding this now I'm going to do some testing, I did notice that with the windows down or up and A/C on it blows hot air at feet, and cold air out everywhere else. Not sure what the intial starting phase is, I know it doesn't do this from a cold start though with windows either up or down.

[GRAND_LS 4]

Guys, this has to do with the position of the cats, they are very close to the drivers foot well, and heat up after driving for a bit. Best way is to set your AC to recirculate helps alleviate the problem.

[tbear24]

I have a 94 SC400 and have the same problem. I think it is coming from the air dam under the care that cover the engine. The holes are getting bigger in the two shields forcing air up into the compartment. Look under the car at the front and back shields.