91 Ls400 - Temp Gauge Running 3/4 Up / Needle For Tach Is Dead?

[91LS400Lexus]

Hi guys,

It has been a few years... well since I sold my last LS400, which was around 2010 or so. Well I have owned several other cars since then and even won a new Honda in a contest in late 2012. lol.

Well I have a new Hyundai now and a '91 Cadillac with only 70k that I am using as my second car to keep the miles down on my new car.

I have decided I want to replace the Cadillac and have the fever for another LS400. I found a local '91 LS400, ironically the same color as my old '91 LS. The only difference is that this LS has the seldom seem cloth interior and no sunroof, which is fine with me. The car drives good, it has 167,000 miles, which is well under either of my old LS400s I had in the past (I had a 90 and 91).

**There are a couple of issues with this one that I am looking at that kept me from grabbing it tonight. One is the temperature gauge stayed about 3/4 way up on the gauge. Even when driving, it stayed right there. If I recall, it would run slightly under 1/2 way on my LS400s. It sounds like the clutch fan is working and the coolant appeared to be full. With that said, I am not sure if it is a weak water pump, or ? All of the dash cluster lights work, but some of the lights are out in the HVAC panel and the usual outage of the LCD panel. The tachometer didn't work, it was well below zero, not sure what that problem is and lastly the check engine light was on. They said they had it checked and the mechanic said they didn't know what was wrong, but the car seemed to run perfect. IIRC, the CEL was on in my 91 as well and never had any running problems. The fuel pump was recently replaced they said. The two issues my '91 had (valve cover gaskets and motor mounts) didn't seem to be an issue on this car, yet. The A/C does not work. They said they got it charged and it worked for about 30 minutes... has been converted to R134a however.

Any advice on the above? They want $1900 for the car, not sure how much lower, but I know with those problems I do not want to give $1900. The body is good, the paint is good, but there is a small dent in fender and a small dent in quarter panel. The interior is nice.

Sure would be nice to own another gen-1 LS400, but not sure if I need to keep searching. I do love the white with gray cloth interior.

Thanks in advance!

[billydpowell]

read about the trunk hinge wiring harness failures

[VBdenny]

$1900 is more than it is worth. The temperature should run slightly under half so 3/4 indicates to me that a problem has occured. The trunk wire thing is real common on the early LS400's and since there are several wires, I have heard of (and experienced) all kinds of problems with that situation. Took me a long time to unwind all the old, black sticky tape but there it was, bigger than Dallas, two broken wires and one about to break. I added extra length and then left it kind of loose since my first repair tore after I forced it back into the channel. Hey, put your location on, it really helps with helping you.

Denny

[91LS400Lexus]

Thanks for the replies.

I added my location... funny I did have it on here last time I was on here, but it has been a couple of years. I went ahead and updated it all.

Yeah, I think $1900 is way too much as well. I sold my '91 LS400 for that back in 2010 and while it had about 40k more miles, it was as nice as this one is now. I was thinking of maybe offering $1500 and even that may be too much considering the A/C does not work and the CEL light is on. Also no record of when the timing belt was last changed, if ever??

You know when I looked in the trunk of this LS400 tonight it dawned on me about the trunk hinge wiring issues and I was trying to remember if this was the cars that had that common problem and sure enough it is. You would think that after owning a '90 from 03-05 and a '91 from '07-10 I would have remembered. I didn't worry as much about the CEL or even the dead tach that has a needle even lower than when the car is just switched off, but the temperature gauge has me concerned. As mentioned above I never seen the temperature guage more than 1/2 way up on either of my old LS400. The car was full of coolant however and it sounded like the fan was whirring as it should. I think maybe a weak water pump and I remember what that cost me on my '91 when I had some sort of bearing go out and I had it replaced.

Thanks again!

[M.Yasir]

When i purchased my '98 LS400 it had two issues

1.) The famous check engine light was on

2.) The engine was vibrating like hell, meaning rev upto 3000 rpm and you could feel whole steering wheel vibrating

Now what i did first thing, i took it to a garage drained out all the fluids i could, engine oil (which was turned into water, with 0 viscocity), gear oil (again the same situation), and the radiator coolant (although it was full, but when i drained it was water) all this i changed with good fluids also replaced filters

Now when i drive surprisingly all the lights are gone or may be i am lucky,

For the vibration problem a good car wash did the trick, good means you lift up the car on the hydraulic bay and spray diesel with full pressure, also open the hood and spray diesel with full pressure, well this method may sound wierd but it did the trick for me now my LS is super smooth, otherwise i was afraid that if the vibration does not go I might have to replace the engine foundation rubber pads

For temperature there is a high probability that the water pump is dying since your temp gauge is going above the normal limit, first try to change the coolant with a good one, completely replace dont add up

[VBdenny]

The trunk wires cause all kinds of weird problems. I thought my transmission was going out the first time.

[schujd3]

too much for that car. I paid 3200 or 3500 for my 99 and it only has 103k miles on it. Just needed to do the timing belt. A.c. works and so does everything else. Needs new upper ball joints now but that's not too big of a deal. 1500 May seem fair but I would get a temperature laser and see exactly what the coolant is running at. Could be a faulty coolant temp sensor. Check the engine light by jumping te1 and e1 under the dash near the hood latch there will be a cap that opens. Then use lexlstutorials.com to check to see what the problem could be. Good luck Joel

[Exhaustgases]

^{Sounds like a pretty base model with cloth seats and no moon roof. And maybe a 500 dollar wonder too boot..This site is locking up and cant type in here too good}