Heater - Works Great When Rpm's Are Up...

[jc19907]

When the car is idling and @ normal engine operating temperature, the heater seems to blow air that is about room temperature..? As soon as I hit the gas, the fan blower picks up in speed and the air gets much warmer (probably maximum temperature). Not sure what this is? Maybe a Thermostat stuck a tad open...???

a failing battery..? My gut tells me a have a partial blockage in my cooling system....

As the engine speeds up the water pump spins faster and thus I have more heated coolant going through the core than when the car is idling... I'm old school though and this car is pretty high tech when it comes to the HVAC system (especially with the NAV system).

This isn't a real bother as the car gets toasty when traveling etc. But, in cold weather when sitting in traffic this is a nuisance and a possible precursor to a bigger problem.... I think I'll start with a system flush...

Anyone gone through this on their LS? And what'd you do?

THX

[RFeldes]

The fan "speeding" up at speed would be indicative of an alternator malfunction. If the battery were weak, It would be difficult to start. Autozone could check both for free. I would start there.

[bartkat]

The fan "speeding" up at speed would be indicative of an alternator malfunction. If the battery were weak, It would be difficult to start. Autozone could check both for free. I would start there.

←

Agreed, sure sounds like not enough power for the fan.

[Kennyr]

My fan has always run faster with higher rpm's. Lower at idle. Then just a couple months ago I replaced my dead alternator and guess what? Same thing. I'm not worried about it. I was always curious if it was the alternator or just normal.

[mustang2v]

When the car is idling and @ normal engine operating temperature, the heater seems to blow air that is about room temperature..?  As soon as I hit the gas, the fan blower picks up in speed and the air gets much warmer (probably maximum temperature).  Not sure what this is?  Maybe a Thermostat stuck a tad open...???

a failing battery..? My gut tells me a have a partial blockage in my cooling system....

As the engine speeds up the water pump spins faster and thus I have more heated coolant going through the core than when the car is idling...  I'm old school though and this car is pretty high tech when it comes to the HVAC system (especially with the NAV system).

This isn't a real bother as the car gets toasty when traveling etc.  But, in cold weather when sitting in traffic this is a nuisance and a possible precursor to a bigger problem....  I think I'll start with a system flush...

Anyone gone through this on their LS?  And what'd you do?

THX

←

I have seen this happen when the water level gets low or there hsa been some work done to the cooling system. There is a air pocket in the cooling system. That is kind of hard to get out. You will need to take 1 of the heater core hoses off and back fill it with coolant. Make sure that the car has cooled off first

Shane

[VBdenny]

Any of the above could be correct, add a failing fan motor to the list. Sometimes they suck in a leave of pin needles which cause a real drag on the fan motor. Normally they probably don't draw enough current to have the RPM's make any difference but when they are full of trash? I have found all kinds of thing s in them.

Maybe someone knows if they are easy to get to. I doubt it, but if you cleaned it out it might end up being a free fix. I'll watch to see what the verdict is. Good luck.

[93ls400walt]

When the car is idling and @ normal engine operating temperature, the heater seems to blow air that is about room temperature..?  As soon as I hit the gas, the fan blower picks up in speed and the air gets much warmer (probably maximum temperature).  Not sure what this is?  Maybe a Thermostat stuck a tad open...???

a failing battery..? My gut tells me a have a partial blockage in my cooling system....

As the engine speeds up the water pump spins faster and thus I have more heated coolant going through the core than when the car is idling...  I'm old school though and this car is pretty high tech when it comes to the HVAC system (especially with the NAV system).

This isn't a real bother as the car gets toasty when traveling etc.  But, in cold weather when sitting in traffic this is a nuisance and a possible precursor to a bigger problem....  I think I'll start with a system flush...

Anyone gone through this on their LS?  And what'd you do?

THX

←

I've a 93 ls the fan speeds up on acceleration and slows at idle. But my air temp is constant. I would look at the coolent level. also the water pump if the coolent is full. with the rad cap off you should see the coolent flowing by at idle.

[jc19907]

When the car is idling and @ normal engine operating temperature, the heater seems to blow air that is about room temperature..?  As soon as I hit the gas, the fan blower picks up in speed and the air gets much warmer (probably maximum temperature).  Not sure what this is?  Maybe a Thermostat stuck a tad open...???

a failing battery..? My gut tells me a have a partial blockage in my cooling system....

As the engine speeds up the water pump spins faster and thus I have more heated coolant going through the core than when the car is idling...  I'm old school though and this car is pretty high tech when it comes to the HVAC system (especially with the NAV system).

This isn't a real bother as the car gets toasty when traveling etc.  But, in cold weather when sitting in traffic this is a nuisance and a possible precursor to a bigger problem....  I think I'll start with a system flush...

Anyone gone through this on their LS?  And what'd you do?

THX

←

I've a 93 ls the fan speeds up on acceleration and slows at idle. But my air temp is constant. I would look at the coolent level. also the water pump if the coolent is full. with the rad cap off you should see the coolent flowing by at idle.

←

I added some water to the system as it read low. Still not much help... After toying with it a little - I found that it gets the most warm (at idle) when I run recirculated air to the floor vents only. I also make sure to turn the A/C off - seems like it blows a little warmer with that off. I have also noticed that the car is about 20% weaker @ idle than when driving. My windshield wipers go faster when driving, not idling... This may be coincidental... Still scratching my head on this one...

[thisisludicrous]

I had the same problem on my '95 LS400. Even though I was just a tad low on coolant, my indie shop insisted that all I needed was a top off AND a new coolant resevoir cap, with a fresh gasket. I didn't believe them, but let them go ahead with their plans. My feet have been nice and toasty for 2 years now at idle, stoplights, etc,...and I'm finally beginning to believe my mechanic...

Give it a shot, it's only a couple of bucks.

[jc19907]

I had the same problem on my '95 LS400.  Even though I was just a tad low on coolant, my indie shop insisted that all I needed was a top off AND a new coolant resevoir cap, with a fresh gasket.  I didn't believe them, but let them go ahead with their plans.  My feet have been nice and toasty for 2 years now at idle, stoplights, etc,...and I'm finally beginning to believe my mechanic...

Give it a shot, it's only a couple of bucks.

←

I think I'll try the new cap idea! Toping things off has seemed to help some, but I'm not convinced. I know these cars are insulated like crazy too, so it may not take heat equivalent to a C-J 5 to keep the car nice and warm. I started this post based on this being annoying only. It's really only bothersome when I start the car each a.m. Once, I'm rolling things are fine.

I've determined that I put the temp setting on HOT - turn off the A/C and run the heat on the floor (off course topping off the fluid). This works the best in heating the car quickly. Otherwise all else works a bit slower. THX

[sv7887]

Hi Everyone,

I have a similar problem. I took out my LS today for the first time in ten days and the heat seemed to blow colder than usual. It wasn't blowing completely cold, but not very hot either. They replaced the Coolant Cap 5 years ago, and the entire coolant container three years ago. It's weird, last winter it was perfect. I'm wondering whether my incompetent dealer messed something up when they were working on the Steering Rack...Who knows?

Sam

[sv7887]

Hi All,

I checked my Coolant level and it was indeed low. Should I use a Specific Toyota fluid to fill it back up? Also, does the low fluid indicate a leak somewhere? I probably should have had all the hoses replaced by now.

Sam

Hi Everyone,

  I have a similar problem. I took out my LS today for the first time in ten days and the heat seemed to blow colder than usual. It wasn't blowing completely cold, but not very hot either. They replaced the Coolant Cap 5 years ago, and the entire coolant container three years ago. It's weird, last winter it was perfect. I'm wondering whether my incompetent dealer messed something up when they were working on the Steering Rack...Who knows?

Sam

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[blake918]

I think I'll try the new cap idea!  Toping things off has seemed to help some, but I'm not convinced.  I know these cars are insulated like crazy too, so it may not take heat equivalent to a C-J 5 to keep the car nice and warm.  I started this post based on this being annoying only.  It's really only bothersome when I start the car each a.m.  Once, I'm rolling things are fine.

I've determined that I put the temp setting on HOT - turn off the A/C and run the heat on the floor (off course topping off the fluid).  This works the best in heating the car quickly.  Otherwise all else works a bit slower. THX

←

I'm having the same problem with lukewarm heat at stop lights or what have you except that my fan speed stays constant. My coolant is full, so I'll try a new cap. They're about $10, so I guess that's a good place to start! The gasket did look worn but not in bad shape. I'd be too happy if that cured it!

[jc19907]

I think I'll try the new cap idea!  Toping things off has seemed to help some, but I'm not convinced.  I know these cars are insulated like crazy too, so it may not take heat equivalent to a C-J 5 to keep the car nice and warm.  I started this post based on this being annoying only.  It's really only bothersome when I start the car each a.m.  Once, I'm rolling things are fine.

I've determined that I put the temp setting on HOT - turn off the A/C and run the heat on the floor (off course topping off the fluid).  This works the best in heating the car quickly.  Otherwise all else works a bit slower. THX

←

I'm having the same problem with lukewarm heat at stop lights or what have you except that my fan speed stays constant. My coolant is full, so I'll try a new cap. They're about $10, so I guess that's a good place to start! The gasket did look worn but not in bad shape. I'd be too happy if that cured it!

←

Blake,

Try and let your car warm up to normal operating temperature, before touching the HVAC system. LEAVE ALL HEAT/AC CONTROLS OFF; INCLUDING THE FAN. I think these cars have a slow-weening heat valve in the set-up. So you don't steal heat from your cars engine upon warm-up in the a.m. By the time I get to work each day about 10 minutes my car still isn't warm - plus I have my windshield defroster on. This has been the obvious wrong way to drive this car for me. I've learned that the heat blazes, if a little patience is used. My 2 pennies....

If I have snow and ice on my windows I'm still going to wait until the car is at normal operating temperature until I turn on the controls to defrost the windshield.

I posted this in another post earlier today. THX

[blake918]

UPS dropped off a new cap today. The seal on the old cap looks pretty bad next to the new. I'll test it tomorrow to see if it does anything to my idling heat problem and report back.

[sv7887]

Hi Everyone,

I took my car (1992 LS400) to the dealer to sort out this problem. Here is what they told me:

1) Air pocket in the cooling system

2) Thermostat

3) Clutch Fan wasn't engaging properly** (What is this? Are they talking about the actual Climate System Fan)

The Shop Foreman is working on the car. We've had this car for 10 yrs, currently at 97K miles. We've spent several thousand dollars in Service over this period. It's garaged and detailed regularly.

I'm not too impressed with the long term reliability of this car. I've seen ordinary Toyotas with 200K on the clock not needing the amount of attention that this car has. I've replaced the following so far

- Timing Belt and Water Pump

- Leaking LCD** @ 64K

- Burnt Out Dash Cluster** @ 86K

- Rear Shocks @ 64K

- Power Steering Pump** @ 84K

- Power Steering Rack** @ 96K

- High Pressure Steering Hose @ 96K

- Rear Carrier Bushings @ 96K

- Stabilizer Bar Bushings (2x) @ 96K

- Upper Control Arms (Later deemed not necessary by dealer and Refunded $$$)

- Window Switch** @ 82K

- Ball Joints

- Rear View Mirror Not Working** (Replaced with a part from Wrecked LS) @ 96K

- Wood Trim around Gearshift Cracked** @ 60K

I can't say I'm overly impressed with the vaunted Lexus quality. I've owned 4 LS cars, this 92, a CPO 98 (was a compete disaster), a new '02 (Required replacement of the Steering Column, Rain Sensor 3 Times), and my new '05 (No problems yet)

The items I marked with asterisks are those that I feel are not part of normal maintenance. I certainly have not had these issues on the other cars I've owned. I think the someone posted on another thread that his 85 S Class Mercedes had a better record. I'd concur with that. These repairs seem hardly normal for a car that has been garaged and pampered for the majority of its' life.

I don't think my next car will be a Lexus considering my experiences thus far. For short term reliability most of the Competition will do nicely. For longer term reliability, I feel any Toyota would be better. I've known enough people with Camrys that run upwards of 200K without any of these "extra" issues. The list of repairs I've posted doesn't differ much from those posted by my colleagues in the Jaguar forums (XJ8). If you do some research the XJ's reliability has improved marketedly in the past ten years. Frankly I'm quite disappointed.

Sam

[RFeldes]

Sounds like a Toyota is your cup of tea.

[sv7887]

Hi All,

Sounds like a Toyota is your cup of tea.

The point is that a Lexus costing in excess of $55K should outlast a "basic" Toyota considering they are built to a so called Higher Standard. The notion Quality and Luxury Cars are mutually exclusive is pure bunk. The Mercedes cars until 1992 are proof positive of this. This car should not be having the amount of problems given its mileage and repair history.

SV

[ko90ls]

listen to yourself... you have owned four LS's. why? is it because a LEXUS isn't a TOYOTA! or is it because you DO have all of those bells and whistles that NEVER break on a toyota because they are NOT included? granted my LS isn't even worthy to be called a CPO, the car rolls and starts on every crank! can MB or BMW make that claim? and in another post about quality another member posted that jaguars have a 7% component failure rate. which components? engine? drivetrain? axles? starter/alternetor? but don't take this personally, like my friend told me, "cars are all about luck, you can drive one brand new off the lot and not a foot farther, or buy a used one and drive for 10 years. you never know." Good luck with the 05'!

[sv7887]

Hi All,

listen to yourself... you have owned four LS's. why? is it because a LEXUS isn't a TOYOTA! or is it because you DO have all of those bells and whistles that NEVER break on a toyota because they are NOT included? granted my LS isn't even worthy to be called a CPO, the car rolls and starts on every crank! can MB or BMW make that claim? and in another post about quality another member posted that jaguars have a 7% component failure rate. which components? engine? drivetrain? axles? starter/alternetor? but don't take this personally, like my friend told me, "cars are all about luck, you can drive one brand new off the lot and not a foot farther, or buy a used one and drive for 10 years. you never know." Good luck with the 05'!

Well said. I agree with you. The only thing that really bothers me is the breakdown of the Steering Rack and this latest Fan Clutch. If I'm not mistaken these are common components to all cars. It's weird to be experiences these sort of repairs. What other things should I be looking out for? Money isn't an issue, I'll pay what it takes to make this car Show Car quality. I've already spent $3,500 on cosmetics and mechanicals. The only things I haven't addressed yet:

1) Exhaust System..I'm guessing at 13 yrs old it needs to be done sooner or later

2) Alternator..

3) Transmission Mount (Engine Mounts were already done)

4) Fuel Pump, I've heard about this going about 200K

Anything else I'm missing?

I might tell the dealer to hold on to it, and get the Shop Foreman to inspect it to look for any additional issues. The only reason I got upset is that this is the second trip I've made to the dealer in 6 weeks, after spending all that money!!

Sam

[blake918]

UPS dropped off a new cap today. The seal on the old cap looks pretty bad next to the new. I'll test it tomorrow to see if it does anything to my idling heat problem and report back.

I've got heat!! I put the new cap on yesterday, but I only had time to make a short, 10 minute trip in which the heat was still cool at stop lights. This morning I start the car, and immediately after it started, it sounded like Chewbaca was trying to talk to me...it only did it for 2-4 seconds. But now, I have heat even when I'm idling!!!! :D A $12 fix on a LS400...surely, I'm dreaming!! Thanks guys especially ludicrous!

[id1]

UPS dropped off a new cap today. The seal on the old cap looks pretty bad next to the new. I'll test it tomorrow to see if it does anything to my idling heat problem and report back.

I had similar problem for the past 1 month... as the Engine warms up, some times cold air is blown from vents. This happens inconsistently, there is no pattern. My mechanic said there is 'air loc' in coolant system and worked on it. It is working normal now.

[Paul Sherman]

I recently had a similar problem. Found the folks that fixed my

AC mis-adjusted the heater water valve. Tweaked it a bit to

open completely and all is good now.

Suggest checking the valve. It's on the firewall about center, hose

going to it. Warm up the car and set the heater to max heat. In my

case, the valve arm should be at ~1 o'clock, looking from the passenger

side. If closer to 3, then it needs adjusted (now to remember how I did that...)