Go Back   Club Lexus Forums > Lexus Model Forums > LS Models > LS400
Sign in using an external account
Register Forgot Password?

Low Coolant - Possible Causes??

Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
Old 02-26-09, 08:37 PM   #1
margarita
Rookie
Trader Score: (0)
 
Join Date: Sep 2007
Location: ca
Posts: 75
Default Low Coolant - Possible Causes??

Hi All - My '94 LS400 is losing coolant, just noticed today. I check under the hood fairly frequently, so believe this is a new/recent development. The coolant level is about 1 inch below the minimum marking on the reservoir. Definitely has lost fluid just in the past few days. I noticed excess fluid around the plastic cap of the reservoir yesterday (on the outside, surrounding the cap). When I lifted the cap's rubber lid, I can see a whiteish plastic disc, with two wires coming out of it. Some of the fluid has a gum=like consistency in places. So I wiped it all off, and removed the gummy residue. Today, when I checked again, the gumminess and the fluid are back. Same as yesterday. I am only driving short distances (to the store and back) because I know it is not wise to drive with coolant fluids low. Do you think the coolant is disappearing from the reservoir (since there is dampness outside/around the coolant reservoir cap? If so, is it possible to just replace a cap, and not the entire reservoir (assuming that is the problem)? I pray it is not something else. What are the other possible causes of coolant leaks? This could not happen at a worst time.
This ad is not displayed to registered members.
Register your free account today and become a member on Club Lexus!
margarita is offline   Reply With Quote
Old 02-26-09, 11:27 PM   #2
GSteg
Rookie
Trader Score: (14)
 
Join Date: Jul 2005
Location: CA
Posts: 14,899
Default

that sludge could be engine oil. If your headgasket is leaking, oil could be entering the cooling system. Check your oil dipstick. After your car is warmed up, see if you get any smoke from the exhaust. If you get white smoke, then its most likely your headgasket.
GSteg is online now   Reply With Quote
Old 02-27-09, 12:40 AM   #3
PureDrifter
BahHumBug
Trader Score: (10)
 
PureDrifter's Avatar
 
Join Date: Aug 2004
Location: California
Posts: 22,551
PureDrifter
Send a message via AIM to PureDrifter
Default

i will bet money it isnt a headgasket, i have never seen one blow on a 1uz nor heard of it in my years of owning/working on LS/GS 1UZs.

most likely you have a simple leak in the cooliing system, check the hoses and cap for leakages, what kind of coolant are you using?
__________________
1. Black on Black 1999 LS400 PM-spec
-Maya-Megan-Magnaflow-LSportline-Xenondepot-PPE Engineering-Duce-Platinum VIP-Figs Engineering-R1Concepts-
2. 1989 Toyota Supra white package
Current Status: -500 Internal System Error-
3. Black 2004 IS300 -Manaray-HKS-Eibach-
4. Ebony Teal 1995 LS400 11-8-06
PureDrifter is offline   Reply With Quote
Old 02-27-09, 06:22 AM   #4
19psi
Lexus Champion
Trader Score: (0)
 
19psi's Avatar
 
Join Date: Feb 2007
Location: Lou-Evil KY
Posts: 2,492
Default

don't worry about a head gasket, a slight bit of sludge in a cooling system is normal if the system hasn't been maintained properly over the years.
have you ever done a water pump or did the PO do it? i bet it's leaking.
you can always buy a cheap pressure tester and test the system. if it's a leaking hose or fitting, you'll find it. the water pump won't show up on a pressur test though. look underneath after removing the belly pan. yo ushould find coolant dripping from somewhere. follow it up; theres' your leak. if it's dripping from the crank pulley area, you need a water pump.
__________________

Dodge Ram cummins turbo diesel, 5 speed, 344 HP, 788lb.ft. 18/21mpg, shooting for 1000 lb. ft. on stock turbo.

Kawasaki Ninja ZX-12R 1200cc's, 190 hp of pure evil on 2 wheels.

95 Jeep Cherokee BDS/hybrid 5" lift, 32x11.5 BFG mt's, welded rear diff, long arms, etc. trail beater.
19psi is offline   Reply With Quote
Old 02-27-09, 06:27 AM   #5
AzHotLS
Pole Position
Trader Score: (1)
 
AzHotLS's Avatar
 
Join Date: Jan 2009
Location: AZ
Posts: 299
Default

What type of coolant? Toyota red or yellow/green after-market stuff?
__________________
95 LS400 Pearl White
90 LS400 Pearl White R.I.P. 11/2008
AzHotLS is offline   Reply With Quote
Old 02-27-09, 06:51 AM   #6
LiCelsior
Liberty's VIP STi
Trader Score: (30)
 
LiCelsior's Avatar
 
Join Date: May 2007
Location: NY
Posts: 11,979
LiCelsior
Default

toyota red....guys i think hes talking about the sensor that is located on the overfill tank.

the rubber cap thats next to the coolant cap..
Click the image to open in full size.

OP mine leaks too, but i just keep an eye on it. ill replace it soon enough.
__________________
RIP Liz 7/18/09 RIP Brendan 10/7/11
RIP STi, http://i254.photobucket.com/albums/h...ps5bda09fe.jpg
Like the LibertyVIP facebook page, http://www.facebook.com/pages/Libert...48632848491351
LiCelsior is offline   Reply With Quote
Old 02-27-09, 07:23 AM   #7
GSteg
Rookie
Trader Score: (14)
 
Join Date: Jul 2005
Location: CA
Posts: 14,899
Default

You guys never seen a headgasket go bad on a 1uz-fe? My uncle use to own a mechanic shop and once in a while, and LS would roll in with smokey exhaust :P The likelyhood of one having it is low, but trust me, it does exist!
GSteg is online now   Reply With Quote
Old 02-27-09, 09:15 AM   #8
PureDrifter
BahHumBug
Trader Score: (10)
 
PureDrifter's Avatar
 
Join Date: Aug 2004
Location: California
Posts: 22,551
PureDrifter
Send a message via AIM to PureDrifter
Default

Quote:
Originally Posted by GSteg View Post
You guys never seen a headgasket go bad on a 1uz-fe? My uncle use to own a mechanic shop and once in a while, and LS would roll in with smokey exhaust :P The likelyhood of one having it is low, but trust me, it does exist!
$5 says that the smokey exhaust was from the power steering idle up pump spewing PS fluid into the intake rather than a blow headgasket. very easily mistaken. basic rule of thumb is that unless the oil has the consistency of a milkshake it's NOT a BHG.
__________________
1. Black on Black 1999 LS400 PM-spec
-Maya-Megan-Magnaflow-LSportline-Xenondepot-PPE Engineering-Duce-Platinum VIP-Figs Engineering-R1Concepts-
2. 1989 Toyota Supra white package
Current Status: -500 Internal System Error-
3. Black 2004 IS300 -Manaray-HKS-Eibach-
4. Ebony Teal 1995 LS400 11-8-06
PureDrifter is offline   Reply With Quote
Old 02-27-09, 09:56 AM   #9
AzHotLS
Pole Position
Trader Score: (1)
 
AzHotLS's Avatar
 
Join Date: Jan 2009
Location: AZ
Posts: 299
Default

Not that the coolant type/color would matter in this case...

It could be the sensor's O-ring causing the leak, or the tank is cracked:

Coolant Tank Leak

In post 7:
Quote:
The sensor unscrews and when you remove it you'll find an O-ring around the top thread area. Be sure to get one the exact diameter and thickness of the ring. Or you will not be able to screw the sensor all of the way in. If you can wait just order one from Lexus.

This fixed my leak.
__________________
95 LS400 Pearl White
90 LS400 Pearl White R.I.P. 11/2008

Last edited by AzHotLS; 02-27-09 at 10:02 AM..
AzHotLS is offline   Reply With Quote
Old 02-27-09, 10:58 AM   #10
margarita
Rookie
Trader Score: (0)
 
Join Date: Sep 2007
Location: ca
Posts: 75
Default

Ok, here's the latest...not great news. Yesterday the coolant was at about 1 inch below the minimum marker on the reservoir. Still plenty in there. I drove it a short distance, maybe 2.5 miles round trip on store run (low speed). Parked it and it sat overnight. This morning, no puddles of any sort under the car, but also almost NO coolant is visible now...maybe 1/2 inch in the bottom of the reservoir. I do have a gallon container in the trunk of Red Toyota Antifreeze Coolant (not sure if that is the exact title). I kept that from May 2007, when I had a disappearing coolant problem. I took it in to the dealer and spent a small fortune on replacing the water pump, timing belt and related components (it was due for replacement anyway, and they recommended that I deal with it as long as they were going in there), upper and lower radiator hoses and radiator cap. In September of '07, I had to replace the radiator,which was leaking. The antifreeze was switched out at that time. I looked all around the coolant reservoir, and see dampness around the rubber cap that is next to the coolant cap. There's not a lot of it, but definitely visible. The hoses that I can see related to the coolant tank do not appear to have fluid around them. There is no fluid splashed on other nearby parts. I will add some coolant to the reservoir and start it up to see if there is white smoke and will report back. Lexus warranty on any work only last a year, I believe...but this really sucks if I am back to the same issue with water pump, etc.
margarita is offline   Reply With Quote
Old 02-27-09, 11:23 AM   #11
RA40
Moderator
Trader Score: (6)
 
RA40's Avatar
 
Join Date: May 2003
Location: California
Posts: 15,449
Default

Pull the oil dipstick...is it clear brown?

An obvious coolant leak is easy to smell on a warm engine and most instances of that, there will be puddles/drips. Barring those it's going elsewhere and yours doesn't sound good.
__________________

Mike
RA40 is offline   Reply With Quote
Old 02-27-09, 11:23 AM   #12
PureDrifter
BahHumBug
Trader Score: (10)
 
PureDrifter's Avatar
 
Join Date: Aug 2004
Location: California
Posts: 22,551
PureDrifter
Send a message via AIM to PureDrifter
Default

...check the thermostat, if it's stuck it could be causing the tank to surge as it's cooling pushing hot/warm fluid up into the tank.
__________________
1. Black on Black 1999 LS400 PM-spec
-Maya-Megan-Magnaflow-LSportline-Xenondepot-PPE Engineering-Duce-Platinum VIP-Figs Engineering-R1Concepts-
2. 1989 Toyota Supra white package
Current Status: -500 Internal System Error-
3. Black 2004 IS300 -Manaray-HKS-Eibach-
4. Ebony Teal 1995 LS400 11-8-06
PureDrifter is offline   Reply With Quote
Old 02-27-09, 12:21 PM   #13
link13
Lexus Champion
Trader Score: (0)
 
link13's Avatar
 
Join Date: Nov 2001
Location: Relaxed
Posts: 2,899
Default

Quote:
Originally Posted by PureDrifter View Post
...check the thermostat, if it's stuck it could be causing the tank to surge as it's cooling pushing hot/warm fluid up into the tank.
I was going to suggest this as well. Does the car warm up slower and run warmer than what you are used to?
__________________
TLN #13
2014 IS250 F Sport, Ultra White/Rioja Red
1994 Lexus GS300
1985 Toyota Corolla GT-S
Los Angeles Kings hockey
link13 is offline   Reply With Quote
Old 02-27-09, 03:14 PM   #14
margarita
Rookie
Trader Score: (0)
 
Join Date: Sep 2007
Location: ca
Posts: 75
Default Coolant Leak: Update

Quote:
Originally Posted by link13 View Post
I was going to suggest this as well. Does the car warm up slower and run warmer than what you are used to?
Ok, I called Lexus and was told it was OK to add water to the remaining coolant in that gallon (red/antifreeze coolant). The mix is probably about 75% water and the rest coolant. I topped off the coolant reservoir. It took less than I thought -- only a cup or so to bring it up to the upper level marker. I decided to add up to the higher level on the theory that I would be losing some as I drove.

The car runs normally, the temp gauge starts out cold (normal) and moved up to midpoint normally (it stabilized a little past the second white marker...so near the middle between cold and hot). I got out to look at the exhaust pipes and the exhaust was whitish for about 30 seconds, after which it cleared up. Car was sitting out overnight, so I think that was condensation. At least that is what a dealership told me when I asked them about that ages ago. I drove about a quarter mile (slow 'in traffic' speed), then got out to look at the exhaust. There was too much white in the exhaust, but again, that cleared up later (I checked several times throughout the drive).

I looked all over under the hood and under the car. I don't see any big splashes of anything, though there is fluid around the reservoir cap (not the coolant cap, the rubber cap next to it). It seems limited to the top, though, and is not dripping down the sides. I've looked at the hoses (as much as I can figure out where they are, and do not see any leaks. I am not a mechanic so have no idea how to loosen it to check the entire reservoir for cracks or how to check the sensor's o-ring.

Read the manual and checked the engine oil accordingly. The oil looks fine; it's brown, not clear, but also not milky at all. It's just dirty. It's a reminder that it is time for an oil change.

The only other thing I saw was across from the reservoir, on what I think is the transmission, I saw seepage (not leaking) along a seam. It's best described as dampness of about 1/3 inch width running along the seam. Probably not a good sign, but isn't gushing by an means. Minor seepage best describes it.

I haven't been able to locate the receipt just yet, but I did have head gasket seals (?? I think that is what it was) replaced about four years ago at the dealership. Cost around $500 if memory serves.

I ran the A/C and it worked normally. Cranked it down to 69 degrees and it got really cold. I did not use the heater (hot here today).

So I will check the level again tomorrow. If it's low again, I will get it in someplace ASAP for diagnosis. Glad it appears to be driveable right now.

The only thing I can think of that I did differently (recently) was drive the car with the A/C off. I almost always have that on, for better air quality. Would that have had anything to do with the shift in coolant levels?

Thanks for everyone's comments. Very helpful. I hope it is something simple like that sensor's o'ring. I'll post back here to let you know what happens.
margarita is offline   Reply With Quote
Old 02-27-09, 03:17 PM   #15
margarita
Rookie
Trader Score: (0)
 
Join Date: Sep 2007
Location: ca
Posts: 75
Default

Quote:
Originally Posted by AzHotLS View Post
Not that the coolant type/color would matter in this case...

It could be the sensor's O-ring causing the leak, or the tank is cracked:

Coolant Tank Leak

In post 7:
How would I get to the sensor to check the ring? Looks to me like the only access I have is the two caps on top -- the rubber cap and the coolant cap. Is the sensor inside? Where? If it is something simple, and with detailed instructions, I would try to look for that tomorrow.
margarita is offline   Reply With Quote
Old 02-27-09, 03:17 PM
 
 
 
 
Reply

Tags
1999, 470, 91, adding, coolant, gx, level, lexus, low, ls400, removal, reservoir, rx300, sensor, yellow

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

All times are GMT -7. The time now is 03:34 PM.

Join ClubLexus
Advertising


Copyright © 2000-2008 Internet Brands, Inc. All Rights Reserved
Privacy Policy | Disclaimer | Terms of Use | JOBS


Get all contact info

Content Relevant URLs by vBSEO 3.5.2