Notices
SC - 1st Gen (1992-2000)

SC300 overheating - Radiator empty, steaming from engine

Thread Tools
 
Search this Thread
 
Old Jan 14, 2013 | 11:27 AM
  #1  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default SC300 overheating - Radiator empty, steaming from engine

I've done searches on the forums and understand what to look for (somewhat).

The SC was running fine until the other day on the way to work I noticed the engine temp gauge going up. I pull over and the engine is super hot and steaming. I wait a bit then open the radiator to find it bone dry.

I let the car cool down, filled the radiator and drove it home (only about 5 miles).
By the time I got home the car was just starting to get hot again.

After these 5 miles, the raditator lost about 3 liters of fluid and I saw a good amout of steam coming from what appeared to be underneath the engine itself.
Fluid had also boiled out of the radiator overflow tank there in the front.

Would this mean that it is likely the head gasket?


Or would steam be coming from this area anyway since boiling radiator fluid was on the splash guard under the engine and coming up?

I don't see an obvious leak from the bottom, like the radiator plug being lose or out.

What does this sound like?
Obviously it could be a bad radiator, thermostat, water pump and or head gasket.... But does the description lean to any one of those over another??

* Also, when starting the car cold, there is no pressure in the radiator lines, so no fluid is running into the engine itself. (does this mean it is likely the water pump or thermostat?)

Any input is appreciated. Thanks!

Last edited by IS_Sunny; Jan 14, 2013 at 11:48 AM. Reason: overheating, radiator, thermostat, tempurature
Reply
Old Jan 14, 2013 | 11:34 AM
  #2  
DIrEctQL's Avatar
DIrEctQL
Chicago Lexus Club Moderator
20 Year Member
Photogenic
Photoriffic
Shutterbug
 
Joined: Jul 2001
Posts: 3,721
Likes: 14
From: Illinois
Default

Originally Posted by IS_Sunny
I've done searches on the forums and understand what to look for (somewhat).

The SC was running fine until the other day on the way to work I noticed the engine temp gauge going up. I pull over and the engine is super hot and steaming. I wait a bit then open the radiator to find it bone dry.

I let the car cool down, filled the radiator and drove it home (only about 5 miles).
By the time I got home the car was just starting to get hot again.

After these 5 miles, the raditator was again empty; however, I saw a good amout of steam coming from what appeared to be underneath the engine itself.
Fluid had also boiled out of the radiator overflow tank there in the front.

Would this mean that it is likely the head gasket?

Or would steam be coming from this area anyway since boiling radiator fluid was on the splash guard under the engine and coming up?

I don't see an obvious leak from the bottom, like the radiator plug being lose or out.

The car burnt an entire radiators worth of fluid in 5-10 miles.
The steam appeared to be coming from just under the engine itself.

What does this sound like?
Obviously it could be a bad radiator, thermostat, water pump and or head gasket.... But does the description lean to any one of those over another??

** Also, when starting the car cold, there is no pressure in the radiator lines, so no fluid is running into the engine itself. (does this mean it is likely the water pump or thermostat?)

Any input is appreciated. Thanks!
It's safe to say that you have a leak somewhere. If it's coming from the bottom of the engine then I would say go look there.

This is most likely not the case but one common problem is the plastic heater core cracks behind the dash and chews up your water. You should use the less acidic radiator fluid (red), not the common green type.
Reply
Old Jan 14, 2013 | 11:46 AM
  #3  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

** Update

After topping off the fluid I notice a small drip coming from what seems to be directly under the engine. More towards the front of the engine, about 6 inches left of where the power steering pump is.

This is literally just a drip, drip, drip... not pouring out whatsoever. It would take an hour to fill a cup at that rate, but it does seem to be coming out.

( I don't have a jack or stands with my at the moment so I can't really fit under the car).


I thought it could just be from some fluid spilling when I poured it in; however, I was very careful not to spill any.
This is not where the radiator plug is... so what could be leaking coolant from this area?

_

Last edited by IS_Sunny; Jan 14, 2013 at 11:54 AM.
Reply
Old Jan 14, 2013 | 12:55 PM
  #4  
Vrank's Avatar
Vrank
Lexus Test Driver
iTrader: (4)
 
Joined: Feb 2011
Posts: 969
Likes: 2
From: TX
Default

If you haven't let it get full on hot, I doubt the hg is toast. Does your radiator have the plastic tanks? If so, I'd be willing to bet it has cracks in places that you can;t see, and is what started the overheating problem. Also, the small coolant hoses that route through the throttle body/iacv tend to rupture after a million miles, and hoses that are in bad condition don't take over heating too well. Also there's a hose just above the oil filter housing that will give you problems too. I'd investigate all of these. I bought an aluminum ebay mk4 radiator for my gf's sc for arolund 140 shipped, awesome upgrade, have zero complaints from it. if you need a radiator, you might wanna consider that if you're like me and want something that gets the job done instead of making fanboys say oooh and ahhhh because koyo/fluidyne etc. I'm a function over form type
Reply
Old Jan 14, 2013 | 10:15 PM
  #5  
Truccc's Avatar
Truccc
Driver School Candidate
 
Joined: Jan 2013
Posts: 22
Likes: 0
From: FL
Default

It sounds like you need to jack up the car and check. Cause radiator fluid doesn't go bye bye that fast. in the mean time I would suggest not driving the car. You don't wanna overheat the engine and constantly looking at the temp gauge while driving.
Reply
Old Jan 15, 2013 | 12:54 AM
  #6  
czar07's Avatar
czar07
Lead Lap
 
Joined: Dec 2009
Posts: 550
Likes: 1
From: Western Australia
Default

Sounds like you need a new waterpump
Reply
Old Jan 15, 2013 | 10:09 AM
  #7  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

Thanks for the posts folks, I appreciate it.
I'll get under the car today and see if I can find a active leak.

I ran the car (idle) for about 3-5 minutes yesterday and there was definitely no fluid flowing from the radiator into the engine or vice versa.
Reply
Old Jan 17, 2013 | 01:45 PM
  #8  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

I replaced the Thermostat and the radiator cap and still no coolant flowing.

I just drove the car about 3 miles continually checking to see if any fluid was flowing in or out of the radiator. I just squeezed both the upper and lower hoses. At no time did either hose have any pressure whatsoever.

The car ran OK since it was only 3 miles, it didn't smoke; however, the fluid in the overflow tank was just starting to come to a boil.

Does this sound like a bad Water Pump?
Is there anything else that it could be? (bad radiator all together, clog int he radiator, etc?)

Thanks!

-
Reply
Old Jan 26, 2013 | 07:08 PM
  #9  
KahnBB6's Avatar
KahnBB6
CL Community Team
15 Year Member
Photogenic
Liked
Loved
iTrader: (5)
 
Joined: Jun 2010
Posts: 7,418
Likes: 1,364
From: FL & CA
Default

I haven't a solution but I've had a similar problem myself although without your monster leak causing you to lose so much fluid in only a few miles. In my case, only twice has my car's temp gauge gone way up very suddenly and in both cases I was able to grab bottled water very quickly and refill the radiator. The engine exhibits no blown headgasket issues so I avoided the worst. Oil is fine when I check it with no sign of contamination and the engine power and operation is normal.

I have noted some burbling behind the dash over the winter when I was using my heater and this has led me to wonder if the culprit may be my heater core, heater control valve or a hose to the heater. Otherwise I would assume I am in line to replace the radiator soon since it's likely the original.

I have only put 20k miles on the car in two years since buying it and at that time I replaced my water pump and thermostat with brand new Toyota parts. So this can happen with a good water pump and t-stat.

I topped off with pre diluted coolant today but couldn't locate my leak yet.

I don't know if this can help but I hope you can get this diagnosed soon. Sounds like an obscure hose or perhaps the OEM radiator to me.
Reply
Old Jan 28, 2013 | 10:19 PM
  #10  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

I did find the leak; albiet I have no idea WHAT is actually leaking.
Anyone have any idea's?

It's coming from the right (driver's) side of the engine.
If you were looking at the front of the engine it would be to the left of the power steering pump right there on/near the engine.

No leak on the left side near the water pump or thermostat or the rear of the engine.
No leak from the upper rad hose dripping down. The actual leak is below the upper hose area.

Could this be the Head Gasket??
Other then overheating, the car runs fine. No rough idle, it doesn't shake or smoke... just sprays out antifreeze and gets hot.

Right around this area.
SC300 overheating - Radiator empty, steaming from engine-hvrvvdw.jpg

Thanks for the info and posts too!

Last edited by IS_Sunny; Jan 28, 2013 at 10:43 PM.
Reply
Old Jan 28, 2013 | 11:13 PM
  #11  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

Originally Posted by Vrank
Also there's a hose just above the oil filter housing that will give you problems too. I'd investigate all of these.
Do you know what hose this actually is?
Seems relevant to the area I can see leaking.
Reply
Old Feb 13, 2013 | 11:58 AM
  #12  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

*UPDATE
** SOLVED


In case anyone runs into this issue... the leak was coming from a split in the rubber Water Bypass Hose.
This hose is on the right side of the engine just below where the main coolant hose from the radiator attaches to the top of the engine.

I had to remove the belt, fan, top radiator hoses and power steering pump

No real reason for the cracked hose other then the car having 270k miles and I assume the hose was OEM.

So happy to have finally found the damn thing though!
Thanks for the posts and suggestions! CL always helps.

Last edited by IS_Sunny; Feb 14, 2013 at 11:59 AM.
Reply
Old Feb 13, 2013 | 03:06 PM
  #13  
Ali SC3's Avatar
Ali SC3
Lexus Champion
CL Folding 100,000
15 Year Member
Liked
Community Favorite
iTrader: (10)
 
Joined: Oct 2007
Posts: 10,806
Likes: 469
From: CO
Default

nice find, a drip can turn into a real spewer once it gets hot thats probably why you didnt notice it.
Reply
Old Feb 14, 2013 | 12:01 PM
  #14  
IS_Sunny's Avatar
IS_Sunny
Thread Starter
Lead Lap
iTrader: (1)
 
Joined: May 2007
Posts: 451
Likes: 1
From: FL
Default

Originally Posted by Ali SC3
nice find, a drip can turn into a real spewer once it gets hot thats probably why you didnt notice it.
Exactly.

When the leak first started it was barely dripping out.
Then after I was testing for the leak and getting the car hot a few times, at some point to drip turned to more of a noticable pour.
Reply
Old Jun 23, 2015 | 04:05 PM
  #15  
scsexy's Avatar
scsexy
Advanced
iTrader: (1)
 
Joined: Apr 2015
Posts: 593
Likes: 76
From: Denver, Colorado
Default Water bypass hose number?

I've got the leak from the same hose but i can't find it online to buy anywhere. Where did you get yours?
Reply



All times are GMT -7. The time now is 02:41 PM.