COOLING SYS ANOMALY!! (1 Viewer)

[shaun21ss]

Hey everyone! I've had my 94 FZJ80 (1FZ-FE) since October 6th and so far the cooling system has haunted me. The PHH cracked (replaced it) and recently I did the Tstat.

This morning I was driving and noticed immediately my temperature was rising quickly (it was cold this morning too) So I kept an eye and sure enough it started to overheat. I pulled over and noticed coolant dripping near the petcock drain. I wiped it, kept coming, and I didn't see any other areas leaky so I just tightened the valve. Then I put some coolant in, turned it on and it was fine yet again. I personally don't think that tightening the valve did anything. After work I put some more water in and drove it around, everything is fine again. I'll give it two days or so but I bet it comes back. I'm confused, any thoughts? I was going to replace the radiator but it seems everything is working just fine.

 

[baldilocks]

So you ran hot, then you put water in the radiator, and then it ran normal, and somewhere in there you found a coolant leak. I would say you were low on coolant due to a leak. Keep a close eye on the coolant level until you find the leak. If you replaced the Tstat, you obviously drained the radiator. Is there a possibility that the mechanic left the drain cock loose and now that you have tightened it, the leak is fixed???

 

[Tools R Us]

A cooling system pressure tester is the tool of choice for finding leaks.

 

[shaun21ss]

So you ran hot, then you put water in the radiator, and then it ran normal, and somewhere in there you found a coolant leak. I would say you were low on coolant due to a leak. Keep a close eye on the coolant level until you find the leak. If you replaced the Tstat, you obviously drained the radiator. Is there a possibility that the mechanic left the drain cock loose and now that you have tightened it, the leak is fixed???

I have done all the work on it. I monitor the coolant level pretty well. It's weird because it seems like there is no visible leak, except today. If that valve was loose it should have been leaking prior. I already checked the HG, it's good, the heaters work as well.

 

[baldilocks]

I have done all the work on it. I monitor the coolant level pretty well. It's weird because it seems like there is no visible leak, except today. If that valve was loose it should have been leaking prior. I already checked the HG, it's good, the heaters work as well.

Don't allow the OCD nature of Mud to send you into a tail spin of paranoia and insomnia. Verify that your cooling system is full and run it in your driveway at perhaps 1500 rpm for as long as it takes to find a leak or not. The pressure tester mentioned above is a great method if you can get your hands on one preferably for free..

 

[shaun21ss]

Don't allow the OCD nature of Mud to send you into a tail spin of paranoia and insomnia. Verify that your cooling system is full and run it in your driveway at perhaps 1500 rpm for as long as it take to find a leak or not. The pressure tester mention above is a great method if you can get your hands on one preferably for free..

This is my next move, first thing tomorrow.
I guess what I'm asking is, if there is no visible leak but I'm losing coolant (large amounts) and my HG and Heater core is good...what is it?!

 

[whaler]

probably a coolant thief in florida.

how did you test the HG?

You may also have a leak that is going onto the engine and getting burned off before you notice a puddle on the ground.

 

[BILT4ME]

Some of these have had leaks that only show up at temp and at pressure.

Also change your radiator cap to a TOYOTA cap. I had a cap that failed to open fast enough and blew a radiator.

Check your hose clamps.

 

[rolliges]

Prob a crack in the plastic radiator housing that only leaks under temp AND pressure (after driving a bit).

Find and repair; or else (sshhhh: head gasket)!

 

[shaun21ss]

probably a coolant thief in florida.

how did you test the HG?

You may also have a leak that is going onto the engine and getting burned off before you notice a puddle on the ground.

I had a shop check it. I believe they hooked up that hand held pump to the heads.

 

[shaun21ss]

Prob a crack in the plastic radiator housing that only leaks under temp AND pressure (after driving a bit).

Find and repair; or else (sshhhh: head gasket)!

tell me more. the HG is apparently good and I've seen no other symptoms. How would I find and repair?

 

[rolliges]

more:

The coolant system (like the A/C system) is closed; that is there should be no leaks for it to function properly.

With a leak it loses both coolant and pressure (which lowers the boiling point of the coolant).

If you overheat you can blow your head gasket and be stranded and/or destroy your engine.

So: find leak, repair or replace, flush system, add fresh coolant, no leaks, peace of mind.

DONT put this off.

 

[BILT4ME]

tell me more. the HG is apparently good and I've seen no other symptoms. How would I find and repair?

Yours is a 94 and SHOULD have a brass radiator (Metal top and bottom tank, not plastic)

That said, brass radiators CAN be rebuilt. The exact fit 94 radiator is NLA (I think) and there are lots of threads here with everyone searching for the "perfect" radiator. I'll let someone else advise on this, as mine is a 96 and has a plastic tank radiator.

If the radiator is leaking, it MUST be repaired or replaced. Most folks replace, as repair can be done, but is expensive comparatively.

You need to determine what coolant you already have in your cooling system, if any.

If it is clear, it is water. If it's green, it's green. If it's red, it MAY be Toyota red. If it's brown, flush it with a gareden hose first, then a number of distilled water flushes.

Do this immediately as this is very important to your engine.

Fillit with coolant, warm it up and look for leaks. Make sure the radiator is as full as it will go. Then start and idle with the cap OFF. Watch it until all air bubbles stop and the coolant starts to overflow. Then install the radiator cap and drive it.

Fill the overflow bottle with the same coolant mix prior to driving. Fill to the "FULL" mark, as it will draw some coolant back in because you cannot get all the air out until you drive it.

Wathc for leaks by placing cardboard under it and watching the seams with a flashlight while it's warm and idling.

 

[John McVicker]

Reread post #3. Until you do this, everything is guess work. Maybe an educated guess, but still a guess.

 

[ppc]

94 models came with plastic top and bottom tanks, not metal and with Copper/Brass core where later models had Aluminum core.

 

[OGBeno]

Yours is a 94 and SHOULD have a brass radiator (Metal top and bottom tank, not plastic)

Why does this incorrect information keep getting perpetuated? Are you all a part of some mis/dis-information agenda? I've been saying literally the same thing for years now and still BS information is posted on here. People just need to not talk when they have no idea what they are talking about.

All 80 series radiators for the US market had plastic top and bottom tanks from the factory. No exceptions. None of them had metal top or bottom tanks from T.Rad (Toyo Radiator who manufactures OEM).

And both the early brass radiator and the later aluminum radiator are readily available through any dealership.

16400-66040: Brass, 3-core: 32 in the country with 2 in transit from the mothership:

16400-66081: 2-core aluminum; 33 in the country, 7 in transit from the mothership.

 

[rolliges]

20+ years, the radiator may not be original anymore. Doesn't matter; find the leak under pressure and repair.

 

[baldilocks]

This is my next move, first thing tomorrow.
I guess what I'm asking is, if there is no visible leak but I'm losing coolant (large amounts) and my HG and Heater core is good...what is it?!

Mud OCD..... if the coolant isn’t on the ground or on the floor of the cabin, it’s escaping through the tail pipe. A HG job isn’t the worst thing that can happen to an 80 owner.

 

[BILT4ME]

Why does this incorrect information keep getting perpetuated? Are you all a part of some mis/dis-information agenda? I've been saying literally the same thing for years now and still BS information is posted on here. People just need to not talk when they have no idea what they are talking about.

All 80 series radiators for the US market had plastic top and bottom tanks from the factory. No exceptions. None of them had metal top or bottom tanks from T.Rad (Toyo Radiator who manufactures OEM).

And both the early brass radiator and the later aluminum radiator are readily available through any dealership.

16400-66040: Brass, 3-core: 32 in the country with 2 in transit from the mothership:

View attachment 1851469

View attachment 1851470

16400-66081: 2-core aluminum; 33 in the country, 7 in transit from the mothership.

View attachment 1851471

View attachment 1851472

Maybe because EVERY 93 and 94 LC I have seen HAVE the metal tank radiators?
And MOST folks here show a metal tank radiator when it's a 93 or 94?

Is that what you are saying or are you referring to AVAILABILITY?

Not saying it didn't happen, but did EVERYONE upgrade the radiator in their 93 and 94 LC's from the plastic tank units?

The trucks I have seen this way have verified histories with family lineage back to original.

I want to make sure I understand your rant and I will make sure I don't re-post crap, but I want to understand the idiosyncrasies of what you're stating.

Maybe THIS has something to do with it...
Not EVERYONE is a Beno.......

 

[shaun21ss]

more:

The coolant system (like the A/C system) is closed; that is there should be no leaks for it to function properly.

With a leak it loses both coolant and pressure (which lowers the boiling point of the coolant).

If you overheat you can blow your head gasket and be stranded and/or destroy your engine.

So: find leak, repair or replace, flush system, add fresh coolant, no leaks, peace of mind.

DONT put this off.

I understand I need to find the leak. I'm asking if you know any particular way to find this said leak on the plastic piece you mentioned...that only leaks under temp and pressure.