Unexplained coolant loss (1 Viewer)

[CO_Hunter]

Does anyone have one of those UV leak test kits I could borrow?

After last weekend I noticed my overflow bottle was nearly empty. The second time I have filled it in about 5k miles. I don't have any noticeable leaks, though I need to look closer. I don't notice any smell like it were a small leak burning off. Haven't had a chance to pull plugs, I know it can be a pain on the 1FZ. I don't even want to mention what I fear it is...

 

[cool breeze]

Plugs are quite easy to pull, don't know where you heard that. Check all the common spots:
phh
heater lines behind motor
heater line coming to of firewall, would fall on exhaust and disappear into thin air
rear heater
head gasket, you can get an exhaust gas detection kit for this

Good luck, you'll need it!

 

[EricG]

Have you tried the bubble test with the overflow bottle? How's you oil look?

Plugs may or may not be a bitch - #6 was on mine, the rest were ok. Have some of that copper antisieze available to put it back together.
Good luck

 

[black95]

Was the radiator low and drawing off the bottle to refill itself?

I doubt it's your head gasket. I'm with Josh, check all the hoses. Sounds like that PHH thing is usually the problem.

Lots of Rising sun guys are sending their oil into that testing facility to keep an eye on their head gaskets. Blackstone I think? Might be worth a test to see if there's antifreeze in the oil before damning the head gasket.

 

[CO_Hunter]

Thanks for the ideas, yes the PHH can be the culprit but the PO had it done . He also had recently done all the plugs,wires, cap before I got and that's why I haven't been in there yet. Maybe it's not he plugs it changing boot and seals that can be a pain if they are old and brittle. The an oil report may be in my future. I'm guessing the radiator was getting low and refilling through the bottle. I'll dig into things today but a UV kit could save me a lot of time.

 

[LCPilot]

I had the same problem on my '94 Fj80. I wiped down the engine and then drove it then looked under it, nothing. I washed the engine at the car wash, drove it home and looked real close. I finally hooked up a small hose tee to one of the small (1/4") cooling lines on top of the engine. To the hose "T" I hooked up a compressed air regulator set to 10 psi. I let it sit for about an hour. I chcked the floor under the engine and saw a couple of drips. Followed it back and then learned about the PHH. Even if it has been done before I would still check it under pressure. Mine was only leaking when I was driving and such a small amount it was not seen when parked. If you send off an oil sample it will be checked for anti-freeze in your oil. That means head gasket.

I have the setup if you need to borrow it.

 

[CO_Hunter]

Dave, thanks for the offer, went to Autozone and got a pressure test kit and a block tester as loaner tools.

Pressurized the system to 12 psi it leaked down to about 11.5 and held there forever while I crawled and looked everywhere. I did find a bit of oil at the HG just below and to the front of PHH, only a few inches was damp. Next I warmed up the truck and checked for exhaust gas in the coolant. Nothing, liquid stayed blue. Coolant and cap looked nice and clean.

Changed the oil, it was due anyway and it looked fine, nothing milky etc. Will do Blackstone next oil change. Didn't pull the plugs as I will replace them soon anyway. I lost track of time, I have had the LX longer than I thought. Seems like I drove it home almost yesterday!

Drove it back from Autozone and held the rpms about 4500 for a minute or so. Took a look again and no visible leaks, overflow was where I left it. Only thing I can think was last weekend running it hard at the hill may have been just enough of a pressure increase to cause some leaking. Or, when I replaced a thermostat, about a month or so ago, I didn't get all the air out. Could have sworn I went back and topped off the overflow then, after driving and burping the system.

At least I feel a little better now, I was thinking I was going to have to cancel the Kokopelli trip.

 

[Uncle Ben]

You're doing all the right things! Cup your hand in the exhaust exit and quickly bring your cupped hand up and smell the fumes both after cold start then later after full warm up. If it's burning coolant you'll smell it. Also, how is the coolant in the recovery tank? Most times when a head gasket is breaking down there will be a blackish gray sludge in the bottom of the recovery bottle.

 

[CO_Hunter]

No coolant smell in the exhaust after start up didn't check when warm. There is still a little bit of staining gunk I didn't get out of the overflow tank after I bought the LX. I don't think there is any more "stuff" in there.

 

[black95]

After you drained the system to replace the thermostat, did you turn on both heater valves to fill the heater cores? I'm betting you just had air in the system somewhere.

 

[CO_Hunter]

Maybe not right after but it had been driven prior to that and I'm pretty sure I topped off the overflow after driving and "burping" the system. I have done two complete flushes/back flushes since I bought it. It's do again this summer/fall. I refilled the overflow tank and marked it and I have the miles and date of oil change so I can better track this. All that said, I hope you are right!

The Autozone tool loaner program is really nice, they even give you the test fluid to use

By the way I never would have found that I had two cooling system issues if I had not done the temperature gauge mod. I found my t-stat was opening early so I replaced it. I had a cooling issue under heavy load so I replaced the oil in the fan clutch, what a difference. I haven't been able to confirm it solved the high temp problem since winter set in but the clutch oil was shot. The 80 factory temp gauge runs in the middle unless you are really hot. I highly recommend this mod to other 80 owners, 1fz.

 

[CO_Hunter]

water pump

Found the leak using a small mirror and looking up under the water pump pulley. Sure enough saw signs of leaking out the weep hole. Replaced the pump and complete system flush while I was at it. Should be good to go.

 

[jstew0903]

I have the same issue going on. I smell antifreeze in engine compartment occasionally but don't see any visible leaks. Thanks for the info on this thread. I'll let you know what I find.

Btw I do see blackish residue on the overflow once it gets low.