white smoke at startup, coolant reservoir empty

[60series777]

I'm wondering how concerned I should be about seeing a single puff of white smoke when I started my 1985 fj60 this afternoon. For context I drove down the street on my lunch break to surf and when I got back in the car to head home (roughly 1 hour later) I noticed the smoke. I have been daily driving with no issues and no overheating whatsoever but reading through some of the threads on this forum has me concerned it could be a sign of a head gasket issue. Back at home I popped the hood and noticed the coolant reservoir, which I filled roughly 300 miles ago, was nearly empty. Then I checked the coolant in the radiator. It was full and bright green (whew). I pulled the oil cap and the dipstick and I did not see any signs of milky oil or coolant residue. I thought maybe my reservoir or the connecting hose had a leak but I pulled both out and they seem fine. The only loose bit is the cap on the coolant reservoir, it doesn't really seat properly on the lid, just kinda sits on it loosely.

I started the truck maybe 5 more times in the driveway. First time there was a much smaller puff of white smoke. The next few times there was little to none. Drove around the block and did not see any smoke at all. Am I catastrophizing? This truck is new to me and I'm very sensitive to any abnormalities. Are there other at home tests that can rule out a bad head gasket? I don't have compression testing equipment.

As always, thank you to everyone for their guidance on this forum. You're all legends.

 

[OSS]

There’s only suspicion and fear at this point. Keep a close watch on the radiator overflow tank and monitor its consumption.

After a coolant change, it’s normal for the radiator to sip some extra coolant as it purges out bubbles, but if the cooling system wasn’t touched and the engine keeps on consuming coolant - no matter how slowly- then there is a leak somewhere: either internally (head gasket or crack in the cylinder head) or externally (leaking hose fitting or even heater core).

To put some fears into perspective, the head gasket on the 2F doesn’t last forever. It’s not uncommon to need to change it before the engine has 200K miles on it.

When everything is OK, the radiator overflow tank shouldn’t lose any coolant at all for at least a year.
Steam blowing out of the tailpipe is normal on a cool humid morning when the engine is still cold. When an engine is hot, no steam should be visible.

 

[60series777]

When I pulled off the radiator cap yesterday there was some pressure and some of the coolant spilled out. I attributed that to the car not being completely cooled down. However the same thing happened today when I pulled the cap and I haven't started the truck since yesterday. Is it normal to have some pressure even when cool or is this another warning sign?

 

[OSS]

The spring loaded radiator cap requires about 14 psi of pressure in the cooling system to push its valve open and purge into the overflow tank. Once the pressure drops even a tiny bit below it’s opening pressure, the spring pushes the valve down, preventing any more coolant flow.
As long as the coolant is hot or warm, there will be pressure in the cooling system.

The radiator cap also has a one way coolant intake valve in it that opens when the pressure in the cooling system becomes negative when the hot expanded coolant cools down and contracts. When this valve opens, the radiator sucks coolant back out of the overflow tank.

Normally on a cold engine that hasn’t been run since the day before, the pressure in the cooling system is at an equilibrium and there’s no pressure in it.

I think the next step you should try is replacing the radiator cap with the correct cap for your radiator and see what happens.
Like everything on the engine- it doesn’t last forever.

 

[Gimme a 60]

I would suspect a head gasket.. nothing lasts forever like OSS said. I recommend doing a leak-down test, if it needs a head gasket no big deal, I did one on a Toyota pickup 3.0 with no prior experience and it runs great to this day.

Good luck!

 

[60series777]

I am a total newb but maybe I can take on the head gasket if needed.

I put a new radiator cap on and re-filled the reservoir. I started the truck a couple of times and still see smoke (albeit trace amounts). Going to drive it tomorrow and see how it goes.

It is worth mentioning I don’t really get a sweet smell coming from the exhaust. It smells more like rich gasoline to me. Also, the truck is not overheating at all.

 

[60series777]

Here is a video from today.

 

[OSS]

That video shows nothing unusual.
A perfectly running engine can billow tons of steam out the exhaust pipe when it’s cold n the morning.

Seeing steam out the exhaust isn’t a diagnostic tool, only a potential warning. If you’re concerned about it, get a coolant exhaust tester at an auto parts store to test to see if there’s any exhaust contamination in the coolant.

Also, if you keep losing coolant and there’s absolutely no leaks on the outside for sure, then there’s a small leak internally.

 

[2mbb]

You can rent or borrow a cooling system pressure testing tool from some auto parts stores. It’s a hand pump with a pressure gauge that hooks onto the radiator in place of the cap. You can use this to look for leaked when the engine is cold. With an adapter the tool can also be used to test your radiator cap. If your system won’t hold pressure but you can’t find any leaks then your head gasket could be leaking into the engine cylinders.

 

[Seth S]

I see steam and maybe a little oil smoke but nothing that would send me running to fix anything. Often when you have a head gasket fail or a crack and are burning coolant it looks like the white smokescreen from a James Bond movie.

 

[60series777]

Thanks gents this is all giving me a bit of relief. I’m going to keep an eye on the coolant consumption. I drove around for 30 minutes or so this morning and didn’t notice any drop in the reservoir level. Looking back at the video now the smoke isn’t totally white, it’s a bit darker.

For peace of mind I may take your advice and get a pressure testing kit, or one of those kits that tests for fuel in the coolant.

Glad it’s *probably* not as bad as I thought. My wife has been super supportive of this new hobby of mine but it’s been hard to explain how something so expensive can be so temperamental

 

[Seth S]

Thanks gents this is all giving me a bit of relief. I’m going to keep an eye on the coolant consumption. I drove around for 30 minutes or so this morning and didn’t notice any drop in the reservoir level. Looking back at the video now the smoke isn’t totally white, it’s a bit darker.

For peace of mind I may take your advice and get a pressure testing kit, or one of those kits that tests for fuel in the coolant.

Glad it’s *probably* not as bad as I thought. My wife has been super supportive of this new hobby of mine but it’s been hard to explain how something so expensive can be so temperamental

Self edited. Sounded funnier in my head. Reads a bit harsh and awkward

 

[60series777]

Bit of an update here as well as a question to my fellow MUDers…

After driving another 30 miles or so I noticed the coolant level in the reservoir dropping again, and this time I saw some coolant on the street where I had parked. Initially I thought it was the water pump going bad so I went out and bought a new one, but when I started to pull things off to do the swap I noticed a single drop of coolant fall from the upper radiator hose, then another, then another. Boom! I think I found my leak, and hopefully this means I don’t have to address the water pump at this time.

My question - is it important to get an oem upper radiator hose or is it fine to use something aftermarket? Seems like it shouldn’t make a big difference but curious to hear what you all think. Secondly, do I need to drain the entire cooling system prior to pulling the hose?

 

[OSS]

The Toyota hose fits perfectly. An aftermarket hose probably won’t.

If you’re just replacing the top hose, you only need to drain out maybe 1/2 gallon. It’s the highest spot in the cooling system.
I’m guessing 1/2 gallon. Maybe less or a little more.

90916-01172 - Toyota Parts Deal

www.toyotapartsdeal.com

 

[60series777]

The Toyota hose fits perfectly. An aftermarket hose probably won’t.

If you’re just replacing the top hose, you only need to drain out maybe 1/2 gallon. It’s the highest spot in the cooling system.
I’m guessing 1/2 gallon. Maybe less or a little more.

Great, I'll order the hose from the dealership just to be safe. Thanks for the tip.

 

[Beehanger]

I see steam and maybe a little oil smoke but nothing that would send me running to fix anything. Often when you have a head gasket fail or a crack and are burning coolant it looks like the white smokescreen from a James Bond movie.

Hey Seth. Heres a video of mine. I have no cat, and a header, and this thing had been idling for at least 20 minutes. Its 32 degrees outside and winter in Idaho... high elevation. Is this a normal amount of smoke? would the condensation leave the exhaust pipe within the 20 minute idle period?

More Info:
Could this just be from condensation?I was told white smoke could be a sign of detonation/misfiring etc. newly rebuild engine, coolant is not milkshake, just did lean drop.Its winter outside and 32 degrees, white smoke doesn't go away after driving it for a while. Does this while idling.Vacuum advance is not hooked up, mechanical advance is at 14 degrees..



Thanks,
Dan

 

[Seth S]

Hey Seth. Heres a video of mine. I have no cat, and a header, and this thing had been idling for at least 20 minutes. Its 32 degrees outside and winter in Idaho... high elevation. Is this a normal amount of smoke? would the condensation leave the exhaust pipe within the 20 minute idle period?

More Info:
Could this just be from condensation?I was told white smoke could be a sign of detonation/misfiring etc. newly rebuild engine, coolant is not milkshake, just did lean drop.Its winter outside and 32 degrees, white smoke doesn't go away after driving it for a while. Does this while idling.Vacuum advance is not hooked up, mechanical advance is at 14 degrees..



Thanks,
Dan

That doesn’t look like bad exhaust especially on a cold morning. Looks more like condensation. If you are burning coolant it will look like a thick white cumulus cloud and there will be other signs. Your vacuum is rock stead. ~18” is about normal at sea level iirc.

 

[Seth S]

 

[Seth S]

Here is a good example of coolant burning.

 

[Beehanger]

Here is a good example of coolant burning.

thanks Seth!
Headgasket wasnt the concern, was moreso what a buddy told me about detonation can create white smoke.