Coolant mystery, no overheating

[HeadacheManNYC]

I know theres a million posts regarding coolant, but im having what I think is a unique issue.
I started noticing low coolant levels in the resevoir a few days ago (just bought the truck last week). I refilled it,checked again two days later, low again. Took it to my mechanic, he changed the fluids, cleaned the injectors, diddnt find anything wrong. checked this morning, again, resevoir was low. Im not noticing any coolant on the ground, no wet spots in the interior, no smells indicative of burning coolant. Truck can idle in stop and go traffic all day and engine temp stays where it ought to be. Any idea where the coolant is going?

Thanks all

Luke
89 FJ62 165K

 

[JLH911]

maybe you were low on coolant to begin with and it's finally filling in the air pockets?

Other than that, I'd have to say it's burning off somewhere...get it tested to make sure.

 

[Wile E Coyote]

maybe you were low on coolant to begin with

X2. Great point, and a nice, common reason to boot.
If you really want to know if you have a leak, it's time to get happy with a UV dye kit. Don't ignore the rear heater or the oil cooler.

 

[Toadhopper]

X3 on that last point.
I think since its new to you there is a possibility that its been low for a while.
But that makes me wonder WHY it could be low in the first place.
Try burping the system (search here for posts) and look for coolant tracks off the water pump or hoses.

Make sure to have a pressure check done to the system if your mechanic hasn't done one already.
Bryan

 

[HeadacheManNYC]

If coolant is leaking into the combustion chamber, would I be seeing white exhaust smoke all the time, or just on start up? I don't think this is the problem, but just checking.
In case you can't tell, I'm not much of a mechanic

Thanks for the replies

 

[MangoMan]

You are not filling it to the top are you? It should be filled to the low mark when cold to allow for expansion once at running temp. Leave it at the low mark and monitor it over a few days. If it stays there then its fine.

 

[JLH911]

I guess it would depend on how much was getting passed into the combustion chamber to burn off. If it's not a lot, you might not see it.

 

[HeadacheManNYC]

I have been filling it to the top. Maybe this is my (stupid) problem? I haven't seen any overflow, though.

 

[2mbb]

If you fill it up to the line on the overflow container, then you can watch it increase when the engine is hot then decrease back to the line when cold.

 

[HeadacheManNYC]

Any NYC locals?

The level drops while the truck is sitting, engine off. If there's nothing on the ground, would that suggest air in the radiator? Also though, When the engine is up to temp I don't see any increase in the overflow reservoir.

Basically, I can't afford to take another trip to the mechanic at the moment, but don't want to risk a blown head gasket or something to that effect. Is it unreasonable to be driving under these conditions?

Sorry for all the questions, just trying to quell my new owner paranoia!

 

[Butt Ugly Chuck]

How long has it been doing this? Maybe you're just burping air out of the system.

I've got an OEM rad now which seems much easier to burp. When I still ran the aftermarket version, I resorted to this to burp my cooling system.

Good luck!
Butt

 

[fj4play]

I know theres a million posts regarding coolant, but im having what I think is a unique issue.
I started noticing low coolant levels in the resevoir a few days ago (just bought the truck last week). I refilled it,checked again two days later, low again. Took it to my mechanic, he changed the fluids, cleaned the injectors, diddnt find anything wrong. checked this morning, again, resevoir was low. Im not noticing any coolant on the ground, no wet spots in the interior, no smells indicative of burning coolant. Truck can idle in stop and go traffic all day and engine temp stays where it ought to be. Any idea where the coolant is going?

Thanks all

Luke
89 FJ62 165K

could have a heater core leak

 

[cruiser88]

yea I was going to mention heater core. Do you hear any gurgle on start up?

 

[lehiguy]

Any NYC locals?

The level drops while the truck is sitting, engine off. If there's nothing on the ground, would that suggest air in the radiator? Also though, When the engine is up to temp I don't see any increase in the overflow reservoir.

Basically, I can't afford to take another trip to the mechanic at the moment, but don't want to risk a blown head gasket or something to that effect. Is it unreasonable to be driving under these conditions?

Sorry for all the questions, just trying to quell my new owner paranoia!

This is normal behavior. As the engine and the coolant cool off, a vacuum is created in the cooling system which draws in extra fluid from the recovery tank. That's what it's there for. It should show highest after running and lowest in the morning after cooling off completely.

 

[tetonguy]

A defective head gasket does not always result in white smoke out the tailpipe. If the gasket leaks on the block side the coolant will run out on the block and evaporate right away. Close the hood and let it idle a bit without moving the truck. Pop the hood and stick your face all around and see if you smell any antifreeze.
Also I think you can get still buy the coolant test strips which you hold over your open radiator cap with the engine running. If they change color then you have CO in your radiator and a faulty head gasket. If the coolant leaks out then exhaust gases leak in to the coolant system. The chemical strips make it easy to detect that. Good luck.

 

[HeadacheManNYC]

Thanks for all the input, its a huge help.

Regarding coolant smell:

It can be hard to discern the individual odors that come out of these trucks, or any older vehicle. Coolant seems to smell different depending on where it is or whats happening to it, so if its coming out of the exhaust, what type of odor should I be on the prowl for? what should "normal" exhaust smell like?

Thanks again,

Luke

 

[alaska60]

Burp it. Check out the threads on burping the cooling system. Its just air in there. It may take several attempt to get rid of it. The funnel trick works best!

 

[alaska60]

Any NYC locals?

The level drops while the truck is sitting, engine off. If there's nothing on the ground, would that suggest air in the radiator? Also though, When the engine is up to temp I don't see any increase in the overflow reservoir.

Basically, I can't afford to take another trip to the mechanic at the moment, but don't want to risk a blown head gasket or something to that effect. Is it unreasonable to be driving under these conditions?

Sorry for all the questions, just trying to quell my new owner paranoia!

Check out Gotham City Cruisers.......
A cruiser club in NYC.

 

[HeadacheManNYC]

Thanks, Alaska