coolant low after timing belt change

[mikeinaustin]

2002 v8 toyota tundra, 93k miles. work done 3k miles ago. since then i have added 1/2 a gallon of coolant to get it back to the full line in the overflow tank.

however, i can see no sign of coolant leaking. there is not even the tiniest amount present on the skid plate, floor of the garage, near the thermostat or anywhere else. there is never the slightest smell of coolant either.

checked the oil last night and it looks great (3k miles on it as well). still amber and clear. not very different from brand new oil but this is normal for this engine.

with the engine totally cool, opened the radiator cap and the coolant was all the way to the very top, you could not put anymore in it if you wanted to.

engine temperature is always rock steady.


any ideas?

 

[Bill in Utah]

They did not fill it up all the way when the belt was changed?

Did not "burp" it?

I would not worry. If it continues to need coolant, then start the worry cycle.

Bill

 

[ChiTDI]

If you changed water pumps as part of the TB job, you may have allowed air into the system.

 

[mikeinaustin]

water pump was changed. when i got the vehicle back, i waited about 2 days and then filled the overflow tank with a bit, maybe 1/8th a gallon. been driving it ever since (almost 3k miles). when i checked last night, the overflow tank was almost completely empty (the radiator was completely full). this is why i am kinda worried.

 

[PandaBear]

If it continues to happen (check for a couple more weeks), something is either burnt or leaking. I could be a pinched hose or a cracked radiator, or a damaged Head Gasket.

 

[Market525]

My guess would simply be air was in the system. It's now purged, you've refilled, so all should be good. Head gasket failrures are not common on these engines, plus the fact that you've seen zero coolant on the ground tells me you're gonna be fine!

 

[ChiTDI]

+1 on above post.

 

[mechtech2]

It's tough to bleed cooling systems, and get the vehicle back to the customer as quickly as possible.
It can take a while, but they generally purge themselves.
Like mentioned above, keep an eye on it for any future changes.

 

[kschachn]

I would agree that it is probably air. I've changed out the water pump on my '99 Sienna (I assume it is the same 1MZ-FE engine) and it took a good two weeks of adding fluid before the recovery bottle stopped going down. It also didn't go down the same every day, some days it stayed the same and on others it was way down.

I thought too that I had a coolant leak (this was part of some other, more major maintenance) but like you there were no symptoms. I even got down and smelled the exhaust and couldn't detect any coolant.

If it quits taking coolant after a couple of weeks then you are OK.