Coolant leak by trani? 1st gen 4.7

Hello everyone! I’m new to the page and hope I could get some help cause I’m a little stumped on a coolant leak on my 00 tundra 4.7

It’s coming from directly under the center of the engine where the transmission touches the engine (directly above the center of the steering rack) but I’m not seeing any coolant running down from obvious spots to tell where exactly it’s coming from.

When the truck is at idle it doesn’t seem to leak. After I drove it around for about an hour and a half today I got home and that’s when i noticed it leaking on the driveway. When I topped it back off It looks like it lost about 12 oz of coolant.

Is there anything towards the back end of the motor or even around the trans that could be causing a coolant leak? I haven’t taken anything apart yet which will be my next step. If anyone has had an issue common to this and can offer any advice or recommendations I would greatly appreciate it!

I can take some pictures if that would be more helpful. Thank you!

 

Freeze plug

 

I will take a look into this. Thank you

 

@bmf4069 We love pics....like a lot !

 

@Scross yeah we need some pics. Also pics of that truck would be great.

I think someone else had a leak at the same location. If we confirm I'll try to find that thread.

 

Don't forget the pics!

 

Sorry if their not the best pictures. And I’m working on getting the bottom cleaned atm to be able to get a better idea

 

This is her, she likes to throw a fit before a road trip

 

Zooming in shows some major grease slinging going on....how's the CV's look ?

 

Thank you for pointing that out bubba, I did notice that and the Cv boots on both sides are blown and will need replaced. That will be after the coolant issue is resolved lol

 

Great catch

 

I'll be honest, I'm really not seeing any leaking coolant. Maybe once you clean it up it will be easier to tell where the source is. Nice truck BTW. If that's platinum metallic they only offered that in 2000 and I've never seen one in person.

 

@Scross is this what you're referring to? I think what's throwing me off is that the coolant in our trucks should be pinkish red. Do you have Prestone or some other color coolant in there?

 

Yes that is what I was referring to firstgenvol. It was filled with pink but topped off with prestone so it’s a little mixed atm. Does that not look like dried coolant? My apologies if it’s not. Also thank you I appreciate that! I’m not sure if it’s platinum metallic but I’ll check it out

also winner, I checked more into the freeze plugs and found one on the back passenger side that looks a little sus. I can’t get a good clear picture because of the angle and there’s a mount in the way but I used a small mirror to get the best shot I could

 

I didn’t mean to put that photo in the middle of that convo oops. That’s a photo of the freeze plug on the back passenger side

 

being serious, are you familar with what anti-freeze taste/smells like....speaking of spillage on driveway !

 

The smell yes. the look, not so much. It has been a while so like my truck I’m a little rusty when it comes to some things but I’m remembering as I go.

after a little more digging around I did find this leak by where the top radiator hose connects to the engine (I’m not good at naming off parts) but it looks like it could have been flowing under the intake manifold towards the back causing the dripping from the back. Here’s some pics of what I found

 

I was wondering, because the driveway pic shows it more to front of truck given driveway incline and was simply wondering if indeed was coolant. Having to add approx a cup is not much according to how and when measured

 

This is Looking through the manifold on the passenger side right under the connection of the radiator hose to the engine

 

Best way is to get a pressure tester, I do hope it’s not the freeze plug. It’s a 8hrs job for a $2 parts

 

I think it’s the thermostat housing for upper radiator hose

 

Ooof I hope it’s not a freeze plug then. I’m leaning more towards the thermostat housing too winning8 and since it’s an easily accessible space and cheap to replace just a gasket I might just try that before the pressure test and see if it fixes the leak

 

We’ll after some more research I found that the previous owner attempted to make a gasket rather than buying one. I’m certain this is the issue but we’ll find out when I top her off

 

In their defense, if properly cleaned and using FIPG or seal packing, let dry about an hour, one does not have to use a gasket. For thermostat, yes !

 

That’s good to know if I ever get in a situation then. Thank you!

 

Perhaps I should have worded it differently....there is no gasket for that backside portion of thermostat housing according to FSM and Toyota parts online.

Radiator & Components for 2000 Toyota Tundra | Toyota Parts (mcgeorgetoyota.com)

 

Ohhh okay. I read that there was one (for the square connection) there’s just not one that goes in between the housing for the thermostat. Is that what you mean?