Coolant leak above valve cover?

Personal experience using those on older Chevy and Ford motors... I would not personally use them.

The brass ones can be a pain in the ass in comparison but I've never had a new one I've put in leak like the rubber one I put in my old 300 inline 6 especially.

 

I think before you pull the intake off or freeze plugs look at the radiator and radiator hose.

You have antifreeze leaking trails everywhere

Your leaking from the top of the radiator that is probably getting blown over the engine.

You have multiple antifreeze stain marks from leaking.

You can see the top radiator hose is leaking and the top radiator fins are covered
with antifreeze.
I would replace the clamp 1st and the top hose.

Then look at the radiator 2nd for hairline cracks.
The plastic radiators are common to crack and cost 100.00 or less and a new cap

You might have a throttle body hose that is leaking too that has antifreeze in it

 

Good point on the upper radiator hose and clamps. I think I will replace those for sure while I am doing the work.

I’ll keep looking on the radiator but I’m not seeing hairline cracks - the upper fins being filled with coolant is concerning me though. Also, I should mention when I noticed the leak, I ran the truck with the hood open and let it warm up to temp. I could see the coolant seep/puddle in the location I mentioned earlier (above the lower intake) but could not tell where it was coming from. I didn’t see anything coming out of the radiator at this time.

on the throttle body, the hoses were tight and clean, no residue near them. I will clean out the IAC valve while I have the throttle body off though

 

Quick update! I pulled my skid plate off to take a closer look at the freeze plugs and start draining the coolant (btw Autozone lied to me, they did not have a coolant systems pressure tester). This is what I found on the front diff tube:


Took a look at the P/S freeze plugs. Here is the one below cylinder #1:


I suspect that the PO replaced this one because it is the only one that is easily accessible...
And here is the culprit (#3):


It was difficult to get a photo of the plug (its directly above that wetness/leaking spot) but the plug looked like crap. The #3 plug is directly underneath the motor mount. I was unable to see the condition of the #6 plug because it is behind the starter. Honestly it's looking like the best course of action is to pull the motor and replace all of the freeze plugs while it's out of the truck.

 

Lower intake manifold is out. Well, there's my problem




More bad freeze plugs. The coolant bypass pipe has some residue around the seal. While I'm in here I'll replace it.


The plugs, seals, and gaskets are adding up

 

Lots of updates and a couple new issues. The other night I was able to replace the three plugs that sit on top of the block. Pretty easy to get at:


While I was in here I also pulled the water bypass pipe and re-sealed it. Next, I took this opportunity to do a little clean up of my lower intake manifold and the intake plenums as well as the IAC valve & throttle body. I started reassembling with new gaskets all around (lower intake manifold, plenum gaskets, TB gasket, o-rings for fuel injectors, etc.) When I placed the lower intake manifold gaskets, I sealed around the coolant ports with permatex gasket maker.






Next step is to replace the freeze plugs on the side of the block. The biggest problem one is the middle plug on the passenger side. It's leaking the worst of all of them, but the problem is that it is behind the motor mount and coil bucket. I started approaching this problem by removing the heat shield on the exhaust headers. I also pulled the passenger side wheel to give some room to work.

I placed my jack stand underneath the engine to take the weight off the motor mounts and started removing the P/S motor mount.



Even with the motor mount out of the vehicle, you don't have enough clearance to get at the freeze plug. There is pretty good access to the bolts which hold the motor mount standoff to the block, if you use a long extension. I started pulling that next.





Once that is out, you have good access to the middle freeze plug. So I took my handy extremely long screwdriver and used that to pop the plug out.



Now the only thing left is to pound in the new plug. You have to attack it at an angle:



This is where the problem lies. Even with the standoff off of the motor, there's not enough room. I've spent the past day and a half trying to come up with a creative way to apply enough force to pound this plug in. I've used every combination of extensions and sockets I have, but I haven't been able to get the plug all the way in. The coil bucket being in the way is preventing me from being able to drive the plug in straight. So I always end up with the plug half-way in and usually cocked to one side. I currently have a plug in the freezer, trying to get it to shrink just enough to pop it in place. Anybody have any other ideas?? Has anyone done this plug while the motor is still in? I feel like I've wasted enough time at this point, that I should just pull the motor out of the damn truck.

 

I just ordered this tool, which is coming Monday. I’ll keep this post updated, I think this may be the best way to install the plugs with the engine still in the vehicle. I also got a jug of Thermocure on the way. The inside of my block is a sad orange color behind all of the freeze plugs. The radiator has a light coating of rust but it’s not as bad as the block. Hoping the thermocure takes care of it. It’s also worth noting that the coolant ports on the lower intake manifold gasket basically disintegrated when I removed them. That’s probably where the leak above the manifold was coming from.

 

The tool came in yesterday. Some progress was made... though not much. I spent all night after work yesterday getting one single plug installed.



This is the one underneath the motor mount standoff on the passenger side that I could not drive in with the socket and extension. I rate the tool about 6/10. It accomplished its task on this plug but it’s still an extreme pain to try to get these plugs in with the motor still in the vehicle.

Tonight I was able to get one more plug pounded in.



This is the first plug on the driver side directly above the oil filter. I tried to use the tool but was actually successful with a socket and extension.

My biggest concern is this next plug:



It’s the second plug on the driver side, just to the right of the coil bucket. You can see the pin hole on the plug where there was some coolant residue leaking. There’s not enough room to get my tool in straight. Also not enough room to use a socket to drive the plug in straight. Not sure what I’m going to do with this one. May have to remove the UCA and/or motor mount on this side. This is the only plug left that had visible coolant residue on the outside. I would like to replace the remaining plugs for good measure but I’ll probably run out since I’ve already ruined about 4 plugs in my attempts.

 

I would make sure in the future you keep tabs on changing your coolant more regularly. If you don't use the premixed use distilled water only. From the looks of your pictures you have plenty of corrosion in your cooling system. If your radiator has never been replaced this is a good time to do it. With these plastic components, they will crack with age.

 

For sure. I meant to flush it when I bought the truck but that became one of those things that I just never got around to. I have no one to blame but myself on that. The radiator looks good, I’m not sure when the PO replaced it but it’s looks like it has been replaced recently. I have Toyota red coolant ready to do this flush once I finish these freeze plugs

 

She runs!



Those are the 3 plugs on the driver side. I was able to get them all seated. I did 2 of 3 plugs on the passenger side. I reassembled the engine and have filled it with Thermocure and distilled water to flush out that rust.



My only concern right now, is that since I got it back together I now have a fuel leak on the back side of the engine by the firewall
I took the upper intake plenums off again last night and made sure that my injectors were seated in the fuel rail and the lower intake manifold.

This is what I'm dealing with:


I think worst case scenario, there's not a good seal between the lower intake manifold, gasket, and block. Thoughts?

 

I was able to take care of the fuel leak. The injectors were not seated properly easy fix just took some time to get the plenums off and back together again lol.

After I took care of the fuel leak, I started flushing the coolant system.



The red bottle was the original coolant that came out of the truck. I ran a quart of Thermocure + topped it off with distilled water... and what came out was pretty bad! Got lots of black water and a bunch of chunks of rusted freeze plug.

Looking inside the radiator cap now, it’s clean as a whistle.



I flushed with about 14 gallons of distilled water. This was the result I got on the final flush:



Once I was done flushing, I topped it off with 50/50 OEM Toyota coolant. It’s running like a champ!!! Very satisfied with the results of the Thermocure flush.



she’s very happy to be back on 4 wheels

 

Holy mother of dick! Glad you got her flushed and running good again. Every taco deserves a good flush. I'll flush soon.

 

Do you have a part number for the Freeze Plugs that are on top of engine block, below the lower intake manifold? Thanks