Coolant Leak Issue, Near Throttle body.

[muleski]

The leak is definitely coming from the plug. There was a very consistent mist coming from it. I'll take care of that, and JB Weld is a great idea to secure it. That will be one step in the process. I'm going to just replace the radiator cap. Will presssure test the rest. I may do all of my hoses and clamps now, as well.

I might ask CS about it. Not like they know the vehicle well. I bought it in Denver, private sale, had them look it over, then did a real extensive baseline and drive it home, Now it's 2200 miles to the East. 5 years and 45K miles later.

But curious as to what purpose the plug serves, etc.

Thanks, all.

 

[PLROD]

The plug is likely for a different application/car and not required on your car. Once you finish the repair and are ready to start the car, leave the radiator cap off as the system will get rid of air faster this way, turn the heater on front and back and once the tstat starts to open you should see some gurgling which is air coming out, eventually the gurgling will stop and then you put the cap back on and fill the reservoir to the proper level. Then monitor the reservoir after a couple of hot/cold cycles and add if required. good luck...

 

[unfast]

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[muleski]

Perfect. Thanks for the picture. Sort of explains why I had never noticed it. I gently tapped the plug back in. It is soft aluminum. Then I just covered it with a coat of JB Quick Weld. I've got a few hours in the temp range for it to harden quite a bit. So, fingers crossed on that step.

I pulled the lines on the throttle body, and all seems fine. I have no idea what that plug worked loose, but I am convinced that I lost a lot of fluid through it. And being under the plastic engine cover did not notice it.

I also "trust" the reservoir level too much. Better to check the radiator. I'll throughly burp it the old fashioned way. Probably will end up with a new radiator cap, maybe a new thermostat, new OEM hoses and clamps, and obviously a flush a new coolant.

Might need a new sending unit for the temp gauge. A lot of it is 14 years old. Might as well do it right.

I'll be back in a few days.

 

[Arya Ebrahimi]

@muleski,

Any followup on this? My wife's 03 100 did the exact same thing today(popped that aluminum plug and peed all over the ground). I found this post after I already tapped the plug back in and probably seated it a little deep, but that's spilled milk at this point.

 

[Moofers]

Perfect. Thanks for the picture. Sort of explains why I had never noticed it. I gently tapped the plug back in. It is soft aluminum. Then I just covered it with a coat of JB Quick Weld. I've got a few hours in the temp range for it to harden quite a bit. So, fingers crossed on that step.

I pulled the lines on the throttle body, and all seems fine. I have no idea what that plug worked loose, but I am convinced that I lost a lot of fluid through it. And being under the plastic engine cover did not notice it.

I also "trust" the reservoir level too much. Better to check the radiator. I'll throughly burp it the old fashioned way. Probably will end up with a new radiator cap, maybe a new thermostat, new OEM hoses and clamps, and obviously a flush a new coolant.

Might need a new sending unit for the temp gauge. A lot of it is 14 years old. Might as well do it right.

I'll be back in a few days.

Any UPDATES on your fix? My 2003 Tundra just started doing the same and the dealer quoted a pretty penny for a whole new TB!?

 

[muleski]

I'm sorry to have not noticed the alerts.

Yes, the fix seems to have been perfect. Tapped it back in, carefully. Applied two layers of JB Weld. Zero issues since.

Fingers crossed that it lasts.

 

[MGBYLR]

I had the same issue on my 2003. Slee removed the plug, tapped the hole, and installed a tapered threaded plug. Over 1 year later and so far no leaks. The alternative was to spend $800-$1,000 on a new TB.

 

[James Bentley]

I was doing the belt, tensioner and idler pulley on my 2004 LX today (165k mi) and noticed similar residue at my plug on the throttle body housing. Cleaned it up with some Purple Power and will get some JB weld on it. Would be nice to see the part removed and know what parts Slee used to repair

 

[abuck99]

Noticed mine leaking slighty from the same plug this week. 194k on the odo. I cleaned and used a drift to tap it down just below the edge of the fitting. Mixed up some JB weld and coated the top and then applied a cap ( a quarter) to add some structure/rienforcement to the top of the fitting to create a stronger bond. Time will tell if it works. Wouldnt it be great if it holds indefinetly!

 

[James Bentley]

Well, it has been several months and 5k mi later and it is seeping again. The last repair was using 2-part epoxy (I really thought I had some J-B weld but did not). So today, I removed the epoxy and tapped the plug down a good bit (maybe 1/8 of an inch), quick sand by hand with some 60 grit paper, cleaned/flushed with rubbing alcohol, sanded a quarter on one side, filled plug/hole with JB and put a light film on the quarter. I'll keep tabs on it and see how it holds up. A thick, wooden toothpick helped mix, spread and apply the JB in the hole and to the sides of the quarter.
Thanks to @abuck99 for the quarter idea!

 

[abuck99]

Now its called the "E Plurbus Unum" mod.

Nice work- I didn't tap my plug down that far, hopefully mine holds. Welding it is my next option if it fails

 

[Rotten Rottney]

This is a strange one. 2003 LC. Our second LC. 135K miles. Drove our 2000 to 288K miles. I am not as clueless as I'm going to sound! Do a lot of my own work; it's in great shape. Wife's DD.

Two nights ago in the driving rain, my wife calls me to tell me that there is steam pouring out from underneath the hood. Thermostat looks normal. Car is driving fine. I meet her and follow her the three miles home. Take a quick look under the hood. Reservoir empty. Odd. Decide to check that radiator after the rain. Today. I did notice what looked like orange fluid under under the engine? Huh? Could it be RainEx.

So a couple of hours ago, I was able to look at it. The fluid has dried or evaporated. No clue. The radiator was low, and filled it to the top of the fins, and also added the right amount to the reservoir. Start it up, ran perfectly.

Once it warmed up, I noticed a ton of steam and cooling smell coming out from under the engine cover. Off it comes, and I expected to find a hose. BTW, I replaced the T fittings again last summer. Nope. No hose issues.

However, I did find what is shown in the picture. Here's where The clueless comes in. This is uncharted territory for me.

Note the open hole and the loose plug next to it, right in front of the manifold. Looks to me like a plug might/could be missing. So...what is it?

What caused it? What is the fix? And what else should I be concerned with?
I'm hoping that this can be a fairly simple fix. Like not a new entire TB housing.

BTW, the hose in the pic is in better shape than it looks in this night shot. I have no idea what the pinkish stuff on that metal plate is. Almost like white lithium that was tinted by coolant?

BTW, bought the car in Denver, and had Mr. Slee perform a very detailed baseline on it before driving East. Had 90K one owner miles, and decent service records.

Any thoughts? Thanks!

View attachment 1375317

I had the same issue on a 2004 Sequoia. Have no idea what that plug is, but it blew completely out a couple of days after a historic hard Texas freeze.
Lost most of the coolant. Did find the plug and tapped it back in with a mallet using a drift. No leaks afterward, but it has only been a couple of days.
Maybe some type of freeze plug for the throttle body leg of the cooling system? I'm uneasy, but will keep an eye on it. If anybody KNOWS what this is, please share.

 

[AFei]

I have the exact same leaking on the Throttle Body on 2004, and think the JB fix is a good cheap fix instead of over $400 into a new Throttle Body.

Just have one question to whom know how it works. Is there any possibility for the coolant to get into the cylinder through the Throttle Body? Asking so as the shop say coolant may get into throttle body causing misfire/limp mode.

 

[James Bentley]

I have the exact same leaking on the Throttle Body on 2004, and think the JB fix is a good cheap fix instead of over $400 into a new Throttle Body.

Just have one question to whom know how it works. Is there any possibility for the coolant to get into the cylinder through the Throttle Body? Asking so as the shop say coolant may get into throttle body causing misfire/limp mode.

View attachment 2865015

I suppose "anything" is possible, but more than 2.5 years later and I have not had any coolant loss, coolant in the cylinder or misfire/limp mode.
Misfire I did have was ignition coils going out (which I replaced them all with Denso from Napa).

 

[abuck99]

Good question- I don’t see anyway coolant could get into TB unless the TB somehow cracked at a cooling passage/ definitely not from the JB weld spot. Thats my guess.

 

[AFei]

I suppose "anything" is possible, but more than 2.5 years later and I have not had any coolant loss, coolant in the cylinder or misfire/limp mode.
Misfire I did have was ignition coils going out (which I replaced them all with Denso from Napa).

Good question- I don’t see anyway coolant could get into TB unless the TB somehow cracked at a cooling passage/ definitely not from the JB weld spot. Thats my guess.

Thanks for the confirmation. Very helpful. Will get the old TB back to do the same repair...

 

[tw22]

Mine popped out as well, lost a bunch of coolant, and had to punch it back in. So glad the plug wasnt lost. Would still like to know what caused it.?

 

[AFei]

Finally set to get this issue fixed. Just one question: Do you need to remove the Throttle Body from the engine to perform this repair? Or just tap the plug down without removing it? Thx!

 

[abuck99]

Gently tap it down flush & seal it.