What is this coolant “leak”?

[4OYOTER]

2008 4.7 with 130K miles. I noticed my coolant reservoir was slightly now, and also noticed this pink crust. This is under the intake tube looking under the top engine cover. Any chance this is something to do with a timing belt/water pump job done at 116k mikes? Thanks for any help!

 

[BackOff]

Looks like the thermostat.
Seems like a little o-ring was on the V6...if I remember right.

Maybe a bad o-ring/seal?

 

[AThomas0312]

Looks like the thermostat.
Seems like a little o-ring was on the V6...if I remember right.

Maybe a bad o-ring/seal?

second this! should be a simple fix.

 

[4OYOTER]

Thanks for the replies. Researching this shows one area is an o-ring and the other uses RTV sealant. Can anybody verify which method this area gets sealed by?

 

[gaber6]

O ring for sure. Probably $5 from dealer or $.20 from an ace hardware store.
The sealant is for the main timing cover.

 

[Seymore Butts]

That leak doesn't look like enough to drop the reservoir by a noticeable amount. Is there a crusty accumulation anywhere else? Especially from the coolant pump.

 

[boostedprozac]

Mine is actually doing this right now! That is definitely enough to drop the reservoir. As the pressure rises, it’ll leak down and in time, you’ll notice a drop. I can smell the coolant on idle now. That is the only leak I see so I’m going to just do a flush, replace the thermostat and seal! Get to it!


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[4OYOTER]

Seeping has gotten much worse. I chatted with the shop that did my timing belt job 15k miles ago. They replaced the o-ring and thermostat at that time. I was hoping they would cut me a nice deal even though it’s out of warranty, but they wanted $120. Looking at my Haynes manual, it says to drain the cooling system before replacing this o-ring. Is this necessary, or can I just top off after replacing the o-ring?

 

[fdbyrne]

You don't need to drain the coolant. Also, it's not a job that requires this level of contemplation. It's a 15 minute (1 beer) job. Just buy a new thermostat and some coolant to top off the system afterwards.

 

[riceandpho]

i would just drain the radiator to do it, remember if that is the lower hose to it, itll just leak when you remove the hose from that part. so take a gallon or 2 jugs and drain the fluid out and reuse it later. also make sure to bleed the air out.