V6 head gasket external coolant leak?

Doing a big 150K mike service on my 99. Wrapped up timing belt and related parts, now doing the valve cover gasket and Denso Fuel Injectors. Figured since I was in that far I would do intake manifold gaskets (they were trashed) and knock sensor harness, as well as re FIPG the coolant crossover tube. Got the intake manifold out and found some dry pink/red residue externally out of 3 cylinders, see pics.

how soon till I’m back in here doing a head gasket?

I am the 3rd owner but I know the first 2 owners. I believe truck had the factory coolant till ~2010, then went green until 2019 when I switched it back to red. I’m adding fresh red after done with this service. Truck runs great despite a couple exhaust valves being slightly above their clearance spec. I’m inclined to continue on and run it for another 10 years and not worry about head gaskets. But curious if anybody has any other experience after seeing this. Thanks for any data points!
Thanks!

 

I just finished doing the same job a couple months ago. I also had coolant down by the intakes but it was sitting on top of the block so I didn’t worry about it as my intake plenum gaskets were trash and there is coolant that runs through that gasket. But seeing that yours is coming out right around the cylinder it could possibly be the early signs of HG. Personally if I saw that on my truck I would just do them since I’d already be that far into it. With that being said if you replaced your timing belt prior to the valve covers then you’d have to redo that. I chose to do my timing belt and valve covers at the same time which made both very easy.
If anything before moving ahead, do a compression check. I’m not 100% sure if you even can with the intake plenum removed but I don’t see why not. Might just have to reconnect any plugs and I suggest unplugging your fuel pump so you know 100% that there will be no fuel being pumped while testing. Hope this helps

 

Thanks. On my other 99 which has a mostly unknown past and more miles, it looked far worse, but the previous owner did the head gaskets prior (45k back) so figured it was before that. I did in fact wrap up all the timing belt stuff, not eager to reverse that work haha but will think about it. Once you refresh the hoses and gaskets it’s not that much more work to get back into it later. As far as I know I’m the first person to take off the intake plenum and down since this thing left the factory...

Compression test should be possible w/o intake manifold, worth thinking about

 

Stick with Toyota Red coolant. I would do the head gasket while you are there as it is leaking. Did you check the plugs yet?

 

Your 3/4 the way there,
You probably should do the head gasket now,
Once a leak shows it’s selfish it’s a matter of time before it comes back.
Your situation is probably just a head gasket and not cracked heads

 

If your decision point is when you lose a cylinder, it could be a while. Or when you crank it next.

For me that would be on a dark cold rainy night when I really needed the vehicle to get me somewhere.

How lucky do you feel?

 

BTDT, it will eventually fail and puke coolant

 

Thanks all. My old 1996 Tacoma (sold a couple years ago) went 2+ years with a small leak of coolant into the cylinder, steamed on startup from time to time. I ultimately used some of the stop-leak which worked great (and I hate using that stuff) but eventually the leak came back as the gasket eroded/cracked.

This one shows no such signs of coolant to internal cylinder leaking, only this external leaking. I may do a compression test, but if the leaking was only external that would test good. Unfortunately, I don't know of a way to do a coolant pressure test with the intake manifold removed (would have to design and build a blank off plate over each head and the upper radiator hose I think), which means I would not be able to visually see if it's leaking or not. Plugs look great, all cylinders look the same, all the intake valves look the same and intake valve clearances are within spec.

So guess it comes down to whether I want to roll the dice today...LOL. Luckily I have two 1999 tacos which allows me to have a backup so long as it breaks down close to home!

 

How many gallons of coolant do you add per hundred miles of driving??

I have seen people so sloppy coolant ends up every place.

It might fail in 10 miles or 50,000 no way of knowing Might luck would be 5 miles .

Do the pressure test when things are back together go from there .

You are the final decision since you have a spare it is not that critical as the person needing to ride there bicycle on the 50 mile commute to work.

 

Truck back together, running great with the new injectors. Gonna run it for a while and keep an eye on coolant but no problems yet...