282K miles - Blown HG, what other PM? (1 Viewer)

[LongDuck]

Still not a conclusive finding - I've seen "lung butter" on the inside of oil caps before without any other issues other than combustion moisture buildup in the oiling system, so a few more things to check.

1) no obvious other leaks in the radiator, water pump, hoses, or the rear heater core?
B) is your overflow bottle changing level when you drive it? It should go up when hot - to the max line - and then go back down to the min line. If it never moves, your cap is never venting, and...
III) you could still be losing coolant through your exhaust being burned. How much coolant did you have to add to bring the radiator back up to full?

Still hoping it's just a lot of short trips for you, as we're all a little touchy about Head Gaskets,

 

[JDUBinCO]

Still not a conclusive finding - I've seen "lung butter" on the inside of oil caps before without any other issues other than combustion moisture buildup in the oiling system, so a few more things to check.

1) no obvious other leaks in the radiator, water pump, hoses, or the rear heater core?
B) is your overflow bottle changing level when you drive it? It should go up when hot - to the max line - and then go back down to the min line. If it never moves, your cap is never venting, and...
III) you could still be losing coolant through your exhaust being burned. How much coolant did you have to add to bring the radiator back up to full?

Still hoping it's just a lot of short trips for you, as we're all a little touchy about Head Gaskets,

You make a good point here... I've seen some quickly evaporating spots under the car (front passenger side) that I'm thinking are the "constant tension" hose clamp not providing good tension and letting some coolant out of the lower radiator outlet, and the radiator reservoir is not down. Could it be condensation and a bad radiator cap that's not venting??
You're getting my hopes up.
I guess I'll get a fresh radiator cap, some more coolant, a new clamp, and scope #6 before I do anything else.

 

[LongDuck]

Pulling the plug on #6 and getting your scope in there would give you a big indication. That tends to be the cylinder that the head gasket affects first. Further, hot coolant evaporates quickly from any leaks, making them hard to detect. If you're running Toyota Red, at least it leaves a hard and crusty pink residue that can help with diagnosis, but you sometimes have to search.

Testing the Radiator Cap venting should include blowing through the line from radiator to the cap of the reservoir, as well as blowing through the overboard vent on the other side. Sometimes these can get clogged with crap and not flow air or coolant as it expands and contracts.

 

[manofthewoods]

Well it finally happened - Stopped for gas, checked the oil (like I do every fill up) and there's a little foam on the dipstick, foam on the oil cap, and a little wisp of steam escaping the oil fill hole. I think 282K is a pretty good run but its not done and I'm going to fix it and get it back on the road. 4,000 miles ago I did a complete oil seal job and tune up and it wasn't leaking a drop. I ran a scope down the cylinders when I did spark plugs and the pictures are a bit fuzzy, but the cylinders look pretty good. It never overheated.
Its always consumed oil, with the blue puff on start up, so I know I'll be doing valve seals while I have the head off. What else should I replace proactively or upgrade while I'm in there? Head studs? Timing chain?
I don't mind spending the money on quality parts but the garage is pretty cold and I want to be efficient while I'm in there. Any advice is appreciated!

You can do a coolant test for blown HG. My local Autozone loans the kit for free. Really easy and accurate.

 

[tmxmotorsports]

Pulling the plug on #6 and getting your scope in there would give you a big indication. That tends to be the cylinder that the head gasket affects first. Further, hot coolant evaporates quickly from any leaks, making them hard to detect. If you're running Toyota Red, at least it leaves a hard and crusty pink residue that can help with diagnosis, but you sometimes have to search.

Testing the Radiator Cap venting should include blowing through the line from radiator to the cap of the reservoir, as well as blowing through the overboard vent on the other side. Sometimes these can get clogged with crap and not flow air or coolant as it expands and contracts.

Mine blew on number one 187k

 

[whiteyota]

Like MOTW I used the coolant tester, mine immediately changed colors.
95,260k, no maintenance records
Unless I'm mistaken, that is a definitive test?

 

[JDUBinCO]

Update on this...
Thanks a bunch to all for the suggestions. I rented a coolant contamination tester and the results were negative, in fact the rented fluid was a bit contaminated and it turned fully blue in the test tube with my testing. Seems good enough for me to call the HG good to go. I gave it a new radiator cap, topped it up 1.5L of fluid, and adjusted the clamp on the lower radiator outlet. Keeping an eye on it, but it seems like I reacted too quickly to a lot of condensation on a 5 degree morning and the radiator cap had stopped doing its job of releasing pressure into the overflow tank so was forcing it out around the lower radiator clamp.

 

[LongDuck]

Sounds like you're on the riht track. Just keep an eye on your overflow bottle. As it burps, expect some fluctuation of the level, and then - after a week or so - the level there should go up when hot and down when cold, like clockwork. Good luck with it,