'06 V6 HG Failure Early Warning (Sort of)

[telum01]

Hey guys n gals, been a long time since I've been on here. I started a company dealing with Astons so I've been focused on that for the last several months. As part of it, I've been making videos for YouTube. A long time ago I started a thread for catch cans, and a bit of ignorance derailed it so I left it alone:

http://www.toyota-4runner.org/4th-gen-t4rs/176480-any-interest-catch-can-kits.html

Fast forward to a few days ago and I was doing a video showing that catch cans work on all engines, even on a 4Runner. During the video, I found out that I've got coolant mixing into my engine oil.

https://www.youtube.com/watch?v=if4Y2fCf-Bw

I haven't been on this forum for months, so I don't know if anything has changed, but last time I was on here regularly the HG issues had stopped by '06. Unfortunately, mine is an '06 with about 150k on it. So it looks like the issue continues into that year as well.

I've only noticed one time when the engine didn't feel right, and that was trying to pass someone on a two-lane road. I gunned the engine and it sounded fine but had no extra power to pass. I kind of dismissed it because it's felt fine otherwise. Most of my driving is stop-n-go DC metro area traffic so I don't really subject the engine to too much performance demand. Coolant gauge has been rock solid consistent. But as soon as I drained my catch can... it was pretty nasty. Like gloopy mud. Just a heads up to the '06+ V6 owners that the issue may continue into our years.

 

[97hb]

Been rocking a catch can since 200k. It has caught so much junk that would have gummed up my manifold. My civic fills its can in 1 pass compared to the 4runner at 5000 miles lol. Blowby is so awesome!!!

 

[njsanna]

So, to clarify your message, the benefit of this relating to the sort of common head gasket failure on early 4th gens is... If I have "the" head gasket issue this will start collecting oil thereby letting me know I have the head gasket issue?

 

[97hb]

No it will collect oil if you have a healthy engine also. No matter what you will get blowby, its impossible to completely seal your combustion chamber. If you have milkeshake in your can you probably have a headgasket issue. Sometimes in the winter you get milkshake due to condensation in the oil galllery. If it comes out looking like oil you are good.

 

[Drunner97]

It's rare but the 06 4.0s have had some HG failures. Probably depends on when they changed the HG in 06. I think it's been seen more in the Tacomas than the 4runners though (whereas you see more 05 HG failures in the 4runners than the Tacomas, pretty odd really) My 06 Tacoma has 105k on it and I haven't had an issue with it.

 

[docboy]

No it will collect oil if you have a healthy engine also. No matter what you will get blowby, its impossible to completely seal your combustion chamber. If you have milkeshake in your can you probably have a headgasket issue. Sometimes in the winter you get milkshake due to condensation in the oil galllery. If it comes out looking like oil you are good.

Would this "goo" also show up if one unscrews the coolant cap and look at the cap underneath? I was looking at 08 4R V6 Urban Runner and was attempting to unscrew the coolant cap and look at the cap, but the salesman didn't want me to unscrew the cap. Said something about it being a pressurized system... I'm calling b.s. on this.

 

[97hb]

Would this "goo" also show up if one unscrews the coolant cap and look at the cap underneath? I was looking at 08 4R V6 Urban Runner and was attempting to unscrew the coolant cap and look at the cap, but the salesman didn't want me to unscrew the cap. Said something about it being a pressurized system... I'm calling b.s. on this.

Usually you push coolant out of the expansion when head gasket goes. Test hydrocarbons in the coolant to see if combustion is getting past the gasket! Or a leakdown, but I have seen a leakdown look good and still be the gasket. Hydro test is best for radiator.

 

[telum01]

Basically, a catch can is designed to capture oil vapors that would otherwise go into your intake manifold. An engine produces a lot of heat and pressure in various places aside from the combustion chambers - the heads, the crank case, the coolant passages. The heated, pressurized air has to be vented to maintain ideal operating environments within the engine, however, that air contains oil vapors. EPA doesn't allow oil vapors to be vented to atmosphere, so the vent hoses are plumbed to dump into the intake manifold so the oil vapors can be burned off during the combustion cycle.

An oil catch can is inserted into the plumbing prior to the intake manifold. It separates and collects oil vapors from the air, which then continues to the intake manifold to be burned as part of the combustion process.

An oil catch can doesn't prevent or fix the HG issue. What happened in my case is I was doing my oil change and drained my catch can. The catch can contained muddy oil. Muddy oil is what happens when coolant and oil mix. Since it is plumbed into the hose that goes from the head to the intake manifold, it's a pretty clear sign that coolant is getting into the head, which means bad head gasket.

It's possible that the catch can helped reduce the damage muddy oil can cause - it went into my catch can rather than back into the engine - but there's no way to know how much bad oil kept circulating in the oil system until I tear into the engine.

Point being, in normal driving my T4R feels fine. If not for the catch can collecting muddy oil, I would have had no idea that my HG is bad, so I can fix it before the problem gets worse and maybe reduce my repair costs as a result.

 

[iBison]

On min, and others I have read about the leak was slow and would accumulate a small amount in cylinder #6 or sometimes #4. It would run rough for a bit when first started for a bit. I never had and I never read of anyone having an issue with performance while it was on the road like that. I would think if it was leaking enough to do that your coolant would disappear very quickly. I'm no mechanic, just my thoughts and observations.

 

[telum01]

On min, and others I have read about the leak was slow and would accumulate a small amount in cylinder #6 or sometimes #4. It would run rough for a bit when first started for a bit. I never had and I never read of anyone having an issue with performance while it was on the road like that. I would think if it was leaking enough to do that your coolant would disappear very quickly. I'm no mechanic, just my thoughts and observations.

I'm not sure if it was entirely related. I was doing about 45 mph when I laid into the gas pedal to pass, and it was super hot out (in the 90's), so maybe it was a combination of speed, gearing, ambient air temps... only conjecture, really. I only mentioned it because it's the only time I've had any indication that something might be wrong. Otherwise, my T4R runs fine and I would have had no idea that I had a HG issue if not for the catch can.