Coolant system issues

Sorry I never replied. I sure had that same symptom... used the coolant funnel and when burping just random slow bubbles and they never stop.

Today I got a CEL when starting. It was cool, high 50s F. Stumbled a bit then CEL with VSC/Traction off (not really sure why traction control is affected?)

Anyways, hit up O Reily's on my way home to use the code reader, and sure as shit just as I suspected P0306 (Cylinder 6 Misfire), and P0456 (Evaporative Emission Control System Very Small Leak).

Came home and searched YouTube one more time because once again, my block test came back negative. And the very helpful Schrodinger's Box channel came in clutch... took 3 30 minute videos but are all very educational for anyone with a 4th Gen V6, especially 2003-2006.

2004 Toyota 4Runner P0306 Misfire Diagnosis - YouTube
04 Toyota P0306 Pt2-Can Compression Test Lie? - YouTube
04 Toyota P0306 Pt3 -Art of Puzzle Solving - YouTube

Now I am convinced I have a HG leak. I think the course of action I will take is to use BlueDevil radiator flush and leak fix fluid. A user here, can't remember his handle here, but Dylan from the YouTube channel Trail Benders Overland used it and posted a very good video of it
How to fix your Head Gasket for $100 with Blue Devil Head Gasket Sealer! - YouTube

Anyways, that video is far from the only Blue Devil success story, just the only 4th gen T4R that I could find.
might be in the same boat, have an 05 with 172k miles,the reserve tank reduces by half an inch in 6 to 9months, i suspect a hg leak, however, no misfire as well
 
might be in the same boat, have an 05 with 172k miles,the reserve tank reduces by half an inch in 6 to 9months, i suspect a hg leak, however, no misfire as well

I like the Blue Devil idea.

earthrealm; 1/2 inch isn't enough loss to tell you much. Could be evaporation.

Just don't let it overheat. Keep an eye on the temp gauge.

My 2005 V6 4runner has never had an overheat (150,000) miles. I lift the hood to look at the water/coolant in the overflow tank every week.

One overheat can ruin an engine.
 
Last edited:
I like the Blue Devil idea.


Yep, so I did that yesterday. Takes about a full day.

Drain, remove thermostat then fill with water. Run 10 minutes

Cool.

Drain, fill with radiator flush. Run 10 minutes

Cool.

Drain, fill part way with water, slow pour of blue devil, run 50 minutes.

Cool.

Replace thermostat (I used a new one with new housing due to bending the old one getting it out of housing)

When I started this morning engine ran butter smooth and no water fall noise. Topped with Zerex Asian vehicle antifreeze and burped.

Took for a spin to O Reilly’s to clear the fault code and then to the car wash to spray off mud from under rear skid plate that I now have access to since the front skid is off.

Planning on running for about a week to see what happens, then a drain and fill of antifreeze to make sure I have the right ratio before a freeze comes (probably will still be a couple months before that here in Mississippi)


Sent from my iPhone using Tapatalk
 
I used BlueDevil in August before I ever got any codes and misfires. My coolant temps were hot though (over 200 degrees in Texas summers at red lights). I figure the earlier I did it, the better it worked.

Well, I'm not convinced my HG is entirely sealed but it did slow down the leak. Honestly I'm driving around perfectly fine right now. No codes, no hiccups, coolant temperature stays at 180 degrees all day.

If temps don't hold, I'll just replace the HG. Big job but I like this truck.
 
So it has been about 2 weeks since I put the Blue Devil in. I drove it to work every day for a week (the T4R isn't my usual DD) and I had no waterfall sound, no CEL/misfire/rough idle. I'd say the stuff is effective. It's cooler this week and I need to go to Lowe's and do some yard work so I'll keep this updated.

Now my big thing to tackle is the noisy idler pulleys, so now I have those on order and a new water pump because I fear I'll find evidence of that failing, and when a new one is $95, might as well for piece of mind.
 

Members online

Forum statistics

Threads
278,305
Messages
3,554,044
Members
248,016
Latest member
Advally Service

Trending content

Back
Top