[eagleeye]

what HG sealer did you use.

subaru coolant conditioner? ...or some miracle stuff.

what is the 3rd code?

do not let this car overheat, it is easy to melt a aluminum engine. (just pull over and let the car idle until it cools)

EZ30D might take more then one burp cycle to get all the air out of it, (need a funnel that locks to the rad neck,...or taped to the rad neck, face the car up grade and let cool, put the funnel on and start it up, run heater inside car, as car heats the coolant will rise in the funnel, and any air will burp out,....= hopefully no exhaust gases).

miles on this? (and is it a VDC or a plain limited)

 

[Krispypoptart]

OK so, I used the blue Devil Hg Sealer. Also used the flush of the same brand.
The car itself has 176000 miles on it.
P0131 is the third code
P1139 and P1140 are the other two

Im still having a issue with my car warming up not overheating it hasn't gone passed the first bar once it is at operating temperature.
We did a pressure test to see if my car was actually leaking or losing pressure at all.
It held did not lose pressure.
my radiator fluid will push out of the radiator into the reserve tank but will not go back into the radiator after the engine cools. Even overnight. it remains in the reservoir so i have to fill the radiator with fluid so it will not overheat because there is a lack of fluid and thus the process repeats.

Could it be the water pump?
Why won't the radiator fluid go back into the radiator:?
Would the pressure test determine if the Hg is bad?


Now i know the codes are related to my oxygen sensors.
Im pretty sure my cat isnt clogged and my sensors are new
Thanks for your help
Im pretty sure the car is plain limited

 

[Richard Pare]

Double-check that you do not have a lot of junk stuck between the condenser and the radiator - my '01 was 1/3rd blocked when I got it.

 

[eagleeye]

@idosubaru we have a EZ30D car with blue devil in it,

I see in the distant future a donor JDM 212hp engine,.... if its a rust free car.

too hard to do head gaskets on that,
the blue devil clogs more then it helps,...so its probably not a great one anymore to try a long hard head gasket job on
and rounding up a USDM EZ30D that is actually any good is a pretty hard thing.

 

[idosubaru]

Replace the rad cap and make sure the overflow hose isn't so close/tight to the bottom it's blocking flow.

But yeah you have blown headgaskets. Seen a bunch of H6s and what confuses most people is normal to those that know them well.

It's definitely not the water pump. Modern Subaru water pumps simply don't fail unless it sat in corrosive water for years.

Install a JDM engine

Ignore the sensors until the overheating is gone. Pointless to throw money and time at those when the engine is clearly problematic.

 

[eagleeye]

this is one of the cheapest prices I have seen, and a few places around NYC and NJ have them, and they deliver.
one member here drove up from baltimore to the NYC area to get one,...in a 99 camry sedan, just went back with the trunk tied shut.

(not to be confused with the EZ30 245-250hp engine that came in later cars,...not that much faster from behind the wheel).

https://jdmnewyork.com/product/00-0...egacy-lancaster-6-3-0l-engine-jdm-ez30-ez30d/

 

[botenredwolf]

Well, this sounds familiar.

Burping these things of any bubbles is a nightmare, and I have a bubble that keeps coming back. What you can do to avoid high temps in the meantime while diagnosing, is what I do, if you're ever so slightly mechanically inclined:

Check the res pretty much every day before driving. If it's filled up at or near the top, take it out and pour it back into the radiator. Do a quick burp (run it till it warms up, spills a little, etc. then re-cap it). Sometimes I've gone months, sometimes a day, before having to do it again. I'm tracking down where I keep getting these air bubbles from, but an air bubble in the system will cause an overheat. This is also a good time to see if there's debris building up in the res tank, which could cause flow restrictions, as well as seeing if the coolant stays super green and smelling right (which can help disprove head gaskets as a cause, as they typically* don't go out on these cars unless something is seriously wrong and a critical overheat happened for quite a time period). This method also keeps track of whether or not you're losing coolant, as you'll notice real quick if you're burning/leaking/purging it if you're just recycling the existing stuff instead of constantly adding more.

Not sure who else may have gone over it, my brains a bit off, but check all of the metal pipes as well as rubber hoses for even the tiniest breaches. Air can squeeze through stuff that water can't. Suck air into the system, get an air bubble, and poof, you're overheating.

This is my experience and your mileage may vary, but it's worth considering my random rambling.


*Mine popped a set due to who-knows-what alongside piss-poor maintenance by the prior owner. Outside of my overheating issue, basically problem-free since a replacement went in.

EDIT: adding stuff... if the gasket was breached in this engine, best of my knowledge, it would likely be between combustion chamber and water jacket, and would therefore not hold pressure. I'm not going to wave the HG flag quite yet,

 

[Krispypoptart]

Ok, thank you to everyone that has taken their time and given me some ideas.
I recently used a thermal imager to determine what was going on. Turns out my radiator was not flowing evenely. So it caused half the radiotor to heat up and the other half to remain around 91 degrees.

So good news broke a rad line on the way to change out my radiotor so I was able to fix that also.
I haven't been overheating since the switch so I can finally rule out the HG
Plus I don't have any signs that it could be that.

However I still have my codes that are on for my 02 sensors. Which they are new and when I used the thermal imager looked to me like that were functioning properly and that cat wasn't showing any hotspots. Any suggestions for this nightmare?

 

[eagleeye]

"P0131 is the third code
P1139 and P1140 are the other two"

@plain OM might have suggestions on those 3.

on a 2002 H6 with new o2 sensors.

and moving thread to the 2000-2004 section out of the head gasket section ...happily.,..and updating title.

how much rust is on the exhaust before the cats.? any openings?


what brand are these o2 sensors.?

any whistling from the engine,...like a vacuum leak ?

 

[plain OM]

DTC P0131 — BANK #1 AND SENSOR #1 OXYGEN (A/F) SENSOR
(FRONT RH) CIRCUIT MALFUNCTION (OPEN CIRCUIT)

DTC P1139 — BANK #1 AND SENSOR #1 OXYGEN (A/F) SENSOR
(FRONT RH) HEATER CIRCUIT RANGE/PERFORMANCE PROBLEM

DTC P1140 — BANK #2 AND SENSOR #1 OXYGEN (A/F) SENSOR
(FRONT LH) HEATER CIRCUIT RANGE/PERFORMANCE PROBLEM

I wonder if clearing the codes and then seeing which one(s) comes up first would help.

As it is, there's two codes for the Bank 1 Sensor 1 (right side A/F Sensor) and one for the Bank 2, Sensor 1. That might be due to a common heater supply problem, perhaps just bad connections at one of the engine-bulkhead wiring connectors, or at the ECU.

 

[Krispypoptart]

Sorry for taking so long to reply. I have been trying different things out
Recently my car will warm up but will remain between the two lines wont go above and does not necessarily cool down to normal operating temp.
Weird part is if I take a Hard left turn my temp gauge will drop significantly. Like as if it was operating at normal temp.
So that confuses the **** out of me.

I have smelled a light radiator smell while driving but im not losing or burning it as far as I can tell.
(recently had a bad leak at a top hose....)
I keep recycling whatever goes into the reservoir when it warms up.
Thank you to @botenredwolf your suggestion was helpful.

I have not heard any whistling with the car and the exhaust looks fairly clean was thinking about changing exhaust gaskets right where it begins. because i have dropped that before when i did my Rack and pinion.

How many sensors does this car have for temp. I know the main thermostat and the coolant sensor. I have changed both of those. Im going on a trip soon and I'm unsure if I should drive it. I mean the car does not overheat just warms up and stays within the middle not going above the first line on the temp guage. Like a four hour car ride type trip.

 

[botenredwolf]

I keep recycling whatever goes into the reservoir when it warms up.
Thank you to @botenredwolf your suggestion was helpful.


How many sensors does this car have for temp. I know the main thermostat and the coolant sensor. I have changed both of those. Im going on a trip soon and I'm unsure if I should drive it. I mean the car does not overheat just warms up and stays within the middle not going above the first line on the temp guage. Like a four hour car ride type trip.

Just one sensor from what I can recall, and it's up on the top of the engine somewhere.


Attached is a cheat sheet for the temp gauge (taken from the manual on mysubaru.com for my model year, a 2001 H6). From 170F-220F it will hover just above the second line (just below straight left, or "west southwest" if pretending this is a map). 220-240F spans the remainder of the gauge. 240+ will put you solid in the red, and that's the no-no zone. A quick "tattletale" will be the "VDC OFF" light illuminating for no apparent reason, this happens when you break 220F and won't turn back off until you go below 216F. AC also shuts off around 230F. If none of that stuff has happened, I think you're in the safe zone and can safely drive it, even on longer trips, as long as you mind the air bubble that keeps popping up.



If you haven't had a chance to burp it like a boss, I just did mine the other day and it's been behaving rather well for the last few hundred miles. Get it on a steep hill, front of the car pointing up: pop the radiator cap, recycle some of the coolant from the reserve (leave it between the lines), put the reservoir back in, start it up, and fill the radiator up. Go in and turn the heater all the way up (85 and it just won't stop trying to heat the car). Let it run until the gauge makes it to generally "west". Keep an eye on it to make sure it stays there during the rest of this. Bubbling/dripping/leaking/overflowing from the rad is normal at this point since you're still uncapped. This next part will make a mess, so mind any spillage and nearby creatures, as they like the smell, but consuming it will be bad. Slowly increase the engine RPM to stir up any remaining bubbles in there and force 'em out. I usually go up to about 2,500-3,000 for maybe 5-8 seconds. Many times when spinning up and/or when releasing the throttle, a good amount of coolant will spill out. Ensure it's still full afterwards. Re-cap and enjoy. It should heat cycle properly for at least the next few driving cycles, even if there is a small breach somewhere allowing air to get sucked in.


((( The pretty chart is just showing the temperature swings I've seen before from my car from a data logging computer I installed mostly for this reason... so I totally know your pain and confusion )))

 

[botenredwolf]

DTC P0131 — BANK #1 AND SENSOR #1 OXYGEN (A/F) SENSOR
(FRONT RH) CIRCUIT MALFUNCTION (OPEN CIRCUIT)

DTC P1139 — BANK #1 AND SENSOR #1 OXYGEN (A/F) SENSOR
(FRONT RH) HEATER CIRCUIT RANGE/PERFORMANCE PROBLEM

DTC P1140 — BANK #2 AND SENSOR #1 OXYGEN (A/F) SENSOR
(FRONT LH) HEATER CIRCUIT RANGE/PERFORMANCE PROBLEM

I wonder if clearing the codes and then seeing which one(s) comes up first would help.

As it is, there's two codes for the Bank 1 Sensor 1 (right side A/F Sensor) and one for the Bank 2, Sensor 1. That might be due to a common heater supply problem, perhaps just bad connections at one of the engine-bulkhead wiring connectors, or at the ECU.

Swap banks or totally omit one, electrically? Unless there's a known good one around you can swap out one at a time to see if these/which codes come back after clearing...