Mild overheating on ez30d. May have found the culprit...thoughts?

[DanielsHardLoyale]

Hello all! I am the proud 2nd owner of a 2003 Outback LLBean (ez30d) which just hit 221k miles. I have had little to no issues driving the last 30k miles. This car is quite the machine! I am very impressed with it in every aspect; what a great daily driver. Also the previous owners loved the car and had lots of good maintenance logs. Unfortunately I have had mild overheating issues and have been trying to pin it down. It has been high of 80°F lately in my area. Car temperature has risen past the 9 o'clock position 2-3 times but never hit the red. I obviously get very paranoid when I see that temperature dial move...

I'm going to be driving the old girl from Nevada to Pennsylvania soon and wanna be ready. Im praying it's not a head gasket but honestly don't think it is! I just replaced the thermostat and some rad hoses and started to fill with new Subaru coolant but happened to notice a small hole in the radiator fill neck area. It seems to be feeding into the radiator itself? I haven't really noticed any loss in coolant...and also did a coolant flush 5k miles ago. Any thoughts on how this hole would affect the system?? I imagine a new radiator is in my future...

 

Thanks all!

[DanielsHardLoyale]

Imgur link just in case 

https://imgur.com/gallery/ZqlMkQV

[idosubaru]

Looks original and old. If you’re not seeing losses or leaks then it’s not leaking externally. The only failures I’m aware of are external leaks, damaged necks preventing the cap from sealing, and interval clogs. I’ve never heard of internal leaks but failure of the plastic is no surprise on 10+ year old radiators and yours is 20 yo. If you have tractor or equipment repair shops or one of the few remaining radiator repair shops around they can test the radiator. But for the time you can just buy a new one. 

Ebay is the go to radiator source. They’re very inexpensive and aftermarket is a surprisingly decent option for Subaru radiators.  I’ve seen H6 Subaru radiators for under $70. 

Edited June 15, 2023 by idosubaru

[azdave]

Appears to be a  defect in the molding process in the radiator neck and I can't really see how that would be an issue as it has probably been there from day one. If you haven't been losing anti-freeze constantly then that defect is nothing to worry about. It is below the port to the overflow tank so that would not affect the expansion and contraction of the coolant either.

I've seen several cases of people here concerned with their temp gauges reading higher than normal and I was one of them. In my case, the needle was at the red line but never boiled over or showed any other signs of running hot.  When measuring the radiator hoses or the thermostat housing with an IR temp gun, things were normal. I had a bad temperature sensor where moisture had wicked inside and internal corrosion was raising the resistance of the circuit and causing the gauge to read high when all was actually normal. 

Are you noticing any other signs of a hot engine? Do you have a way to measure the coolant temps with another device? I used a cheap Bluetooth remote BBQ thermometer to confirm the temps while driving. I temporarily attached the temp sensor to a coolant line under the hood and then watched the readings on the base unit inside the car while driving for a few days.

[el_freddo]

36 minutes ago, azdave said:

It is below the port to the overflow tank so that would not affect the expansion and contraction of the coolant either.

I’d think if there was a hole there it would push out coolant until the level in the radiator couldn’t get to the hole any more. This would do two things - first, the cooling system would never pressurise, leading to poor cooling performance. Second, reduced coolant volume will circulate the coolant quicker through a cooling system at or above normal operating temp. 

And if that’s your original radiator you’ll probably find it’s full of crud. If that hole isn’t your issue the partially blocked radiator could be. 

Last thing, do you still have the air dam/engine undertray piece still fitted? This is designed to develop a low pressure system in the engine bay at speed to draw air through the radiator. Without this you could find your engine running warmer than normal in hot weather but I doubt it will allow the cooling system to boil. 

Cheers 

Bennie

[1 Lucky Texan]

you're low on coolant - should up at the top of the inner seal.

 

did you install an OEM-style thermostat?

 

make sure there's no build-up of grass/bugs type debris between the rad and the ac condenser.

 

confirm fans are OK

 

cut the bottom of the o'flow tube at 45* angle. If the o'flow bottle is dirty, take it out and put some pieces of ice in it and shake like crazy.

 

until you think this is solved, check coolant level IN THE RADIATOR , the o'flow bottle is an untrustworthy reflection of total coolant volume.

 

 

Edited June 15, 2023 by 1 Lucky Texan

[DanielsHardLoyale]

I ended up throwing a duralast radiator in after an AutoZone comment said "works great with my 2003 LLBEAN" Replaced the old thermostat (NOT OEM) with an OEM thermostat. Also...a bolt was finger loose (YIKES) on the thermostat housing so I'm thinking that was where air was getting into my system and messing with the thermostat. I hadn't touched those yet in my 30k miles with the car. I feel very lucky. I bled the system of air and added coolant with a funnel kit and the new thermostat opened just fine. I used my OBD to monitor the ECT temp and it bounced between 190°F and 199°F as it opened and closed. Burped some air bubbles and I hope it's all good :--) I will be ordering a new temperature sensor even though it seems to be working fine while bleeding the system... At 220k miles, why not.

Fans are also kicking on and off as intended. I will definitely be cutting that o'flow tube at 45*, that is very smart. O'flow was also pretty filthy at the bottom so cleaning that was good too.

5 hours ago, el_freddo said:

Last thing, do you still have the air dam/engine undertray piece still fitted? This is designed to develop a low pressure system in the engine bay at speed to draw air through the radiator. Without this you could find your engine running warmer than normal in hot weather but I doubt it will allow the cooling system to boil.

I definitely don't have that...I will make a trip to pick and pull to try and grab one! 

Also no other signs of engine overheating that I could tell...just that temperature dial moving a bit (I think it was happening on hotter days...but the AC on also seemed to stress the system. With my potentially bad/dirty radiator, dirty overflow, loose thermostat housing bolt and non OEM thermostat...kinda makes sense it was running hot...

Thanks ALL for the help :--) will keep updated on the new rad + oem thermostat

[DanielsHardLoyale]

So the test drive (500 miles with a 96° outside temp and AC on the whole way) was a complete success. Car ran beautifully the whole drive. Some coolant was slightly spilling out weep holes at the top of the reservoir halfway through the drive. I could smell coolant so I pulled over and ended up siphoning some out of reservoir. I just assumed I filled the reservoir up too high... Car temperature was perfect the whole drive.

Fast forward a few days of mild city driving (probably 150 more miles over a few days) and the temps were creeping up again. I noticed the reservoir level stayed too high and didn't really fluctuate much at all. Today when I opened the new OEM rad cap (cold car sitting for a few days) there was a big release of pressure and also checked and there was a definite lack of coolant in the radiator. So I added some more coolant and bled the system again. It bled beautifully and fans/thermostat are operating as intended. I didn't have a hose clamp on the hose that fills the reservoir, so I added one just in case that was messing with my pressure. I cut the reservoir hose a little bit shorter and added a 45° angle to it.

I noticed a slight brown dirt like substance under the new rad cap and at the bottom of the (recently cleaned) reservoir. Could be head gasket material, the Subaru conditioner additive (that looked very brown/chalky and I wish I shook up better....), Or oil/coolant mixing but it seems like coolant only and it didn't look like all the pictures I seen online. Oil dipstick and oil cap both looked normal inside. 

I'm gonna see if there is a decent reviewed shop nearby that can pressure test for me. Unsure what else to do.

Also wondering if the aftermarket rad and OEM rad cap aren't cooperating...

 

Edited June 25, 2023 by DanielsHardLoyale

[DanielsHardLoyale]

After bleeding the system I went for a small 5 mile test drive and the temperature was constant at the 9 o clock position. The reservoir was more filled than where I left it at the full position and also both coolant hoses felt very hard swollen right after the drive so I assume I have some pressure issues. Head gasket? Yikes...... Guess I won't be driving to Pennsylvania after all 😞

[heartless]

17 hours ago, DanielsHardLoyale said:

The reservoir was more filled than where I left it at the full position and also both coolant hoses felt very hard swollen right after the drive so I assume I have some pressure issues. Head gasket?

that would be my guess...
and they dont typically mix oil & coolant... at least not in the beginning.

[1 Lucky Texan]

the level in the o'flow should only go up a few ounces, then those few ounces should be pulled back into the rad during cooling off.

kinda seems like you are experiencing a lot more coolant going into the o'flow on a single drive, that does point to headgaskets (more so if you can spot bubbles when hot and idling)

if, it takes several drives to fill up the o'flow, that seems more like an issue with the rad cap or maybe some air leak somewhere.

[azdave]

Be careful with aftermarket radiators (is there anything else these days). On the one I bought for my 87 DL, I found the inner filler neck sealing surface was not at the correct depth for the caps we use. It was too shallow but the radiator cap fit and I didn't even notice the issue at first. The over-pressure relief spring was being compressed too tight so no fluid could expand  into the overflow tank. This was not a problem while there was still some excess air in the system from the refill but once the air was burped the trouble started. Coolant would properly be sucked from the overflow bottle when the car cooled off at night, but no fluid could expand out when I drove. This worked for almost a week with no overheating or leaks. Eventually, all of the air is burped from the system which is a good thing up until the antifreeze needs to expand ever so slightly but has no place to go. I started seeing antifreeze leaks in several places, all while the engine was running well within normal temps. To prove I was right that the shallow filler neck depth was the issue, I installed a pressure gauge on a section of the heater hose and before the engine was anywhere near operating temps I was already seeing pressures well above 25 PSI. Sadly, I did not catch this soon enough and it cracked the plastic heater core case and also swelled up several hoses and caused the new radiator to leak at the tanks seals. 

Moral of the story is to be sure you have the correct radiator cap and test it. I bought at least 5 caps and also tried every cap they had at both NAPA and Autozone. Not one of them fit correctly. I have a lathe and ended up making my own adapter. I could not send the radiator back because I picked it up long ago but did not install it until much later. This repair was done in April and now that we are hitting 110F here in Phoenix and I'm running the A/C full time, I have no leaks. The flow in and out of the overflow bottle is as expected and I rarely see anything close to 13 PSI on that temporary pressure gauge. Highest coolant temps I've hit are 205-208F. No issues at all now.

 

[DanielsHardLoyale]

Definite head gasket. Exhaust gasses in cooling system and it's gotten bad enough to show some gnarly bubbles at idle. I really didn't see notice this when I bled the system the last few times. Not sure how long it's been an issue.

I am planning to part ways with this beautiful car. Big respect to the 2003 LLBean. What an amazing daily. Was very much looking forward to the drive across the country in this comfy beast.

I learned a lot from the car and definitely will take more preventive measures on all the future vehicles I own.

[el_freddo]

EJs can have a slightly blown head gasket for ages before it’s picked up! 

Sad you’re moving the vehicle on. A HG swap isn’t too difficult, a second hand engine could be easier if a HG job is outside you’re scope of confidence. 

Cheers 

Bennie

[forester2002s]

16 minutes ago, el_freddo said:

EJs can have a slightly blown head gasket for ages before it’s picked up! 

True. But the subject line says that this is not an EJ, but an EZ30D. Different engine.

[heartless]

totally different engine to the EJ series... and a LOT more work

We have an 06 LL Bean with the H6, also with headgasket problems.. it is parked on the car trailer at the moment while we decide what to do with it...

 

[DanielsHardLoyale]

If it was an ea82 I would 100% throw another engine in or attempt the head gasket but this big ol ez30 seems to be a little out of my scope with my current situation. I have $1000 to my name right now LOL not really possible, unfortunately.