Having trouble keeping my ej22 cool in my l series. I've fitted an aluminium (cheap ebay one) ej radiator and have both thermo fans hooked up together.

It runs fine on the highway and in cooler weather but when the ambient temperature starts getting over 20⁰C the temperature will start climbing, especially on the beach and in stop start traffic. 

There is a slight coolant leak that I can't find, used maybe 1 litre on a recent 700km trip. Could that cause overheating?

if it leaks, and fails to pull coolant back in from the overflow bottle, that could be a recipe for disaster. Until this is solved, be certain to check coolant level in the radiator itself, don't trust the overflow bottle's level.

perhaps the thermostat is failing to open completely?

Leaky head gaskets would be suspect number 1 I think. 

EJs can pop the head gasket that only leaks a tiny bit or only leaks under certain conditions. 

If you don’t know the history of the HGs I’d suggest it’s tie for replacement. 

Cheers 

Bennie

Any air in the cooling system is bad.  It doesn't take much to collect in the water pump and stop the circulation of the coolant.   This is bad for head gaskets.  My experience with older engine models you don't get away with this condition not leading to a headgasket up reseal.

What EJ22?

What indications that it's overheating? Factory gauge? Aftermarket gauge? Infrared thermometer? Does the heat work when it happens?

 

Use a radiator test kit to pressurize the system and look for your leak. Could easily be introducing air into the system, which is causing your problems.

On 10/21/2021 at 7:36 PM, el_freddo said:

Leaky head gaskets would be suspect number 1 I think. 

EJs can pop the head gasket that only leaks a tiny bit or only leaks under certain conditions. 

If you don’t know the history of the HGs I’d suggest it’s tie for replacement. 

Cheers 

Bennie

Man I sure hope it's not the headgasket as the motor only just went in to replace a motor with leaky headgaskets but I haven't been contemplating taking the motor out to replace the clutch so that will be a good time to do the headgaskets. Will a compressions test pick up on a leaky headgasket?

On 10/21/2021 at 11:05 PM, DaveT said:

Any air in the cooling system is bad.  It doesn't take much to collect in the water pump and stop the circulation of the coolant.   This is bad for head gaskets.  My experience with older engine models you don't get away with this condition not leading to a headgasket up reseal.

Surely by now all the air would be out of the cooling system? Or can air work it's way in at any time?

 

On 10/22/2021 at 1:57 AM, Numbchux said:

What EJ22?

What indications that it's overheating? Factory gauge? Aftermarket gauge? Infrared thermometer? Does the heat work when it happens?

 

Use a radiator test kit to pressurize the system and look for your leak. Could easily be introducing air into the system, which is causing your problems.

Phase 1 (1989) ej22e? Well tbh I've only had a block temp gauge to go off but I can certainly tell when an engine is running hotter besides the block temp reading considerable higher, a large amount of coolant overflowing from the radiator and the smell of a cooking motor

18 hours ago, Raynman1989 said:

 

Surely by now all the air would be out of the cooling system? 

No. 

18 hours ago, Raynman1989 said:

 Or can air work it's way in at any time?

Yes.  What takes the coolant's place when it leaks?  Air.  The coolant reservoir is meant to compensate for *pressure*, not capacity/volume.  Sometimes that's correlated, often it's not, particularly in situations like this. 

 

No chance some rag got stuck in there while doing the engine swap? or something wild like that? 

Compression tests aren't always a good test here.  But if it's been bad then it probably was when you go it and it may be bad enough to show iteslf.  Pull the plugs and see if one looks considerably different than the others.  That can suggest coolant entering combustion chamber and burning off in there. 

Those Phase I EJ22 heads are elementary to replace in the car.  No need to even pull it.  External head bolts!  Easy.  Pull the head, resurface (DIY sand it), install Subaru head gasket.  Done.  If you don't pull the engine it wouldn't be a big deal to just replace the one that's bad, not much wasted  time if you ended up doing the other gasket later. 

The main concern I'd have is that it sounds like you got this with existing head gasket issues and I'd wonder how badly it was overheated before you got it. 

Edited October 30, 20214 yr by idosubaru

You check for air in the cooling system by squeezing the upper radiator hose sharply.  Listen for the gurgling, and the giggle pin in the thermostat - which should be OEM or the higher end Stant unit. 

Any air is a bad sign.  If you recently opened the radiator cap, there will be some air.  But to decide if it's a small amount from that or a bigger problem, What to do is check for air each morning before the first drive cycle.  Note the sounds.  Note the coolant level in the recovery tank.  IF everything is right and tight, the amount of air should reduce each cycle, and coolant level should reduce a little to make up for it.  If things do not follow this, then there is a leak somewhere.

Something I have experienced more than once is this - engine runs over normal temperature due to low coolant level.  This causes anything from a tiny nearly in-detectable leak from a cylinder to the cooling system in the head gasket.  This leak can also be much quicker / bigger, if the over temp is worse.  Notice, I did not write overheat.  That's a whole other level of bad.

What ends up happening is that exhaust gasses get pumped into the cooling system, pushing coolant into the recovery tank.  And eventually, enough non liquid airlocks the water pump.

I've gotten away with running an engine with the tiny leak anywhere from 6 days to 6 months - but every time it gets run low on coolant, it accelerates the failure, and eventually you can't get a few miles before the coolant is pushed out.

 

On 10/29/2021 at 7:10 PM, idosubaru said:

 

The main concern I'd have is that it sounds like you got this with existing head gasket issues and I'd wonder how badly it was overheated before you got it. 

If you get to timing covers and see they’re warped/curved in spots - particularly the inner covers where (and because) they’re touching the block, I’d assume this block was severely overheated.  The ones I’ve seen like that don’t last long. I don’t know if other parts can show overheating, that’s where I’ve seen it.  EJ22 is so easy thr HG is still worth replacing but I’d consider needing another block in the future.