33 replies to this topic

[duncanm]

If this is to be believed - http://legacygt.com/...ems-120477.html - then it sounds like a blockage in the heater core (or feed to/from it).

 

This is consistent with some of your results - where everything working ok with the core bypassed..

[natho]

i had some issues with an aftermarket thermostat - it was opening properly, but i could never bleed all the air out of the system. in the end swapping to a genuine one fixed it.

[RX25SE]

If this is to be believed - http://legacygt.com/...ems-120477.html - 

 

I only read the first post. There is some truth but TBH I don't believe most of it.

 

 

 

The OP's issue may still be a blocked or partially blocked heater core.

[duncanm]

i had some issues with an aftermarket thermostat - it was opening properly, but i could never bleed all the air out of the system. in the end swapping to a genuine one fixed it.

 

I suspect this is the function of the little hole + dingleberry on the OEM thermostat.

[podmak]

Hi guys, thanks for the input, but if you read a couple of earlier posts you'll see the heater core is bypassed, so that can be ruled out.

The thermostat is a genuine subaru part, brand new out of the box, working. We can rule that out too.

Pressure test shows the system holds presure, so we can rule out the leak.

Which leaves what. Water pump, or clogged waterways.

I heard an interesting theory lately.

The small propeller inside the water pump that is connected via the rod to the pulley may be viggling (jeez is that a word?) and when there is an obstacle in the water circuit, such as thermostat, the viggle prevents the pump from creaing enough propelling power to cycle the water.

This would explain the lower hose not heating up due to poor water pump performance, but - is the thermostat, even an open one, really such an obstacle that would completely stop the pump from propellig?

I mean... It's not really maling much sense...

[duncanm]

no - that makes no sense.

 

I think you're saying if the impeller shaft has play - and the impeller wobbles, then the pump vanes won't work.

 

Problem with that theory is, I think, that the pump would be leaking through the shaft like a biatch.

 

Cold lower hose means thermostat not opening.

[Kgraham75]

First thing I would do is replace the radiator. Second, go buy a hand pump with the red hoses, tape the outlet so it can't blow the hose off. Put three gallons of coolant in a clean bucket. Get appropriate pipe fittings for your upper hose and an extra top hose you can cut to fit another fitting. Get the nose of the car as high as possible. Make sure you have the inlet and outlet (pump hoses) submerged and pump coolant into the engine. You'll see bubbles in the bucket, when they quit you're good. Attach the top hose and top off with coolant.
First thing I would do is replace the radiator. Second, go buy a hand pump with the red hoses, tape the outlet so it can't blow the hose off. Put three gallons of coolant in a clean bucket. Get appropriate pipe fittings for your upper hose and an extra top hose you can cut to fit another fitting. Get the nose of the car as high as possible. Make sure you have the inlet and outlet (pump hoses) submerged and pump coolant into the engine. You'll see bubbles in the bucket, when they quit you're good. Attach the top hose and top off with coolant.

[RX25SE]

Take a read at this:

http://www.autospeed...esting&A=110478

 

 

I had a bloke with a vehicle (not a Subaru) that would blow a radiator apart at least once a year and sometimes it would blow fairly new hoses. Tried everything, caps, thermostats etc., even tried a lowering the cap pressure from 13psi to 7 psi by fitting a lower pressure cap.

 

One day it's in for repairs and I end up replacing the pump. The old one looked OK from the impellor side, just had a small leak.

 

He phones a few days later asking "What did you do my car?" I'm thinking the worst so I ask him what he means. "It's running better and seems to be using less fuel. Did you tune it?" No I say, just replaced the pump and a leaky hose.

 

 

Pondered over this for a few years until a mate told me about a bloke who hand finishes custom water pump impellors (he also showed me this pump test) and conducts efficiency test on the pumps before he lets them out of the shop. Said mate had fitted one to his 350 Chev and experienced a similar thing, better running and no overheating in traffic.

 

 

 

 

Moral of the story, don't underestimate the water pump.

[podmak]

Hi again. I hope you guys had a good new year's and Christmas. 

 

 

Just a quick recap. 

1. Heater core is bypassed. 
2. Cooling system flushed. 
3. New radiator. 
4. New thermostat (tested and working). 

When bleeding the air out of the cooling system, when I still have my bleeding funnel in the reservoir above the turbo (turbo tank), and the thermostat is opening for the first time, the lower radiator hose warms up for just a little while. Then this happens: 

1. Fan comes on.
2. The thermostat closes and lower radiator hose cools down.
3. The fan stays on indefinitely and the thermostat doesn't open anymore. 
4. Lower radiator hose doesn't warm up anymore. 
5. This may require further burping once the thermostat opens (I am yet to confirm this). 
6. It comes to me as if there was air entering the cooling system somewhere, but the mechanic said he did the cooling system pressure test and it passed. ... (Do mechanics lie?)

And I discovered something else, when I was flushing the cooling system. When I poured water into the top hose, the water came out through the thermostat housing on water pump - so far so good. Then I clogged the outlets to see if the water can flow freely through individual outlets, and I discovered that the water doesn't flow through the outlet number 1. This one goes to engine block through the oil filter housing. (See attached image below) 

 

 Untitled.png   3.18KB   6 downloads

 

Can anyone recommend a good diagram of the EJ20HDWAJE waterways? 

 

Or just give me your feedback, as always, it's greatly appreciated. 

no - that makes no sense.

 

I think you're saying if the impeller shaft has play - and the impeller wobbles, then the pump vanes won't work.

 

Problem with that theory is, I think, that the pump would be leaking through the shaft like a biatch.

 

Cold lower hose means thermostat not opening.

 

Yep, nope - it's not the water pump. You're right. The noise and leak would give this away. 

[podmak]

UPDATE:

 

My lower hose finally warms up.

1. One of the hoses connected to the water pump housing (where thermostat is) was kinked.  Untitled1.png   8KB   5 downloads
2. The rubber water hose connector below alternator was leaking a little.

Replacing these seems to have helped the proper coolant circulation, but now I noticed the coolant level fluctuates a lot. There are two parts to this "problem" I would like to be considered:

 

1.) I was bleeding the air out of the system, and the water level in my funnel was going up and down a lot:

• from totally empty bleeding funnel (totally empty as in I was pouring more coolant into the turbo tank)
• to completely overflowing the bleeding funnel and spilling coolant into the engine bay (ehm...)

2.) After I bled the system, I put the turbo tank cap back on, I let the car idle for a while, and the water level kept on rising and falling, all the way to the point where the coolant started to pour out of the overflow tank.

 

 

My suspicion is this might be a malfunctioning coolant reservoir pressure cap? The cap on the overflow tank may be too weak? I am wondering, what's the correct pressure reading that's supposed to be on both the radiator and the turbo tank caps? This is EJ20H engine.

[podmak]

Problem solved. I replaced both pressure caps and bled the system thoroughly.

Whoever made it all the way here; here are some hints to look out for when you're experiencig similar behaviour as described above:

1.) pressure test your cooling system.
2.) check all hoses for kinks/breaks
3.) flush the cooling system as well as the radiator
4.) take off your intercooler and flush the heater core separately; bypass it if need be.
5.) make sure your termostat opens and closes properly.
6.) Don't be cheap and buy new caps, thermostat gasket and hose clamps. (Use common sense)
7.) Bleed properly. Can't stress this enough.
8.) above all, don't loose hope!

 

P.s.: Thanks Duncanm, I found your comments most helpful.

P.s2.: The heater core is still clogged. That should now be pretty straight forward... Thanks to all who participated.

[motoboy76]

Nice work Pod glad you got it sorted....

[Arfreedom]

I'm definitely no expert here but just share my experience.
I saw online that a guy flush the radiator with the engine running. So one day I did that and I capture the water as always but this time I found more stuff than ever.
I put the hose to the top tanks and when it start to leak from the bottom I started the engine and after it warm up a bit rev the engine and I think the stuff came from inside the pump and every where internally.
Just my 2 cents


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[duncanm]

glad to hear its sorted -- what a marathon of an effort.