I want to do a radiator & heater core flush...

[2nd Hand Yank]

Should I remove the radiator and/or heater core as a repair manual suggests?
Or can I do it carefully, with the radiator in place, just disconnect some of the hoses and fittings?

My radiator has full coulant level, but the heat output is paltry vs. a newer vehicle.
I've seen old vehicles heater cores come back to life with a simple flush with a garden hose.

When my car is up to operating temp and I'm at a steady cruise RPM
I can make the draught out of the vent about 25 C higher than ambient, dial set to max heat.
I'm used to being able to bring it up about 40 C higher than ambient;
nearly burn your hand when it's above 4 C outside.

Obviously, you need a much higher outlet temp to make a warmer cabin temp.
I would like better heat output before it reaches operating temp,
so that it will more quickly burn the fog off the windows that we seem to get every morning.

If my avatar pic isn't very good, I have a 93 L series 4wd.

[El_Freddo]

The heaters in the subarus are built very well and are the first to start heating during warm up. If you're heater isn't blowing hot enough yet the cooling system is still keeping up with the job of keeping the pesky little EA82 cool, I would say that you have a film of debris on the heater core that could be partially blocking the air flow through the heater core.

25 degrees C sounds reasonable to me - I think you'll be surprised how well it will work when you need it. But if you want to check out your heater core properly you'll have to remove the entire dash to get to the heater box and then the heater core itself. And if you're going to do this I would recommend buying a new core especially if you find out your current one has plastic end tanks as they will pop eventually. A replacement copper/brass unit will be near $250! Worth it though. I've popped about 3 different cores over the years so lashed out and got the all copper/brass unit.

Do a search - There's a write up somewhere here about removing the L series dash, I remember writing it a couple of years ago...

The radiator, if it is not cooling effectively, remove it and take it to a radiator joint to have it "rodded". This is where they will push a rod down each cooling channel to remove 20ish years of crap that may have been building up in the radiator. It'll cost a bit over $100 usually but could ultimately save your engine and your radiator. Apparently the L's radiator can usually keep up with the cooling effort at about 50% blockage - then it just takes one day of extra loading or a little more heat and then you've got a temp issue!

Cheers

Bennie

[2nd Hand Yank]

The heaters in the subarus are built very well and are the first to start heating during warm up. If you're heater isn't blowing hot enough yet the cooling system is still keeping up with the job of keeping the pesky little EA82 cool, I would say that you have a film of debris on the heater core that could be partially blocking the air flow through the heater core.

25 degrees C sounds reasonable to me - I think you'll be surprised how well it will work when you need it. But if you want to check out your heater core properly you'll have to remove the entire dash to get to the heater box and then the heater core itself. And if you're going to do this I would recommend buying a new core especially if you find out your current one has plastic end tanks as they will pop eventually. A replacement copper/brass unit will be near $250! Worth it though. I've popped about 3 different cores over the years so lashed out and got the all copper/brass unit.

Do a search - There's a write up somewhere here about removing the L series dash, I remember writing it a couple of years ago...

The radiator, if it is not cooling effectively, remove it and take it to a radiator joint to have it "rodded". This is where they will push a rod down each cooling channel to remove 20ish years of crap that may have been building up in the radiator. It'll cost a bit over $100 usually but could ultimately save your engine and your radiator. Apparently the L's radiator can usually keep up with the cooling effort at about 50% blockage - then it just takes one day of extra loading or a little more heat and then you've got a temp issue!

Cheers

Bennie

Thanks for the detailed response.
I figured its a bit blocked.

Worth looking into, especially if it looks like I'll still be owning it next winter.

Will look at dash removal. It may help in adding the gauges I want.

Radiator rodding... Sounds interesting.

I have a fan system that might be aftermarket.
Or does this sound Subaru?
It seems to be electric and is mostly on after I've been driving slowly. (under 30km/h)
It will stay on for 5-8 minutes AFTER I shut the car off.
It sounds a bit like a vacuum cleaner.
I'm a bit concerned if the fan is occaisionally working hard and it's still winter.

Also, the factory hot/cold gauge,
the needle hardly budges, or doesn't budge from cold if I drive 50+km/h
yet it pumps out a reasonable amount of heat if I want it.
If I drive slower and this fan turns on,
the hot/cold needle will move about 1-1.5cm above cold
or about 1/3 the distance from cold to hot.

Does my cooling system still sound like it's working all right,
or are my suspicions correct,
that I should at least clear out the radiator before real hot weather arrives?

[El_Freddo]

I'd take the radiator in for a clean, pull the dash at the same time and see what's going on with the heater core, if it's plastic and looking brittle then get an all copper/brass unit - you won't look back or ever have to worry about blowing the core - a hose maybe - there are units in the US that are all brass/copper from the firewall all the way to the core rather than having the rubber hoses under there between the firewall and the core (from factory and my replacement core is the same so there's still a weak spot there).

Change the thermostat too. If it's moving around like that now I'd be getting on top of it during the cool weather before the temp rises as summer approaches.

I'm not sure about those fans, I know my cabin fan can take 20 seconds or less to turn off with the ignition in the lock position... This isn't normal and I've not looked into it. I can see the advantage of having your thermos operate for a few minutes after engine shut off but 8 minutes is nearing battery killing territory I'd reckon!

Grab some pics of your thermo fans so we can have a look at what you've got in there - this way we'll be able to tell you if it's factory or an ad on Pics always say a thousand words - just don't try to submit three for a three thousand word essay at uni, a mate taking the piss found out that it doesn't work like that

Cheers

Bennie

[2nd Hand Yank]

http://s92.photobucket.com/albums/l9/He ... tos004.jpg

http://s92.photobucket.com/albums/l9/He ... tos005.jpg

http://s92.photobucket.com/albums/l9/He ... tos006.jpg

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http://s92.photobucket.com/albums/l9/He ... tos021.jpg

I can't figure out how to attach them as images. When I used the "insert pic" with [IMG] it just went blank. Okay on closer inspection there are two entirely different shaped fans bolted to the radiator, including different shaped shrouds. I'll have a listen next time I hear the "vacuum cleaner" to see which fan is going, if both aren't.

So you say that my thermostat is probably stuffed?
Cheap and easy just to buy a new t-stat rather than the time taken to test it?
(with a high likelyhood of failure?)

[2nd Hand Yank]

Looking under the bonnet after a long slow drive,
it seems the plastic fan on the driverside is the one that keeps going.

Does anyone want to have a look at my links?
Sorry I couldn't insert them as a picture.

[RSR 555]

Does anyone want to have a look at my links?
Sorry I couldn't insert them as a picture.

Fixed

I'd do as Bennie has mentioned (get the Rad rodded at the Rad shop) but personally I wouldn't pull the dash out just yet. I'd look at flushing it in-situ by disconnecting the heater hoses off the engine and using the garden hose, just flush each hose back and forth a few times (at least 3 or 4 times). I'd also replace the thermostat and whilst that is out, I'd flush (again using the garden hose) the engine with lots of water. Then drain as much of that tap water and once Rad is back in fill with good quality coolant.

[RSR 555]

Looking at that LH side fan, that is an aftermarket fan. That will be the one sounding like a vacuum cleaner. I'd say both are wired up together but without looking, it's a bit hard to be 100% sure.

[2nd Hand Yank]

Looking at that LH side fan, that is an aftermarket fan. That will be the one sounding like a vacuum cleaner. I'd say both are wired up together but without looking, it's a bit hard to be 100% sure.

Thanks RSR

So the original Subaru had a twin electrical fan set up
and they replaced the driver's side fan with this one?

Does anyone think this fly-screen is too restrictive?
If it isn't, then I appreciate it being there to protect the radiator.
If it is, I'd rather remove it and replace it with metal mesh with a larger grid pattern.

[TOONGA]

the mesh is just right any bigger and it won't stop anything, any smaller and it will restrict air flow

TOONGA

[El_Freddo]

the original Subaru had a twin electrical fan set up
and they replaced the driver's side fan with this one?

No, the L series had one mechanical fan and one electrical fan on the RHS - someone has replaced the mechanical fan with the electrical one.

What Paul (RSR555) is wondering is wether someone has wired the second fan directly off the original fan's wiring... This will not operate the fan properly - it needs to be on its own relay to get its full 12V rather than trying to suck from the factory wiring that's probably having enough fun keeping up with the factory thermo - I think you'll find that it's running near 9V so the fan is not as noisy to keep the consumer happy.

I've got this other diagram that might be helpful - I've worked on these over a few years, I don't just pull them from my arse



I've got my three fans wired in like this and it works well - all referenced from the same wires but run their own relay each

Cheers

Bennie

[2nd Hand Yank]

the mesh is just right any bigger and it won't stop anything, any smaller and it will restrict air flow

TOONGA

thanks TOONGA

[2nd Hand Yank]

No, the L series had one mechanical fan and one electrical fan on the RHS - someone has replaced the mechanical fan with the electrical one.

What Paul (RSR555) is wondering is wether someone has wired the second fan directly off the original fan's wiring... This will not operate the fan properly - it needs to be on its own relay to get its full 12V rather than trying to suck from the factory wiring that's probably having enough fun keeping up with the factory thermo - I think you'll find that it's running near 9V so the fan is not as noisy to keep the consumer happy.

I've got this other diagram that might be helpful - I've worked on these over a few years, I don't just pull them from my arse



I've got my three fans wired in like this and it works well - all referenced from the same wires but run their own relay each

Cheers

Bennie

Okay so my mechanical fan is replaced with an electical fan.
Could that be any better or worse than the original?

So this fan is too fast or powerful, so they might have run it at 9V deliberately?
I should check the wiring?
or perhaps folks on Subaru could do it for me with pictures I provide?

Thanks for posting the wiring diagram that you made yourself.

You have 3 fans wired into your radiator? How did you make them fit?

[RSR 555]

The original fan on the LHS was a viscous hub fan driven off the water pump pulley, so the electric fan will work fine. Like Bennie mentioned, I'm hoping someone wired it up correctly and most importantly, I hope the blades turn the correctly way around??

I too think the mesh is fine and shouldn't cause that much trouble.

[2nd Hand Yank]

The original fan on the LHS was a viscous hub fan driven off the water pump pulley, so the electric fan will work fine. Like Bennie mentioned, I'm hoping someone wired it up correctly and most importantly, I hope the blades turn the correctly way around??

I too think the mesh is fine and shouldn't cause that much trouble.

Which is the right way for it to be turning?
Can I test it with my hand to feel it sucking or blowing from in front of the grill, or behind, under the bonnet?

Thanks. I thought the mesh was a nice touch; to protect the air-con condensor from stones.

[RSR 555]

Which is the right way for it to be turning?
Can I test it with my hand to feel it sucking or blowing from in front of the grill, or behind, under the bonnet?

Thanks. I thought the mesh was a nice touch; to protect the air-con condensor from stones.

You need to look at the profile of the blade and it should dish like a spoon and scoop the air from the radiator and then flick it out.. if this makes sense?? The cutting edge of the blade should be closest to the rad. Then just need to check the rotation when on.

[2nd Hand Yank]

You need to look at the profile of the blade and it should dish like a spoon and scoop the air from the radiator and then flick it out.. if this makes sense?? The cutting edge of the blade should be closest to the rad. Then just need to check the rotation when on.

so its supposed to suck air through, not blow it back out? I think your comments make sense.

Is it simple to perform a rad flush?
What tools do I need, beside a garden hose and some replacement coolant?
I'd rather do it myself if it is, to save money on labour.
I already have the proper coulant for an aluminium engine and "rad flush scrubber, safe on alloys"

[El_Freddo]

You want something to catch the old coolant as it is not good for the environment...

Other than that what you've said is pretty much it. Maybe a phillips head or flat head screw driver to undo the hose clamps.

Fans should suck through the radiator to the engine Checking with your hand is easy - just don't get them caught in a fan belt or fan blade...

Cheers

Bennie