83 Brat GL Overheating

[divinicus]

Hi All, 

My 83 Brat GL has a new issue, it is overheating during normal drives around town. 

It is blasting hot coolant into the overflow bottle. 

The main fan is running all the time, so I'm guessing the water pump needs replacement? 

All the hoses and clamps are good. 

Any help really appreciated! 

[skishop69]

Is the fan blowing hot air while it's running? If not, I'd replace the t-stat to start. Older and good quality water pumps don't usually snap or 'spin' the impeller and just stop pumping.  Could be a plugged radiator or HGs, but I doubt it's blown HGs. It's rare on an EA81.

 

Edited August 22, 2019 by skishop69

[el_freddo]

HGs aren’t “rare” on the EA81. They’re not super common but they do happen from time to time. 

My immediate thought on the issue is that your head gaskets are toast. 

But, checking those areas as identified by skishop - blocked radiator will have hot and cold patches at full operating temp. Thermostat could be stuck. Use genuine. 

Also try tightening your fan belt, this will increase contact on the water pump pulley and reduce slip if there is any. 

Cheers 

Bennie

[divinicus]

2 hours ago, skishop69 said:

Is the fan blowing hot air while it's running? If not, I'd replace the t-stat to start. Older and good quality water pumps don't usually snap or 'spin' the impeller and just stop pumping.  Could be a plugged radiator or HGs, but I doubt it's blown HGs. It's rare on an EA81.

 

Thanks a lot. I didn't mention the temp gague on the dash has never worked since I got this Brat last June, so replacing the tstat sgoild also fix that? The fan runs all the time from the point of turning the key. Hope to God its not the head gaskets. Are you also saying put in a new radiator if the tstat doesn't do the trick? 

[DaveT]

The sensor for the temp gauge is most likely a single wire thing that bolts into the intake near the thermostat.   

I skipped over EA81 engines, but I suspect that multiple overheats are just as bad for their  headgaskets as they are for earlier and later engines. 

Most important thing to keep at 100% in Subarus is the cooling system.   Radiator free flows, all the fins attached to the tubes.   All of the various cooling system hoses maintained, not just the 2 radiator and heater hoses.  System always 100% full of coolant,  little to no air.  Usually air is the initial sign of problems coming.

[divinicus]

3 hours ago, DaveT said:

The sensor for the temp gauge is most likely a single wire thing that bolts into the intake near the thermostat.   

I skipped over EA81 engines, but I suspect that multiple overheats are just as bad for their  headgaskets as they are for earlier and later engines. 

Most important thing to keep at 100% in Subarus is the cooling system.   Radiator free flows, all the fins attached to the tubes.   All of the various cooling system hoses maintained, not just the 2 radiator and heater hoses.  System always 100% full of coolant,  little to no air.  Usually air is the initial sign of problems coming.

Thanks again for your help. 

Good news I think, I just checked the oil it is squeaky clean and no signs of contamination.

But I do want to jump on this overheating issue, would you recommend a new radiator, this is the original from 1983.

 

 

[DaveT]

Oil condition rarely indicates headgasket integrity in Subaru engines.  It's been rare on my experience to have coolant get into the oil.

Around here, a radiator typically rots out in around 10 years.   

What matters - cap off the ports. fill it with water.   Leave the cap off, highest point.  Quickly release the cap on the bottom hose.  The water should fall out fast, in a second or 2.

Look at the thin copper fins that are vertically zigzagging between the tubes...  are they intact,  attached, and not blocked up with road crud?   Especially look where there are sheet metal air guides for the fans.

Are the end tanks metal or plastic? 

[idosubaru]

8 hours ago, divinicus said:

I didn't mention the temp gague on the dash has never worked since I got this Brat last June, so replacing the tstat sgoild also fix that?

Cracksmoking monkeys! Thats about the worst decision possible for a 37 year old car besides drive it off a cliff or drain all the fluids and race across the Sahara.

With no temp gauge, in all likelihood it was running hot for awhile and you didn’t know it, and you were beating an injured elderly man while he’s down every time you drove it  

Hopefully you’ll find a simple solution...I’d want to diagnose it before guessing and throwing a bunch of parts and diagnosing it with money. 

Look for bubbling in the coolant overflow right after you start it (before the engine gets to normal operating temp or above   

Radiator - Run a garden hose to the radiator with both hoses pulled.  Can it flow the volume of the garden hose (assuming you have a normally spec’d water supply)?   If it’s clogged the inlet side will get all backed up, flow out and only a trickle or partial flow comes out the other side. 

Thermostat can be tested  in boiling water. Install a new Subaru one if replaced.

make sure radiator and everything in front of it is free of debris, bugs, clogs and not preventing airflow to the radiator  

 

Edited August 23, 2019 by idosubaru

[divinicus]

11 minutes ago, idosubaru said:

Cracksmoking monkeys! Thats about the worst decision possible for a 37 year old car besides drive it off a cliff or drain all the fluids and race across the Sahara.

With no temp gauge, in all likelihood it was running hot for awhile and you didn’t know it, and you were beating an injured elderly man while he’s down every time you drove it  

Hopefully you’ll find a simple solution...I’d want to diagnose it before guessing and throwing a bunch of parts and diagnosing it with money. 

Look for bubbling in the coolant overflow right after you start it (before the engine gets to normal operating temp or above   

Radiator - Run a garden hose to the radiator with both hoses pulled.  Can it flow the volume of the garden hose (assuming you have a normally spec’d water supply)?   If it’s clogged the inlet side will get all backed up, flow out and only a trickle or partial flow comes out the other side. 

Thermostat can be tested  in boiling water. Install a new Subaru one if replaced.

make sure radiator and everything in front of it is free of debris, bugs, clogs and not preventing airflow to the radiator  

 

Gosh thanks! I will do all that and get back to you right here! 

[el_freddo]

Ok, no gauge makes it tricky but there’s a list of things you can do, many already mentioned by DaveT and idosubaru, I’ll list them all here, but coolant blasting out of the overflow bottle is usually a “good” indication that you’ve got a HG issue. 

- have the coolant system tested for the presence of exhaust gasses.

- radiator - check for air blockage through the fins. You should be able to see through the radiator fins when you’re 100% perpendicular to the radiator. 

- radiator -check water flow through the core. If it’s the original unit it could be worth having one end tank removed and the channels “rodded” to remove any crud that’s deposited itself in there. The all brass/copper radiator is good until corrosion kills them.

- radiator cap. If it’s old, or history is unknown, get a quality new one 

- thermostat. Test/replace with a new genuine unit 

- back flow the heater core and ensure the “H” tap isn’t blocked when redirecting coolant back to the engine instead of through the heater core. 

- check the system for leaks. Any hoses or clamps that need replacing, replace them! 

On your radiator there’s a plug on the RHS (vehicle’s rhs), it’ll be a single wire plug with a yellow wire to the plug. This is the thermo fan switch. There should also be a small wire on the top of the radiator that’s also screwed to the body work. 

^ this system is the factory EA81 thermo fan trigger system. Someone has bypassed this and either hard wired the trigger wire (yellow wire), or they’ve just hard wired the fan to the ignition “on” system. With some investigation you should be able to work out this setup and get it running right. 

Cheers 

Bennie

[divinicus]

5 hours ago, el_freddo said:

Ok, no gauge makes it tricky but there’s a list of things you can do, many already mentioned by DaveT and idosubaru, I’ll list them all here, but coolant blasting out of the overflow bottle is usually a “good” indication that you’ve got a HG issue. 

- have the coolant system tested for the presence of exhaust gasses.

- radiator - check for air blockage through the fins. You should be able to see through the radiator fins when you’re 100% perpendicular to the radiator. 

- radiator -check water flow through the core. If it’s the original unit it could be worth having one end tank removed and the channels “rodded” to remove any crud that’s deposited itself in there. The all brass/copper radiator is good until corrosion kills them.

- radiator cap. If it’s old, or history is unknown, get a quality new one 

- thermostat. Test/replace with a new genuine unit 

- back flow the heater core and ensure the “H” tap isn’t blocked when redirecting coolant back to the engine instead of through the heater core. 

- check the system for leaks. Any hoses or clamps that need replacing, replace them! 

On your radiator there’s a plug on the RHS (vehicle’s rhs), it’ll be a single wire plug with a yellow wire to the plug. This is the thermo fan switch. There should also be a small wire on the top of the radiator that’s also screwed to the body work. 

^ this system is the factory EA81 thermo fan trigger system. Someone has bypassed this and either hard wired the trigger wire (yellow wire), or they’ve just hard wired the fan to the ignition “on” system. With some investigation you should be able to work out this setup and get it running right. 

Cheers 

Bennie

Thanks a lot, Bennie!

I will do the following:

1. Remove upper and lower radiator hoses.

2. Plug the bottom hose with a cap, leaving upper one open.

3. Fill the radiator with water, then release lower hose cap.

If the water flows out fast, then the radiator is ok, is that right? I will also check the front of radiator to make sure the fins are clear of debris.

Another thing to report, last summer when I bought the car in Tallahassee, I drove it all the way up to NYC without even a hint of overheating, loss of power, or anything else. It drove like a champ. 

I've put less than 600 miles on the car since I got back to Staten Island a year ago, so I haven't been pushing this thing at all. Just sayin'!

Thanks again, by the way, I'm having no luck finding an OEM thermostat, from Rock Auto or anyplace else, Can you recommend the part supplier?

Best wishes.

[idosubaru]

10 minutes ago, divinicus said:

Thanks again, by the way, I'm having no luck finding an OEM thermostat, from Rock Auto or anyplace else, Can you recommend the part supplier?

Subaru

 

Search USMB for EA81 thermostat part number:

 

[divinicus]

7 hours ago, idosubaru said:

Subaru

 

Search USMB for EA81 thermostat part number:

 

Ok, I ordered an original E81 thermostat and housing for it, just have to get a gasket. Just ran the engine and did a boilover teat for about ten minutes, nothing came out of the overflow tube. Will replace the thermostat and do the flow test to see if this radiator is clogged. Don't mind throwing some more money in with a new radiator, but I have a lot of trouble believing the hgs are toast with only 130k miles. 

[divinicus]

I just made a visual inspection under the engine. 

The two exhaust headers just below the heads on either side are bone dry, as are all the surfaces of the head covers where they meet the engine.

As I said, I truly don't believe this E81 has blown HGs. 

I will keep everyone updated step by step. 

What is needed to get the dash engine temp indicator working again?!

Thanks.

[DaveT]

Miles don't kill headgaskets, overheat while low on coolant does.  Temperature cycles do seem to wear them / limit life.

The most common sign of hg failure beginning is small continuous supply of bubbles out the overflow tube into the tank.  Sometimes, you might get a seep to the outside.  The bottom edge is the oil return passage, no coolant passages down there.

You might be lucky, since you saw no bubbles with the test run.  Sometimes they survive, but not usually. 

[ferp420]

heres a video of my rig with a non sealing home made headgasket you can clearly see bubbles in the radiator

take the cap off when its cold top off the radiatorvand squeese the hose a few times then run the engine if you have a bad head gasket it will look like this

 

 

[el_freddo]

Temp gauge could be a few things - check the wire is plugged snugly onto the sender at the thermostat area (this is where you’ll find it). 

Unplug the engine harness plug near the coil (it could be on the other side for the USDM, but I don’t know exactly), check for corrosion etc. it’s worth scratching up the pin sets to ensure a good connection. 

If everything under the bonnet checks out but the gauge doesn’t move, you can ground the temp wire and that gauge should go sky high if it works. If it doesn’t work I’m stumped - fit an aftermarket gauge (these are accurate rather than just an indication of temp). 

Cheers 

Bennie

[divinicus]

3 hours ago, ferp420 said:

heres a video of my rig with a non sealing home made headgasket you can clearly see bubbles in the radiator

take the cap off when its cold top off the radiatorvand squeese the hose a few times then run the engine if you have a bad head gasket it will look like this

 

 

Thank you so much! 

I'm pretty sure I'm out of trouble, I saw no evidence if bubbles in my first test but I will do more extensive tomorrow. 

So, fill the radiator right up to the top, start the engine and let it run for a few minutes, if the hgs are toast then bubbles will start ro come uo through the coolant? 

 

 

[ferp420]

yup

[el_freddo]

It’s also good to do the rad fill, run and bubbles check with the front of the vehicle on car ramps - it generally gets the radiator higher than the engine and can help with burping the cooling system. 

Cheers 

Bennie

[DaveT]

Yes, on a first refill,  there will be some trapped air that has to work out.  Even with a 100% good system, it can take a few drive cycles to get rid of all of the air.  The key is instant steady -  but it can even be very slow - stream, or just never stops. 

If you get to where it isn't bbubbling from a start, idleing, etc. Re check after a short drive.  Don't open the cap, only watch for the bubbles in the overflow at this point.  When you open the cap, you let in air.

 

Going forward, before each drive, check the level in the overflow, AND squeeze the upper radiator hose and listen for gurgling and the jiggle pin in the thermostat.   Note the sounds, and look for less gurgling each time, if everything is well sealed.

[divinicus]

7 hours ago, DaveT said:

Yes, on a first refill,  there will be some trapped air that has to work out.  Even with a 100% good system, it can take a few drive cycles to get rid of all of the air.  The key is instant steady -  but it can even be very slow - stream, or just never stops. 

If you get to where it isn't bbubbling from a start, idleing, etc. Re check after a short drive.  Don't open the cap, only watch for the bubbles in the overflow at this point.  When you open the cap, you let in air.

 

Going forward, before each drive, check the level in the overflow, AND squeeze the upper radiator hose and listen for gurgling and the jiggle pin in the thermostat.   Note the sounds, and look for less gurgling each time, if everything is well sealed.

Thanks, Dave! 

By the way, what is the correct part for the overflow bottle mine is missing and a temporary solution, an empty plastic bottle, is on board right now. 

[el_freddo]

MYs didn’t have an overflow bottle. An overflow bottle is only good if you have a coolant return cap. 

Cheers 

Bennie

[DaveT]

Oh,  hmmm...   If I had one of those, I would get an aftermarket recovery add on, and get the right kind of cap.  Thinking about it,  my 76 didn't have a stock recovery system, but I added one.  I ran 76 and 78 models until I got my 86, which was an EA82 engine and those come with oem recovery tanks.  

[divinicus]

9 hours ago, DaveT said:

Yes, on a first refill,  there will be some trapped air that has to work out.  Even with a 100% good system, it can take a few drive cycles to get rid of all of the air.  The key is instant steady -  but it can even be very slow - stream, or just never stops. 

If you get to where it isn't bbubbling from a start, idleing, etc. Re check after a short drive.  Don't open the cap, only watch for the bubbles in the overflow at this point.  When you open the cap, you let in air.

 

Going forward, before each drive, check the level in the overflow, AND squeeze the upper radiator hose and listen for gurgling and the jiggle pin in the thermostat.   Note the sounds, and look for less gurgling each time, if everything is well sealed.

Good news, I did an extensive radiator test this morning and the coolant is 100% clear and bubble free after running for ten minutes from a cold start, so it appears my hgs are just fine. 

What I did detect was the engine block getting hot to the touch, so I assume the coolant is nit getting past a stuck thermostat, new one on order. 

Are there any other tests you want me to run prior to changing out the thermostat?!