If the thermostat is original, it is certainly old enough to be bad.  OEM or the high end Stant thermostats are what I have used.  They will have the jiggle pin.

Normal operating temp is around 190 degrees, which is pretty uncomfortable to touch.

A meat thermometer is a low cost option for testing.

Not a test, but I want you to get a proper temp gauge. 

Did the thermo fan(s) cycle in that time? 

Cheers 

Bennie

On 8/24/2019 at 9:43 AM, divinicus said:

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?! 

Ok, I got new OEM thermoatat and housing and two new radiator hoses. Should I ask my mechanic to flush out the radiator when he installs? Also got a recovery/overflow tank and will install. Thanks again! 

It needs to be checked to be sure it is free flowing.  And the condition of the fine fins and tubes.

 

Also, if the hoses were original,  make sure you find all of the cooling system hoses,  and replace all of them.  New radiator hoses don't stop a bypass hose that's 30 years old from failing.  An EA82 engine has 7 cooling system hoses.   The older ones had 1 or 2 fewer.

Ok, thanks to everyone I am getting close to getting this engine cooling issue fixed. 

Two things left I need help with, please identify the two different parts needed, one is the thermo switch to turn on the radiator fan(s), and secondly, the sensor that will reactivate my temp gauge. 

Thanks again! 

Edited September 10, 20196 yr by divinicus
Spelling

The fan thermo switch is on the radiator.

The sensor for the dash temp gauge is a single wire sensor with a hex head, screwed into the intake manifold near the engine thermostat.

ALso make sure your radiator is grounded with the little ground wire at the top of the radiator to the upper rad support panel. 

Engine temp gauge sensor is a 17mm hex head  

Cheers 

Bennie

On 9/9/2019 at 10:24 PM, el_freddo said:

ALso make sure your radiator is grounded with the little ground wire at the top of the radiator to the upper rad support panel. 

Engine temp gauge sensor is a 17mm hex head  

Cheers 

Bennie

Hi Bennie, I was able to get both sensors, but the intake manifold temp sensor has only one spade lug on it, not two like the original and corresponding to the wiring connector. Can you advise? 

The engine sensor should only have one plug/tab. The sensor is grounded through the intake manifold and is basically a thermal resistor, the single wire is what goes to the gauge to make it do its thing. 

The radiator fan switch is also a single plug unit. It too is grounded but through the radiator. The other wire earths out the relay that triggers the thermo fan(s). 

If you have a two wire unit, it’s for an L series but will still work if you ground one wire - I’m not 100% sure if this is specific to one wire or either wire. If you’ve got this unit your radiator doesn’t need to be grounded. 

Cheers 

Bennie

The most basic, cheapest and easiest service item has been mentioned - the radiator cap. It not only meant to hold the wet stuff in, it holds in the pressure that builds up.

Increasing the pressure increases the wet stuffs boiling temp

If this ten dollar part has failed on you it will cause your problems described

You could possibly drive one of these EA81 for years and miles from new without a gauge and have no problems. Bit riskier trying at this age

I had the same issue with my 86 BRAT. A new radiator cap and a thorough Radiator flush did the trick.

I got the Brat over to my mechanic today. The radiator was leaking so I ordered a new one as part of this job. 

Question, since I am restoring the fan system, how are the two fans wired? Does the smaller fan operate independently? 

Thanks again! 

Hello all, 

Thanks for everyone's help! 

Got the car back from my mechanic, new radiator, thermostat, hoses, etc. System all flushed and running well *(not overheating). 

However, even with new manifold sensor installed, dash temp gauge still doesn't work. 

As an alternative, can't I just get an AM temp gauge and connect that up? 

Suggestions? 

Thanks again. 

Yes. I have run my EA82MONGREL for years without the factory water temp gauge.

Instead I use two metal temp gauges, one purely as a high temp alarm set to 96° C

They are simple, cheap, Chinese made and sourced 12V aquarium digital units with switching for alarm as I first mentioned, the second is my visible in digital numbers and also set to turn both fans on at 92°C metal temp

I used to run separate fan switching so I slow traffic just to manually turn one on, but two at same time have been working well, they cycle on and off pretty quickly

Great and thank you, can you semd links to those parts? 

How is the temp sensor attached to engine block? 

 

On my tablet I have no clue how to link. So go to your preferred online access to China, use search terms such as 12v aquarium digital temperature alarm and look through the million possible choices

Some are twin circuit, twin channel, some mains voltage get shoved into category so make sure you get 12v

They come with screw terminals to add a relay or buzzer. I use these to drive the relays 85, 86 switching.

I use the ones that are about 75 mm wide,25 high, come in matching grey body with red digits

The sender is about 4 mm diameter by about 19 long probe

You can just make a mount tab from some aluminium flat, 6 mm thick about 20x20, drill hole to suit probe tight fit, 8.5 mm hole to mount tab on thermostat housing hold down bolt or do two circuits, one on left head, other on right

Or get one of these: 

https://www.ebay.com.au/itm/Engine-Block-Head-Temperature-Alarm-ENGINE-WATCHDOG-TM1/132987012774?hash=item1ef6a4c6a6:g:JJsAAOxyk99R3NSK 

can do Fahrenheit units too. 

Cheers 

Bennie

2 hours ago, el_freddo said:

Or get one of these: 

https://www.ebay.com.au/itm/Engine-Block-Head-Temperature-Alarm-ENGINE-WATCHDOG-TM1/132987012774?hash=item1ef6a4c6a6:g:JJsAAOxyk99R3NSK 

can do Fahrenheit units too. 

Cheers 

Bennie

Hi Bennie, 

I like this solution! Where do you recommend the sensor gets mounted on the block, and in Fahrenheit, what is the safe range and upper limit that should sound the alarm? 

Thanks again! 

@divinicus - I’m sure you set the alarm to whatever temp you want. 

Find a bolt on one of the heads to use as the reference point, this is where the most heat is generated and where the coolant does most of its cooling transfer work (collecting heat). 

Cheers 

Bennie

1 hour ago, el_freddo said:

@divinicus - I’m sure you set the alarm to whatever temp you want. 

Find a bolt on one of the heads to use as the reference point, this is where the most heat is generated and where the coolant does most of its cooling transfer work (collecting heat). 

Cheers 

Bennie

Thanks, Bennie. 

So you mean anywhere on the block near spark plugs, etc. 

I found this unit made in Australia that looks good, also allows a second sensor to read temp at surface of oil filter. https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F163559066517

Which brings up another related issue. My Brat has auto trans. Doesn't the cooling system keep the tranny running cool? 

What maintenance and checklist is important here? 

Thanks again! 

There are uitsyou cagey to monitor the trans too. I wouldn’t bother with the engine oil temps as the idea of the metal sensor on the head is to alert you to high temps regardless of whether or not you have coolant. 

Find an in-used bolt hole on the head and use that. 

Cheers 

Bennie

I have had a couple of watchdog tm2 and at one tenth the price I like my aquarium units

Sensor location recommended by Watchdog is simply the thermostat cover housing bolts!

My gauges each run off both these bolts. The cam cases also often has spare threaded holes in them but that is thicker metal than thermo housing and closer to coolant

There is a lower priced engine guard also sold here in Aus for $100 I think

The watchdog us powered via cig socket , best if you hardwire. TM4 is a twin setting or twin circuit, can't recall

These Chinese units I make up been tested 150,000 km so far

Have a look in post called " Subaru Brumby not priming" it has a simple guide and photos for your temp gauge.

Thread started by Mike

Edited September 28, 20196 yr by Steptoe

Hi All, I'm installing the Australian-made high temp gauge which has two sensors, one is under one if the two bolts holding the thermostat body and the other will wrap aroumd the oil filter. I will start a new topic once it is set up. 

Not happy with the mechanic that installed new radiator and thermostat in my Brat. Now, although the overheating issues seem to be solved, the car is riding roughly and struggles to get to second and third gears (mine is an automatic). The tranny was working beautifully before this latest job. 

I also noticed one of the air hoses near the thermostat is not connected, but to me this is almost like a computer issue or loose connection. 

I did make sure that the tranny fluid was topped off. 

I'm wary about going back to the same shop! 

Thanks again! 

I think the more you take a specialist sort of vehicle to either wrong specialist, or an ordinary workshop - the more you will want to learn to diagnose, fix and maintain your beast yourself.

Maybe mount the oil filter sensor to a magnet to make oil changes easier. Grease monkeys likely to not expect an oil filter sensor. Do your own oil changes now.

An overheat often kills engines and transmissions. Maybe a compression test for engine now a good starting point?