hi everyone.  i am losing a lot of coolant in the 1986 dl wagon.  the temp gauge does not go to overheat.  what could cause that?  could it be a hose.  i don't think it is the head gasket since it don't overheat.  going to check hoses and the recovery tank.  maybe water pump?  any ideas.

 

 

Try filling up the radiator and pressure testing the cooling system. If you don't have a pressure tester and can't borrow one try running the car at idle with the radiator full and the cap on. Watch for any leaks as the pressure starts to build up in the cooling system.

I’ll try that. When I just check the reservoir was empty.  Only drove it about a mile.  I can see coolant in the radiator when I remove the cap.  

there is a little coolant hose under the intake manifold. check that if it’s leaking there it’s very hard to tell

I’ll check tomorrow. Thanks.  

Ig it has an EA82 engine,  there are 7 cooling system hoses.  Check all of them.  Check the radiator.  Check the water pump.   There should be very little to no air in the radiator.  The best way to check the coolant level in the radiator is sharply squeeze the upper radiator hose and listen for gurgles and the jiggle pin.   Cold engine, off.  Opening the radiator cap allows air into the system,  and you cannot monitor the quantity of air if you break the seal while trying to check.

Beginning of headgasket failure is most often coolant missing slowly. ,  as it progresses, bubbles in the recovery tank. .  Once you get over normal temperature while low on coolant,  the failure rapidly gets worse . 

Until you find and stop the leak, check the level and air before each start from cold.  If you use the temperature gauge as a coolant level checker,  you will be needing headgaskets. 

 

probably only leaks on the highway when its the hottest and highest pressure in the system, took a few days to find my leak since it would only occur in those circumstances, turned out to be where the radiator fins and side passages meet up at, weird one.

pressure testing it would work to eliminate that too like Crazyeights mentioned, and any pinhole leaks on any hose.

Why doesn’t it overheat? 

Lucky so far....  once there is enough air in the system, it will go over normal temperature.   Then it's too late.

Also, if the radiator is older than 5 years, carefully inspect that the fine fins are attached to the flat tubes.  Especially if you are in snow country. 

Don't rely on the temp gauge!

get an accurate aftermarket one that actually gives you a temp reading/value. 

If you miss the "heat spike" on the factory gauge it'll then show as running cooler than normal - because it's no good at reading the temp of steam... Job done by then too.

Cheers

Bennie

it's not overheating because it hasn't lost enough yet. 

 headgaskets don't always cause overheating, that doesn't mean it isn't the headgaskets but don't rule out anything just do proper diagnostics and look for the leak.

besides just leaking externally, it's not the water pump, highly unlikely on Subarus. 

keep looking for leaks.  pressure test it.

EA82's have a shared coolant/air passage at the intake manifold gasket on top of the head.  if that gasket leaks coolant will leak internally, use coolant, and you'll never see it. 

i'm unsure how to confirm that as a leak source though.  does anyone know a good way to test for this?

If the intake gaskets are original,  they are probably leaking by now.  If you replaced them with anything other than oem from a dealer, they will fail in a fairly short time.   Ypical way I decide to dissasemble to check those is after verifying that I cannot find any other seeping leak, and that I am not getting exhaust gases pressurrising the cooling system. 

 

The best way I have found for removing the 6 manifold bolts without snapping one is to drive until the engine is at normal operating temperature,  then park it in the garage and immidiaty and carefully remove the 6 bolts, while everything is hot.

 

therE is a hose under the carburetor that is leaking. Going to replace a few other hoses that are stiff. 

That's one of the first hoses I swap out with the EA81 and EA82s.

there will be another similar sized hose on the other side of the carb that taps into the heater coolant circuit. Change this one too otherwise it'll be the next source of your frustrations...

Cheers

Bennie

 At this age you can find the mild steel barbs the hoses fit to can be corroding away so even a new hose won't fix it.

 

Some drill mild steel out and taper tap 1/16 bspt or 1/8 bspt to add brass or stainless barb to carry on the job

 

Using coolant instead of muddy water is always best to help identify leak sources.

Temp sender unit. replacement is good idea too if you can't add a digital gauge to measure block metal temp