Temp Issues.

[CzarMohab]

So I found that leak in the coolant I mentioned before. The outside temps have been raising recently, and as it turned out that had a detrimental effect on my engine's ability to cool itself at idle. Why idling at 800+/-100 is hotter than 2700+/-500 while driving, considering the problem, is beyond me, seeing that my Thermostat wasn't passing any coolant, as indicated by a recent 30 minute hot idle and local differential temp test.

 

The start of this investigation was 2 almost super-hots in drive-thrus, though I normally shut her down anyway when the lines are long. It never got above the last line before the reds, so not that hot. Both shutting down and driving on cleared them up, and normal op temp (NOP) is usually mid meter or mid-low (I have the digital display and I am looking to do something about the accuracy later).

 

Getting home was ok, and once it cooled enough, I poked around and found nothing of note. I did do an op-check and bench test of the aux electric fan, which failed, but it turns out that it didn't matter.

 

That was 2 days ago, though I did replace the aux today, and when I was in the in car test phase, nothing happened, and I did let her idle for about 30 min, watching temp creep up to the turn off line (one before red) with AC on max, min, and off, and nothing.

 

I shut her down and went inside to get my digital optical thermometer and started it up again and traced the hoses, block and radiator by temp and I was amazed. D-temp of the heater hoses was approx 30F, so if nothing else, I can pull 30F off. D-temp of the block side of the thermostat to the radiator, however, blew my mind, as it was almost 120F!! The coolant in the radiator was a whopping 76.5F at both hose connections. The top of the thermostat housing was only 86F and the block side was about 180 (dropped the thermostat, it lived)...

 

While it was hot idling, I noticed that the hoses swelled... alot... and the increased pressure caused a small seeping leak at the upper hose/radiator junction. Tightened the hose clamp and that leak stopped. Hope it was the big one.

 

Removed and bench tested the thermostat (boiling water test) and it started to open at about 190F but I never saw it more than crack off of its shut seat, i.e. it only started to open, never finished. I tried the test again after squeezing it a few times and the same results.

 

So now you've read my saga. Sorry to be so long winded, but I try to cover everything. Now for the part where I ask you nice people for some info and advice.

 

1.) Is there a best type of thermostat I should use?

2.) Perhaps one that will last longer than 1000 miles?

3.) Just to satisfy my own curiosity, does the flow go from the thermostat to the block (down) or from the thermostat to the top hose (up)? Up makes sense to me, but it would not surprise me if it went the other way.

4.) So why is there enough engine cooling at highway speed and not at idle if the Tstat is hosed?

 

Think thats it for now. Thank you for your time! To date, you all have answered every one of my questions, and for that I do thank you all!

 

:headbang: :headbang:

[misledxcracker]

Use an OEM thermostat.

 

Thats what everyone says anyway, I havent changed mine personally.

[daeron]

higher engine RPM means higher water pump RPM, which means its pushing it through the thermostat with more force. Also, as you pointed out, your auxiliary fan was dead.. so at idle, there was only a limited amount of air moving over the radiator.. normally, the thermoswitch cuts the aux on whenever it reaches the tempo threshold, and the aux fan helps keep it below that threshold.. on the highway, you dont need ANY fan; the car is moving more air than the fans could ever DREAM of..

 

You mentioned the electric fan failing; does the fan function when you give it 12 volts? IF the fan itself DID function, don't forget that the little thermoswitch that mounts in the radiator that controls the fan coming on frequently fails; I just bypassed mine with a jumper wire in the car harness plug which leaves the fan on all the time when the key is on. If the fan failed to function with direct 12V (i think thats what you meant but I wasn't entirely clear) then a replacement is likely all you needed, as far as THAT goes.

 

You might want to try running without a thermostat for a while and see if it cools adequately, and whether it leaks or not.. I say this living in the tropics; but its not a good idea to do forever.

 

The subaru OEM thermostats are generally recommended as the only ones to rely on; but I dont have anything in there. Again, I am in the tropics.. I know there are a couple of good arguments for me re installing one, but its not important enough to me right now.

 

The coolant flows up through the thermostat and into the top of the radiator; most cars have hot coolant going into the top of the radiator rather than the bottom, so the heat doesn't soak up into coolant that has already passed through half the radiator and lost most of its heat. Hotter coolant on the top, cooler coolant on the bottom is the rule of thumb.

 

I think that covers most of your questions.. I would recommend feeling your radiator coils for any uneven temperatures, to make sure there arent any clogged spots.. The cooling systems on these cars are the achilles heel.. protect at ALL costs!! Is this a turbo car?? if it is (or even if it isnt) you *may* have given it close enough to an overheat to make the headgaskets unhappy.. I hate to tell you, and you may just as well be safe, but be aware of that possibility in the future. For now though, it sounds like maybe a new OEM thermostat, and a properly functioning auxiliary fan, should have you going again

[Bucky92]

+1 for what dearon said...since I just went threw the same thing with my XT6..this is what I have done to cool it off..removed the thermostat..( cooled it right off cept in long idle it would still start to heat up...flushed the cooling system...removed the radiator and checked the fins and cleaned out any garbage that desided to live between them...my thermosensor for my one fan is bad so I just jumped my fan switch to run all the time when thecar is running....nice and cool now...no heat but its finally warm out...waiting for an OEM thermostat right now and will get a new thermosensor soon

[daeron]

and just to clarify.. your engine has a total of three temperature sensing components.... these are what they are, and their most common technical names as they relate to the subaru, its manual, and the people who work on them...

 

1. Coolant Temperature Sensor (in other vehicles sometimes referred to as thermosensor) or CTS; this is mounted in the thermostat housing, has two wires on it, and tells the ECU how warm the engine is;

2. Thermoswitch- this is mounted in the radiator, has two wires, and is just an "on/off" switch that closes at a set temperature to turn the auxiliary fan on; (this is the switch I recommended bypassing if your functional fan doesnt come on "at temperature)

AND

3. okay I cant recall the utterly unambiguous, technical term used in the FSM for the temp sending unit for the dash temp gauge.. but you get the idea for this one :-p

 

I dunno, I just figured I would make that abundantly clear. Please forgive me if I am teaching you things you already know

[Gloyale]

3. okay I cant recall the utterly unambiguous, technical term used in the FSM for the temp sending unit for the dash temp gauge.. but you get the idea for this one :-p

 

QUOTE]

 

This one is called the Coolant Thermometer. Makes sense because all it does it take a temp and display it.

[Durania]

OEM thermostat and gasket all the way! I changed mine out two weeks ago and it does sweet, the gasket doesnt have to have any junk put on it cause it will seal itself once the motor gets warm. Buy buying one from autozone you get a thermostat that can fit everyone else's cars and having just a random operating temperature. Buy using a subaru one you it is made specifically for your car. Only about 17 bucks for mine.

[CzarMohab]

This Tstat came with the car, all nice in its wrappages, brand new... I figured that eventually it would need to go in. And when I finally looked, there wasn't a pre-installed Tstat to begin with, so in this one went, and now all these issues. All I wanted was a working heater...

 

I was pretty sure coolant went top down, makes sense from a thermodynamics point of view.

 

The old aux fan failed the 12v test, and I rescued a "new" one from a dead GL that passed the 12v. Before condemning the old fan, however, I verified that there was an electrical current at the plug when the radiator was actually warm (which is why the Tstat was not my first suspicion). Even tested to verify current to the fan (pass) it just didn't turn. After installing the "new", I tested the old one one last time and after a second or two, slowly spun up and then whirred like a top. Go figure.

 

So this OEM Tstat... Is that a dealer item? or is there a brand that would fall into OE? and what is a good temp range? I don't have the book handy at the moment, but 190F? 180F?

 

Thanks again!

[Tom63050]

So this OEM Tstat... Is that a dealer item? or is there a brand that would fall into OE? and what is a good temp range? I don't have the book handy at the moment, but 190F? 180F? Thanks again!

 

Just get one from the dealer to be sure. 190 degrees. A 180 won't give you good enough heat in the passenger compartment in the winter (so I hear).

[sube92]

Wow you wrote alot.

 

Overthinking is never like overcooling...

 

anyway,

the ea82 subes are very simple.

the water enters the pump from the bottom radiator hose drivers side, it pushes it into the block, heads and rises out into the intake, the heater core back to the thermostat housing to do it all over again. Can't forget that little hose from the center of the block that also returns to the thermostat housing. It plays with itself until it realizes there is a flow. The playing is the bleeder of air bubbles. Listen to the thermostat housing while it is running. even the tightest of ea82s give a squishy sound until contently open and flowing.

So now there is 4 different pressures to play around with the thermostats stubborness. they still get stuck. A new one by any brand claiming to fit is a good one. I found "Stant" thermostats are simple, weak springed and allow flow sooner. There are not many probs that cause a demand for alot of air and hot idle:

1. clogged radiator

that is really a tricky one. when runners in radiator are cool they are smaller, not flowing as much. Easy to check, just reach hand in after wot and find the cool clogged ones to see if they really are.

2. Heater core can be plugged and still not be a bother if all other parts are good.

3. the gaskets stretch under the intake. It prevents cool air for cylinders and hinders coolant. A double negative. (my guess is that is the problem).

4. All carbed subes without a clutch fan like a Loyale ought to have one. Now that they are 20+ years old (most of them), give the little buggy what it has always deserved and install one from a Loyale.

5. Hot firing plugs on a retarded timed engine (very thumpy idle) aren't helping unless all else is good.(rare prob)

6. Flushing the sytem is always good.

 

I have run these half full of coolant and realized it ran better due to the fact the intake wasn't filling up with hot fluid, allowing more cool air into the cylinders, giving it more power and to breathe. They battle themselves with just one of the problems above and make it seem worse than it isn't.

 

normal stuff like thermostat, first thing, should take you to more complicated quests to resolve if it didn't fix it.

Oh: Don't Ever Use "Sierra" brand coolant. (it has a mountain pictured on the jug) Horrible Stuff.

I have never found another brand that didn't work great but that stuff.

[Gloyale]

2. Heater core can be plugged and still not be a bother if all other parts are good.

 

Yeah, but that wouldn't cause overheating. The flow through engine would still be fine, although the radiator would likely be clogged as well in this case.

3. the gaskets stretch under the intake. It prevents cool air for cylinders and hinders coolant. A double negative. (my guess is that is the problem).

I just don't understand what you mean here. If the gaskets where leaking he would be burning coolant.

 

4. All carbed subes without a clutch fan like a Loyale ought to have one. Now that they are 20+ years old (most of them), give the little buggy what it has always deserved and install one from a Loyale.

Just a guess, but being a GL-10, his car may be SPFI,MPFI. And if it has a/c it should already have a clutch fan. I assume it does, because he refered to the Elec fan as *auxillary* I'm not sure but i would think Loyales without ac would not have a clutch fan.

 

5. Hot firing plugs on a retarded timed engine (very thumpy idle) aren't helping unless all else is good.(rare prob)

6. Flushing the sytem is always good.

This would show up as overheating under load, not at idle

 

I believe you're problem is with the fan thermoswitch.

[CzarMohab]

Reinstalled new Tstat, a 180 to be sure (they told me OE was 195, go figure!) and it passed most of the tests I put it through, which leads me to suspect other problems associated with the whole coolant system.

 

At slow (normal) idle, I didn't notice anything abnormal, the digital thermometer I had handy read 155F on the block side of the T, 150F on the rad side of the T, 120F on the hose, and 130F entering the rad. I'm assuming that there is obviously a 30F drop across the metal(s) and including a discrepancy in the thermometer itself. And of note, I was not in the car at all for this part of the test, but I didn't note anything abnormal.

 

Driving from cold iron, however, led to the wierdest thing i've ever seen: Temp rose to 1 line below the red, then dropped to 1/2 like a rock, before I could do anything. A second test was needed and after a stop to eat and spend some quality time with the wife, I got to perform the cold iron Tstat test again. Obligingly, this was an exact duplicate of the previous test, in just about the same amount of time. I can only assume 2 things then. 1) that line #7 on my digidash's temp gage = Tstat open, and 2) the thing is snarfed.

 

I've read the above, and thought of some things for myself, but can someone point me to the right direction to start? The Tstat works, proven by hard data. Is it possible that the Temp gage thingie (I guess it is a meter) is actually messed up and I really don't need to panic so much?

 

Similar but different topic, the aux electric fan (in my case the only electric fan) isn't working when installed. Troubleshooting reveals its not well grounded. Where's the ground wire at and could I jumper around it?

 

Thanks again!!!!!!

[daeron]

if memory serves, the thermoswitch wire is the ground wire.. check with a multimeter first, though.

 

Seriously, since its summertime anyhow I would just jumper the thermoswitch so that the fan is always on with the key.. foolproof and darn near failure proof.

 

As has been stated, OEM thermostats are the only ones to trust reliably.. some may say otherwise, but what is your experience telling you? I must admit that my only experience with a thermostat was a failed one that was there when I got the car, and another failed one that was a stant replacement. Now I have nothing; so I can't REALLY vouch for the goodness of the subaru part.. but get it from the dealer. Until then, pull your thermostat so you know you arent having OTHER problems.

 

ALSO, with our lovely digidashes, the temperature gauge can be INCREDIBLY off from a poor grounding connection inside the dash, or a crummy wire connection going to the gauge itself. In other words, now that the car is 20+ years old, voltage variances (ie, added load from turning on the AC, say) can make the gauge read a hot condition when the car isnt spiking in temp at all. Once again, this is hearsay.. BUT from reliable sources. Don't ASSUME that is what you are seeing; but keep your thermometer in the car and next time you get a hotspot, pull over, pop the hood, and check it out to verify that you are in fact seeing a spike in coolant temp.

[Gloyale]

My 86 digidash, the temp meter would *disappear* then come back on. It never showed hot. Even when I know the car was. BUt it sounds like yours is working. I would for sure use an oem thermostat. Any other kind I've used, i get either the same as you where it takes alarmingly long to open, and the car gets hot first. Or they just stay open and the car stays too cool.

195 is OEM for non-turbo cars. 180 is sometimes spec for turbo. But not according to FSM, it says all are 195.

 

Adn yes, the ground for the electric fan is provided by the thermoswitch.

[Sonicfrog]

I'm late to the party, but have had overheating issues with Murphy, the $500 87 T-Wag. I had similar issues with heat fluxuations on my meter. It would kinda wonder around, never staying in one place for too long. Plus I was blowing through cooling system hoses like crazy. Turns out my radiator was a bit on the clogged side, and since I had the crappy 3 speed auto tranny, which makes your engine run at high RPM's all the time, I was building up way too much backpressure in the cooling system. The EA82 T is not very forgiving of overheating, and I learned the hard way - blown head gaskets.... twice. If you haven't already done so, I would highly recommend replacing your radiator with a dual core type. This may go a long way to resolveing your temp issues.

 

PS. Oh, watch for the little coolant hose right under the turbo. I had a leak in that one once. The leak was hard to spot since the water was squirting on the hot block and evaporating before it could drip to the ground, and that hose is a beyatch to get to - have to remove the turbo - no short-cuts around it.

[Gloyale]

PS. Oh, watch for the little coolant hose right under the turbo. I had a leak in that one once. The leak was hard to spot since the water was squirting on the hot block and evaporating before it could drip to the ground, and that hose is a beyatch to get to - have to remove the turbo - no short-cuts around it.

 

Yeah those turbo hoses are important to check on. You can get the lower coolant hose of the turbo without removing it. You gotta take off the sheilds, and get at the screw from behind the turbo. It's not too hard if you already know how everything is plumbed back there. If it's you're first time, probably best to remove the turbo to get a hands on look at everything back there. Then that makes it easier next time.

[CzarMohab]

I am beginning to hate my car... At least, the coolant system.

 

So a dual core rad, huh? Might help.

 

Aux fan's ground is it's thermoswitch, but I know the switch works (it sends the signal) so how do I reground it?

 

Anyone know where the temp sending probe is located? is it the probe-thingie on the side of the Tstat housing? Haynes says "right side of the intake manifold" but thats at least 1/3 of the engine... Also says see ch. 4A, Fuel systems- carb'd models...

 

I won't condemn the rad just yet... I know that there is flow, and everything worked just fine before. Despite a small blemish on the eng side the vanes are great. and coolant gets cooled there, 160F (Tstat housing top) in, 100F +/-10F out (H2O pump out).

 

I'm seriously hating this, as when the last "hotspot" happened, everything I temp checked was less than 180F... I hope its just a bad wire and I can get on with my life. :confused:

[daeron]

the gauge temperature sender is a one wire sender, on the passenger side of the manifold, on the back side... there aren't too many one wire items that it could be confused with, and none of them appear to protrude into a coolant passage.

[CzarMohab]

Looks like I'd have to pull the air intake thingie (the shiny "Subaru TURBO" thing) to get to it. Am I right? If I am, then at a recent "hotspot" my hand held thermometer read 172F, and I give it +10F error and +10F or so for losses in the metal, so 190ish in the coolant there? I think I'm just going to pull the Tstat and go without until I can fix everything else.

[Gloyale]

Looks like I'd have to pull the air intake thingie (the shiny "Subaru TURBO" thing) to get to it. Am I right? If I am, then at a recent "hotspot" my hand held thermometer read 172F, and I give it +10F error and +10F or so for losses in the metal, so 190ish in the coolant there? I think I'm just going to pull the Tstat and go without until I can fix everything else.

 

No, the one that sends to the gauge is on the front side of manifold, underneath and to the left of the therostat cover. Between it and the dipstick. It is right up front and easy to access. The one for the ECU is the one in the back, and you don't have to remove anything else. Although the EGR thermoswitch is really in the way.

[daeron]

No, the one that sends to the gauge is on the front side of manifold, underneath and to the left of the therostat cover. Between it and the dipstick. It is right up front and easy to access. The one for the ECU is the one in the back, and you don't have to remove anything else. Although the EGR thermoswitch is really in the way.

D'oh! Now *I* am the retard, huh? Or (in THIS thread,) should I say, "I'm not that cool"? I wasnt thinking about a turbo car, I was picturing it on mine.. and I guess maybe I could even be wrong about that..

[CzarMohab]

I can't deal with it anymore hehe

 

I'm taking it to "Arctic Radiator" here in town, they have equip I don't to better poke and prod. I need to go there anyway to price check a new radiator... $170 at the auto store... thats going to be my last resort.

 

I also looked into the possibility that the water pump might be going bad. I don't think I should be able to move the pulley up, down, left or right... it might be that beastie going too... $47 at the auto store, +$7 for the good gasket and +2 for the good sealant...

 

I haven't been able to test the temp sender yet, partly because I don't have a multimeter, partly because I haven't yet found it. $20 per sensor, plus $20 for each other sensor, like for the aux fan...

 

best case scenario: it fixes itself.

Worst case: $300 in repairs on an $800 car.

 

Time for bed, and to hunt up cheap parts just in case.

Thanks for the help all!

[Sonicfrog]

I can't deal with it anymore hehe

 

I'm taking it to "Arctic Radiator" here in town, they have equip I don't to better poke and prod. I need to go there anyway to price check a new radiator... $170 at the auto store... thats going to be my last resort.

 

I also looked into the possibility that the water pump might be going bad. I don't think I should be able to move the pulley up, down, left or right... it might be that beastie going too... $47 at the auto store, +$7 for the good gasket and +2 for the good sealant...

 

I haven't been able to test the temp sender yet, partly because I don't have a multimeter, partly because I haven't yet found it. $20 per sensor, plus $20 for each other sensor, like for the aux fan...

 

best case scenario: it fixes itself.

Worst case: $300 in repairs on an $800 car.

 

Time for bed, and to hunt up cheap parts just in case.

Thanks for the help all!

 

Look online for dual core rad. I got mine for $139.00

[mikeshoup]

I also looked into the possibility that the water pump might be going bad. I don't think I should be able to move the pulley up, down, left or right... it might be that beastie going too... $47 at the auto store, +$7 for the good gasket and +2 for the good sealant...

There's at least one of your problems. A good waterpump won't have any play in the shaft. You need at least a new water pump.

[daeron]

I made a nice long post in your other current thread, where I suggest resealing the oil pump and replacing the water pump and oil seals when you do the T belts. This info about your water pump is more ammunition in favor of my suggestion. If you blow your water pump, you are very likely to overheat; if you overheat, you are VERY VERY likely (almost certain on a high mileage engine) to blow a headgasket.

 

oc fourse, in all honsety I couldnt afford water pump when i got my car for replacing the timing belts.. so I didnt heed my own advice at the time.. and eventually blew a water pump, then my headgaskets.. and I am just one of countless tales of this ilk here at the USMB. Its what makes a subaru (of the 80s) a subaru (of the 80s)