Thermostsat Question

[CrankyAl]

Without getting into a long dissertation about my engine.....2.5L  98 Legacy GT wagon..... can I run my car with a gutted thermostat for a month or so. Hot weather now in Oregon, and more to come. I just want to know if it will damage anything. I imagine my mileage will drop because of the sensors wanting the coolant on the hot side,  but will anything else be affected?  Cat maybe?

[86BRATMAN]

you can, but what sort of issue are you trying to circumvent by removing the thermostat?

[CrankyAl]

Crap!! I knew this would take an explanation. Just bought a 1998 Legacy GT Wagon from a local small dealer. They advertised the car as having  new head gaskets,timing belt,idlers,cam seals, waterpump......etc. I asked the dealer about paperwork on the work done but really never saw such paperwork, just what they advertised in the paper and craigslist. I test drove the car 3 times during a weeks time.

All seemed fine.

 

Bought car, drove to work 35 miles away, and all seemed fine. Car seemed to be a bit hot so I popped the hood. Top hose hot, bottom hose cold. About 1 inch more water in overflow bottle. No over heat showing on gauge. After it cooled the extra water disappeared from the overflow bottle. Drove home, same thing. I read many posts about headgaskets ,thermostats, radiator caps, mucho etc.....

 

I checked the thermostat and yup, aftermarket. Changed to Subaru thermo, Subaru radiator cap also. Refilled slowly with burp screw on top of radiator open. Ran the car to temp and the bottom hose finally got hot. Eureka!!!! Car cooled for a few hours and I went to town for chinese takeout. Got home and top hose hot, bottom hose cold with about 1.5 inches more water in overflow. bottle. Crap!!

 

Fans always came on, no bubbles coming out of coolant. Re-burped engine 2 more times....Back flushed radiator and very good flow.

Still no joy. So I just thought maybe gut the aftermarket thermostat and put it in so I at least can drive the damn thing. Maybe drive it to GD in Portland or Gloyale in Corvalis if either of them have time to check it out, I don't have anyone in Bend I would trust and my mechanic skills are going downhill because of lots of pain issues crawling around on the floor to work on cars.

 

The coolant is clean, used the chemical test for hydrocarbons in coolant, negative (for now). Heater blows hot.

Edited July 15, 2013 by CrankyAl

[CrankyAl]

Thanks 86Bratman, but will running the car without the thermostat cause any damage to the engine such as plugging up the cats? It seems to me the car may run a bit rich or am I erroneous in my thinking?

[86BRATMAN]

It almost sounds like there has been some stop leak or something ran in the car, was there any kind of build up on the thermostat when you took it out? 

 

Did you refill the engine through the top radiator hose into the engine or just fill the radiator.  You could still have some stray air pockets in there.

[CrankyAl]

Read my post above about the the supposed work done on the car. The thermostat I removed was clean as well as the radiator cap. The overflow bottle was clean, no oily residue, no bubbles.

 

I did fill from the top hose. Very slowly, then the rest via the radiator. I realise I probably have air issues but I am getting frustrated after so many attemps at filling it properly, if I could just get the POS to Gloyale or GD,  folks I would trust, then maybe they could figure it out.

 

I gutted the aftermarket junk thermostat but have not installed it yet. I wanted an answer about other damage it might cause to the engine. I am going to do the REALLY SLOW fill via the small diameter hose while I go and watch paint dry.

 

BTW when the engine heated up I never saw the gauge peg, just start to rise when I would shut the car down.

Edited July 15, 2013 by CrankyAl

[86BRATMAN]

I didn't see any mention of whether or not the thermostat had anything on it, just trying to cover any potential problem bases. 

 

 

There should be no real damage done to the engine by running no thermostat for a short while, I wouldn't recommend prolonged running without it though.  But I've seen it done to mask the overheating on a blown head gasket ej25 a few times in my life, usually when they are being sold or traded.

[manchuscout]

Honorable Subaru Master, I have nearly the same problem. Last September discovered head gasket leak. Tried to plug with "Alumaseal Stopleak." (Stupid idea)! Problem persisted. Three weeks later I flushed cooling system & tried to plug leak with "Bar's Leak Head Gasket Repair." Leak seemed plugged, but 8 months later engine overheated & radiator coolant was discovered to be way too low. Replaced coolant, kept radiator filled on inspection. Ten days ago added Subaru Cooling System Conditioner. Coolant began backing up into coolant reservoir, nearly filling it to the top every 75 miles, with foam floating near the top. Five days ago tried using "BAR'S LEAKS Head Gasket Repair." Looked good! No steam or water exiting tailpipe, and level of water in coolant reservoir remained steady — BUT — was only able to get 4 quarts of fluid into radiator! Engine now overheats in 15 minutes. Removed thermostat — no change. Top radiator hose hot, bottom hose cold. My guess — I plugged radiator with all the gunk I poured in. What's your guess? Can I flush that crap out with some commercial additive, or should I just get a new radiator?

Edited July 15, 2013 by manchuscout

[mikaleda]

I would put a new radiator In and do a system flush.

The main reasons for not running without a thermostat for prolonged periods are

#1 if you are using multi viscosity oil it will never get up to the right viscosity and could possibly put increased wear on the bearings.

#2 carbon buildup running cool can make combustion less efficient causing carbon buildup wich in turn could clog your cartilitic converters

#3 the reason for the malfunction of the thermostat could be a head gasket failure and prolonged running like that could cause excess damage

I just thought I would answer your original question

[CrankyAl]

Well folks, The on going saga of the 2.5L in my 98 Subie. I did gut the thermostat just so I could get to work 35 miles away. Top hose hot, bottom hose hot...finally. Drove to work and gauge seems to stay in normal range. Open hood when I get to work and ta da there

be the dreaded bubbles coming into the overflow tank!!  Yup, brand new headgasket repair already blown....I don't even have 600 miles

on the rig. I took it to the mechanic that supposedly did the work and he said that the heads had been surfaced and that he used a gasket set from the Subaru stealership. He said he did a complete gasket reseal including the rear main. I asked him about the oil separator plate and he looked at me like I was from another planet. These mechanics work on all cars and don't know about Subarus in general. The dealer said that they would honor the repair but I do not have a warm fuzzy fealing about the mechanic or the repair....not from these guys. :-(((

[Fairtax4me]

I don't see the problem.

The car isn't overheating, the extra coolant in the overflow when hot is NORMAL. The system pressurizes as it gets warm, which causes some of the coolant to push out into the reservoir. When the system cools that coolant is drawn back in. This is the whole reason WHY there is an overflow reservoir.

 

The lower hose is cold because that's the OUTLET from the radiator, which is what COOLS the liquid.

 

None of this means coolant is not flowing, and if its not overheating, or even running slightly warm, I don't see the issue.

[CrankyAl]

Fairtax4me,     Where are all the bubbles in the overflow tank coming from then? After I gutted the thermostat and got circulation the bubbles appeared in the overflow tank. I rev the engine and a lot more come bubbling up. At idle the bubbling is less. I did not have bubbling before gutting the thermostat.

[Fairtax4me]

So you gutted the T stat, filled the system, and drove 35 miles. Bubbles after all that is not a good sign.

 

If the system is definitely full (holds something like 1.5 gallons) any air bubbles should work out if you leave the cap off and let it idle for a few minutes. With no t-stat any bubbles should be free to escape because coolant flow will be unhindered, so any new air entering the system is almost certainly coming from the head gasket.

 

There are plenty of places for bubbles to hide in the engine and heater core so make sure to bring engine speed up a little to increase coolant flow while purging the air. If after 10-15 minutes there are still large bubbles then its time for head gaskets.

Edited July 19, 2013 by Fairtax4me

[CrankyAl]

On the way to work I pulled over several times to check for bubbles. I saw them everytime. I drove back home yesterday and pulled over several times and bubbling away. Got home and bubbling away. When I refilled I did the long slow watch the grass grow way. Coolent refill bottle on top of the strut tower and a 1/4" hose. Nose of car up. With the t-stat gutted the coolant just spews out of the radiator!! when running the engine with cap off.Had to refill and let car sit for awhile then recheck level of coolant. Gauge come up to temp real fast now,but I figured it would without a t-stat.

 

Not real sure what LARGE bubbles are. the ones coming into the overflow tank are about 1/4" in diameter. Less at idle and when I rev engine after a 1 second lagtime a nice stream of the suckers come a-bubbling out.

Edited July 19, 2013 by CrankyAl

[mikaleda]

Yep sounds like a head gasket, something went wrong.

[CrankyAl]

Ahhhhhh, more to add to the Subie saga! The small car lot where I bought the 98 Legacy said that they would honor the 3 month 3000 mile warrenty. The chief cheese mechanic ran mutiple tests on the engine ( leakdown test, compression test, even the chemical test) and said all is well. I told him the most of the tests don't indicate a blown head gasket. He said I was plenty dumb about cars.( In another life I was a mechanic). I wanted him to go for a ride with me to get the engine to temperature and check the overflow tank after

I pulled over by the side of the highway. Said he didn't have time for that. Ughhhhh! I will try to get in touch with Gloyale in Corvalis or General Disorder in the Portland area to see what their time schedual might be to get anothe opinion, if I can drive the car that far. 130 miles to Corvalis and 160 miles to Portland.

Thanks to the forum and all the help, you guys are the best.

 

Allan

[mikaleda]

Wow I'm sorry to here your bad luck it sounds like they don't want to honor their warranty.

[CrankyAl]

Yes, it sure seems that way. The easiest test of all....go for a warmup drive and check the overflow tank with engine still running and watch the bubbles spring forth. The mechanic refused to do that, even suggested that I get a new radiator cap!!!! I just put a new Subaru cap on. So that tells me that they do not want to honor the warranty and do the headgasket work again. Geeze, what a crock of crap!