Cooling System Problem!

[MI55DK]

Ok...so please bear with this lengthy post, but I'm hoping to get an inkling of what's wrong before I go spending lots of money when I might not need to.

I bought a 1998 2GEN last week and the coolant was putrid. I drove it to Newcastle from Sydney and then to Singleton where we did a service on it (Spark plugs, oil, coolant/flush, air filter, 2 belts and fuel filter.) I then drove it to Buladelah and back to Newcastle. No problems so far. (It had two ECU issues, Knock sensor and Oxy Sensor)

Then I went to work on Tuesday and went home, my temp gauge shot up. So I limped the car home after letting it cool down (At no point have I driven the car whilst it has overheated). We fixed the Oxy sensor and then the thermostat (it had been snapped off). Took the car for a drive and on different angles, the gauge would rise and fall. I figured it was an air lock...The car when it said it overheated wasn't actually hot, I could touch the coolant and the radiator cap without any problems and the engine didn't feel hot enough. I had the radiator then bled and a pressure test and dye test done by a Subaru wrecker and repairer. He said the Dye test and pressure test came back fine (so it can't be the head gasket) and with a prayer, it was just an air lock.

It's not an air lock.

The coolant is pushing into the overflow bottle and going a short distance (about 10km), I am needing to put in 2lts of water back in. There is no leak, and the Mechanic said that the engine might be stuffed if the other person or I overheated it. (said there were only two ways to kill a Subaru, no oil, no coolant.) To me, this didn't make sense since the problems have ONLY arisen since we did the service. Today, I drove around, and same problems as before...and it seems to be on angles that it does this, not to mention the temp gauge is dropping within less than 5 mins for me to drive it again - again, it isn't hot enough to actually be overheating.

I have changed the radiator cap today, and I am now thinking it is a block in the radiator because I sat the car in my garage and revved between 4-5 thousand revs and had the air con on 18 degrees....no changes in temp. Now, it might be the sender, but that doesn't explain the coolant pushing into the overflow bottle and spewing from there.

I'm guessing, water pump or radiator. Although if it was the water pump, wouldn't the water be pushing from the easiest spot, the motor?

Thoughts? Experiences? Anything at all??

My next step is to change the radiator...and if that doesn't work (set the car on fire)...to save up and do an engine swap.

[teK--]

Exact same thing in my gf's car. I flushed out brown putrid coolant. Weeks later water pump leaked badly and radiator blocked up. Turns out my favour flushed loose lots of built up corrosion which was keeping pump watertight, which then went on to block radiator core.

[MI55DK]

teK,

Did you need to replace both or just one??

And thannnnkkkk you!!! I was thinking radiator!

[teK--]

Had to replace both radiator and water pump. Luckily head gasket ok.

[mattrx]

hay all
i have had the same drama with my 2nd gen libby.. after replacing the radiator and coolant it kept overheating.. but the engine wasnt to hot to touch so i don't think it was getting anywhere near as hot as the dash was saying. i have no idea what to do with it.
any ideas?

[Dropz]

I have seen this a few times at work and on a mates 1GEN.

I've found 2 reasons, A: The thermostat is faulty and is stuck closed.
B: The thermostat was not put in the right position. The little bleed hole in the thermostat must face the front of the car (if mounted under the engine), or upwards (if on the front of the engine).

Other reasons could be a blocked radiator, or an air lock that won't bleed out.

Have you bled the coolant through the bleeder screws? (only some Subarus have bleeder nipples) They are either in the heater hoses, or on the drivers side of the radiator top tank.

When bleeding the coolant get a funnel or something like a coke bottle with the bottom cut off and shove it in the radiator and half fill it with coolant, this means the guaranteed highest point of the cooling system is that coke bottle and hopefully all the air will bleed out.

One other thing I tried when that alone didn't work, I unplugged the cooling fans, ran it to just under 3/4 of the temp gauge, plugged the fans in and let it idle, once it got to operating temp I let it sit for ~15 mins to let the air bleed out. (all this was done with a funnel in the radiator)

[mattrx]

thanks mate
funnel worked a treat..

[steveconti]

Hey there..!! Nice stuff..!! Thank you for sharing it with us.