Changing/flushing antifreeze Lebaron, ''95, 3.0L V6.

Well, I can't believe it but I've forgotten how to change the anti-freeze. This must be the start of Oldtimers Disease.

It was warm in Baltimore yesterday, and a good day to flush the cooling system. Lebaron, ''95, 3.0L V6.

I ran the engine until it was hot or at least warm.

The petcock opens with no tools -- that's nice.

I drained the coolant into one of those rectangular bottles that lie in their side; I removed the thermostat and flushed for 5 minutes with a garden hose in the radiator neck until the water ran clear. Let it drain, put back the petcock, put back the thermostat, filled the radiator with 50/50, but it took less than a gallon.

Ran the engine a minute or two until I realized that maybe I had only filled the radiator.

Went to see if I could add more coolant, but I couldn't. Usually I can keep adding and adding, even when it starts way above empty.

I added about 3 quarts, when the capacity is 8. (That's right, isn't it?)

After sitting all night, today I could add a 3 or 4 ounces more.

Could it be I never drained the engine after all? How could that be when I removed the thermostat and the petcock and after flushing let it sit until nothing was coming out of the petcock hole.?

There's a big chuckhole in the road near here. Maybe I should go drive over that.

I found a lot of webpages about changing antifreeze, and all but one said nothing about the thermostat, not even to consider changing the thermostat when changing the antifreeze. Lots of webpages about flushing the engine and not a one about removing the thermostat to help this. Even though one page went into the fact that the thermostat closes when it's cold. -- They all seemed to talk about flushing the radiator and not about flushing the engine.

P.S. I also got a Felpro gasket for the thermostat and it has a brown plastic ring on the inside circumference on one side. But nothing on the card to say which side of the gasket goes up. Which does?

Thanks.

mm

its always good to change the thermostat every couple years, or if something's wrong with it. never heard of pulling it to flush. i would have opened the petcock on the engine block and got the rest of the coolant out of the engine myself.

I don't want to use chemicals, which might cause the radiator to start leaking again, I just want to use running water to get as much crud out of the engine and especially the heater core as possible. If the thermostat is in there, it will be closed because the water from the garden faucet is cold. Even if I ran hot water from the kitchen sink, it's only about 140 and the thermostat fully opens at 185, or in my case, 195.

I don't understand, "got the rest out of the engine myself". Myself? How?

there should be a drain plug or petcock on the block down low on one side or the other.

they also sell flush kits that you connect into your heater hose to attach your garden hose, so you can flush the heater core.

I see. Thanks. I'll look.

But how come I didn't get most of the fluid out of the block by removing the radiator petcock. Most of the engine is higher than that, right, and water seeks its own level. So shouldn't it flow through the lower radiator hose, into the radiator, and out the petcock opening? How could it not do that?

That would be good. I'm still looking for the heater hoses! I have a shop manual around here some place. :(

Mike

On a "normal" engine it would but IIRC on a Mitsubishi 3.0 the water pump is driven by the timing belt and the lower rad hose goes to a pipe that runs down the valley between the heads below the intake manifold hence it is up higher than the block water jackets and would prevent a full drain.

"But how come I didn't get most of the fluid out of the block by removing the radiator petcock."

a lot of times your water jackets in the block sit lower than your water pump so it will drain down to the level of the water pump/lower radiator hose and you wont get the rest. it just depends on the block you have and the drain location.

Thanks, Daniel, Rob. I guess I really have to find that manual. I look whenever I walk around the house, but that's not enough. I'm going to have to dig. I may have to blast.

To fully understand what you both said.

Stop a just about any auto parts store and get a Prestone Flush-n-Fill kit. Permanently nstalls in a few minutes, use whenever you need a complete flush. This system has been around for decades. Works well, lasts a long time.

Thanks a lot. I'll look into this. The url says it does just what I want.

You are absolutely right.

You were right to begin with and then I found my shop manual, with a picture!

I ended up prying the heater hose off the engine tube. I used a ruined phillips head screwdriver that I had sharpened and it worked so well, it was so easy to get off, even on a 16-year old car, that I went after the other heater hose that is more hidden but which would allow a reverse flush.

I had a small brass device, that I bought 40 years ago and had never used, that was meant to replace the petcock in an all-metal radiator and connected to a garden hose at the other end. I clamped some rubber fuel line on the small end and easily forced that about 6 inches into the heater hose. It was a good fit and no water came out, but brown water came out the other end for a full 5 or more minutes before it ran clear. I connected the other hose back to then engine and was able to flush the engine and the radiator at the same time, with the water coming out the other heater tube from the engine and the petcock opening. Again it took more than 5 minutes to run clear.

There was no need to drain the engine as long as I could flush it adequately.

I certainly wasn't going to take out a freeze plug, or whatever that would be, and then try to replace it properly, so it woudn't leak, outside in February, with or without a lift, and it wasnt' necessary.

To refill, I removed the thermostat housing and also added via the radiator -- neither alone was enough -- and I got a whole gallon of anti-freeze in, and much less than a gallon of added water.

And best of all, the heater works as well as ever now, putting out hot air when the temp gauge is a full mark short of the max value that it reaches. When last month it only put out slightly warm air at most.

The air is still not as hot and there's not nearly as much of it as with my full-size Pontiac and Buick convertibles were, but they had

318, 359, and 400 CID engines. The engine on this car doesn't even get hot enough to melt the snow on the hood. (Although I just noticed that a friend's small size Nissan pickup had a hot hood 5 minutes after turning off the engine. I thought maybe no cars generated so much excess heat since the engine mileage laws.)

I saw the the Prestone device at the store and the pictures made it much more understandable than the webpage QX gave me (which had no pictures or drawings! It would be very good on any car it would fit, but there just wasnt' space to connect it here.

Tbanks to all of you, and thanks to you, Paul.