Nasty Cooling System - '93 Chevy Caprice

[Renken2000Classic]

This is a car I bought for the engine several years ago, but ended up just adding to my collection and driving it.

I put a water pump on it early on and remember that the coolant was kind of dirty, brown stains in the overflow tank and that. I flushed the radiator several months ago, and had to flush it and flush it and flush it to get it anything near "clean". It was rusty brown.

Today I got it out in 100F heat and it was running way warmer than usual. I thought it had a coolant leak and was low, but when I added some water to the overflow (empty), it was really brown in there, and when I opened the radiator, there was like mud on the underside of the cap, and the radiator itself didn't seem too awful low (though I think there's a leak somewhere).

Now I think the over-warm running is due mostly to a partially stopped radiator. What the heck? I don't remember having a car that dirtied up the cooling system like this one... I had a 50-50 mix of antifreeze and water when I got done with the flush. It's almost like the radiator has a buildup in the bottom that is getting loosened over time or something.

 

[ezbtr]

flush it

 

[Renken2000Classic]

Lol. Yeah, I started that process yesterday and the running temp was perfectly fine today. I'm gonna have to do it several times though. Idk for sure if the radiator's the source of built up gunk, but I've ordered another one since I'm pretty sure now it's got a new leak anyway. Just never seen a system get so nasty like that, and so quickly.

 

[Scott Danforth]

If you mix orange and green AF, you get a brown sludge

flush it

 

[Renken2000Classic]

It had some iffy maintenance from PO - NO air filter, rear brakes weren't done right (instead of a F and R shoe on each side, there was 2 fronts on one side and 2 rears on the other), etc., so antifreeze mixing might've gotten done somewhere along the line. I didn't know it was a prob, and can't remember if I've ever done it or not. I always stick with the green stuff to the best of my memory.

 

[Scott Danforth]

I always stick with the green stuff to the best of my memory.

The 93 caprice with the LT1 used orange coolant.

I think you created your own mess

 

[Renken2000Classic]

The 93 caprice with the LT1 used orange coolant.

I think you created your own mess

Lol. I've certainly done my share of that, but I think this bad boy was rusty/dirty when I got a hold of it. It's only the 5.0L anyway, sigh. With 2.56:1 gears yet. And whoever thinks that was a good idea in a car that size has little use for acceleration. Gets about 25mpg on the hwy though...

I think my Suburban originally took Dexcool, but when it got it, it had green in there. Only other car I've had that took it was a Pontiac.

 

[bigdee]

Dreaded Dex-cool cocktail. Flush,flush,flush.....Cascade dishwasher detergent helps alot. It is very important to get that brown mud out of the system as it is corrosive and will eat paper gaskets!

 

[Renken2000Classic]

The heater barely works in that car too. I was down to thinking it was the blend door (I've done the feel-the-hoses-at-the-firewall test, and things seemed correct like it was flowing through the core), but I'm 2nd guessing that just a little. I dread tearing the dash apart (though maybe I can see it if I pull the pad?). It's a cable operated door.

I'm still in the flush and drive process (mostly drive) and it's running where I'd expect on the gauge now, even though it's 100+F outside. Heater's still not very warm though. Gotta remember to 'winterize' it within the next few months.

 

[Scott Danforth]

The heater barely works in that car too. I was down to thinking it was the blend door (I've done the feel-the-hoses-at-the-firewall test, and things seemed correct like it was flowing through the core), but I'm 2nd guessing that just a little. I dread tearing the dash apart (though maybe I can see it if I pull the pad?). It's a cable operated door.

I'm still in the flush and drive process (mostly drive) and it's running where I'd expect on the gauge now, even though it's 100+F outside. Heater's still not very warm though. Gotta remember to 'winterize' it within the next few months.

Your heater is now full of mud from mixing fluids

 

[Renken2000Classic]

Most unfortunate!

Well, maybe the heater core is an easier change than accessing the blend door. But I won't bet on it.

The good news is that I got this car for less than $1,000 with a trans that was acting up. Turned out to be low fluid from a bad leak in the pan gasket (first thing I did was add to it before even driving home). Had the trans serviced/checked and it's been shifting like a champ ever since.

Then after I'd had it about a year, a drunk turned in front of me and I caught him in the Rt Rear with my Rt Front. He tried to run, but I boxed him in. Turns out he was insured and I wound up with over $3,000 - that was after I paid his co. $650 to keep my car.

I put a new headlight assembly on and have just lived with the slightly cockeyed bumper since.

Anyway, I've more than gotten my $ worth from it. Have put over 25,000 miles on it too.

 

[bigdee]

The heater barely works in that car too. I was down to thinking it was the blend door (I've done the feel-the-hoses-at-the-firewall test, and things seemed correct like it was flowing through the core), but I'm 2nd guessing that just a little. I dread tearing the dash apart (though maybe I can see it if I pull the pad?). It's a cable operated door.

I'm still in the flush and drive process (mostly drive) and it's running where I'd expect on the gauge now, even though it's 100+F outside. Heater's still not very warm though. Gotta remember to 'winterize' it within the next few months.

Try reversing the heater hoses, add about 2 oz. of cascade and run engine for about 20 minutes then do a complete flush. May have to repeat a few times but it will definitely help/