Question for you auto geeks

Paul Downes

Member
Messages
959
Location
Westphalia, Michigan
I blew the radiator on my Chevy S-10. This is a 2001 truck 2.2 liter engine with 188,000 miles on it.

So I put a new one in today and I don't think the coolant system is right. I did replace the thermostat. It is blowing lots of coolant out of the reservoir overflow tube. Another thing is that normally I leave the radiator cap off for a few minuets and top off the fluid. When I started the truck up it blew radiator fluid like a geyser. So I figured there must be a major air bubble and put it back on. That's when it started blowing the fluid out of the overflow tube.

I've replaced radiators before and have never seen anything like this.

Any Ideas?
 
Sounds like you could have a bad head gasket and getting compression into the cooling system. Is it running fine? Is it doing this as soon as you start or after warm up?
 
Hope I'm wrong with this, but it could be leaking combustion gasses into the cooling system resulting in high pressure in the cooling system blowing coolant out through the path of least resistance.

I just saw Garry beat me to it.
 
I'll check that out in the morning. I will also do a compression check on the engine to see where that's at. Sure will suck if the engine is shot. Just bought new tires and radiator.
 
I too would agree with the head gasket problem, does not take much of a leak to do that.

Why not replace the head gaskets, what is this truck a straight 4 or a V-6? If the head is not warped, a head gasket job is not a big deal, price of the gasket and some elbow grease and you should be good to go!
 
Paul, I think you've got some good advice so far. Did the truck overheat when the radiator blew? Also, did you replace the thermostat? If it's not running rough and no antifreeze in the exhaust or on the plugs, then it may just be getting hot and boiling out if the thermostat is stuck. can pull the stat and test it to know for sure.

http://chevytalk.com is a good chevy site too.
 
Also can pull the hose off of the thermostat housing and with a loooooooooooong screwdriver, punch a hole in the thermostat. Good emergency roadside fix to get you home. Lets water circulate if the thermostat was frozen shut. Did you put a "new" radiator in it or a "new to you/out of junkyard" radiator? Are you sure the radiator you put in lets water circulate?
 
Yah the thermostat is in correctly and new. The engine did overheat some. The idiot gauge never reached overtemp because there was no coolant in the engine to show that. I do treat all my engines with Motorcoat, because I know race engine builders that have used the stuff. My former engineering boss used it in his air plane engine and saw significant oil temp reduction and a much smoother, quieter, engine. That being said I thought I smoked the engine. While I knew better, I lied to myself and thought I could get it home by filling the radiator with water every few miles (about 20) and letting it cool down between fills. I guess I didn't think the coolant was blowing out that quick.

That being said, it has been doing the boiling into the reservoir tank off and on for a year or so. I couldn't figure it out because the coolant was always up to level. You would think a guy with my experience would know better.

I already rebuilt the transmission. This truck has seen 3-4 kids learn to drive a stick so the tranny gets used hard sometimes. Maybe time for a brick and a rope. Or I might decide to pull the engine down and see if it's fixable.
 
I checked with the junk yard today and they said they will sell me a used head for $100. So I think I will pull the engine down and see how it looks. They would drop in an engine/ transmission for $1800 but I will try the cheap route first and maybe just send it down the road if more than the head gasket or head are toast.
 
Well I'd buy a rebuilt before I spent 1800.00 on someone else's problem. Just me, I haven't had that much luck with junkyard engines. And just a few years back I got a yard to install a 4 cylinder in a Ranger for 900.00 , that included tow, engine and labor so 1800 sounds really high to me..

Garry
 
Just to give you an idea as to how tough that engine is I ran mine with broke head bolt up to 145,000 miles. Thats when the thermostat stuck and I got it hot enough in winter that the engine quit. Towed it home thinking it wouldn't run. When I got it home I started it up and ran it into the garage.

Pulled the head off to replace the gasket and head bolts, found a crack in the head when I took it to have the valves ground. The guy just peened it shut and I reinstalled it. Took it out to go to town and it got hot enough that the engine shut down again. That's when I found the thermostat was stuck, replace it and ran the truck up to 208,000 miles (still wasn't using any oil) before selling it and the only reason I did that was because the body was getting a lot of rust.

Wish I still had it.
 
I have a 98 dodge truck I use for wood hauling/woods work. The speedometer quit working around 245,000 miles and I figure it is up around 260,000 miles now. The engine does burn some oil but it runs well. I try to watch the oil pressure gauge but have been caught a few times with the oil way low. I treated this engine with motorcoat as soon as I got it and even when the oil gets low it has never showed signs of over heating. I have had vehicles with the 318 engine-very solid performer. This one has the 360.

I also have a GMC truck but don't care for how it drives nor how the 4x4 performs. The dodge has pulled the stuck GMC out of the ditch a few times. The only time I got a dodge stuck it was more on it's side in a snow bank and only had 2 of 4 wheels driving.
 
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