[hotroddr32]

I noticed a couple of weeks ago I was getting air in my cooling system. Everything I did that I saw on other posts weren't working, and I noticed the water pump was leaking around the weep hole. So as a process of elimination, After running some flush and water through itI changed out the water pump,belts,lower hose, and new fan clutch. The T-stat was only a year old. The good news is that I have no gurgling, but the 3rd day I drove it. It got about 5 miles down with the heat on, and the heat goes cold, and the gauge maxxes out @ 270. I pulled it over in a parking lot and let it cool down before driving it home. All the hoses and lines are clear, the heater core is clean, and I put a new t-stat in. And it done the same thing. I really need some help on this..could it be the new pump gone bad? :think:

Sorry for the long post..I like to be clear on info!

 

[Beatdown Z]

Was it a cheap pump? Maybe the impellers fell off... either that or you have to purge again.

 

[hotroddr32]

No, it was a new pump from o'reiley's. I checked the pump out, and noticed a little play in it, but I'm not sure. I've ruled out all I know. what screwd me up was the fact of the heater went from warm to cold in about 20 seconds, and the temp went from 190 to 270 in about 2 minutes.

 

[Ketis]

sounds like a blockage...

 

[Hit Man X]

Tstat in proper direction? Also put a 1/8" hole in it to help burp the system, I always prefill the block prior to hooking the hose to the radiator (this is with radiators with caps)... otherwise I prefill the block and rad w/ the hose.

 

[hotroddr32]

T-stat is right. I thought the same thing, so I replaced it on wednesday after it cooled off. i thought it was blocked too until I pulled all the hoses off and blew the core out. Nothing. When I flushed it I ran water through the whole system for about 10 minutes before I pulled the pump off. Seemed to be circulating fine. What would cause the core to provide heat to the cab, and keep the engine normal tempature, then start blowing cold air, and the engine overheats all in a 1 mile stretch? I'll take it down the road again and see what happens...just kinda sounds like the new pump quits.

 

[hotroddr32]

Piece of crap did it again! It ran just fine as I ran it at idle. I ran 2-3 miles down the road, with the heat on, and I feel the heat go away, then the water temp shoots to 270 degrees in a couple of minutes. Has quite a bit of pressure on it. I think it has to be the new pump... does that make sense?

 

[Hit Man X]

T-stat is right. I thought the same thing, so I replaced it on wednesday after it cooled off. i thought it was blocked too until I pulled all the hoses off and blew the core out. Nothing. When I flushed it I ran water through the whole system for about 10 minutes before I pulled the pump off. Seemed to be circulating fine. What would cause the core to provide heat to the cab, and keep the engine normal tempature, then start blowing cold air, and the engine overheats all in a 1 mile stretch? I'll take it down the road again and see what happens...just kinda sounds like the new pump quits.

Air in the system. Just put a small hole in the t-stat

 

[Beatdown Z]

If you don't mind making a mess you can also pull the small hose that goes to the coolant crossover off the passenger side of the radiator. Hold it up high, in a bottle with the engine running (hot, but not dangerous hot) and it will let all the air out quick.

 

[hotroddr32]

Tstat in proper direction? Also put a 1/8" hole in it to help burp the system, I always prefill the block prior to hooking the hose to the radiator (this is with radiators with caps)... otherwise I prefill the block and rad w/ the hose.

I'll give this a shot tomorrow after work... do you just pull the t-stat and pour the coolant down the hose or the intake? I hate to be dense, but how could air cause what I have going on?

 

[Beatdown Z]

Drilling the small hole inside the thermostat will do more for you then pouring coolant in the hoses. The problem with air in the block is that it has no where to escape. To easily get rid of it, you have to go to the highest point. A month ago I changed the thermostat on one of my trucks('00 4.8l) and I started the truck without purging the air and the temp gauge shot up quick. I did what I suggested in the above post and all the air escaped and everything was good and cool.

 

[hotroddr32]

Alright, I got the t-stat drilled and pre-filled the block and radiator. Runs good without overheating at all. Only thing is I still have the sound of dribbling coolant in the core. Hopefully over the next few days it will work its way out. Thanks for the tips! Much Appreciated!