hello my 1998 s10 blazer 4.3l runs very hot, new radator new thermistat, my question is can the radator cap cause it to run hot?
i took out that devils fliud and put in the green stuff , car runs about 220 and about 205 with out the a/c on.yesterday it ran up to 245 and it boiled over,
any hints? thanks glen

 

Did you do a good flush? Were you having overheating troubles before you did all of this work?

 

yes i did, and no i did not do a real good flush, i will try that this week-end.. still has a brownish look to it.. (devils fluid, is evil!) thanks

 

and yes a bad cap can cause that... not expensive, get a new one.

 

A cap should be one of the first things to replace whenever doing work on a cooling system. For the cost (~$10 or less) and ease of installation, why even ask...

 

I would flush out the heater core too. It doesn't seem to flush properly
unless you do it at the firewall where the hoses come through. It gets
a little messy doing it that way, but you will see much crap come out
of the heater core.

 

thanks guys and or girls i will buy a new cap and flush the crap out of it, (get it? flush the crap out of it?) well i thought it was funny[&:]

 

I flushed out my heater core this spring. I used 3/4 and 5/8 garden hose with clamps. I removed the heater hose and clamped the garden hose on so that I would not get COOLANT on the distributor cap or make a mess, I then put the hoses in 5gal buckets and flushed out the "devil fluid" until it was clear. Might have to do the whole block flush this next time. Also I have a friend with a GMC Highrider and he uses a camaro radiator cap since it is 2lbs more pressure and the more pressure the less it tends to overheat...I think the stock for an S10 is 12lbs and the camaro is 16lbs....the radiator is rated to 18+lbs.

 

I'm getting a kick out of the "devil fluid" comments you guys are makin'...

Anyway, be careful with a higher rated rad cap. The rad might be rated for that, but is the weak heater core?