ive been on the site for a few months and checking out everybody else's sweet ride's. i now have a problem myself and need help. i have a 2002 chevy 4x4 blazer with a v6 4.3 liter 4door. it has 93xxx miles. im haveing heating problems and im now afriad it might be something more. last year i had perfect heat. i bought a new thermostat and put it in and it made no difference. ive had the coolant system flushed like 5x and ill have heat for about a week and then ill have to have it flushed again. it did overheat (not in the red) but everytime its been driveing since its not even come close to overheating. when they do flush it they get a wet leafy looking like stuff coming out. A friend suggested that who ever might of had it before me had a hole in a gasket and ran some kind of liquid plug through it and now that im flushing it its actually breaking up and coming lose. so the only thing ive been told is to get new intake and head gaskets. any suggestions?
thanks

 

Had the same problem with a friends Jeep Cherokee. Ended up being a head gasket. Sorry it's not better news but that's what it's sounding like.

 

It is possible that someone used a sealer in the engine and that is causing you fits with your heater core. Any of the times that it was flushed, did they do a chemical flush to actually clean, dissolve, and remove that junk?

Before jumping to the conclusion that the head gasket is at fault, pull the plugs and do a compression check. While the plugs are out, inspect them. If the head gasket is allowing coolant into the combustion chamber, the plug should be a nice white color since the coolant will literally steam clean the porcelain.

 

well i had the entire coolant system flushed AGAIN (this makes like 7x) and then i had them flush it with chemicals and do a compression check all done by a certified mechanic and when he did the compression check he said it all checked fine. he did the checmical flush and a regular flush and he seen the wet leafy looking like substance and he said that it looked like some kind of sealant also. after he did all of that i had heat for literally 48hrs and then it went right back to cold. any other suggestions? The guys said he's never seen a blazer act like that before that out of everything he did that its always worked and now he said that he doesn't no where to go from there. Thanks once again.

 

well i had the entire coolant system flushed AGAIN (this makes like 7x) and then i had them flush it with chemicals and do a compression check all done by a certified mechanic and when he did the compression check he said it all checked fine. he did the checmical flush and a regular flush and he seen the wet leafy looking like substance and he said that it looked like some kind of sealant also. after he did all of that i had heat for literally 48hrs and then it went right back to cold. any other suggestions? The guys said he's never seen a blazer act like that before that out of everything he did that its always worked and now he said that he doesn't no where to go from there. so do i still replace the intake gasket like one guy suggested? do i continute to do flushes? do i start replaceing the radiator, heatercore, i just have no clue what to do next.
Thanks

 

I have come across this problem a few times in the past myself. Generally it is do to someone having a small leak somewhere in the system that was sealed with a cheap sealant add in product probably not rated for the coolant type in the truck. Or in the last case that I saw, added to the coolant when it was supposed to be used in the system with only water in it until the leak was sealed.

New gaskets are not going to help you if you are not leaking coolant from anywhere.
Getting all the gunk out of your cooling system which is clogging up your heater core is going to be quite a chore but it can be done.

The best way and obviously worst for winter time is to do a very long and thorough flushing with a garden hose after a chemical flush, of the radiator, block, and heater core each separately. Including removing all the hoses and cleaning them individually.

Alternatively you can install an inline coolant filter to catch the debris as they dislodge themselves from your cooling system. I will attach a few pictures of one style that I know of but there are a few types available and some people even manage to make them themselves. You must remember to check and clean the filter often though to prevent a total blockage with the amount of gunk in your system now.

With the filter installed you may still get a plugged heater core once in a while at first as your green slime circulates. (unless you get a coolant filter style that connects to the heater core inlet hose)

You can unplug this without flushing the whole engine by disconnecting the heater hoses to the core and cleaning out just the core using a garden hose and flushing from backwards from the outlet hose.

In winter when a garden hose is unavailable due to temperature you can also use a wet vac connected to the inlet hose with the outlet hose dunked into a bucket of water/coolant or a cleaning solution if you wish.

You can also blow the debris out with compressed air but you must be careful to use a low pressure so as to not damage the heater core.


The attached pictures are of a Tefba brand coolant filter, But there are a few different manufacturers that have them for various size hoses including ones that attach to the heater core hoses rather then to a main radiator hose.

 

Have you checked the valve in the heater system--may not be opening all the way--allowing only a small amount of "crud" to block it--also have you checked for a partially colapsed heater hose ?? I can't imagine this being a intake or head gasket problem--not without any other symptoms---

Gary