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Chevrolet Blazer Thermostat Replacement

23 messages,  Last post on Jan 28, 2009 at 7:41 PM

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What is this discussion about? Chevrolet Blazer, SUV

Messages Page 3 of 3

#16 of 23 2003 Blazer Thermostat problems by kdes

Dec 17, 2008 (9:16 pm)

My Blazers engine light has been coming on lately once it gets to around normal operating temp ,it blows good warm air but seems to be just below its usual operating temp.After a harsh cold snap it would not start. once i got it going it seemed to run a little rough once it warmed up.I am thinking it would not hurt to change the thermostat.I warmed it up today and then I checked the hoses after and found that the top hose was warm and the bottom hose was cold and the thermostat housing was leaking.
The only thing I am not really sure of is where the drain plug is on the rad and how does it open.I think I found it on the passenger side but I am not sure.
Does any of this make any sense?
I am more familiar with older vehicles so this is fairly new to me.

#17 of 23 Re: 2003 Blazer Thermostat problems [kdes] by jlflemmons

Dec 19, 2008 (1:56 pm)

Replying to: kdes (Dec 17, 2008 9:16 pm)
Oh, yeah, it makes sense. That radiator is a pain in the butt.
 
I just changed the thermostat on my '02 a couple of days ago. I ended up pulling the top hose at the radiator and aiming it down to a bucket under the car. you will probably have to pull the cruise and throttle cables and their brackets from the throttle body to get to the back thermostat bolt. I know it looks like nuts on studs, but it is a bolt with a stud on top.
 
Once you get the hose off and the coolant down, the whole job takes about ten minutes.
 
And yep, if the thermostat is not closing fully, the engine will not warm up in the prescribed time and the light will come on with a P0128 code set.

#18 of 23 Temperature Gage Flucculates by jermster2121

Jan 22, 2009 (4:49 pm)

Hello,
 
I have recently ran into a temperature problems with my 2000 Blazer. I recently replaced the heater core in May of 08. So I don’t think that is the problem. My Blazer still blows warm but not hot air, and the defrost works but not the best.
My temperature gage flocculates from normal of just under 210 to almost over heating, but as soon as it gets close to that point it shoots back to the cooler side (This happens when driving). The Blazer is going through a gallon of Antifreeze every two too two and half weeks. I have not noticed any leaks coming from the engine.
 
Any suggestions on what it could be would be helpful.
 
I am mechanically challenged, and am not to sure what the problem could be. I would like to solve it before it grows to a bigger more expensive ordeal.
 
Thanks

#19 of 23 Re: Temperature Gage Flucculates [jermster2121] by jlflemmons

Jan 22, 2009 (11:08 pm)

Replying to: jermster2121 (Jan 22, 2009 4:49 pm)
If you are going through that much antifreeze and don't have an external leak, you are running it out the tailpipe or filling the crankcase. Have you checked to see if the overflow tank is cracked? Seriously, that is a lot of fluid loss to not be showing up somewhere. Any smoke out the tailpipe when you first start up?

#20 of 23 Re: Temperature Gage Flucculates [jlflemmons] by jermster2121

Jan 23, 2009 (6:58 am)

Replying to: jlflemmons (Jan 22, 2009 11:08 pm)
It is cold here, so I am unsure if it is the smoke because of the antifreeze. Would it be more white or darker? I've not seen anything dripping from the pipe either.
 
I checked the overflow tank it does not seemed to be cracked.
 
Could the Blazer be burning that much antifreeze if a sensor is off, or if the water pump is not working right?
 
You side it could be filling the crankcase; that would be the part of the engine with piston which gives the car its power from, right? And if that is the case, it sounds like an expensive job?

#21 of 23 Re: Temperature Gage Flucculates [jermster2121] by jlflemmons

Jan 23, 2009 (9:06 am)

Replying to: jermster2121 (Jan 23, 2009 6:58 am)
I hate to be the bearer of bad news, but if you are going through that much antifreeze and not finding a leak, it is going to be expensive. If it is not leaking, it is probably being burned in the engine. That could mean intake manifold gasket, head gasket, that sort of thing. Not a job you would want to tackle yourself as it is a big job even for an experienced do it yourselfer.

#22 of 23 Re: Temperature Gage Flucculates [jlflemmons] by jermster2121

Jan 28, 2009 (6:47 pm)

Replying to: jlflemmons (Jan 23, 2009 9:06 am)
I yesterday I put in more antifreeze, and then discorved a leak. I took it to Autozone to get a read on my check engine light to see if that was part of the ordeal. After the scan two codes came up, P0101 and P0420. The print out that was given to me listed several things for each number.
When I asked the guy to give more details on the items that it had said, it did not seem like he knew what he was talking about.
Here is some of the things that were listed,
P0101:
1.Vacuum hose off
2.Throttle body intake tube loose, cracked or off
3.BARO (Barometer)/ MAP Manifold Absolute Pressure defective
4.VAF (Vane Air Flow) MAF (Mass Air Flow) sensor dirty or defective.
 
P0420:
1. Catalytic Converter defective Do to possiably to 2, 3, or 4.
2. Engine misfire or running condition
3. Large Vacuum leak
4. Engine oil leakage into exhust-valve guide seals piston rings.
 
The guy at Autozone said I should try and do the vacuum leak first cause it showed up on both of them. Now, to me,he did not know what he was talking about, so i want to make sure before undertaking this ordeal it is handled the right way the first time.
 
If any of those could be linked to the leakeage of antifreeze and the heat not working, could you let me know. : ) Thanks car guys.

#23 of 23 Re: Temperature Gage Flucculates [jermster2121] by jlflemmons

Jan 28, 2009 (7:41 pm)

Replying to: jermster2121 (Jan 28, 2009 6:47 pm)
Where did you find the antifreeze leak? If you found it up on the intake manifold area, you probably have a blown intake gasket which would cause all sorts of problems such as what the code reader found.
 
Intake manifold gasket failure is somewhat common on high mileage 4.3L engines.

Messages Page 3 of 3

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