Temp guage / thermostat....ideas?

Hey all,
 
     98 Blazer LS, wondering where your temp gauge normally points.  Not a correct reading, I know, but ball park.  Reason I am asking, she has 169,000 miles, engine surges between 1500 - 2000 and SES light is on.  Some postings seem to point to engine not getting to proper temp.  I just haven't had time to get the SES codes read, and you know those can be misleading too.
 
     My guage points to the first qtr increment, never past that, could be about 185 degrees?
 
     If you look at the gauge, far left is 100 degrees, 210 degrees is straight up and far right is red and 260 degrees I believe.  the increments don't mathematically count right. 
 
     I believe that I need to replace the thermostat.  Thoughts?
 
     Where is yours normally.  I only know of one person who has a Blazer, he sold it, but THOUGHT his temp gauge was always right at the 210 mark.

A stock stat should be 195, mine shows about 200-210 on the gauge.  It does sound like you probably need to change the thermostat.

All OEM gauges that read parameters that are normally constant or in a particularly tight range (oil pressure, coolant temp, voltage, etc) are made to be straight up when they are at or near the proper range.  This is so it is easier to notice one gauge being off...

If you are only on the 1/4 mark on the temp gauge and the PCM is complaining about the coolant temp as well, chances are your t-stat has failed open.

After I changed my thermostat(195), waterpump and headgaskets My temps went down alot.
 
Used to be 200-210 now its at a quarter(165-170) and blowing heat like never before.
 
I don't think it's normal but I'm not really worried about it either.

I see you pulled the heads, how did you get the heads off the block? I am needing to put a new set of heads on my grandson 96 blazer. Cant seem to get to the bolts under the exhaust manifolds.
 
 

Take off the exhaust manifolds.

LOL,,, we tried to, but the bolts are so rusted could not get them off. I did spray them with WD40. Can try again tomorrow night. Thanks
 

Well, it's not like they are in an unfriendly environment......  They can be a real bear to get off. PB Blaster is a bit meaner than WD40, and should be available at the parts store. I love the stuff. Sometimes, if they are 1/2 in. (just an example) you can tap a 12mm socket on them to break them loose. Occasionally, the mere act of beating on them with a hammer will convince them to break loose. But, in any event, the manifolds MUST come off to get the rest of the head bolts out.

As a last resort, you could torch the heads off the bolts, pull the manifold, and, once the head is out, extract the remaining portion.... It's an exercise, but, I have had to do it before..... Not a great deal of fun......

That's a lot of rust!

You may need to bust the rust out from around the head of the bolt with a chisel and hammer (or air hammer with a pointed tip).

Thanks for the IDs, I am also thinking about a impack wrech, just don't want to break the studs off, but I guess they could be replaced once I get them off.

dont use WD-40 to eat rust, it ownt do the trick. WD-40 stands for Water-Displacing, 40 th attempt. It is not designed to eat rust, its a modern day 3in1 oil and nothing more.

PB Blaster WILL eat rust, the hotter you get the nuts and bolts the more it soaks into the threads. If oyu cannot get heat on them, spary, and tap with a hammer. The tapping helps it soak in. If that is out, spray and let it soak, spray and soak.

Another trick, and this onegoes counter to logical thinking, initially.
After several rounds of spraying, try tighening the bolt/nut, and then try to unbolt it. Sometimes all you need to do is break the rust bond.

quote:

ORIGINAL: HeyYou

Well, it's not like they are in an unfriendly environment......  They can be a real bear to get off. PB Blaster is a bit meaner than WD40, and should be available at the parts store. I love the stuff.

 
HeyYou,
I got the heads off tonight, that PB Blaster is some good stuff. Only had to heat one up with a torch. Now I hope I get the new heads before to long. Got lots of cleanup work to do not to get ready to putter back together.
 
Thanks again

quote:

ORIGINAL: Slow Rollin

quote:

ORIGINAL: HeyYou

Well, it's not like they are in an unfriendly environment......  They can be a real bear to get off. PB Blaster is a bit meaner than WD40, and should be available at the parts store. I love the stuff.

HeyYou,
I got the heads off tonight, that PB Blaster is some good stuff. Only had to heat one up with a torch. Now I hope I get the new heads before to long. Got lots of cleanup work to do not to get ready to putter back together.

Thanks again

I love the stuff. Been using it for decades. Won't have a garage without it.

Absolutley awesome!! Have fun with it. What variety of heads are you getting? Is there such a thing as high performance heads for a 4.3??

Not getting anything high performance just a good set of heads.
 
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