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Is there a problem with my cooling?

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Location
Virginia
A few months ago in between PCS from Camp Lejeune to Hawaii myself the wife and two dogs took a roadtrip across the US. Long story short, plastic tank by the upper hose gave out, I used some quick fixes to keep us on the road but kept my eye on the temperature gauge. Quick fixes consisted of magic in a bottle and plastic welding the crack which kept dripping. My new Griffin radiator came in this past Thursday and now the temp gauge registers something whereas before it would rarely register. It seems like the coolant temp isn't getting hot enough and when it does get to the mid point of the gauge, it usually cools quickly.
Not sure if my thermostat is bad now but I'll be looking to change it to a 195 stat as soon as I can get my hands on one. Also, my fuel mileage has sucked with the leaking radiator. Not sure if the new radiator fixed this. With the leaking radiator it was about 11-12 mpg. Before it was bout 18-19.
Any suggestions? Thanks for any help/insight!
 
what year rig? I believe our tstats fail in the open position which could be some of the guage issue. also if you have an air pocket it will mess up the guage. cool engine will decrease mileage but that seems lik alot of difference
 
1994. I've been driving it around hoping to get all the air worked out. Is there an easy way to get all the air out short of parking backwards on a steep hill and using the bleeder screw? Something going on with my waste gate solenoid also. I know it's less than 6 months the old because I replaced it but the code popped up again. I'm going to clean it with carb cleaner and chase it with brake parts cleaner when I get home. On the way to pick up a 195 stat from Napa right now. I heard carb cleaner is pretty tough and brake parts cleaner is good to get all the carb cleaner residue out.
 
Mine goes to the midpoint, then drops quickly when the thermostat opens. I have a new rad and 195 stat.

Open the bleeder screw and put some rags around it. Then add coolant til it comes out the screw, and tighten the screw.
 
1994. I've been driving it around hoping to get all the air worked out. Is there an easy way to get all the air out short of parking backwards on a steep hill and using the bleeder screw? Something going on with my waste gate solenoid also. I know it's less than 6 months the old because I replaced it but the code popped up again. I'm going to clean it with carb cleaner and chase it with brake parts cleaner when I get home. On the way to pick up a 195 stat from Napa right now. I heard carb cleaner is pretty tough and brake parts cleaner is good to get all the carb cleaner residue out.

waste gate solenoid issue:
brake parts cleaner?! carb cleaner?!
You need to think about what this stuff does to rubber parts! Not something you should use in the WG system. Why is there this much dirt in the system that you need to use it - must be a leak sucking in dirt.

I would start over by checking for a good vacuum from the pump. Then check the WG actuator for leaks. Double check the lines for cracks and bad boots/rubber connectors. 6 month old part or brand new part doesn't mean it is a good part. Recall where most stuff is made and their reputation for lack of anything resembling quality.

Cooling system:
Look at the heater fitting on the t-stat crossover. There should be a restriction device in the fitting. These get tossed during service and can allow lots more flow and cooling with the t-stat closed. You have to pull it apart to check it and may as well have a replacement on hand. 3/4 hose fittings, a popular mod, of course do not have a restriction.
 
Thanks for the responses guys. I'll have to dig out my vacuum guage sometime and check the vacuum from the pump (still unpacking from the move) What should it read at idle? I don't think that restriction devise was removed. Gauge worked fine before the radiator blew and I was the one that swapped the radiator out this weekend. Curious to know where this restriction devise is though. So more insight on that would be helpful. Also, not too worried about the vacuum system/wastegate since I'm in the works of getting an A Team Turbo from Dennis.
Where is a good inexpensive place to get a hold of the ACDelco thermostat part # 13191. I believe this is the thermostat for single thermostat 6.5s but it's listed as 190 deg instead of 195. Is this right?
 
If you can find an auto parts store that sells ac delco stuff the tstat may be cheaper there than from a gm dealer. Only acdelco tstat offered here now in this neck of the woods is a 190. Could well be different elswhere.
 
Changed the thermostat to a Napa stat that was rated for 195 and made in the USA. Seems to be working great now! Warms right up and cools down to just under 195. The last stat I had in there was an ACDelco. Not sure what happened to it. Looked fine to me but I can't remember what temp it was rated for. Also, rockauto looks to be a good source for the ACDelco stats if you can afford to wait for the mail. Thanks again guys! I'm still diagnosing my wastegate solenoid fault issue. New solenoid but it still shows. I haven't checked the vacuum pump yet though.
 
I used one from NAPA and it was fine until I towed, it opened way too late.
 
Yeah, I'm definitely not keeping the NAPA one in there but I should be fine since I don't forsee towing anything right now. ACDelco stat will go in as soon as it comes in. Does anyone know how much vacuum I should be seeing from the vacuum pump? I'm still trying to diagnose my wastegate solenoid fault issue. New WG solenoid installed Sunday but code still pops up and is probably the cause of my crappy mileage. All the Vacuum hoses looked good from using my calibrated suck/blow method.
 
Haven't found my vac/pressure guage yet but I did receive my two ACDelco stats from Rockauto on Saturday eight before I had to leave for the ball. I did get around to seeing if I had any vacuum leaks and got to pulling the hose that goes from one side of the vacuum pump to the other side and lo and behold it looks like the hose somehow dislocated itself. I felt the hose all around to see if it was in good shape and after determining serviceability, properly shoved it into place. Hopefully this solves my problem for now while I wait for my A-Team turbo. I've been looking around for that particular replacement rubber hose but haven't found one. Is the only way to get one new by purchasing a new pump?
 
image.jpgimage(1).jpg
NAPA and bad AC Delco stat for comparison. NAPA stat still works but I went ahead and switched to a brand new Delco stat. Not sure how the Delco stat failed.... looks good to me.
 
Sheeeeeeeeeeeeeeeeeeees back!!!! Culprit was a bad vacuum pump. Finally sucked it up and bought a new vacuum gauge and pump. Tested the old pump and it pulled very little vacuum at idle. Took the old one off and swapped pulleys and wham at least 25 hg at idle. Turbo whistle is back and going up hill at wide open throttle no longer produces an SES light. Thanks everyone!
 
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