Anybody ever have a stuck thermostat (closed)?, Either that or air---pissing me off! Options

[Teutonic Speedra...]

Any of you guys ever have a thermostat stuck closed? I swapped mine a few weeks ago for a Evans hi-flo, 160 stat and topped the fluid off. I then started it last night, and was trying to get the air out, but the temp on my aftermarket gauge climbs to 200-210 rather quickly (<5 minutes). Every time I let it sit and cool, it takes a little bit of coolant. (Checked it at 5:15 this morning, probably took another pint). It seems that there is an air pocket so big that the thermostat doesn't open up yet.

Few notes:

1. The aftermarket gauge sensor is on the passenger's side head.

2. Stock gauge is on the driver's side head. Stock gauge shows ~210....of course, that's what it always says from 160-225!

3. Is there air or vapor making the aftermarket gauge show ~210, while the stock one is upto ~190 according to the Mastertech scanner? If it was at 195, the fans would kick on (LS1Edit). I've yet to hear the fans kick on while attempting to get more fluid in.

4. I always shut the car off when the aftermarket gauge shows ~210 in fear of doing damage.

5. I've taken the hose off at the top of the driver's side head, and coolant flows right out, no bubbles.

I guess when I get home I'm going to try starting it up again and see if it will open again? I just don't know how long to wait before I fear the heads are getting too hot from no circulation and/or air pockets. If that doesn't work, I'm going yank the thermostat and see if it is defective.

It's weird, last time when I had the waterpump and t-stat out for my cam install (~15k miles ago), I had virtually no problems adding coolant and purging air without even messing with the little hose coming off the heads.---But, I did have the front of the car on ramps, elevating it about 10" higher.--Was that enough to make the radiator neck the high point of the system, thus allowing the air out quickly?

Just don't want to overheat my motor/heads!! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/banghead.gif)

[00 SS]

Since the stat is in the lower hose, the system will trap large amounts of air. I've seen two techniques used to remove it. One was to squeeze the lower hose several times with the engine running to help "burp" the system. The other is to remove the upper hose at the radiator and pour coolant directly into the engine using the hose as a funnel. I've used the second method with success.

[jensend]

Dennis- Don't know if this would be useful or not but, virtually all Honda/Acura products have a simple bleed fitting that is tapped into the housing where the upper radiator hose is mounted. By opening this fitting air is released either during the fill process or when the motor is cold by squeezing the hose(s). If all else fails, you might want to plumb a fitting in a similar fashion. Good luck. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/huh.gif)

[GlennCMC70]

put water in the upper hose (on the water pump) to fill the block. you need water in the block that can get heated and that water will conduct the heat to the thermostat. if you don't do this, your relying on air to transfer the heat to the thremostat. not a good conductor of heat.

[Teutonic Speedra...]

you need water in the block that can get heated and that water will conduct the heat to the thermostat. if you don't do this, your relying on air to transfer the heat to the thremostat. not a good conductor of heat.

I knew this was the problem, I was just concerned about getting the heads too hot before the thermostat opened. I went home, and my buddy (mechanic) stopped by just to check it out. Started it up, let it come up to 100+, then gave it a fast idle (2k rpm) with a couple of blips. I was watching the gauges, it went up to 180, then 195, then 210, then I was watching him, feeling the hoses. Then he goes check the gauge now, and it had dropped from 210 to 180. Bam---I'm done! I was also putting an IR temp gun on the t-stat housing. I saw it go upto 150 when the heads were at 180ish, then 155, 156....160, bam, the t-stat open. I was so close last night after I had slowly added coolant, cooled, added coolant cooled.

I'm happy now. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif) I'll let it cool overnight and check the levels again in the morning.

Next step, align my front end (U/L CA's), mount hawker, install lexan. 2005 season is almost here and I'm still on schedule. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/2thumbs.gif)

Thanks guys for the suggestions! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/beerchug.gif)

[Teutonic Speedra...]

Man, this thing is really starting to bother me. Driving it to my buddy's shop again tonight, and back, the thing when starting from cold, it heats up and then shows 250F on the autometer until it seems the t-stat opens up (AutoTap shows 205F). I think the drivers side keeps getting cool water from the radiator, while the passenger side just keeps heating up until the t-stat finally kicks open....and when it does kick open, the Autometer temp rapidly drops from like 250-180 (within a minute), and the Autotap temp goes from like 205 to 180. I'm not sure if the Autometer gauge is bad, or if the thermostat sticks a bit, and then once upto temp it functions normally.

What do you guys think? I'm about ready to throw the old stock thermostat back in.

Got the PHR Relo brackets finished. But, one step forward, one step back. My passenger side parking brake cable melted on the exhaust (recently lowered car). I had the e-brake on while we were working.....so it siezed itself on. So in order to get home, we had to pull the cable off on the passenger side. Now I need one of them.

[robz71lm7]

Just throw a stock one in and see what happens. Demand a replacement/refund from Evans if the stocker works fine. It seems you know how to bleed the LS1 colling system if it worked fine before.

[Teutonic Speedra...]

Just throw a stock one in and see what happens. Demand a replacement/refund from Evans if the stocker works fine. It seems you know how to bleed the LS1 colling system if it worked fine before.

Yeah, I never had a cooling system problem or air, or anything until I did the swap, and I've flushed the system a few times before, and had the stock t-stat and water pump off for the cam install. I think I know what I'm doing. I'll be happy if the stock t-stat solves my problem. Then I can move on to bigger and better things.....like my Hawker and the lexan.

[Teutonic Speedra...]

OK. Update-

I e-mailed Evans Cooling this morning describing the situation. They agreed, that it definitely sounds like a sticking thermostat, or one that is set at the wrong temp. They said it would be the first defective one, but it is possible. Their first response to the e-mail was that they were sending me a new one first thing Monday with a return label for me to send the other one back at MY convenience. I then decided to call them and Dave was very helpful. We talked a bit and a stuck thermostat made plenty of sense. He also talked a bit about the cooling system, and water pump in the LS1. It is uneven slightly, but he didn't try to sell me on their pump which is a bit pricey. He said he would suggest that when the stock pump goes, or if you are overhauling the motor. He also talked about how their thermostat has a better bypass operation helping the cooling.

All in all, very helpful! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/biggrin.gif) Two thumbs up for customer service! I didn't even request a new thermostat, they just said they would send one. I hope this one eliminates my problems.

Then I can stop doing this..... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/banghead.gif) (IMG:http://www.frrax.com/rrforum/style_emoticons/default/banghead.gif) (IMG:http://www.frrax.com/rrforum/style_emoticons/default/banghead.gif) ---When I have problems and they have anything to do with the motor, it bothers me until it's fixed. Unknowns are the worst.