ex-x-fire

OP, did you have to use any adaptors to get the sensor threaded into the head? I'm saying this because my trick flow heads have 1/2 npt holes where the originals had 3/8 npt. I used an adaptor for my cooling fan switch but it wouldn't work, even with an extra ground wire (thinking the anodized adaptor wasn't allowing a good ground). I believe my problem was the adaptor pulled the tip of the switch out of the coolant enough that it just wouldn't hot enough. I used another switch that was 1/2 threads & it worked just fine.

kitttransam

No adapter. Same size sensor.

kitttransam

So I think I'm going to sum my problem down to one hell of an air pocket that just won't come out. I tried burping the system and a few bubbles came out and my gauge went down to 208 compared to 217. But it went back to the way it was and now won't go lower than 217 again. I tried really hard to get the air out but ain't happening. Maybe it's the design of the heads? I never had this problem with the original l98 aluminums. So I think I'm going to get that vacuum set for the cooling system. Flush and refill with the vacuum deal and call it done.

GREGGPENN

The explanation of cooler water mixing in at the front of the engine seemed plausible, but you might be right. I had to drain/refill mine 4 times recently. (I swapped coolant, cleaned the radiator, and tried 3 different coolant fan switches.) At least ONE of those times, it didn't take as much fluid as I drained out. Knowing that shouldn't happen, I ran it up to temp, opened the radiator, revved the motor and still didn't get it all to go back in.

Still gotta ask if you really think an air pocket would cause such an internal difference? If there was air AT the dash sensor, I think it would be more "whacked". If there's an air pocket, why do you think the coolant is "normal" at the stat?

Tomorrow, the incredible Hulk is coming over. I asked him to hold the car with the nose WAAAAY up in the air while I refill it!

Seriously, if you think of it, please let me know how your vacuum fill turns out!!!!

ex-x-fire

Try filling it with the front in the air, I like to use one of those fill funnels.

kitttransam

i actually just bought one of those funnels to try and do a good burp session. My driveway is at an incline would that be enough or should I try raising my front end even more?

WW7

I got the unit below and can now refill the cooling system without any air in the system at all........WW

https://www.corvetteforum.com/forums...ere-it-is.html
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kitttransam

I ordered one last night. Not that brand but similar. I'll let everyone know my results.

ddahlgren

Where does the coolant go in?
How to hook up.
BTW impossible to pull -26 lbs.

kitttransam

https://m.youtube.com/watch?v=_WCRcuCZI50

kitttransam

Well I got my vacuum deal in. But I also decided to do a coolant flush because I saw brown flakes in the coolant. I bought evaporust thermocure from summit. Got very good reviews on this stuff even seen before and after pics on the review page. I'm gonna run this stuff in my motor for a week. I'm pretty sure I have rust build up in my block. I do recall taking out my knock sensor and the hole is plugged up. After that 50/50 mix and water wetter going in.

antfarmer2

Have to do both sides mine has two knock sensors. Some have one but still need to clean both sides. if you don't pull them you will leave over a gallon of crap water in it.

kitttransam

Yeah I do want to pull the block plugs after I drain all the junk out.

WW7

My mistake, it should read "26 inches of vacuum" in my other thread.. I corrected the post...WW

kitttransam

Well it's been a few days since I put that thermocure flush in my cooling system. I'm waiting for my next day off before I flush it all out. I have to say it must be doing something I took my cap off and have some crud floating in my radiator. And I'm sure it's from the block. My radiator isn't that old. And I also noticed my temps are going down a bit lower. Down to about 206 when driving on the highway. Versus 215.

ex-x-fire

Better check for debris between radiator & a/c condenser.

kitttransam

Before flush

After flush

antfarmer2

Hope you pulled your knock and what ever is on the other side.

kitttransam

yep sure did. And I'm going to flush with the plug and knock out.

kitttransam

Well temp on the dash still reading high. I'm just going to figure that it's just hotter at the heads compared to the intake. Cools down fairly fast when the fan turns on.