This is going to sound silly this far into the problem...but...replace your thermostat. SO cheap and SO easy, could be stuck!

 

I would be screaming at the dealership a long time ago. I hate it when customers wait a week after you do something to come back in and tell you it's not right. Not only is it irritating for the shop, the customers credability is lost as well. If you pay someone to do something and it's not right don't wait to let them know about it.

 

I saw the water recirculating today , so the thermostat opened up ... but it couldnt hurt to replace it. I am surprised the shop didnt swap it when they changed the waterpump.

I didnt take it back to the shop yet because I havent been able to hook up a ride home from the shop ... I dont know many people around here , and a cab ride home is $30 ... then the ride back. I called the dealership and left a phone message a couple hours after I got the car back, with no return call.

I figured if it was a quick/easy fix I would rather do it myself, BUT honestly it hasnt quit raining since I got the car back!!! I dont have a garage to work in. ---

 

OK, I tried bleeding it again today ... just WAY more thoroughly, and the same ****. I bled from one screw to another back and forth, and in about 30 minutes both were peeing steady. Do you have to bleed it after multiple drives to get everything out?

The car will idle for hours and be fine, but the SECOND I hit the highway (50+mph) the thing shoots up to the red (250 degrees).

THE SECOND I put it up to 3k rpms the temp goes straight down to 180-190 degrees....so I have been driving it home in a lower gear at 65mph.

I am going to guess its a 1/2 stuck thermostat. Blocking 1/2 the flow, so when the waterpump kicks it in high gear it makes up for the blockage? I saw the upper hose move the coolant the other morning with the cap off the radiator, so I know its atleast opening up a bit.

This just goes against everything I understood about engines, usually they overheat at idle ... and stay cool at 50+mph hahaha.

Time to swap out the thermostat. If its not that, I guess the next step is to clean out the radiator. ---

Edit: I just read EVERY thermostat post made, and they said that if I see coolant flowing with the cap off... my heat works good... fluid comes out of BOTH bleeders... and the upper radiator hose gets hot , my thermostat is fine?! I experience ALL of that. Should I mess with the thermostat? WTF could be the problem? ---

 

Man! I am at a loss here but am starting to wonder...an LT1 waterpump, being cam driven, usually doesnt have a high failure rate (unless you count the weeping weep hole on the bottom, which is an opti assasin). Consider this, maybe you are not getting decent coolant flow due to a failure in the coupling of the cam and the pump. Weird, and I dont know if it is even possible, but it would be worth a shot.

I would DEFFINATLY swap the thermostat, it takes 10 minutes, basic hand tools and would be worth the time, specially if that was the problem! Also, throw some water wetter in there (you can pick up a bottle from autozone, or any other parts store). That will get your temp down a couple of degrees. Another idea would be to ensure you have the correct ratio of 50% water and 50% etholeyne glycol (coolant). Just drain and fill it back up, the too lean or too rich and it could run hot.

Did you install new fans? If so, at Autozone, we sell fans that spin reverse (counter clockwise) and they could be working backwards?

Hope something I said helps...probably not.

Charlie

 

If you could review the T_stat closure of the WP internal bypass, you would see that for the bypass to seal the WP will be open untill nominal design temperature is reached. Also, the stock T_stat bypass plug does not really seal the WP bypass hole very good( flat plate on a cast surface). The WP bypass hole can be plugged permanently to stop re_circ of cooling media, and, divert all fluid to the rad core. I did this, but, I run Evans with NO T_stat. I would also check your fans and the air dam. 4th gens require alot of air flow for cooling. B.

 

Thanks guys ... I am starting to wonder if the dealer didnt install the waterpump correctly.

Thermostat here I come. If i go 160 instead of 180 ... do I need to retune the PCM? If so, I will just go 180 again. If I go 160 , the heat would suffer, right?! ---

 

I have delt with this before!!!! First. You do have air in your system. It is not your water pump. If it was your water pump then when you rev the car up it wouldn't make the temp drop down like its doing. You need to check if your coolant reservoir is busted first off. They tend to crack where the tank and the top is molded together. Poor design having the battery rest on it. I have had two different ones break right there. I just put ANOTHER one on mine. Now the proper way to add the coolant to your system is really easy and won"t take that long and you will have minimal air to bleed out of the system. Take the thermostat neck off, there is only 2 bolts to undo, then add your coolant straight into your block where your thermostat sits.(make sure to move the thermostat first.) once that area is full reinstall your thermostat and your thermostat h ousing. Make sure your radiator is completely full and put the rad. cap back on.
(Keep the cap on. your car has to be bled so trying to do this with the cap off is impossible.) Add water to your reservoir and make sure it is full as well. The car should not be running yet. If you see that the coolant is not at the top of the reservoir while the car is still off then You have a reservoir leak. (needs replaced.) Now you need to crank the car and let it warm up a little bit and follow the bleeding directions that were posted earlier, while making sure you keep adding coolant to the reservoir the entire time you are bleeding the car you will know when it is full of coolant and there is no more air in your system when the reservoir is full and not going down any longer and only coolant is coming out of the bleeders.. MAKE sure all of the air is out and it will stop the over heating. You might even drive it for a minute then check your reservoir and add coolant again if needed and bleed again. Sometimes it takes a couple of trys to get it right.

Good luck

 

Thank you SO much. I think my problem was I only bled it ONCE the other night.... then it was too late to do it again and again.

I will try the Thermostat fill idea .

It could be a broken reservoir ( I dont see ANY leaks under the car ) BUT my battery has been known to break free from the tie down ... and could have cracked something during accelleration.

I really appreciate the time and advice ---

 

No problem. You will know if the reservoir is busted if it will not hold coolant all the way up into the top of the neck.

 

[QUOTE=Venomous360;6150231]You can do an Opti Change with minimal tools in less then an HOUR.

What's the procedure to do the change in less than an hour?