Bill Curlee

This is an OUTSTANDING post. I have some pictures of the crossover tubes that I will include. I have a 2002 ZO6 so,, the vent system is different than the early C5s. I did a conversion that allos me to utilize the vents on the rear part of the heads:

C5 ZO6 rear block off plugs removed and a front cross over tube installed. Vent connected to the FRONT cross over with a metal T connector:






97-2000 C5 OEM Steam Vent corss over line under manifold:



2001 C5 Coupe LS1 Look closley and you can see the block off plug on the rear drivers side head:

kazoo794

All this sounds familiar, I will check it this week when the weather clears up. Last night when we were working on it we tried to bleed it but not to that extent. We will try this again and let you know. Thanks in advance!

woodman300

if you want to bleed air from the steam vent tubes, why can't you just pull the rubber hose at the front? when i removed the intake from my 2000, it drained from there until the recovery tank was mostly empty. it appears to be the highest spot in the cooling system. when i get my all my new hoses on and go to fill it up i think i will leave this one loose until i see some coolant coming out. most of the air should be gone, no?

Bill Curlee

Corvettes are back on the road after a long winters nap. Bump TTT so people can resolve their cooling issues if there is trapped air in the system.

Bill

Texas1ao

Another vette back on the road thanks to the great post you find on this site.

WHITLTNG

Can you do this instead of loosining the bolts?

bad455ta

I tried this, and nothing but a couple of drops came out. I even ran the car to temp and nothing. Any suggestions?
My car is idling at 230 and if I get on it it will get over 240!
way over my comfort zone

WHITLTNG

What all have you tried? I'm in the same boat!

73Corvette

Have you checked your A/C condenser and Radiator? I pulled the shroud and jacked up to look under... both ways it appeared to be clean. I tried blowing air thru the fins with a compressor and a tip I modified to slip between the the two cooling coils...I couldn't blow anything out!
SO I PULLED out my radiator... IT was TOTALLY blocked off with tiny little brickets of BS in every little square fin...you couldn't even see light thru it holding it up to the sun... AFTER several good soaking and rinsing sessions I got it CLEAN you could see right thru it...Runs right in the sweet spot now!!!!!!!!!!!!!!!!!!!!!!

This was on a 2004 with 28K miles on it!

bad455ta

It was my thermostat! Turns out it was stuck open and according to my mechanic, it was constantly recirculating the same coolent and unable to cool portions of it enough to stay cool under load or on really hot days. He claims to have let it sit, and run it in traffic and it didn't get above 205
Any how, I'll be picking it up today and reporting back.

TJ Strummer

What if your driver side fan is not working. I can turn it manually without the engine running but not sure what else to check. Please advise.

Thanks

TJ Strummer

How would you check if this fan were broken?

NemesisC5

Stuck closed, a problem. Stuck open, no problem. Curious to see your results. If a new t-stat fixed the problem it was stuck closed.

73Corvette

Copied from a Chuck CoW post years ago....


Here's the deal.... YES, ABSOLUTELY a 160 t stat will lower your temperature.

Do not be mislead by people who don't really know and just like to hear themselves talk.

Some facts...Your corvette left BOWLING GREEN with a 187 deg stat.

Yes, your corvette (with 187 stat) can run at temps of 220 and higher in the summer....

The perfect target temp for LSx engine operation is roughly 190-200. This is our target. Sometimes a bit less and other times a bit more.

But, let's figure it like this.... Your car (with stock stat and programming) will usually get over 215 on a hot day.....

When we do the math.... 187 deg minus 160 deg equals about a 27 degree difference.....Hence, your car can easily run just under 200.

Forget the garbage about stats opening wide after 160 and staying open....It's ABSOLUTELY UNTRUE...especially when the correct fan calibrations are programmed.

The stat does NOT pop open at a pre determined temp.....It (listen good here) BEGINS to open and is constantly opening and closing as warmer water exits the engine and is replaced by cooler water returning from the radiator which actually causes the stat to begin closing slowing the exchange rate between the radiator and engine so that the HOT engine water and COOLER radiator water switch places.

If your stat stayed open, two things would happen depending on the efficiency of your system.

A) your car would overheat badly.

or

B) your car would never reach operating temp.

TO ABSOLUTELY MAKE MY POINT HERE... It is a proven and very well known fact that when a C5 or C6 stat, in a stock or otherwise mildly modified engine, sticks open or fails in the open position the coolant circulates TOO FAST and the coolant temp when cruising down the highway will drop as low as 150 deg in cool weather.

LISTEN UP: This is a good point and everyone should be aware of it. If your Corvette runs at anywhere near 150 deg fully warmed up when cruising at highway speeds at night or in cooler weather....

YOUR STAT IS STUCK FULLY OPEN!

Sorry to be rough on everyone here, but...I'm kinda frustrated with all the "STAT EXPERTS" on this site telling people that what I do is wrong....

The most common failure of stats is by people who install them incorrectly....When a Corvette cooling system is not filled correctly (underfilled or air bound) a pocket of steam develops in the engine and when the owner tries to drive the car...the steam ruptures the wax pellet in the stat and it usually FAILS in the STUCK OPEN position.....when the coolant is eventually filled up correctly....THE VEHICLE RUNS TOO COOL...Usually about 150 or so.

Again, this is TRUTH regarding the "Stat is open and useless after 160" debate.

The corvette cooling system is VERY EFFICIENT and has the potential to run too cool.

NOW, what I suggest is a proper 160 stat and the fan calibrations I use.

Some tuners don't believe in 160s and that's their problem. They believe that it's unnecessary and they can just command the fans on all the time to compensate.

The truth is...

#1.... that it causes big temperature fluctuations in most cars.

#2.... The harder you run the fans....the less time they will last.

#3.... The harder you run the fans.... The louder they will be and more annoying they will be...

#4.... I have proven that running C6 PWM fans at full duty cycle in hot weather will cause the wires to MELT. GM also figured this out as the fan calibrations in C6s are limited to well less than 100% for a good reason.

#5..... Your fans likely draw between 30 and 40 amps and your alternator needs to produce that power which ultimately costs a few horsepower.

It is of the highest importance to have a 160 stat and to properly re-calibrate the fans if you want the BEST performance and to know that your car is running safe.

For you automatic guys...Also understand that your TRANSMISSION is cooled by the engine's radiator and TRANSMISSION fluid does not like heat.....

The life of the transmission fluid (and the transmission itself) diminishes proportionate to the increased temperature it operates at. Again, another proven fact.

NemesisC5

Deleted the rest so not to occupy real estate. Some true..some not, what I stated is fact...I'm not selling anything.

73Corvette

I doubt he makes a living selling stats...

NemesisC5

He Tunes to make a living and any ancillary aftermarket items that he sells he optimizes his tunes to make the most of them. The post was about tuning the car correctly for fan management with 160* thermostat. How many have a 160* t-stat that cools no better than a 187* t-stat in summer weather? Likely everyone. The sale of a 160* t-stat that requires a $900 tune to optimize results is pretty good salesmanship in my book.

I have the utmost respect for Chuck, he is a great tuner but not an expert on cooling system design.

73Corvette

I guess the point was...

If your stat stayed open, two things would happen depending on the efficiency of your system.

A) your car would overheat badly.

or

B) your car would never reach operating temp.

Just sayin... I can't say, I'm not an expert that's why I look to others for their input... unless I have some empirical evidence to suggest otherwise...

NemesisC5

A 160* t-stat in an LS engine will remain open at 160* and above and will only close when coolant temps fall below 160* which will not happen in summer months. It will not cause your engine to overheat and it will reach operating temps in the summer. In cold states during winter months a 160* t-stat will not open until 160* to allow coolant and will likely stay at 160* but never below. Insert any temp t-stat into this in place of 160* and the same will hold true.

foggy

Thru personal experience, I don't agree with the above post.
IF a Tstat is Always open, it won't keep the coolant in the radiator
LONG ENOUGH to dissipate (or radiate) the Heat.. Hence an overheating issue.
A few years ago, I replaced a very expensive radiator thinking IT was the
problem because my Tstat was a high quality new one and I kept running hot.
Only AFTER I was able to drive it on a cool morning, I found my temp on highway
only getting to 140* ish..
But in warmer weather, It ran over 200*. I know it seems strange... but

Replaced my stat and boom.. All back to normal