v8 t-stat, what else should i check Options

[smrz914]

[QUOTE]260 is too damn hot! Is this the way it has always run or a recent problem? [/QUOTE]

It's never been that high untill recently. I was always able to keep some controle over it. I was never happy with it's function but it was at least drivable before.

[QUOTE]So you have high operating temp. at idle as well as at highway speed? Just so we are clear on what you call hot........do you see 260F in both situations? If you start car and just let idle, will it reach same high temp. as while on highway?[/QUOTE]

It always gets really hot, unless I have forward motion and i let it idle, i.e. car is HOT and i'm on the freeway and I coast for a little while and then get back on the gas the temp will shoot down to 180-190 and then start climbing again.

[QUOTE]I would move expansion tank to engine bay and mount as high as possible. This will help eliminate air entering system during cool down. The long length of hose to rear trunk and its low mounting position is not the desired setup.[/QUOTE]

The expantion tank is right up against the engine/trunk wall and wouldn't get much higher if it were in the engine compartment. I would say that the bottom of the tank is at about the same level as the bottom of the intake.

I don't think I have any more wall space for it in the engine bay.

[QUOTE]This is not the proper way to purge air from cooling system and may be the root cause of your high operating temps.[/QUOTE]

I will try the procedure when I put the car back together tomorrow.

[QUOTE]Who's water pump are you using? Since you didn't have bleed holes in your thermostat, there is a chance you damaged impeller if rpm exceeded 2-3000 before t/s opened.

(QUOTE) Interesting because my first one from Renegade hit the fan (one of the impeller blades came off so I went to my FLAPS and they found me a replacement out of steel and not aluminum. The pump is a suspect being that the shaft that connects the pully and the impeller might be slipping.

[QUOTE]Hmmmmm.......the first damaged impeller was most likely caused by not having bleed holes in thermostat and running engine above 2-3000 rmp before t/s opened. Since you just drilled holes in your t/s, you may have performed the same damage again to new impeller. Unless you measured your old impeller with the new one, I would question if the clearances (impeller to water pump housing) are the same. If they are not, the water pump will not work as designed. Go after this last since it is the hardest of what I'm asking you to do.[/QUOTE]

My thoughts as well. and i'll check all the hoses tomorrow before I put the t/s housing back in b/c it takes up lots of room.

[QUOTE]I'd still like to see recent pics of your installation as it would be more benefical than a brief description.[/QUOTE]

I need to get a hold of camera and a faster internet connection I only have 56k at my moms place. I'll keep you posted.

Other:

[QUOTE]1. Have you altered the timing lately? [/QUOTE]

No

[QUOTE]2. Changed air/fuel ratio? Both can effect cooling temperature.[/QUOTE]

Yes, I leaned it out one step to what the carb came as (edelbrock 600) I originally riched it out b/c it had no top end, but my actual problem was the the butterflies were not opening all the way. Different story.

[QUOTE]3. Your method of measuring water temperature is not correct. Since water flows from water pump to block, then to heads and then intake, the desired probe location would be intake. Your 260F reading might be higher than what your seeing now.[/QUOTE]

I know it's a future change as soon as I find a good way of measuring the temp at the radiator.

[QUOTE]4. What are you using to measure temperature? I've seen false readings caused by $10 gauges. Does your engine have that \"I'm hot\" smell after a highway run? If you are really running 260F, you should be able to smell it and even hear some weird sounds when engine is shutdown. [/QUOTE]

I can imagine the smell but it's not there or i'm use to it. I'll have to check the gauge accuracy. It's a VDO guage and wasn't cheep.

[smrz914]

Did i use to many quotes? quotes are not coming up.

[steve@ottosvenice.com]

One way to make sure all the air is out of the system is to raise the front up 18 inches then bleed the system. steve

[smrz914]

ok i'm moving the expantion tank and getting some clear hose. Thanks. Your car looks great. I'm jelous.

[John2kx]

Paul,

Since your car ran fine until recently, I would reverse the only thing you changed (richen carb back up) and bleed the system as described.

Moving expansion tank might not even be required right away. Maybe over time its current location is allowing a small about of air into system but your symptoms seem to be caused by improper air purging from the start.

Something else to try on the cheap would be to replace your radiator cap with a new one. Scott at RH warned me to stay away from the ones with spring loaded relief handle.

John

[smrz914]

John i've had 3 radiator caps in the car all are the same. When i get the system bled then i'll be sure to put a cap that doesn't have a lever. I'm just usin the lever to bleed the system.

[Brad Roberts]

Keep us up to date Paul. I was away from the computer for several days and would like to hear what you found.

Johns explanation of the bleeding procedure was ABOVE anything else I have read/seen on the web. I do it almost exactly like he says.


B

[smrz914]

So I put the car back together and bled it without success. (IMG:style_emoticons/default/sad.gif) Only the first bleeding i did got a little air out, a cubic centemeters worth at most. I even put the car up on a grade so that the front end would be highter. I checked all the hoses and there were no kinks.

So what is my next attack? I thing I should presure check the system. It will at least tell me if there is a leak of some sort that I cant see.

[Brad Roberts]

Yes. Get the pressure checker from Mueller. Do you have a bleeder installed near/at the radiator ??


B

[smrz914]

Mueller i'm sending an e-mail...

Brad I have the petcock on the radiator, if that is waht you are implying. What do I need it for? I need to get a cable for my camera and then i\I can take some pics.

[Brad Roberts]

John pointed out that you need to get *some* heat in the system and bleed it from the petcock valve. Is the valve mounted high on the radiator ?


B

[John2kx]

Paul,

I take it you test drove the car and still had the exact same symptoms?

You won't get all the air out the first time. I assume you followed the procedure I spelled out. I suggest doing the whole bleeding procedure one more time before moving on to something else.

Did you see the bubbles completely go away at your fill point while engine was warming up? If you lower the level at that point about 1" and increase idle to about 1200-1500 or so, you will be able to run engine while water is expanding. If air bubbles you present then, I'd suspect a blown head gasket. You could also pull your plugs.........if a cylinder is pumping water, you'll see a rusty color on plug.

Did you richen your carb back to where it was prior to overheating?

On the subject of pressure testing mentioned by Brad, I've had good and bad experiences with the testers. I've had a nick on the mounting surface where the cap goes give false indication of a leak as well as leaking gasket on the tester.

What about having a chemical analisis performed on your coolant. I've heard these are available over the shelf or you could have a shop do it for you. This will tell you if exhaust gases are entering the coolant system.

Have you checked your dip stick for signs of water in oil?

How old was that used radiator you installed? It could have pluggage.

I would not put all my faith in the one gage your using to measure by..........install a second gage on intake.

John

[Brad Roberts]

Hum.. he is measuring the water temp at its hottest point (top of the cylinder jacket..in the head)

Is this a electrical gauge or mechanical ?


B

[smrz914]

John pointed out that you need to get *some* heat in the system and bleed it from the petcock valve. Is the valve mounted high on the radiator ?

It's at the top, maybe 1/4" from the top edge.

[smrz914]

You won't get all the air out the first time. I assume you followed the procedure I spelled out. I suggest doing the whole bleeding procedure one more time before moving on to something else.

I did do it several times.

Did you see the bubbles completely go away at your fill point while engine was warming up? If you lower the level at that point about 1" and increase idle to about 1200-1500 or so, you will be able to run engine while water is expanding.

I didn't get any bubbles at the fill point for any of the times I bled the system.

How old was that used radiator you installed? It could have pluggage.

I have a new radiator. Speeking of this, when i rebuilt the motor there was some build up of "stuff" inside the engine and i cleaned it as best i could.

I did have problems even with the original settings on the carb.

I'll go through your list John and report what I find.

[smrz914]

I have to move the temp gauge pickup to the tip of the intake. It's an electric gauge.

Another thing is that if i remove an inch of water the car will get up to 180 before it overflows. I'll try though.

[John2kx]

Brad............I understood that his temp. probe was installed in engine block.

Paul.........after running your car, you need to bleed air from petcock at top of radiator and not at fill point in engine bay. (it's not clear where your bleeding air to me at this point) Open until you get a steady stream of water. It may work either way but this is the method used by RH.

Since you didn't have your block dipped/boiled, the crud may have worked loose and ended up in radiator. There are a couple of radiator flush products that may help vs. taking radiator to a shop for rodding.

Just for comparison, I've been running my car for the past several days. Temperature here in Ga. is about 55-60F. My engine temp. runs 170-180F (both gages!) and my driving is a mixture of stop and go as well as 100+ mph freeway blasts. I have a indicator light that lets me know when fans are on and they only turned on 2 or 3 times per day.

John

[smrz914]

I use to use a combination of bleeding from the petcock and the fill point. I cant get more air out. I'll try again tomorrow. The most recent ones i just bleed from the radiator as per the instructions.

The weather here is a little colder i think. Not by much though. not that it matters since it doesn't matter what the outside temp is, my car doesn't like it.

The radiator is new and it does get hot. Maybe there is something that is in my car that i'm not noticing? I don't know.

Tomorrow is another day.

[Brad Roberts]

Depending on what fans you have mounted.. they can actually slow the air down flowing thru the radiator while your moving. Renegade has Ron Davis mount the fans about 2 inches off the actual finned area of the radiator.

Will it sit an idle and not get hot ?? What temp do you have the fans set to turn on ??


B

[smrz914]

It get's hot standing still as well. Doesn't matter if i am moving. I'm having the fans come on when the radiator is hot. It's an adjustable relay for the fans.