Running hot question?

0-60N4

0-60N4

Member
Working on a friends Sy. It was running a little hot, around 200 degrees per diacom. The coolant was very dirty and rusty and it was missing the skid plate. Installed skid plate while converting to a 3 bar MAP and chip. Temp were still high so today flushed the radiator and installed new coolant and replaced the 195 degree stat with a 160 degree. Started up and at idle is settled in at 165. Perfect...but not for long. As we test drove it, the temps went up again to about 210. Checked fluid leve and it was OK but looking dirty again. I looking inside the radiator fill neck while running and could see water flow. Increasing rpm to 3000 caused water level to drop but it came back to full when going back to idle. Thinking about running it with no stat to see what that does. Any other ideas what could be making it run so hot?
 
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denny

Active member
Re: Running hot question?

Is the readiator and upper hose hot, I mean supper hot?
If is not so hot, then it might be the water pump/thermostat, if its real hot maybe a bad radiator/fan.
You check that the radiator cap holding pressure?

I also have a slight heating issue, haven't figure it out yet.
 
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pinellas50

New Guy
Re: Running hot question?

Water drop is normal with the cap off.

Is it heating up at idle or at cruise? Heating at idle is normally a fan issue and at cruise is a radiator issue. Rules of thumb for what it is worth.
 
Don W.

Don W.

Stab it and steer it
Re: Running hot question?

X2 water drop is normal. Easy to check the tstat on the stove, especially if it's not a new one. If new prolly good. My truck has always wanted run a bit hot. My skid plate is off, didn't know that could be an issue. I've had good luck with running rad cleaner through the system. I'm on my third batch and it has made a difference. A clean system is critical. Might need a good old-fashioned rad boil out. Dow (I think it was Dow) used to make a supper duty rad cleaner that came with it's own neutralizer, pretty severe stuff but it worked.
 
Foot Performance

Foot Performance

Donating Member
Re: Running hot question?

I would check the cap first (easy fix) i had a car not a sy but i would run fine at idle but you went down the road and it heated up it was the cap

Also if you could find someone with a BG coolant exchanger it woudl run 4 to 5 gallons of coolant in reverse (back fluching the system) sometimes this helps break some stuff loose
 
SY2932

SY2932

Administrator
Re: Running hot question?

X2 on the radiator cap. On my old daily driver I had a problem with overheating and that's what it was. The upper radiator hose had so much pressure in it, it looked like it was going to burst :eek:. The cap wasn't opening to dump into the overflow.

Dirty and rusty water is a sign that air is getting into the system somewhere. Does he have or did he have a bad heatercore? If the coolant was REALLY bad, all the scale that is built up on the fins may affect the heat transfer. Removing the radiator altogether and reverse flushing it may help too.
 
A

artisticent

Member
Re: Running hot question?

This may not be the answer, but my truck was having a few issues with the water getting too hot and blah blah. All I know is that these trucks are already hot enough so without risking it I went and boutght everything top shelf. 160 thermo, high flow expensive water pump, all hoses and new radiator cap. the truck runs great and cool all the time. considering its just an S10 cooling system figure $200 total for all the goodies is a bargain. My .2C
 
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pinellas50

New Guy
Re: Running hot question?

Foot Performance said:
I would check the cap first (easy fix) i had a car not a sy but i would run fine at idle but you went down the road and it heated up it was the cap
Click to expand...
Yes! I didn't even think of that. Also, if the cap doesn't hold the correct pressure, it will cause cooling problems. The higher the pressure in the system, the harder it is for the water to heat up to the boil point. Same concept as a pressure cooker.
 
TxSy1430

TxSy1430

New member
Re: Running hot question?

I started with replacing the 160 t-stat. Then the water pump...then finally the radiator, it was so plugged that even with the tanks off they could not open it up. so I went and bought a new one. Now the truck stays a needle width below 160 all the time.

Scott
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: Running hot question?

sorry to thread jack but why would the level dip when it is running if it is an enclosed system?

forgive my ignorance
 
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denny

Active member
Re: Running hot question?

Quickstop [UK] said:
sorry to thread jack but why would the level dip when it is running if it is an enclosed system?

forgive my ignorance
Click to expand...


I am no mechanic but would think the water pump spin faster, suck out of the radiator and create more pressure in the engine, also the system is never totally air free.
 
SY2455

SY2455

70's Veteran
Re: Running hot question?

The other thing you can do if you want to inprove the stock cooling system is to install a fan from a 2001 Chevy Astro van
 
0-60N4

0-60N4

Member
Re: Running hot question?

I was thinking there might be a better option for a replacment fan while I had the fan clutch off. What is different about the 2001 Astro Van fan and is that the only year?

The fan clutch was easy. Belt did not have to be removed. Temp are better but the weather is about 20 degrees cooler also. Still not where it needs to be. Running about 180 at cruise now which is not bad.

Anyone ever try the flexalite fans?
 
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SY2455

SY2455

70's Veteran
Re: Running hot question?

0-60N4 said:
I was thinking there might be a better option for a replacment fan while I had the fan clutch off. What is different about the 2001 Astro Van fan and is that the only year?

The fan clutch was easy. Belt did not have to be removed. Temp are better but the weather is about 20 degrees cooler also. Still not where it needs to be. Running about 180 at cruise now which is not bad.

Anyone ever try the flexalite fans?
Click to expand...

This is what is different about it. And yes it comes on other years as well, see links here.

# 1 ACDelco Part # 15-80712 http://198.208.187.182/servlet/com.entigo.acdelcocatalog.servlet.ProcessImageServlet?languagecd=EN&countrycd=US&user=InternetUser&mfgname=ACDELCO&prodlinecd=15&acpartnbr=15-80712

# 2 http://198.208.187.182/internet/VehiclePartFits.jsp?autosel=A&part=15-80712
 
SY2455

SY2455

70's Veteran
Re: Running hot question?

0-60N4 said:
So you are saying it has 11 blades?

All the ones for the Astro Van I have found have 5 like this:
http://cgi.ebay.com/ebaymotors/RADIATOR-FAN-BLADE-chevrolet-ASTRO-85-05-cooling-van-ac_W0QQcmdZViewItemQQcategoryZ33600QQihZ014QQitemZ330163515367QQrdZ1QQsspagenameZWD1V

Could you tell a difference in air flow?
Click to expand...

Yes it has 11 blades and yes it works alot better than the stock fan and bolts right up to the stock Syclone/ Typhoon fan clutch. The E-bay link that jabberwalk posted is a good picture but just my opinion is going to be stated now. Sooooooooooo,

I pick mine up brand new from the stealership for $ 54.00, so I would pass on the E-bay one.:tup:
 
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