Car is running cold... been through 2 stats. Help?

JasinC19

What hole is this!?!

Jun 7, 2011

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Jul 19, 2011

#1

• Jul 19, 2011

• #1

Hey guys,

Looking for some help here. I put an OEM replacement Stant superstat 195 thermostat in my 5.0 and ever since then the temp gauge will *occasionally* reach normal operating temp, then divebomb down to the 2nd mark from the bottom. (which i estimate to be 165f) It will then hold steady for some time.

As the title states, I've replaced the thermostat with another exact replacement, everything is sealed up well, i bled the system according to shop manual, and made sure the spring side of the thermostat was facing firewall.

Can anyone give me some advice?

The Stant t-stats do NOT have a bleed valve, but I've noticed that many other brands do not (including Mr. Gasket which everyone loves)

NOTE: I did pull a code (no SES light on) that said something about the A/C switch output being too high or something. Not sure if this could possibly affect it.

Thanks!
Jason

 

bmo37

Founding Member

Jun 27, 2001

2,368

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New Jersey

Jul 19, 2011

#2

• Jul 19, 2011

• #2

sure your sending unit is working right or the gauge is accurate. I actually have the opposite problem I run overheating under load or cruise. I would verify temps some other way like an IR heat probe gun. Could use under drive pulleys to slow the water pump hence making it run hotter and not pump as much coolant. Do you run electric fans? Sure you installed the stat the correct way, could open up and get stuck open which would continuously cycle coolant not letting the engine get up to temp.

 

lxman

Member

Nov 5, 2010

279

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19

Avondale, AZ

Jul 19, 2011

#3

• Jul 19, 2011

• #3

Try getting your radiator cap tested and pressure test your system. You should test your t stat before you put it in to make sure it operates properly.

 

JasinC19

What hole is this!?!

Jun 7, 2011

312

2

19

Jul 19, 2011

#4

• Jul 19, 2011

• #4

Hey bmo,

No, not electric fans yet. Everything relevant is stock.

Before I switched out the oem t-stat (from '93), everything was fine; Temp gauge in the middle of the range with little movement.

I'm starting to think I either got a MASSIVE air bubble in there somewhere or something.

What would be the best way to check the cooling sending unit? Can I do it with a multimeter?

Would a bad cooling sending unit throw a code?

Jason

 

Kdubslugga

Active Member

Jun 7, 2003

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Akron, OH

Jul 19, 2011

#5

• Jul 19, 2011

• #5

I would think an air bubble would cause overheating? I dunno could be wrong

 

JasinC19

What hole is this!?!

Jun 7, 2011

312

2

19

Jul 19, 2011

#6

• Jul 19, 2011

• #6

Yeah... I know that's the norm.

But seeing as how I'm not 100% sure why it causes overheating, I am guessing it could cause the opposite as well.

It's seemingly not a very common problem...

The thing is, when the engine cannot reach normal operating temperature, fuel economy is basically crapola. (12-15 mpg)

That's why I've been driving my Civic until I figure this dumb problem out.

 

Beasty306GT

Active Member

Dec 19, 2002

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Oxford,Mass

Jul 19, 2011

#7

• Jul 19, 2011

• #7

I would replace the temp gauge sensor and go from there there pretty cheap at autozone

 

J

jka

5 Year Member

Jan 17, 2010

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Jul 20, 2011

#8

• Jul 20, 2011

• #8

If you still have the stock gauge...that may your problem not the t-stat. If you are still using trhe stock gauge... please install an aftermarket temp gauge... because the stock gauges are almost wrong all the time. Your normal temp with a 195 degree t-stat should be 195-210 in the summer and a bit lower than that in fall and winter.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Jul 20, 2011

#9

• Jul 20, 2011

• #9

Though you're doing a relative comparison with the same gauge, I do agree about using an aftermarket or alternative means of checking the absolute coolant temp. You can interpolate the ECT for free if you have a DMM.

 

JasinC19

What hole is this!?!

Jun 7, 2011

312

2

19

Jul 20, 2011

#10

• Jul 20, 2011

• #10

HISSIN50 said:

Though you're doing a relative comparison with the same gauge, I do agree about using an aftermarket or alternative means of checking the absolute coolant temp. You can interpolate the ECT for free if you have a DMM.

Click to expand...

Hi can you clarify this? What is the ECT? Cooling Temp?

What is a DMM? Digital Multimeter? If so, is there a writeup for this somewhere?

Thanks,
Jason

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Admin Dude

Jan 4, 1985

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Jul 20, 2011

#11

• Jul 20, 2011

• #11

Kdubslugga said:

I would think an air bubble would cause overheating? I dunno could be wrong

Click to expand...

+1

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Jul 20, 2011

#12

• Jul 20, 2011

• #12

JasinC19 said:

Hi can you clarify this? What is the ECT? Cooling Temp?

What is a DMM? Digital Multimeter? If so, is there a writeup for this somewhere?

Thanks,
Jason

Click to expand...

Yes and yes.

With the ECT connected, carefully backprobe the output wire (one wire will read 5 V. You want the other wire).

At 194*F, you should read .61V. At 212*, you should read .47V

 

88gt373

Member

Dec 29, 2010

140

2

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Jul 21, 2011

#13

• Jul 21, 2011

• #13

check out this post i just did..... same problem with my cooling system and my w/p was running the wrong way...... mine has to run counter clock wise like most......


check here for post

you want the routing like this:

alt-tensioner-a/c-p/s pump-water pump-crank-smog-alt

or if you dont have smog stuff or ac just make sure the w/p is COUNTER CLOCK WISE... MAYBE THAT HELPS.. GOOD LUCK

 

JasinC19

What hole is this!?!

Jun 7, 2011

312

2

19

Jul 23, 2011

#14

• Jul 23, 2011

• #14

Just a quick update guys:

Changed out coolant temp sensor... no luck

Then I changed out coolant temp sending unit and took her for a spin. Gauge works perfectly now.

Thanks for the advice.

 

D

Dave2000GT

Active Member

Oct 3, 2005

229

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Seattle

Dec 8, 2012

#15

• Dec 8, 2012

• #15

JasinC19 said:

Just a quick update guys:

Changed out coolant temp sensor... no luck

Then I changed out coolant temp sending unit and took her for a spin. Gauge works perfectly now.

Thanks for the advice.

Click to expand...

Any progress on the low mpg issue ?