Water temp: 140F; Oil temp: 180F

[Dangerous Doug]

My water temperature is running at a low 140F, and the oil temp is also reading a bit low at 180F. I noticed this last week, and yesterday I replaced the thermostat, but the odd temperature readaings persist. I popped the hood and felt the heat coming off the engine and it seems quite hot to me.

Any ideas of what may be going wrong here? I hadn't changed anything when I noticed the issue. I did change out the thermostat, rerouted the hose to my Harrison tank, and installed a new water neck while I had the fluid out.

I burped the cooling system from the water neck, but the highest point on the cooling system is at the radiator, not the water neck. I'm wondering if it is not completely burped.

Any ideas?

DD

[Dwight]

Doug, do you have a thermometers? Wife's meat thermometers would work if it goes to 200 plus. Press it against the hose or touch the water outlet.

I use a infrared digital laser pyrometer. Great tool to have when working on a Cobra. No guessing about the temp of the oil, water, block, radiator, headers, etc.
The gauge read low on my oil temp till I moved the sensor to the remotor oil filter.

Dwight

Search Results for laser thermometer - SummitRacing.com

[patrickt]

If I put a pot of water out in my front yard it's going to be hotter than 140 degrees. Get an infra-red thermo gun at the local hardware store and take a couple of readings on your upper radiator hose and other points and see what it says. Maybe you just have a bad gauge.

[rpatton3]

We always tested thermostats on stove with pot of hot water and meat thermometer.
Crude but effective.

[Rick Parker]

Maybe your water temp gauge conked out?

[Dangerous Doug]

I don't think the guage has conked out, as the oil temp is running a tad low as well---even though the engine and coolant lines seem quite hot. I'll mess with it again this weekend. The only things I can think of as a source is the thermostat, or that it's not yet properly burped.

Anyone have air pockets in their cooling system? What are the symptoms?

DD

[strictlypersonl]

The oil temp seems pretty "normal" for non-racing conditions, but the water temperature is pretty low if you're running the recommended 175F thermostat. Pull the bulb out of the intake and test it in some boiling water.

[Rick Parker]

Did you change the type of coolant being used such as 100% water in lieu of coolant/water mix or has Water Wetter been added?

[MaSnaka]

Is it possible you have electronic gauges? You didn't mention that in your post. If so it could be an electric issue??

John

[jhv48]

Test the temp sending unit in boiling water on the stove.

Ten to one, it's time to replace the gauge or sending unit.

[FWB]

maybe wrong t-stat, or it slipped down if there isn't a slight counterbore in the new water neck to hold it in place...it'll run at exactly 140 cruising and creep up to 160ish at idle,,,,,

[WardL]

I used a fail-safe thermostat once and found it to fail open when my coolant got to about 190 F. With the thermostat failed open, the water temps stayed down in the 150 F range until the thermostat was replaced. I decided I didn't want a fail-safe thermostat even though the warranty would give me a free new one!

[CHANMADD]

Have you checked the charge coming out of the alternator?

[Dangerous Doug]

Nope on the 100% vs. 50/50. I always use 50/50 out of the bottle because I can never get the ratio correct while filling.

Well, I pulled the water neck off this evening as well as the thermostat. Nothing seemed amiss there. I'll test the guage sender unit with a pot of boiling water (should read 212F here at sea level) to see if that is the issue. Might as well replace the thermostat, but test it for opening with that same pot of water before I install it.

In the past (yeah, like 20 years ago...) I've installed a new thermostat only to find it isn't working correctly. Good idea to toss it into boiling water to make sure it opens.

The only thing I hate working with more than antifreeze is brake fluid! Yuck!
DD

[FWB]

i put one of these on my intake to bleed out air.....it is so sweet i wish i had one 20 years ago. you just push the plunger with your finger and the air escapes......sold by morosso....


you can see it there next to the distributor

[Dangerous Doug]

Originally Posted by FWB

i put one of these on my intake to bleed out air.....it is so sweet i wish i had one 20 years ago. you just push the plunger with your finger and the air escapes......sold by morosso....


you can see it there next to the distributor

Awesome! I'll sleuth around on Summit Racing to see if I can find one there. No doubt "cooling system air bleed" or something like that. Great tip!

DD

[Dangerous Doug]

And the prize goes to.... PatrickT for being the first to call out the water temp gauge. I put it in a hot pot of water and it went up to 120F briefly, then down to 100F. After that, it was just dead. Just for peace of mind I tested the thermostat and it opened right up.

Good grief. I should have started with the gauge, though I did take the opportunity to change out the water neck to an aluminum one with a port, and reroute the hose from my water pump to my Harrison tank. But, given the opportunity to NOT do all that AND not smell like antifreeze, well...like I said, I should have started by testing the gauge.

Well, Bob, what is the standard coolant temperature gauge that comes with the ERA 289 FIA? Is there an electrical guage that has the same look (bezel, face, and sweep)?

I'll be picking up a couple of air bleeders (one for the Cobra, and one for the KC 331 I'm building in my garage---SummitRacing has them), and a new coolant temp guage.

DD

[patrickt]

Originally Posted by Dangerous Doug

And the prize goes to.... PatrickT for being the first to call out the water temp gauge.

Unfortunately, the prize is an autographed cheesecake photo of Rick Lake.

[FWB]

i think the prize is getting it fixed......

[Dangerous Doug]

Originally Posted by patrickt

Unfortunately, the prize is an autographed cheesecake photo of Rick Lake.

I'll buy you a beer.

Could have been worse: if this had been a 70's game show you'd be the proud owner of a Ford Pinto...

DD