Help! There is Something Not Right With My Gail, but I Cannot Figure It Out...yet...:)

[GerryLP]

Gail is running warmer than usual, and I can't seem to figure out why..

She runs at 200 degrees after warm up, but after a while, she develops some sort of heat soak, and the gage climbs to 230, 250, and ever closer to the red band.

She was doing this with her stock carburetor, and still does it with the re-placement carb I had Chris do for her. Tonight, I took a look closer at her fan and clutch, and it seems to be ok -checks out fine IAW the shop manual.

Now, you guys may be tilting your heads ever so slightly and thinking, "whatchoo talkng bout, Willis?"..."most late C3's do get hot all the time in the summer", but Gail has her Heavy Duty radiator that came with her trailering package, and I have never had a problem with her gage rising as it does lately...and no, it is not a bad gage or sensor...for years, I used to wonder if her electric fan worked, for it never would turn-on, but now, it regularly is turning by the time I get home (as it happened today when coming from work).

So, W.T.H.??? What am I missing? Help is greatly appreciated

GerryLP:cool

I think that it is also causing her hard start in the morning. She acts as if there is no fuel in her carb tank...again, the same with two different carburetors. So, it almost seems as if the heat soak is evaporating the fule from the carburetor tank.

 

[RC81]

Maybe she picked up some debris from the road in front of the radiator? Otherwise have to start at the begining - coolant level, plugged radiator, fan clutch, water pump, stuck thermostat. For that dramatic a change it should be fairly easy to figure out hopefully.

 

[GerryLP]

Maybe she picked up some debris from the road in front of the radiator? Otherwise have to start at the begining - coolant level, plugged radiator, fan clutch, water pump, stuck thermostat. For that dramatic a change it should be fairly easy to figure out hopefully.

I agree! Most problem causes call for a simple fix.

Checked everything except for plugged radiator; however, the radiator does not have a lot of miles since the last complete repair phased it has (approximately not more than 10K miles).

The thermostat may be stuck in the open position, for the upper radiator hose does show signs of being under pressure.

GerryLP :cool

 

[damoroso]

Sounds like a flow problem doesn't it? Maybe it's time for a check of the thermostat, and than a flush and refill??

 

[Hib Halverson]

Couple of questions, here, the answers to which will help those reading make batter suggestions

1) How'd you determine the problem is not the coolant temp sensor or the gauge?

2) Has the engine been using coolant?

3) Has the cap been pressure checked?

4) Has any pour-in stop leak product ever been put in the system?

5) Is the front air dam intact?

6) Do you have a scan tester which can read the ECM's data stream?

 

[Peer81]

What is your oil temperature before and now. As your oil is also cooled by the coolant the temperature of the coolant and oil should be in close proximity to each other I think

And some extra questions:
When the temperature is up around 250 or so is the temperature in the same way lowering to his original 200F and then stay at 200F? This would indicate something like a thermostat sticking closed and then reopen after a while.
Does the temperature always go to a steady near red line temperature or is it different when you let her idle or when you're driving on the throttle?

Greetings Peter

 

[GerryLP]

Couple of questions, here, the answers to which will help those reading make batter suggestions

1) How'd you determine the problem is not the coolant temp sensor or the gauge?

Well, the oil temperature does creep up after a while, the fan does come on, and and it radiates heat like you won't believe. I had problems driving to the Cruise Fest back in June from the tremendous heat at that time, but cruising at 80 MPH's and A-C should not be causing the engine to operate around the 250 Deg F range (on occasions, I did see the temp needle move 20 - 30 degrees cooler ina span of 30 seconds).

2) Has the engine been using coolant?

not normally. However, what was happening on my return leg from Cruise Fest was that in the middle of a down pour, it over heated. And I figured that it had to be the radiator cap, for it was evacuating the fluids from the radiator, so I went to Chandler, OK and found the NAPA store. Bought an 18 psi radiator cap. And after that, it would hold up better).

3) Has the cap been pressure checked?

As I explained above, I replaced the 16 PSI cap for an 18 PSI cap

4) Has any pour-in stop leak product ever been put in the system?

Never!!! ;squint: ......:L

5) Is the front air dam intact?

It's brand new and holds its shape...

6) Do you have a scan tester which can read the ECM's data stream?

Nope...do you mean codes or something else?

I will attempt the thermostat next. As I said, every now and then, I can give it rpm's or step on it, and there is visible change in temperature ...to the cool side of the gage eek:eek

It is relatively new, and it is the fancy brass ones that supposedly never fails(the one that has a fail-safe feature to fail in the open position), but you never know...:ugh

GerryLP :cool

 

[GerryLP]

What is your oil temperature before and now. As your oil is also cooled by the coolant the temperature of the coolant and oil should be in close proximity to each other I think

And some extra questions:
When the temperature is up around 250 or so is the temperature in the same way lowering to his original 200F and then stay at 200F? This would indicate something like a thermostat sticking closed and then reopen after a while.
Does the temperature always go to a steady near red line temperature or is it different when you let her idle or when you're driving on the throttle?

Greetings Peter

Yes Peter,

It would do that every now and then (like at different times of driving the Vette around), but when it was happening with the weak radiator cap during the trip, it would get worse and worse, from dumping all the fluids to the collection bottle and then overfill it. And I was also concerned with arbitrarily placing a higher pressure cap, for I was concerned that it could swell the radiator and perhaps even rupture it.

Sometimes, it is even and so steady at 200, that it is wonderful and Gail loves to run. So as I explained on my previous post, I will attempt the thermostat again.

Everyone, are there any recommendations on type, brand, or rating?

Maybe I should buy the one with the GM part number for the L81...:confused...right?

GerryLP :cool

 

[BLACKDOG]

Dang, Gerry ... sounds like the problem I had with the
BLACKDOG when YODA and I ran to BG back in 2000.

It used to just idle around 180, then as the RPM'S went up, so did the temps ... like to 250+ ad

After the CAP, and the THERMOSTAT, which did nothing to the ad ... just had a shop pull the radiator, do their magic ... and it's been a COOL DoG ever since.

Hoping for the best ARF-ARF !

 

[GerryLP]

Dang, Gerry ... sounds like the problem I had with the
BLACKDOG when YODA and I ran to BG back in 2000.

It used to just idle around 180, then as the RPM'S went up, so did the temps ... like to 250+ ad

After the CAP, and the THERMOSTAT, which did nothing to the ad ... just had a shop pull the radiator, do their magic ... and it's been a COOL DoG ever since.

Hoping for the best ARF-ARF !

Jefff!!!

My man! How are you sir?

The Glass Ship is looking fine in your avatar.


I don't remember if you ever sold Black Dog or not, but it looks real fine on the image.

GerryLP:cool

 

[BLACKDOG]

Up and running !!

BUENOS TARDES from next door !!

The ol' DawG still has the ol' DoG & the SHIP.
So far, AZ is doing o.k.
Pretty much settled in the new casa, and will be checking out the VERDE VALLEY VETTES next weekend
on their monthy breakfast run in the VILLAGE OF OAK CREEK.

Any news on GAIL ??? ARF-ARF !!

 

[bill81vette]

Blackdog makes a valid point,Gerry.
Perhaps the radiator went bad already(I know hard to believe with a relatively new radiator) but perhaps.....

good luck....
perhaps try running a garden hose from the inside out to see how much crap you have picked up in the fins of the radiator...just a thought!

 

[GerryLP]

Blackdog makes a valid point,Gerry.
Perhaps the radiator went bad already(I know hard to believe with a relatively new radiator) but perhaps.....

good luck....
perhaps try running a garden hose from the inside out to see how much crap you have picked up in the fins of the radiator...just a thought!

I will try that, Bill, as well. But today, I will replace the thermostat first, and then road test it. If it happens again, then I will pull the radiator. I am not looking forward to pulling the radiator without first securing help from someone. Lest I slip on my grip and scratch her paint finish. ;squint:

GerryLP :cool

 

[bill81vette]

Lest I slip on my grip and scratch her paint finish. ;squint:

GerryLP :cool

I hear ya there!!!!
seems to me I have to have someone help me get mine in and out as well,cause its a beech!!!!

 

[GerryLP]

Well, I removed the thermostat, and it looked fine, but I went ahead and tested it, and submerging it in water 25 degrees above it's rating (180 deg F), it opens, but very slowly, and it appears to be to a maximum of 1/8 of an inch or so gap.

Makes me think that installing a lower rating one, it will cool the fluid sooner, and perhaps avoid a delayed heat soak ???

I am going now to Autozone to purchase another one. I will post how the test drive went.

GerryLP :cool

 

[GerryLP]

Ok,

I had to go this afternoon to, "The Albuquerque Uptown", mall to deal with my iPhone at the Apple Store, so I drove Gail there in Saturday afternoon traffic (you know, when everyone decides to go to the restaurants and movies all at once :eyerole ), and after warm up she was cool at about 160 or so. Then I drove the Vette with the A-C on, and with the stop and go traffic, and her temperature climbed to 200 Deg F.

So I though, 'ok, so far so good', and I stepped on her...began driving the Vette hard and with purpose (not cruising), and then the gauge needle moved off the 200 Deg marker barely so (what's that, 205 - 210 ???). On the freeway, I am trying to move it, and everyone and their grandma decides they can keep up with a Vette (don't you guys hate that???) Even Soccer Mom gets in the act sometimes...:L...anyway, we're heading to ABQ Uptown, and she climbs to the next marker after 200 Deg F. Which is something commonly noticed lately I have noticed. She climbs on temperature at freeway speeds just a bit; however, with all that ram air crossing in front of the radiator, there shouldn't be a temperature climb...:confused, right?

Alas, her temperature did not climb any higher.

After the Apple Store (which by the way, they had to replace my iPhone 3G, but they were out of them, so they gave me a 3GS iPhone instead... ), her temperature was 200 Deg going home (cruising this time, and it was 6 PM thought, so a bit cooler).

One more thing I noticed after getting her in the garage, she seems to not be radiating as much heat as she was. So perhaps, and for now, it seems to be better.

On a side note, The oil pressure gage became erratic on my way to Cruise Fest after Bud, Nancy, and I left Shamrock, so I took advantage today, and replaced the sending unit. Now it works as before...It's true, if you don't use it, it breaks faster...:L

GerryLP :cool

 

[RC81]

Maybe check your radiator hoses to make sure they arent collapsing slightly?

 

[bill81vette]

Sounds like you found the problem!!!!!
Great news!!!!and an inexpensive fix!!!!!

 

[GerryLP]

Maybe check your radiator hoses to make sure they arent collapsing slightly?

You know what? That is worth checking as well. This Vette came with a spring inserted in the return hose, but when I did the engine rebuild, I tossed it away, for it was rusted/decaying,and I was concerned of metal pieces passing by the water pump. When I went to buy one, everyone was telling me that it was discontinued.

Does anyone know if there is another C3 Vette that had this spring, and have you replaced the spring with a new one?

GerryLP:cool

 

[RC81]

Not sure if mine has one in it or not, but I know as hoses age they lose their strength and can collapse slightly with the suction of the pump. Might be worth looking into, and I would like to know about the spring as well.