View Full Version : Overheating 2 part question

89 D'elegance
06-17-05, 12:15 PM
The other day my car overheated, it was around 95 out and caused the coolant fluid to boil inside of the reservoir and pour out the front underneath the car, today I drove it and it did not overheat or loose any coolent, todays temp. is around 70 degrees. My first question is would the outside temp cause it to overheat and not do it if it is cooler out and my second question is when you need a head gasket how long should it take before your car overheats? Thanks for your help. My car is a 89 d'Elegance with 75k miles. 5.0 engine.

06-17-05, 01:43 PM
You should not overheat in 95 degree weather with the AC on and with a trailer at the load limit of the car.

Check coolant concentration, make sure you have 50/50 mix, prefer with distilled water
Check timing, too low will cause it to run hot.
Check thermostat, is it good? I like a 180 in the 307, but a 195 should be more than acceptable.
Check cap pressure (correct rating, and is it good? Have it pressure tested)
Is the clutch fan working? It should be engaged more often (roar underhood when you accelerate at lower speeds, similar sounds to what you hear on a cold start)

Did it do it driving or once you stopped?

06-17-05, 02:17 PM
Did you add coolant since it happened? Sounds a lot like a thermostat to me.


89 D'elegance
06-17-05, 02:23 PM
It happened when I stopped the light came on said coolant temp. Took it in they found nothing wrong so I had it flushed and brought it back home. They said the thermostat was opening and closing properly, there was no coolant in my oil, all pressures were ok, and there is no white smoke, car runs great otherwise.

06-17-05, 05:30 PM
IMO it can be thermostat or radiator cap.
AND - you must always use distilled water - normal tap water consist too much all kind of salts.

06-18-05, 08:18 PM
if you have no smoke or anything, your headgaskets are probably fine. Most American V8's are pretty tough...

Hotter outside temps put more demand on the cooling system, since there is less temp difference between the radiator and the outside air. But, 95* should NOT be a problem for a properly working cooling system!

Make sure you have refilled the system since losing some coolant. A not-full system is even worse at cooling the engine.

Does your car have an engine driven fan mounted on the waterpump, or is it an electric fan? If it is electric, you might want the fan switch and relay tested, and make sure the fan motor is still nice and strong.

Other things to check: the fan shroud. Is it intact? only about 1" gap between the shroud and tips of the blades?
Also check the radiator and make sure the fins aren't mashed flat everywhere, or the radiator is clogged internally.

89 D'elegance
06-18-05, 11:04 PM
well drove car the past two days with no overheating so I dont know what originally caused it the first time but dont seem to be loosing coolant like it was, I had it flushed and they added some repair leak fluid stuff, not sure what it is called.

06-18-05, 11:17 PM
The leak stop can help small head gasket leaks, but not forever most of the time.

Blanket statements that if it doesn't smoke it probably isn't the head gasket is not accurate. You can, I did. On an Olds 350 no less. You can leak between chamber and oil, chamber and exhaust, chamber and coolant. I have also blown 2 sets the smoky (steam) way. Boosted 301 Turbo V8. But I still smoked (almost litterally) the 302 Mustang each time. It was worth the work to fix it for that....

Easy way to spot chamber to coolant, near instant pressurization of cooling system from a cold start. That is what mine did, and it would boil over when I shut it off on a warm day. But cold days were no issue. It went through very little coolant, maybe a quart a month in the summer, unless it was a bad boilover. In the winter almost nothing.

89 D'elegance
06-18-05, 11:32 PM
I am not smoking at all, it did boil over on a hot day once and all coolant was lost so I put some in and took it in after that they could not get it to overheat so they did a flush and its been fine so far. "knock on wood" Tell me if you need a head gasket, shouldnt the car overheat rather quickly??

06-19-05, 01:15 AM
Common problem and often can be the radiator itself. Next time it is cool pull the radiator cap off and stare at the holes the water flows through on the end of the radiator belot the cap. If they are covered with calcium like deposits the problem can come back sooner rather than later. Those deposits can restrict the flow, big time in some instances. Ordinary flushing won't get that stuff.

06-19-05, 09:11 AM
It is hard to see the other side too, that is harder to clean unless it is taken out.

My dad used to take the radiator out every 2-3 years and have it boiled out at a radiator shop. They could even recore it there, so having a good rad shop might be worth it. I haven't found one here yet.

FWIW, if anyone ever is planning on replacing an raditator, diesels have big ones and have built in engine oil coolers.