Overheating 94 Eldorado !!!!

[rbotti]

Last summer my 94 Eldorado Sport Coupe overheated and I was forced to the side of the road. It was a little strange when the computer shut down the engine to just an idle and the elevator bell started to sound. Once cool enough, I added coolant and continued home without further problem.

Then in August the add coolant light came on and I had to add just under a gallon of coolant. afterwards I purchased a new radiator cap and kept on eye on the engine temp. Then in early November the car over heated about three blocks form home. I checked the coolant the next day and it needed almost two gallons that time.

No leaks form the water pump or hoses, so I found a factory rad cap and replaced the aftermarket cap I bought earlier. Ok, I drove the car around town and performed a few errands without any trouble. Then when my confidence was starting to return I did one more errand, the temp was 199 when I shut the engine off and went in side for 5 or 10 minutes. After I got back in the car and started the engine the temp was 210 and rose to 217 by the time of got out of the parking lot. I got a mile for home when I pulled over and shut off the engine, it was 255.

In November 2007 I had to replace the radiator and thermostat, but it's just my guess that either the thermostat has gone bad or the computer thinks the engine is running cooler than it really is. I do not know how the thermostat works on these cars, but this is gotten out of hand.

Before I bring the car into the dealer, does anyone any suggestions??

[creeker]

Have you considered that it could be the dreaded blown head gasket that are quite common with the northstar engine?.

[winterset]

I wouldn't jump to conclusions - Doesn't sound like the typical HG symptoms. You are loosing coolant, and I suspect the surge tank. make sure your surge line is clear, and that your cooling fans are coming on. 225 is an acceptable range. when you hit 255, you were overheating. Check for powered coolant around hoses, tanks etc.

[Cadillac Jim]

Your symptoms do sound like a head bolt has pulled out. With one head bolt pulled, your first symptoms would be use of coolant where you never previously needed to add coolant, and overheating about a minute after pulling a significant hill on the freeway or passing a truck on a two-lane highway, but no problems driving around town. There are other possibilities such as slipping water pump belt but you can eliminate a head gasket by having the coolant tested for combustion products. A good radiator shop should be able to do this with test strips or solution in a few minutes.

[Ranger]

You are adding too much coolant, too often. Either it's leaking and evaporating before you see the leak (best case), or you are burning it (worst case). Have the coolant tested as suggested before throwing parts at it. That will either condemn or rule out the head gaskets.

[rbotti]

Checking the coolant for combustion byproducts is a good idea. I’ve checked the oil and don’t see any water in it and water in the oil is something I’ve seen several times before on other cars. I have suspected that the when the coolant overheated it escaped through overflow tank. One thing that I remember now is that when the temperature rose to over 225, that it seemed very humid in the car, like steam was entering the passenger compartment. I remember that there were fans running in the engine compartment after I pulled the car over and opened the hood. I've owned the car for 14 months now, and I that time it normally operates in the 199-210 degree range.

Before the car overheated this last time, I drive it on the freeway without a problem, but for a few minutes the temperature rose to 235 and the slowing dropped to 199, that is why I suspected the computer, a sensor or the thermostat.

[Ranger]

I’ve checked the oil and don’t see any water in it and water in the oil is something I’ve seen several times before on other cars.

Northstars rarely put coolant in the oil when the head gasket goes, so don't use that as any type of benchmark.

[MAC]

Checking the coolant for combustion byproducts is a good idea. I’ve checked the oil and don’t see any water in it and water in the oil is something I’ve seen several times before on other cars. I have suspected that the when the coolant overheated it escaped through overflow tank. One thing that I remember now is that when the temperature rose to over 225, that it seemed very humid in the car, like steam was entering the passenger compartment. I remember that there were fans running in the engine compartment after I pulled the car over and opened the hood. I've owned the car for 14 months now, and I that time it normally operates in the 199-210 degree range.

Before the car overheated this last time, I drive it on the freeway without a problem, but for a few minutes the temperature rose to 235 and the slowing dropped to 199, that is why I suspected the computer, a sensor or the thermostat.

Check purge line for blockage. I had the same problem and cleared the purge line and all was fine after that.

[rbotti]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

[growe3]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

Rick,

Unfortunately "funny" usually isn't. The symptoms you describe sound typical of head gasket leakage. In the Northstar engine it is usually sucked into the combustion chamber, and burned along with the fuel.

As mentioned before, the best test is a check of the coolant for hydrocarbons. If it is the head gaskets it will need Timeserting for ALL of the head bolts

I have repaired two STS's, and while both went through large amounts of coolant, they still ran well (except for the overheating).

-George

[rbotti]

Well everything is back together and I admit that I no longer feel comfortable driving the car more than down the street and back.

The radiator shop that I have trusted my other cars to is down on the other side of town and I no longer trust the Eldo. Tomorrow I will drive it some more and see what happens and will get the coolant tested next week. If the head gasket needs to be replaced I'm sure that will be expensive, then the car will not be fixed for a long time. I enjoy driving the Eldorado, but if the gasket needs replacing with only 62,000 miles on the engine it won't happen anytime soon.

Rick

[BodybyFisher]

Have the cooling system pressure tested to see if it holds pressure and also have the coolant tested for combustion by products.

Its not a matter of the 62,000 miles, its a matter of the frequency of coolant changes, with the green coolant you need to change it every 2 years or 24K miles, anything beyond that and the coolant looses its corrosion resistance.

[tommysls]

Before I had my head gaskets replaced, I was still able to drive around town. I figured out that if I keep engine under 2500 rpm,

it gave me no overheating problems. But if I jumped on it - passed another vehicle quickly etc - she would immediately overheat.

[Cadillac Jim]

You have more than one adjacent pulled head bolts.

[KHE]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

When you state: The left side of the engine, do you mean as installed in the car or the rear bank of four cylinders? If it is the left side as installed in the car, it could be the water pump cover, water pump crossover gaskets, or hose leak.

[rbotti]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

When you state: The left side of the engine, do you mean as installed in the car or the rear bank of four cylinders? If it is the left side as installed in the car, it could be the water pump cover, water pump crossover gaskets, or hose leak.

The steam or smoke came from the rear of the engine standing in front of the car on the passenger or left side.

The same side that the purge tank is on, in fact the steam was only a few inches away for the purge tank.

Rick

[Ranger]

Not sure what side your surge tank is on. The "rear of the engine" is on the drivers side (transverse mounted). Is that where the steam is coming from?

[BodybyFisher]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

When you state: The left side of the engine, do you mean as installed in the car or the rear bank of four cylinders? If it is the left side as installed in the car, it could be the water pump cover, water pump crossover gaskets, or hose leak.

The steam or smoke came from the rear of the engine standing in front of the car on the passenger or left side.

The same side that the purge tank is on, in fact the steam was only a few inches away for the purge tank.

Rick

There are so many things in that areas, the tank, three hoses near the tank and the two heater pipes that can cause steam and leaking

[MAC]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

When you state: The left side of the engine, do you mean as installed in the car or the rear bank of four cylinders? If it is the left side as installed in the car, it could be the water pump cover, water pump crossover gaskets, or hose leak.

The steam or smoke came from the rear of the engine standing in front of the car on the passenger or left side.

The same side that the purge tank is on, in fact the steam was only a few inches away for the purge tank.

Rick

Regarding seeing steam, it sounds like your referring to the two lines that go to the heater core. One feeds the core and one is a return line. If you look on the passenger side firewall you will see two lines that feed to the interior by the glove box. The heater core tubes that connect to those lines actually stick out into the engine compartment through the firewall. The heater core is behind the glove box.

[rbotti]

I

pulled the purge line and all is clear. Earlier before I read your suggention regarding the purge line, I ran the engine till warm and noticed steam or smoked coming up from the left side of the engine, it had a funny but not strong smell. I am going to take a break, then put everything back together and see what happens.

Rick

When you state: The left side of the engine, do you mean as installed in the car or the rear bank of four cylinders? If it is the left side as installed in the car, it could be the water pump cover, water pump crossover gaskets, or hose leak.

The steam or smoke came from the rear of the engine standing in front of the car on the passenger or left side.

The same side that the purge tank is on, in fact the steam was only a few inches away for the purge tank.

Rick

Regarding seeing steam, it sounds like your referring to the two lines that go to the heater core. One feeds the core and one is a return line. If you look on the passenger side firewall you will see two lines that feed to the interior by the glove box. The heater core tubes that connect to those lines actually stick out into the engine compartment through the firewall. The heater core is behind the glove box.

That could explain the damp, humind feeling while driving the car.

[BodybyFisher]

Wait, you have steam INSIDE the car?, your prior posts talked about steam from behind the engine. Do you smell coolant? Lift the carpet on the passenger side and look for dampness.

Explain you statement in more detail its vague, if your heater core starts leaking you will smell coolant and have steam on the insides of the windows and dampness under the carpet. But that has NOT sounded like your symptoms, it sounds like either a hose or the heater pipes as I mentioned previously.

[MAC]

That could explain the damp, humind feeling while driving the car.

If the heater core or anything associated with it, such as a line that is connected, is leaking, don't wait until it totally gives. If the heater core gives, scolding hot coolant can travel through the heater venting system and end up hitting your right foot while driving. Take if from me, it can happen.

[BodybyFisher]

That could explain the damp, humind feeling while driving the car.

If the heater core or anything associated with it, such as a line that is connected, is leaking, don't wait until it totally gives. If the heater core gives, scolding hot coolant can travel through the heater venting system and end up hitting your right foot while driving. Take if from me, it can happen.

I have a friend with a 95 Eldo and his went last month with a LOUD BANG....filled the car with steam. I need to change mine ASAP

[KHE]

That could explain the damp, humind feeling while driving the car.

If the heater core or anything associated with it, such as a line that is connected, is leaking, don't wait until it totally gives. If the heater core gives, scolding hot coolant can travel through the heater venting system and end up hitting your right foot while driving. Take if from me, it can happen.

I have a friend with a 95 Eldo and his went last month with a LOUD BANG....filled the car with steam. I need to change mine ASAP

If your car has had regular coolant changes since new, you probably have nothing to worry about. When I sold my '86 Park Avenue two years ago, it still had the original radiator and heater core - 20 years old and 210,000 miles.

[MAC]

That could explain the damp, humind feeling while driving the car.

If the heater core or anything associated with it, such as a line that is connected, is leaking, don't wait until it totally gives. If the heater core gives, scolding hot coolant can travel through the heater venting system and end up hitting your right foot while driving. Take if from me, it can happen.

I have a friend with a 95 Eldo and his went last month with a LOUD BANG....filled the car with steam. I need to change mine ASAP

I would suggest buying a core that is all aluminum. It will cost about $50 and should come with a lifetime warranty. When you remove your stock core you will probably have one that has plastic sides, which is where mine cracked open and sent coolant all over the place, including my foot.