Automotive question

[medjay]

I have a '94 Astro. Lately I've noticed that the engine has been running hot. It hasn't overheated, it just runs at a temperature higher than usual. I poured some coolant into the reserve tank and it went back to normal for a couple of weeks. Then the temp. started creeping back up.

So, these are the questions:

Is it the thermostat? Do I just need a flush and fill? Could it be a radiator problem? I'm not losing coolant but when I drive a few miles I can smell it coming from under the hood. I'd appreciate hearing from any auto savvy folks out there who might be able to clue me in on whether this is a small problem or a potentially big deal.

 

[Pagliacci]

First off. Love the AV

Second,I'd check the radiator first.It's easily done,just see if it leaks by looking nder the car in the morning.
If that's the case then you need to fix it which you can do yourself.
There's a thing called radiator cement which plugs the holes up.
Also check the pipes going to the engine from the radiator so it isn't cracked and leaking from a broken pipe.
If that ain't it then check the thermostat if that's fouled up.If that's broken I guess replace it.

As for how dangerous,well worst case is that the motor overheats and then it'll blow.Which means new car has to be bought

Now I'm no auto mechanic but radiators I know about.This is the best I can do and I hope it helps.

 

[ExLimey]

How well do you maintain this vehicle? When was the last time the radiator was flushed? You're adding coolant but not seeing a leak anywhere? I believe they still sell this stuff like dye that you add to your coolant and after running the engine for awhile, it makes it easier to spot leaks because it "glows". If there are no external leaks you may have a bad head gasket. The gasket itself is cheap but the labor to take the engine apart to put it in can be expensive.
I'm no expert, but i'd advise to take it to someone now before the problem becomes major or it strands you on the side of the road!

 

[Problem Child]

I have a '94 Astro. Lately I've noticed that the engine has been running hot. It hasn't overheated, it just runs at a temperature higher than usual. I poured some coolant into the reserve tank and it went back to normal for a couple of weeks. Then the temp. started creeping back up.

So, these are the questions:

Is it the thermostat? Do I just need a flush and fill? Could it be a radiator problem? I'm not losing coolant but when I drive a few miles I can smell it coming from under the hood. I'd appreciate hearing from any auto savvy folks out there who might be able to clue me in on whether this is a small problem or a potentially big deal.

You say you aren't losing coolant, but you also say you had to add some and the temp went down, then crept back up after a while.

Are either losing coolant or you are not. Keep a very close eye on the overflow tank...check it every day and if you are losing coolant then try to figure out where it's going.

You say you can smell it under the hood...that's a good clue you are losing it, in however small quantities. If you are losing it it can be going to several different places.

If you have a leak in a radiator or heater hose, that's no big deal, just replace the hose.

There's a possibility you may have a bad radiator cap and you could be losing coolant that way. Again, no big deal, they're inexpensive.

If you rule out those two things and you are convinced you are losing fluid, then it has to be leaking out of the engine or into the engine, through a leaky head gasket or cracked head, most likely, but your water pump could be leaking or you could be leaking from a myriad of other places.

You can check your thermostat simply by taking it out and dropping it in boiling water and seeing if it opens or not. Even if it's bad you can put the housing back on and drive the car..if it still overheats, then you know it wasn't the thermostat.

Obviously you also want to make sure nothing is obstructing the air flow through your radiator.

 

[Hot4Heels]

Lastly but not leastly you can be loosing coolant due to evaporation in the hotter summer months.

Smelling it is not a good sign however as it means it is getting onto something hot. My guese would be a leaking hose as head problems usually have more pronounced symptoms.

 

[Texan]

Let me add a couple of thoughts.

If the cooling system is leaking when the vehicle is not running, you will see it in the driveway, and you can figure out exactly where it is leaking from.

If the cooling system is only leaking fluid when the vehicle is hot, it could be several things, but I would guess the "top" radiator hose or a seal around the water pump. There are two hoses to the radiator; one at the top that comes from the engine to the radiator and one on the bottom of the radiator that takes coolant from the radiator to the engine. The water pump only puts pressure on the top hose when the engine is running. The bottom hose would probably leak even when the vehicle is sitting still in the driveway.

A leaking radiator cap can also be the problem. Those are so cheap, it is almost a good idea to replace that first and drive the vehicle.

When the vehicle is turned off after getting hot, can you hear fluid being pumped into the reservoir? Coolant will go from the radiator to the reservoir when you shut off a hot vehicle, but if the thermostat is not working properly, the coolant will usually be pushed through the overflow hose with enough force to hear it. If the reservoir is not overflowing, and you can smell coolant when the vehicle is running, it probably is not the thermostat.

just a few thoughts

 

[medjay]

Thanks for all the input. I guessing it would be safe to assume that somehow coolant is leaking and burning off, that's why I can smell it but discover no puddles on the ground (also why filling the reservoir helps the problem for a week or two). I guess now the trick is finding out where the leak is.

 

[Hot4Heels]

A good way to look for leaks is a clean engine. Wash everything under the hood as best you can. While you may not see actual fluid you may spot dirt that is collecting in the moisture.

If you still dont see anything get the car up to temperature and take a white handkerchief and press this around the radiator hoses. This can locate a small leak under pressure without getting burned. Actuall leaks in the radiator itself are hard to detect so if you still haven't found it take it to a shop to have the radiator pressure tested.

Good luck and hopefully it is something simple like a cracked hose.

 

[sch00lteacher]

Check your oil dipstick. Does it have 'white shit' on it? I'm thinking blown head gasket. Hope not, that ain't cheap. But if you can't find a puddle and you are losing anti-freeze... It is going some place.

The white stuff might now show up all that well in the warm weather. Some times it does, some times it doesn't.

 

[ma_guy]

Just a "heads up" on something that I think is "Astro-specific". I had teh same problem you describe with mine and I know several other people that have had it as well. The reason you can smell it is simple. The heater cores in these things start to rot out. The first sign is a pin-hole leak within the heater core box which tends to blow the scent of anti-freeze all over the inside of the van.

If you aren't finding leaks in/around the engine or radiator give your heater core a look.

 

[ronde]

If it's a head gasket, there are two indications. One is the "white shit" around the dipstick of which sch00lteacher spoke. This means the gasket has cracked between the coolant and oil passages. The head gasket can also split between the coolant passage and the combustion chamber. It this is the case, the exhaust after a cold start will be white for a while. A bad leak will make your Astro look like a steam engine. A cracked head will do the same.

Unless this engine has been really hot, I doubt you have a head or head gasket problem. It is more likely a cracked hose or a water pump seal. This would account for the odor. Hoses get hard and brittle from the heat and age.

If the engine runs at normal temperature when the overflow bottle is full, the thermostat is probably OK.

 

[Weird Harold]

The heater cores in these things start to rot out. The first sign is a pin-hole leak within the heater core box which tends to blow the scent of anti-freeze all over the inside of the van.

If you're smelling anti-freeze INSIDE it's the heater core, but since this problem developed over the summer, I'd be surprised if was the heater core. Turning the heat on full will tell you immediately if the heater core has been leaking over the summer -- you'll get a suffocating blast of coolant fumes from the vents.

From your initial description, it sounds like a pinhole leak in either the upper radiator hose or a heater hose. Take it to a radiator shop and have a pressure check and hose inspection done. You could go to a place like Pep Boys or Autozone and buy a radiator pressure testing kit, but unless you anticipate needing it often, it's probably not worth it.

PS: Check your oil -- if it's discolored and smells funny you're leaking coolant into the oil probably through a head gasket. Oil and Coolant mixed is mud colored and smells like swamp-mud. If you run the engine up to temperature before checking the oil, the oil will be frothy as well -- like capuccino.

If coolant is leaking into the combustion chamber, you'll be able to smell it before you see the smoke/steam mentioned above. Start the car, and immediately go back and put your hand over the exhaust -- before it gets hot enough to burn you -- then examine your hand for moisture and sniff it for signs of coolant in the exhaust.

If you have coolant in the exhaust, get thee to a mechanic quickly before it destroys your catalytic converter as well as damaging your engine.

 

[TWB]

My best advice is not to buy a chevy.

 

[medjay]

If you're smelling anti-freeze INSIDE it's the heater core, but since this problem developed over the summer, I'd be surprised if was the heater core. Turning the heat on full will tell you immediately if the heater core has been leaking over the summer -- you'll get a suffocating blast of coolant fumes from the vents.

From your initial description, it sounds like a pinhole leak in either the upper radiator hose or a heater hose. Take it to a radiator shop and have a pressure check and hose inspection done. You could go to a place like Pep Boys or Autozone and buy a radiator pressure testing kit, but unless you anticipate needing it often, it's probably not worth it.

PS: Check your oil -- if it's discolored and smells funny you're leaking coolant into the oil probably through a head gasket. Oil and Coolant mixed is mud colored and smells like swamp-mud. If you run the engine up to temperature before checking the oil, the oil will be frothy as well -- like capuccino.

If coolant is leaking into the combustion chamber, you'll be able to smell it before you see the smoke/steam mentioned above. Start the car, and immediately go back and put your hand over the exhaust -- before it gets hot enough to burn you -- then examine your hand for moisture and sniff it for signs of coolant in the exhaust.

If you have coolant in the exhaust, get thee to a mechanic quickly before it destroys your catalytic converter as well as damaging your engine.

Checked the oil and it looks fine. The exhaust smells like exhaust. And I can't smell the coolant in the car, just a faint whiff when I get out and pass by the hood.

A busy work schedule has kept me from going to a mechanic but I will make sure to reserve a day next week. Thanks again everyone.