I bought a 2000 Olds Alero about 9 months ago. It's been a great car, but now that I am facing some colder weather I have a small issue. It takes too long for the heat to warm up. It takes about 20 miles before it starts to warm the cabin, and put out decent heat. When it is finally warm, it doesn't feel as hot as it should be. I experienced a little of this last year at the tail end of winter, but didn't spend much time on it. Needle just barely goes above the 1/4 mark on the temp gauge. I would assume that the halfway point would be more appropriate. I have monitored coolant levels ever since I got the car, and I don't think I have lost a drop by looking at the reservoir. There is no oil in the reservoir, and no milkshake in the oil. I don't think there is a head gasket issue, which these cars are known for. What could be another cause? I have considered the heater core, but there does not appear to be any leak, and I would think a blockage would be causing me the opposite effect, and I would be overheating. My only other thought is the t-stat. Either it's not closing all the way or someone installed one with too low of a temp trigger. I may throw a t-stat at it as they are usually inexpensive. Any other thoughts?
Jim
[This message has been edited by jimbolaya (edited 12-01-2014).]
The heater core is clogged. If you check your coolant, the Dexcool probably looks like mud. FYI, it's not the head gasket that's the problem. It's the Lower Intake Manifold gasket.
Blocked heater core doesn't restrict engine cooling. Take the cap off the radiator and look at the coolant. If you're thinking of changing the t-stat, do a coolant flush and change at the same time.
You might look and make sure the P.O. didn't bypass the heater core. I'd also check to see if yours is one that came with a shut off valve in the heater core line that may be partially turned off. Some cars have them, not all by any means, so yours might also. The t-stat could be stuck full open or clogged heater core, as others have said. Curious, does the fan seem to be putting out the volume of air it's supposed to? Maybe something blocking air flow if it's not.
Sounds contradictory, especially in light of the fact he stated his temp gage needle stays down on the low end of the scale, which I assume would be less than normal operating temperature.
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Needle just barely goes above the 1/4 mark on the temp gauge. I would assume that the halfway point would be more appropriate.
Analog indicators traditionally have "normal" (warmed up/operating) position near the straight up 12 o'clock position--this is to allow a quick visual scan of the indicators without having to actually read the #s.
I agree, that the problem is most likely a stuck open t-stat, unless this vehicle also has a valve that directs coolant to the heater core. (been awhile since I have seen a vehicle with one of those valves on it)
Clogged heater core can often be an indicator that the radiator is also partially clogged.
[This message has been edited by maryjane (edited 11-30-2014).]
As I had stated in the OP the reservoir is clean. There is no oil residue or mud appearance to the dexcool. (nor in the oil) I was made aware of the issue with the lower intake manifold gasket, on these cars. It was actually replaced at about 45k if I remember correctly. The previous owner gave me all receipts and I have a copy of it. That doesn't mean it couldn't happen again, car has 95k now, but I don't think that is it this time.
Jim
[This message has been edited by jimbolaya (edited 11-30-2014).]
Does this engine not use the heating circuit for bypass when the t-stat is closed?
Another thought-since you've only had the car since last spring, have you checked to be sure the previous owner didn't remove and leave out the t-stat?
[This message has been edited by maryjane (edited 11-30-2014).]
I have 3 GM vehicles in the driveway other than the Fiero and on those 3, the "normal" temp is a little over 1/4 of the way up on the gauge. If you are getting to that point and not having heat, it is probably the heater core or a restriction in the system. The heater core in my Caprice has to be flushed every season or it takes forever to start getting warm. It is a design flaw due to a flow restriction in the hot-side hose going into the core. I just pull the hoses off and stick a garden hose on the exit side and flush out the crap that accumulated since last year. I've got it down to about 10 minutes My wife's car can be started cold and be getting warm air before you get to the end of the driveway, but my S10 takes forever.
I vote for the t-stat. My Saturn was running at 1/8th, and it wasn't getting warm at all. I changed out the t-stat and put in new coolant and after my first test drive my heat was hot and my gauge was at 1/2.
One more vote it's the thermostat, but it could also be the heater door isn't opening right when you tell it to, or a plugged heater core. Do the thermostat first, it's the quickest and easiest fix and most likely problem, I always do the quickest and easiest things first.
Steve
------------------ Technology is great when it works, and one big pain in the ass when it doesn't
Detroit iron rules all the rest are just toys.
[This message has been edited by 84fiero123 (edited 11-30-2014).]
Thanks for all the input guys. I'm going to go buy a T-Stat today (may not get it installed today) and start there. I'll update when I get it changed out.
Does revving the engine increase the heat output? That's what I noticed on my '99 Grand Am (3400 V6). A reverse flush of the cooling system and heater core helped. My coolant reservoir looked good, but looking in the radiator itself you could see a muddy residue. If it is a restriction in the system, that can cause the gauge to read low even if the engine is running warm/hot depending on the temp around the sensor. I've had cars overheat while the temp gauge read normal - and the gauge was functional.
There's also the possibility of air in the cooling system. There's a bleeder valve on the black metal coolant pipe across the front of the engine IIRC.
Does revving the engine increase the heat output? That's what I noticed on my '99 Grand Am (3400 V6). A reverse flush of the cooling system and heater core helped. My coolant reservoir looked good, but looking in the radiator itself you could see a muddy residue. If it is a restriction in the system, that can cause the gauge to read low even if the engine is running warm/hot depending on the temp around the sensor. I've had cars overheat while the temp gauge read normal - and the gauge was functional.
There's also the possibility of air in the cooling system. There's a bleeder valve on the black metal coolant pipe across the front of the engine IIRC.
Well I just tried to get at the thermostat, and who the hell designs these things? I was happy with the ease of my brake pad change, but this is just stupid. I would have to remove a crossover pipe in order to reach the lower bolt that holds the Thermostat in. I just get so sick of cars sometimes. It's a love/hate relationship. Right now its hate.
On the up side, it has the easiest water pump I've ever seen to replace.
Richpin's video.... Pretty much explains it.
By the way, there's a little L-shaped wrench available to get that lower bolt out easier. Probably can get it on Amazon.
I remember having a stuck open thermostat on an older version of that engine (MPFI and OBD-1). Not only did I have no heat, but it wouldn't even lockup the torque converter. I didn't have any way of verifying, but I think the car was stuck in Open Loop! Replacing the thermostat fixed both issues.
No special wrench, make one, heat one up with a propane torch, then lock it in a vise and Bend it where you need it. They also sell crows foot wrenches for these kind of things and places like NAPA sell them one wrench at a time if you don't want or need an entire set.
Well I just tried to get at the thermostat, and who the hell designs these things? I was happy with the ease of my brake pad change, but this is just stupid. I would have to remove a crossover pipe in order to reach the lower bolt that holds the Thermostat in. I just get so sick of cars sometimes. It's a love/hate relationship. Right now its hate.
Jim
Engineers, that's who, that one they can not blame on the bean counters !
Steve
------------------ Technology is great when it works, and one big pain in the ass when it doesn't
They also sell crows foot wrenches for these kind of things and places like NAPA sell them one wrench at a time if you don't want or need an entire set.
Steve
A handy thing to have, especially if you're a crow.
No special wrench, make one, heat one up with a propane torch, then lock it in a vise and Bend it where you need it.
Not to suggest Steve needs any advice, but I would lock it in the vise first, then heat it. Might not want to lose control of a hot wrench. But Steve may have one of those special hot wrench vise lock wenches to help him. jimbolaya may not have as well-equipped a garage. He may need to do these things by himself.
When I am working with a hot w-r-e-n-c-h had to make sure that was spelled correctly, I prefer to work by myself. No sense in anyone else getting burned
Edit: Oh, you do have a wench. I didn't see your post, Jim.
[This message has been edited by heybjorn (edited 12-02-2014).]
Well I either have a bad head gasket or a repeat of the faulty lower intake manifold gasket these cars are known to have issues with. Oil started to show in the reservoir. It does not appear to be leaking coolant into the oil, just oil into the coolant. Is that indicative of a certain failure? I can't afford to have a mechanic repair it right now, maybe in a month or two. How long might I have before this becomes catastrophic, and how hard is it to repair these gasket on the 3400 motor?
Well I either have a bad head gasket or a repeat of the faulty lower intake manifold gasket these cars are known to have issues with. Oil started to show in the reservoir. It does not appear to be leaking coolant into the oil, just oil into the coolant. Is that indicative of a certain failure? I can't afford to have a mechanic repair it right now, maybe in a month or two. How long might I have before this becomes catastrophic, and how hard is it to repair these gasket on the 3400 motor?
Jim
Coolant in the oil - that's catastrophic right now. Any running of the engine until that's fixed is risking major damage. It can be a Lower Intake Manifold gasket failure again, especially if it wasn't replaced with a new design gasket. You also want to replace the oil pump driveshaft o-ring at the same time.
I know its risky, but by catastrophic, I mean it's beyond repair. For example, if the coolant was is the oil, it would probably already be passed the point of no return. I've decided to park the car for now. I need to weigh my options. I have absolutely zero time at this time of year, (retail) and even less money to consider a mechanic. Why couldn't I have discovered this last spring or summer? I hate turning wrenches in the cold. I'm going to have to do this myself. Being down a car is gonna hurt. I must have caught this kinda early, I haven't lost noticeable coolant, and it has been clear until recently. I guess the loss of heat is related to loss of pressure.
I know its risky, but by catastrophic, I mean it's beyond repair. For example, if the coolant was is the oil, it would probably already be passed the point of no return.
Nothing is beyond repair. I consider catastrophic requiring an engine rebuild. Small amounts of coolant in the oil won't destroy the engine, but over time as it gets worse it can.
I know what you mean about wrenching in the cold. I keep putting off maintenance I need to do waiting for a reasonably warm day that probably won't come until Spring. Good luck with it.
My wife's car can be started cold and be getting warm air before you get to the end of the driveway, but my S10 takes forever.
