3800Impala

Hi. I've got a 2005 Silverado with the 4.3 V6. All winter I've had a problem with no heat. After last weeks polar vortex, I can't put up with it anymore. At first I thought it was just low on anti-freeze. So, I added some. Had heat for a couple of days, then as the temperature dropped, the heat stopped working. Flushed entire system, was NOT clogged even the slightest (despite having 283,000 miles). Refilled, had heat for a 2 days. Each time the problem starts, the temperature needle drops to half way to 210º. During the summer, it was staying at 210. So, I figured, ok it HAS to be the thermostat. Last winter my Impala did the same thing, new thermostat solved it. I finally got around to replacing it this past Sunday. Today, I drove about 300 miles (round trip) to pick up an 03 Camry from an auction. Only second time towing with this truck, and I will say even with only the V6, it pulled the auto transport really well. Well, all day today the temperature stayed at 210º, from the time to drove to Uhaul to get the the trailer, to picking up the car. Heat was a little better, but I've noticed the heat always works if it's warmer outside. Today wasn't too warm, but not cold. About 42º. After I dropped the auto transport off and started driving home, I noticed the temperature gauge started dropping again. Then it rised. Then dropped. Heat was totally cold the whole drive back. I didn't try it today, but in the past, I noticed something else. If you are stopped at a light and go full throttle and really rev it up to about 4-5k, you'll get a couple seconds of heat. This has me thinking now it could be the water pump going bad. Not convinced on that, because I thought a water pump would either work, or it wouldn't and the engine would overheat. I'm really not sure. I have no idea what else it could be. Help would be appreciated! Thanks.

Irrelevant Rant: .......As I slowly go from only liking Chevy (and would rather eat glass shards than even ride in a Toyota).....to actually knowing something about Toyota...and liking them too..........to only liking Toyota (and would rather eat a timing chain........wait no sorry that's what GM 2.4Ls do!) Seriously though. I've really liked Chevy since I got my Impala...but my 97 Malibu and my Silverado aren't making me think too highly of Chevy lately. Which sucks, because I'd still like my next truck to be 2500HD Duramax 4x4 (same generation). Which, I'm sure would be a much better truck. 2WD SUCKS! (Ask me how I know....or all the tow truck drivers around here.) Well, this Camry is my first Toyota....lets see how that goes.

Update: I just checked my radiator. It's been 3 hours since I've gotten back. There was a bunch of air that escaped when I took the cap off. The fluid level is MUCH lower than when I filled it Sunday. (still on the FULL - COLD line though). I don't think it should've been still pressurized 3 hours after driving. 36º outside. Maybe there is just a bunch of air in the system? Explains the lower fluid level, because I don't see any leaks.

oilcanhenry

I am thinking you have a bad head gasket. They can leak, allowing coolant to never be seen in the motor oil, since its going somewhere, like the exhaust or even the intake systems. I highly doubt its your water pump, BTW. Barring a radiator cap issue, which I doubt, I'd get it hot, put water or coolant in it, and look or smell for something that should not be there and things like bubbles coming from the radiator. Of course, since there is little/no pressure with the cap off, it may NOT leak until the cap is back on. I'd be worried either way. If its going out the exhast it MIGHT damage the Cat, and if it's intake, then having coolant, not plain water, might cause internal damage, but I believe that you would see SOME kind of change in your motor oil's apperance, like turning color that is not at all normal brown colored, but milky gray.

Every vehicle, like anything else has a weakness. I personally don't like F-o-r-D's myself, but to each his own. Many of the problems these days is two-fold. One: many manufacturing jobs and parts went overseas or to Mexico, where quality control is lower; and Two: The vehicles manufactures in the US are using every little trick in the book to boost fuel mileage while reducing emissions even further, all at the same time. The problem is that it takes time to get all the "bugs" out of these newer vehicles.

Caterpillar corporation said "bye-bye" to manufacturing semi diesel truck engines, as the emission control system on large commercial vehicles are very tight as well, and Caterpiller is invested in many products that never see the paved road, so they made the call, and stopped production of heavy truck diesel motors in 2009 in North America and other countries in Europe, which is a real shame as thier motors were some of the best ever designed and produced for that market. Sure miss my old
"Kitty-Kat"engines, but corporations and businesses have to make a profit, or die/sell out. I can see a time when no vehicle will run on 100 percent petroleum fuels, with E-85, CGN, Hybrids and full- electrically driven vehicles will be the norm, in the not too distant future. Some semi-trucks already use CGN, but buses use it much more often then trucks do, bar none.

Back in the day, even two-stroke diesels were common, but they really did pollute badly, so they were phased out for four-strokes only. The same with off-road motorcycles. 20 years ago a gasoline/oil mix dirt-racing bike was commonplace, but now the four strokes can pretty much match a two-stroke bike, with less pollution too. The envronmental issues are getting so tough, even small two-stroke gasoline motors like a lawnmower or weedeater use 4-stroke motors now, but not all yet. Chainsaws will be on the list of conversion to four strokes, I am sure, but you can count on those being quite expensive, as they cant make a 4-stroke chainsaw run as well as a two-stroke chainsaw.....yet! .

3800Impala

Well, I certainly hope it's not a head gasket! I haven't seen any bubbles in the radiator. There is no loss of power, no thick clouds of white smoke or any discolored oil. The radiator reservoir is still half full (well above the "FULL - HOT" line). I'll keep checking it and see what it does. I'm not sure what this could mean, but yesterday morning I added coolant and warmed the engine with cap off. The entire time I was doing this there was a "pinging" coming from one of the pulleys. I'm not sure which one it was. After the engine warmed up the sound got quieter, but it was still there. The belt tensioner pulley was bouncing a bit, but those are spring loaded so I think that's normal? The pinging shouldn't be normal, I wouldn't think. I've never heard it before. (Although it's really hard to hear it with the hood closed.)

Oh, and I hear you on Ford! The Camry I mentioned, was actually bought by my sister. I towed it back for her. She got it to replace her Taurus. She's had the car the same amount of time I've had my Impala -1 month. My Impala was bought with a bad head gasket. Replaced that and a few other parts, like the AC condenser and tires and it's been basically just normal maintenance and trouble free. The Taurus? Not so much, she's had to have it towed at least twice a year because something breaks. After purchasing, we discovered the floor pans were totally rotted out. She spent more than the car was worth having it repaired. The engine burns 2 quarts of oil between changes. That is why a tow truck is coming to haul it away later today. My Dad owned a Mercury Sable before he passed away last year. He always swore he'd never get another Ford. He hated that car. And now we cant get rid of it because no one wants it.. I supposed I shouldn't talk too much crap about Ford, though. After all a Ford has had to get my Silverado unstuck 3 times this past month...but let's pretend that didn't happen.

You're right about cost cutting, too. I thought I had a wheel bearing bad on my Impala due to a ton of vibration, especially during turning. Jacked it up last week, shook the wheel and it wobbled all over. Ordered some Timken bearings because they were supposed to be good. They were cheaper than direct from GM, though. They look like a quality bearing, but I wasn't happy to see "Made in China" stamped on it, after people on the reviews said they were made in America. Oh well, turned out I was wrong. Wheel bearings are fine. Returning those. It's the tie rod that is bad. Really. Really bad. I'm not even mad at my Impala or Chevy for this though. It does have a lot of miles, it's expected. Like I said, I love my Impala, it's been a really nice car. Even used it to jump start the Camry. Luckily it started and it even drives. After I put a new battery, tires and replace the bumper and headlights and it'll be a great car, too.

And oh hell no. Not to get political, but yeah, this emissions crap...I know we shouldn't needlessly pollute (like setting a dumpster filled with tires on fire or dump oil on the ground.) But it's getting a little extreme. Electric vehicles. Nope. Don't want to hear it. I'm ok with the Prius and the Volt...but nope. Not this fully electric s**t. I don't care if it makes 7000 lb/ft of torque blah blah. I don't care. I hate it. If they want my gas/diesel powered stuff they'll have to pry it from my cold dead hands.

Update (10:02PM): I've driven this truck 5 times today. Once to go check on the battery charger on that Camry I keep mentioning. 4 mile drive. Heat did NOT work. Drove over to Indiana for groceries (10 miles). Heat worked. Drove back home (14 miles). No heat. Drove to work, had no heat half the time. (6 miles). Drove home tonight, had heat most of the time, 6 miles. I've noticed a pattern. When I HAVE heat, the temperature guage goes up and down. Hottest when at 210 (obviously). When the heat goes out, the temperature gauge STOPS bouncing up and down and stabilizes at a little under 210, like normal. When the heat is NOT working, I got out and checked the heater core hoses. One is piping hot, other is barely warm. This points to a clogged heater core, but I already flushed the entire system and it was totally clear. Also, if it had sludge, why is it intermittent? When my Impala had sludge in the heater core after leaking head gaksets, there was NO HEAT until I flushed it. No problems since. (until the stuck thermostat last year, but that was also an easy fix.) It's like there is a hard blockage that is blocking off coolant flow until it moves out of the way. I know that doesnt make sense, so that leaves something electrical. Is there a valve that shuts coolant flow off to the heater core?

Doug D

Is there some type of heater control valve incorporated in the heater hose set up? I'm not real familiar with Silverado's having owned MoPar's until recently. Just purchased a '14 Equinox in December - wife totaled her Journey on black ice. Back in the day I had a '90 Acclaim that had a heater control valve and they were known to sometimes fail or get wacky.

When you did the flush did you back flush the heater core? Back flushing will sometimes loosen up crude that otherwise won't loosen up. I'd consider another flush but before doing so swap the heater core lines to back flush. Use a product such as Prestone SuperFlush. I've used it with good success in the past.

3800Impala

I thought that, too. I looked for a heater control valve, but there doesn't seem to be one on the 05. Looks like the 2000 still had one, but I'm guessing it was removed in the 03 redesign. I tried flushing it again (back flushing), but it was so cold the stupid plastic connector snapped off. I started the engine, just to see if coolant would come out (this was the heater core outlet, btw). Yep, it flowed out like a green toxic Niagara Falls. So, it must not be clogged, despite the inlet being hot and outlet cold. I'm completely lost on this one. I guess I'm gonna do the thing I've never done before. I'm going to take it someone else and have them look at it. I've made every single repair (including alignments!) myself since the beginning. However, it's cold. I don't really have time to mess with this anymore. I've got 3 cars to repair, a house to finish remodeling, and still find time to go to work. My Impala needs tierods, I've got to replace the front end on the Camry (bumper, fenders, headlights), do an oil/spark plug change and finally get around to replacing the timing chain and putting the engine back in the Malibu. Oh, and lots of drywall work this week. I really appreciate the suggestions, though. If the place I take it to can't figure it out, I'll give an update.