Chevy S10 - GMC S15 and Sonoma Radiator and Cooling Issues
Recently replaced the head, and while doing so, I had broke off the Plug in for the Coolant Temp Switch below the Thermostat, so, I didn't pay it any mind drove it, then a bit later, I broke down and replaced it, (temp gauge before didn't work until I replaced it) so now it works, after ignition and idling about 5-10 mins or so, it would readout 260^, when stated with the new Switch it would idle at 1k RPM, before without it it would idle at about 1400 RPM then Idle down to 1k RPM (guessing when the Thermo opened etc), anyways, I've replaced the thermostat, and thinking it might be the h20 Pump I took that off, and it's in good order, and even reverse flushed the Radiator.
Any Ideas on what else to do, or what the problem might be?
Any Ideas on what else to do, or what the problem might be?
You have a clutch fan on a 95 I assume, will it roar when it gets hot, it should.
260 F is getting ready to boil over. What temp is the coolant in the radiator, I use a candy thermometer, wife doesn't know.
Overheat doing both, and yes it'll engage not all the time, but I checked the spin of it, and it's seemingly stout, and no cracks.
With the New Temp Switch, it's like there is no water moving anywhere, remains stagnant, and is cool/cold (top and bottom hoses are cool as well) with the Switch unplugged water is exceedingly warm, and I can view h20 moving. top hose it hot to touch.
Note, there is a metal tubing going from below the thermostat housing toward the back of the engine, (assume to the Heater core) and it is HOT with both scenarios.
Another thing I tried, was the have the heater on with the new switch, and it seemed like it would take longer to Overheat, but in both cases the Heater was ...doing it's job, nice and hot .
I reread your posts, it did not appear to overheat until you got the gauge working. I don't think your gauge is accurate, check actual water temp .
I did so, had to take off the Thermostat housing, and saw that it was hot, steam, extremely hot to touch.
The problem is, with the thing plugged in, seems like the Thermo is not opening, so I removed the thermostat, and replaced it all together, and it seemed to have worked.
and if that is indeed the case, (Bad thermo) that would make two in a row.
One thing I saw, after taking the housing off, was one time there wasn't enough h20 to fill up to the sensor. (I think that is what you refered to as Airlocked, so I made adjustments and tried to fix that (Jacked up one side, and started with the heater on)
has to be one of two three things
Waterpump (doesn't seem likely, as it was pumping with out the thermo in)
Sensor, that's the only thing I haven't replaced (after the initial replacement)
Any Ideas on what to do/check?
Are you using dex-cool (orange) coolant or the regular green? If using Dex-Cool you have to use a flushing agent / kit to get all of the old crap out; if not you can run into the problems you're having as well.
You still may be having an air problem. You definitely have to have the heater on, blower on high, when your topping off or you can get air trapped in the system. You can do the initial system fill with everything shut off but after that you need to have the engine running and the the heater on to get the air out to finish topping it off. And what do you mean you jacked up one side? Did you jack up the truck so that water / coolant would fill up to the sensor? And you are using water / coolant right, not straight water.
As stated the sensor may be out of spec, not sending out the right signal or is the wrong one. But it wouldn't cause an "real" overheating issue as it shouldn't be blocking a main coolant passage.
Also that it is better to flush coolant out & replace with green anti-freeze.
Any suggestions out there? :confuse:
I did not expect this appox. $700 repair B-4 I've driven truck more than 200 miles.
Any thing else to look for? :surprise:
I've had nothing but probems after that. Service engine light came on, did diagnostic - water temp below engine temp. Replaced temprature sending unit. Same thing? I have to drive 10 miles before engine reaches operating temp?
Any one know where could be the problem?
Drivetrain: 4.3 V6 with Auto trans
I seem to have a coolant leak somewheres. It comes from the back of the motor. When the coolant level gets low enough the leak seems to stop, as well as the heater. When I fill the coolant back up, I can park the truck and after a few minutes (a run into the gas station to pay is long enough), I come back and it is dripping from the back of the motor at a pretty good rate.
When I run the heater, I dont get any odd smells into the cabin, but the heater will quit working once the coolant level gets low enough. I also do not have oil int he coolant or coolant in the oil. No smoking out the back of the tail pipe. The truck runs just fine. The only time it goes wonky is when the coolant level gets low. When the coolant is full, the temp gauge runs just below halfway (210 I think) and stays there. It also gets there quite quickly and always has. I know there is a couple of different places the leak could be, but I was wondering if there is a most likely culprit.
First you need to look closer, prove it is the intake gasket, don't want to tear it all apart for nothing.
You won't see any damage if the temps stay at 210. What you do need to worry about is that in the summer, you might see the temp range in the higher side rather than the low side because of the 195 degree t-stat. That is something that I would be careful of. Instead of operating between 100 and 210, you are now operating between 210 and 260, which can get dangerous on hot days. Especially in rush hour traffic traveling at only 10 MPH.
In my opinion, I would switch back to the standard factory t-stat. Is there a reason you went to the 195 degree one? People make all sorts of claims pertaining to running one, but I haven't tested it to be sure and so I don't know. They all sound like hocus pocus to me.
Here are some things to check... You have a coolant leak somewhere. More than likely it is the intake gasket (see my next post on this very issue). The reason you have no heat, even at 210 is because you have low coolant. You do not have enough coolant to get into the heater core. Do you notice that after you add coolant that your heater works properly? This was happening to me. I would have a temp reading of 190-210 and no heat. I would then add coolant and I would have heat after a few minutes. I was losing coolant at the intake. This is common on these motors to do that (so I have heard)... With the truck running and with a full coolant level, check for drips under the truck. If you have an external leak, you might get lucky and it will be bad enough to see. If you have an external leak you are also lucky in that you won't have water in your oil. If you have an internal leak, check your oil. You should see a white milky film in the oil. You can also check the oil by parking the truck overnight, crawling under and cracking the oil plug. Since water is heavier than oil, it will sink to the lowest part of the pan (where the plug is) and be the first thing to come out when you pull off the plug. You won't have to pull the plug off all the way, just enough so that if there is water in the pan, it will start to come out. If there is water in the pan, more than likely you have an intake manifold that is leaking...
Now see my next post on that...
It was indeed the intake manifold. Boy oh boy was it bad. Okay - here's the short story. A while back, several months ago in fact I realized I had a coolant leak. My heater would quit working and so after doing research (on here mostly) I found it to be low coolant. I wasn't losing coolant rapidly enough for me to do much about it, plus funds were a bit short and it also wasn't or didn't seem to be an internal leak so I didn't worry TOO much about it. I should have and so I know I played a bit of a gamble here. I rolled the dice and luckily I seem to have come out okay, but not counting my chips yet. Anyway...
Fast forward to a couple weeks ago. I am headed to work and my temperature shoots towards hot. I pull over and realized that I am REALLY low on coolant. Like almost out. That'd odd because I had just filled it. Literally like not even a week earlier. I was able to limp home after some cooling off and getting water into it, but while the truck was running, I could look under the truck and see coolant REALLY dripping off. It was coming from the front of the motor and dripping under the water pump area. A buddy comes over and looks at it and determines from what he can tell that the water pump appears to be bad. This is now in addition to the other leak that I know I have somewhere that I think is at the back of the motor, but more on that later. So I trot down to the parts house and get a water pump and tear into the truck and replace it.
I get it all put back together and fire up the truck and...................................... it still leaks just as bad as before. Trouble is, I now have no clue where to look. My friend who originally diagnosed it is now on vacation for two weeks and since funds are short I also can't take it to a shop to have them look at it. He also has a cooling system pressurizer that will pressurize the system with the vehicle off to help in spotting leaks. This is something we should have done in the first place, but at first blush, it really did look like the water pump was bad. On later inspection of the old pump, it does indeed look like it was either getting ready to go bad, or was at least contributing to my loss of coolant so changing it out was not necesarally a bad thing to do. It has now eliminated once possible source. While funds were short, the pump itself was only $60 so it's not a total misstep.
So not knowing where to go since I can't tell with out tearing down the whole thing again where the leak is coming from and with the truck running, I can't see it with everything in the way, I park it till my friend comes home and can help me tear it down and check it out. While talking to him and letting him know what happened, he then says it is probably the intake and confirms what seems to be common even on this thread. He says it is probably the intake. So today, we are able to finally work on it.
I take it over to his house and we start tearing into it. We first put his pressurizer on it and we can see it bubbling and pushing a little bit of coolant out from the under the intake on the front passenger side of the motor. So we have confirmed what looks like a "minor" leak and could be my leak that I saw with coolant dripping from the back of the motor, in that the coolant would run down the valley between the valve cover and intake and off the back of the motor (in theory).
So we start to tear everything off that is in the way so we can see the entire cooling system. Alternator, alternator brackets, power steering, A/C, clutch fan, idler pully, tensioner pulley, air box and mass air flow sensor and air tube. Anything that was in the way of looking at the cooling system that we could take off with out breaking into the cooling system we removed. Now we can see. We hook up our pressure tester and pressurize the system. Immediately we can see at the front of the motor where I had initially been looking water just pouring out. You couldn't see it before because the alternator was in the way. But there was a definite intake leak right there. It just poured out and ran down the front of the motor. Another concern I had was maybe I didn't get the new water pump sealed and mated properly to the block, but that checked out fine.
On to part II
Before starting the truck though, we decided to pressure test it again to make sure there were no leaks. We hooked the pressure tester up and immediately we could hear it losing pressure somewhere. So we start poking around for the source and find it at the upper radiator hose where it mates with the T-stat housing tube. After hunting for a new hose clamp and finding one an hour later after going back to the parts house, we get that taken care. Pressure again and now we can see it dripping still. Another bad hose clamp (we should have just replaced ALL the spring loaded, but we didn't. We replaced that one and now all the clamps that we have removed are no longer the spring loaded ones, but the screw down type. We pressure again and FINALLY seem to be holding pressure and have no leaks, drips or hissing.
We start the truck and AMAZINGLY it fires right up. I say amazingly because we had this thing ALL the way apart practically. Electrical connections were all unplugged, vacuum lines disconnected, distributor taken out and so to have it turn over on the first try as if it had never been apart was really quite amazing. We let it run and inspected for leaks all over. Let it get to operating temperature making sure we added coolant as it needed it. It pushed a lot of air out and finally after running several minutes the T-stat opened and began to draw coolant in and the heater got warm.
We let it run several more minutes, making sure the coolant level stayed full and also checking for drips and leaks. After seeing none, we closed her down, and I came home! It appears that we have fixed it. (Hopefully)... I'll keep my eye on it for a few days and won't venture to far from home, but I think all will be well. Hopefully we took care of that minor oil leak I had too in the process. That would be nice.
You might also have air trapped in the system, especially since you broke it wide open changing the water pump. That air will cause the truck not to vacuum properly and won't push or pull water from the recovery tank. Try bleeding the system. Or taking it to a shop and having it flushed. They can do a pressure flush that will force any air out of the system...
Then pressurize the system with the motor off. You do this by replacing the cap with the pressure tester. It pressurizes the system and will expose any coolant leaks. You can then trace them with out fear of moving parts and fans and belts and pulleys and with out the noise of the motor running.
Here are typical problem areas I experienced and found are typical of the 4.3. I did this on a later generation 4.3 (2001) so I am not sure how much will have changed, but the basic block configuration didn't change much. Heads and intakes changed, but not much else. My 4.3 had a lower intake gasket leak. It was spewing coolant into the valley where the valve covers, intake and heads came together. 4.3's are prone to this leak.
Since you also state you overheated, you might have cracked or warped a head. Especially if you have aluminum vortec heads. If that's the case, you'll have to tear down and replace the affected head. The pressure test though will tell you where it's leaking, unless it's leaking internally into the block. If that's the case, your oil will be full of water.