HeXetic

iTrader: (1)

Pretty sure I have a broken thermostat, but I thought I'd post my observations here and see what other people say before I pull it out (not that it's gonna be too hard to do, from what I've read and can see)

• 2001 Camaro SS, LS1 engine, pretty much stock
• Temperature gauge exceeds 100C (212F) after a few minutes of driving. I know the 2001s have "dummy gauge" lights, but believe me it is getting hot under there. This is during pretty cool weather, 20C (68F), and driving on the highway with lots of nice cool lake breeze
• Air dam present and intact
• Fans come on, both of them, first low and then high speed
• Plenty of coolant, and I've already drained & refilled it using vacuum siphon, so no air bubbles. Checking the rad after the engine cools, radiator is full so no air bubbles are getting in through the overflow bottle.
• Heater still works, blows pretty hot air (used this briefly to "cool" the engine on my way home)
• If driven hard/long enough, engine will actually overheat, needle goes to almost 125C, CHECK GAUGES lights up (I only let this happen once, on my way home when I knew the thing was stricken)
• Infrared thermometer gun thing w/laser pointer shows engine block at 100C, hoses to heater core at around 80C, but hose from thermostat to radiator at only 50C and radiator itself is 20-30C (presumably due to fans)
• Pretty sure water pump is working, I opened up the bleeder tube and fluid started squirting out.

So I feel like I've narrowed it down to the thermostat or *maybe* the water pump, but I'm guessing the thermostat is just stuck at least partially closed. Does my diagnosis sound correct to anyone else? I think the infrared thermometer reading is the smoking gun.

Daniel Richards

iTrader: (1)

go ahead and do the thermostat, that much of a difference in temp would seam to indicate some kind of blockage or lack of flow, so start with the thermostat and see if it is still doing it after.

FirstYrLS1Z

iTrader: (4)

since the thermostat is part of the outlet housing(to radiator),you can remove the thermostat from its' housing with a twist using channel locks. Put the housing back on(less thermostat) and see if free flow solves your problem. A new thermostat comes in a outlet housing. I haven't been running a thermostat for 5 years now and got 177,000 miles on the car. Most say you need a thermostat to bring it up to operating temperature. My ScanGaugeII shows it goes from open loop start-up to computer controlled closed loop between 90-100 F.

Daniel Richards

iTrader: (1)

if he wants to have ANY amount of HEAT in the winter (or hell anything below 55* F) he will need a thermostat, which him living in CANADA (according to his info) he will need.

Yes while the weather is nice you can run without a thermostat to see if that solves the temperature differences and if it does then replace with a new thermostat, I've been running without mine for about a month now while I work on replacing the hoses and flushing all the dex-cool sludge out of the radiator and running straight water while I search for any other cooling system leaks. So I can safely say there is no danger to running without one other then NOT having heat when it gets colder out.

HeXetic

iTrader: (1)

Heh, I actually only drive this guy in the summer (it's a convertible), so I could probably get away without the thermostat, but the thing I see in the service manual is that on the 2001 models, the thermostat and housing are not supposed to be separated. If the thermostat breaks, the manual says to replace both, so I'd be a bit annoyed if I pulled the 'stat out of the housing only to find that it's not the problem -- and then I have to get a new stat+housing anyways if I want to play it safe.

I imagine if the thermostat is completely busted, e.g. chunks all over the place, gasket messed, whatever, it will be pretty obvious when I pull it out, otherwise I've read that you can place the part in a pot full of coolant, bring it to the operating temperature, and see if it's opening properly. That makes sense, right? Definitely won't be using the good cookware for that, though.

LS6427

iTrader: (2)

Pull the tstat out and put it in a pot of boiling water......see if it opens about when its supposed to using a thermometer in the water. If it opens.....you still have air in the system.

And the tstats do come out of the housings and a new one can be put into it.....you never have to buy a new housing. All tstats are two piece.....no such thing as a one piece.

.

HeXetic

iTrader: (1)

Just to necropost my own post, I bought the complete replacement thermostat + housing from my Chevy dealer (total $70 after tax, which I found reasonable), and replaced it this afternoon. After some loops around the highway and a couple of peelouts at lights & onramps, the temperature needle never went above 100C, the radiator hoses were much closer in temperature to the engine block, and the fans never came on once (it was only 24C or so out today, and there was a nice breeze), so clearly the old thermostat was indeed broken.

Thanks to everyone for the advice.

1 FMF

iTrader: (1)

fyi the thermostat replacements for the LS1 can be gotten either way- just the stat piece and you reuse your existing housing, or it comes with a stat in a new housing. when i had to replace mine a few years back, advance auto parts had them both and at the time was cheaper to get the stat and the housing.