'02 Impala 3.4L, 185k: Running HOT !
Full Disclosure: This thing has had a coolant leak for a few months now, and without both time and energy to get to it, I’ve been just filling with mostly water, but enough coolant to prevent freeze damage (although this car is in the Carolinas where freezing is not much of an issue). Leak seemed to be coming from firewall side of engine, but I haven’t been able to determine exactly where. Water sometimes comes down like a waterfall with more than one stream, but then other times, it doesn’t appear to leak at all! Really weird.
Anyway, while I was away for 10 days, wife claims car “overheated” on a short 2 mile trip to place where she runs. “Overheated” means engine temp went to the far right, but she shut off the engine and never saw any “steam” coming out of engine compartment. Car had plenty of water in it at the time.
So I just checked it out and here’s what I found:
1.) On short neighborhood test drive, Engine temp rose quickly to 225 F.
2.) Popped hood and heard loud “SHHHHhhhhhhh” noise coming from cavity between Alternator and Power Steering Pump, but couldn’t see any obvious liquid leaking anywhere. Top of engine does have sooty ‘blemishes’ on aluminum intake, which is something that seemed to be getting more noticeable lately, but that’s it. Also some damp stains on “V” seal on side of block where intake gaskets are, but no liquid oozing out.
3.) LOW COOLANT Message appearing in cluster, but this might be dirty sensor (seen this before). But this was also symptom of intake gasket failure previously.
4.) Radiator cap reasonably clean underneath. No ‘sludge’ or ‘muddy’ residues.
5.) Top radiator hose got HOT during short drive, but bottom hose was STONE COLD. This means bad radiator, right?
6.) Intake gaskets replaced in May 2008 @ 104,980 miles. I used Felpro ‘metal-framed’ gaskets, also replaced all lifters, all disturbed o-rings (injectors, fuel rail, coolant bypass, oil pump drive, t-stat housing pipe), both valve cover gaskets, T-Stat, plugs, wires). Re-used old intake bolts, using blue threadlocker.
7.) Engine sounds and runs OK otherwise.
8.) Plenty of water in overflow tank.
9.) Radiator was replaced 4 years ago, Nov 2010, (Advance Auto, ReadyRad) at 140,700 miles. Might be able to get 1 free replacement if it turns out it has failed internally.