I’ve seen where cheap water pumps cavitate at slow speeds like idle. I’ve also seen new water pumps that didn’t turn the inside impellor and just spin on the outer pulley because the inside impellor broke off. It’s also possible your new thermostat is simply sticking and isn’t opening up enough. Want to test that, pull it out and see if the problem goes away.
If you aren’t losing anti-freeze, the you probably don’t have a bad head gasket. You could easily check that by pulling the plugs and look at them or get one of the $30 boroscopes that work with your phone and look in the cylinders. My guess is either thermostat is wonky or you have a blocked passage in the block. If that’s the case, throw a hail Mary and run some Prestone cleaner through there and see what comes out. Rory From: Af [mailto:[email protected]] On Behalf Of Forrest Christian (List Account) Sent: Monday, September 18, 2017 9:26 AM To: af Subject: Re: [AFMUG] OT: S10 Chevy heating issue One additional thought.. I've had at least one rig where a bad/incorrect radiator cap would cause overheating as the radiator cap in many systems doubles as the pressure regulator for the system, and apparently system pressure matters for some engines. Not sure if this applies in your case. On Sep 18, 2017 9:19 AM, <[email protected]<mailto:[email protected]>> wrote: If you don’t have exhaust gasses in the radiator, it is probably not a head gasket. If you do, then follow up with a compression test. If both tests fail, it is probably a gasket. Sounds to me more like a recalcitrant thermostat. From: Cameron Crum Sent: Monday, September 18, 2017 9:13 AM To: [email protected]<mailto:[email protected]> Subject: Re: [AFMUG] OT: S10 Chevy heating issue Be easier to replace a head gasket than pull the whole motor IMO On Mon, Sep 18, 2017 at 9:57 AM, <[email protected]<mailto:[email protected]>> wrote: That exhaust gasses in the radiator test Forrest mentioned is a sure indicator. Better than a compression test. From: Jaime Solorza Sent: Monday, September 18, 2017 8:56 AM To: Animal Farm Subject: Re: [AFMUG] OT: S10 Chevy heating issue Yep... going have compression test done...we have another 4.3 in a wrecked Blazer we could swap with 111005 miles on it. Might just do that and donate Blazer to Car Talk On Sep 18, 2017 8:51 AM, "Cameron Crum" <[email protected]<mailto:[email protected]>> wrote: I wouldn't run without a t-stat. On a lot of cars you need the restriction to give the radiator time to do its job. Sounds to me like if it was smoking (from exhaust?) when heating, you might have a cracked head gasket. It looks like you've replaced everything else. On Mon, Sep 18, 2017 at 9:04 AM, Forrest Christian (List Account) <[email protected]<mailto:[email protected]>> wrote: One thing to check is if you're getting exhaust gases in the radiator. There are kits to test this. On Sep 17, 2017 6:06 PM, "Jaime Solorza" <[email protected]<mailto:[email protected]>> wrote: My wife bought a 2001 4x4 Chevy S10 Vortec 4.3 from sons wife. We knew it heated up a little...I replaced water pump, fan clutch, thermostat, had system flushed including heater core along with radiator. It doesn't heat up us as much...you can run it on freeway with temp at 210 degrees...once you exit and stop, it gets hot for a bit then cools off again. No detectable leaks, no water in oil...wonder if sensor if faulty...any ideas or tips...we want 4x4 for winter hiking season. Thanks
