l67ss Posted December 2, 2016 Report Share Posted December 2, 2016 All of the house brand pumps I saw for a 3800 had identical impellers to acdelco. The problem I found was they are machined crappy and are actually wrapped. When you tighten them I've had a couple wobble brand new because of the distortion Quote Link to comment Share on other sites More sharing options...
95GS Posted December 2, 2016 Author Report Share Posted December 2, 2016 All of the house brand pumps I saw for a 3800 had identical impellers to acdelco. The problem I found was they are machined crappy and are actually wrapped. When you tighten them I've had a couple wobble brand new because of the distortion actually wrapped...I think you meant warped. I didn't think to check for that. Doh! Would have been easy. Identical impellers to AC Delco - what does that mean? Do the AC Delcos resemble either of my samples above? FWIW, the old pump was just over 2.5 lbs. The new Gates model was a quarter pound lighter. Quote Link to comment Share on other sites More sharing options...
95GS Posted December 5, 2016 Author Report Share Posted December 5, 2016 Wow, what a difference in impellers. Makes me wonder how hard it would be to put a new bearing and seal in it. A mechanic told me rebuild kits for GM water pumps were once commonplace. So it shouldn't be too difficult, once one obtains the parts. Does anyone have a pic of an AC Delco impeller? Quote Link to comment Share on other sites More sharing options...
Imp558 Posted December 5, 2016 Report Share Posted December 5, 2016 Your old one looks to be genuine GM Quote Link to comment Share on other sites More sharing options...
95GS Posted December 5, 2016 Author Report Share Posted December 5, 2016 Thanks Imp. Quote Link to comment Share on other sites More sharing options...
ron350 Posted December 5, 2016 Report Share Posted December 5, 2016 I don’t think you can buy one of those water pumps with a cast iron impeller any more. Several years ago Rockauro sold a AC Delco pump with a cast iron impeller but no more. Quote Link to comment Share on other sites More sharing options...
95GS Posted December 6, 2016 Author Report Share Posted December 6, 2016 Thanks Ron, my impression is that the cast iron model is a better fit & design for moving fluid. So don't toss the old ones. Today I found a Canadian company that 'remanufactures' these and other car parts. http://www.johnstuartpowerbrake.com/Home.page There must be other machine shops in the same business. I'll keep the Gates model for now, at least until summer. An important tip I picked up here is running a 180F thermostat in the summer months. The engine compartment is always roasting in July. Quote Link to comment Share on other sites More sharing options...
Imp558 Posted December 6, 2016 Report Share Posted December 6, 2016 I found that removing the rubber hood seal along the cowl dropped my underhood temps a bunch long ago. There's still a lip there to prevent water from coming under the hood in the back. Quote Link to comment Share on other sites More sharing options...
Padgett Posted December 6, 2016 Report Share Posted December 6, 2016 Just a 180F (I like Stant Superstats) thermostat alone won't do much, you also need to reprogram the ECM or use a secondary thermostat to bring the fans in sooner. to bring the fans in sooner. 160F is too close to turning off the "all in" computer setting. I use a 180F thermostat in al GM computer cars. Quote Link to comment Share on other sites More sharing options...
95GS Posted December 6, 2016 Author Report Share Posted December 6, 2016 I found that removing the rubber hood seal along the cowl dropped my underhood temps a bunch long ago. There's still a lip there to prevent water from coming under the hood in the back. That makes sense Imp. But consider also - last month I was driving a Ford of the same vintage which was missing the hood seal. A transverse mounted V-6. Unknown to me, It had recently developed a rear exhaust manifold leak, later seen to be a 2.5" crack in the pipe. It made me quite ill - apparently the fumes were entering the vehicle at the grill near the wipers. I could barely smell it, although I could hear the leak. Even a home CO monitor didn't seem to notice. A mechanic's tip was to place styrofoam pipe insulators from Home Depot along the hood's trailing edge. That helped somewhat until the owner had the manifold changed. (Opening windows didn't help much either, drawing more in.) So at least in some vehicles, the hood seal helps isolate engine compartment fumes from the fresh air intake. Quote Link to comment Share on other sites More sharing options...
95GS Posted December 6, 2016 Author Report Share Posted December 6, 2016 Just a 180F (I like Stant Superstats) thermostat alone won't do much, you also need to reprogram the ECM or use a secondary thermostat to bring the fans in sooner. to bring the fans in sooner. 160F is too close to turning off the "all in" computer setting. I use a 180F thermostat in al GM computer cars. I found your 3800 water pump notes after I'd done mine! But did mine the same, save for the axle grease. Interesting site Pagdett. Reprogram the ECM. Hmm. I guess you're saying the ECM will just compensate for the thermostat change if not reprogrammed. Not something I've messed with before. Quote Link to comment Share on other sites More sharing options...
Padgett Posted December 6, 2016 Report Share Posted December 6, 2016 Not really compensate, just temp will rise in heavy traffic (little airflow through radiator & fans normally do not turn on until well over 200F unless AC is on). I have reprogrammed my 3800s (and the 3.4) to turn on LO at 185 and HI at 189. This keeps temps under 200F at all times. Quote Link to comment Share on other sites More sharing options...
95GS Posted December 6, 2016 Author Report Share Posted December 6, 2016 Not really compensate, just temp will rise in heavy traffic (little airflow through radiator & fans normally do not turn on until well over 200F unless AC is on). I have reprogrammed my 3800s (and the 3.4) to turn on LO at 185 and HI at 189. This keeps temps under 200F at all times. I like the idea of having some control over that system. I'm sure esp. useful in Fla. with hot weather + infamous traffic congestion. Quote Link to comment Share on other sites More sharing options...
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