88-cnqst-tsi Posted April 21, 2013 Report Share Posted April 21, 2013 (edited) is there a difference between this water pump http://www.napaonlin...2173_0258157938 and this one http://www.napaonlin...1180_0267404090. im only asking because the first one has a cap on top of the blade when the second one doesn't, does it matter or do they work the same. Also there are two holes on side of the case on the dry side that you can see the shaft from, what are they for Edited April 21, 2013 by 88-cnqst-tsi Link to comment Share on other sites More sharing options...
Komeuppance Posted April 24, 2013 Report Share Posted April 24, 2013 Uncapped is 87. Capped is 88. 88 probably flows better, but there is no data on the difference. 86 and below also use the uncapped, but do not have the coolant return port on the pump. Exterior holes are weep holes... when they weep, your pump seals are bad. -Robert Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted April 24, 2013 Author Report Share Posted April 24, 2013 Uncapped is 87. Capped is 88. 88 probably flows better, but there is no data on the difference. 86 and below also use the uncapped, but do not have the coolant return port on the pump. Exterior holes are weep holes... when they weep, your pump seals are bad. -Robertso should it be ok to use the uncapped one Link to comment Share on other sites More sharing options...
Komeuppance Posted April 24, 2013 Report Share Posted April 24, 2013 Yeah, I do... and look how powerful my engine is, it broke 2nd gear last week. -Robert Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted April 24, 2013 Author Report Share Posted April 24, 2013 Yeah, I do... and look how powerful my engine is, it broke 2nd gear last week. -Robert lol did you post in the wrong topic Link to comment Share on other sites More sharing options...
Shelby Posted April 28, 2013 Report Share Posted April 28, 2013 both pics are of the same water pump , the port above the lower rad hose may be plug'd on one but can't tell from pic ,,87 up and late 86 all use'd the same water pump , that port is the return from turbo ,, if your's has the return line from turbo going to water pump ,,then get the one with that portopen Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted April 28, 2013 Author Report Share Posted April 28, 2013 both pics are of the same water pump , the port above the lower rad hose may be plug'd on one but can't tell from pic ,,87 up and late 86 all use'd the same water pump , that port is the return from turbo ,, if your's has the return line from turbo going to water pump ,,then get the one with that portopenthey have the same ports..i know that but in the rest of the post I ask if there's a difference between the capped blades and open blades Link to comment Share on other sites More sharing options...
Dad Posted April 28, 2013 Report Share Posted April 28, 2013 Maybe send an email to the manufacturers and ask them? Link to comment Share on other sites More sharing options...
StarquestRescue Posted April 28, 2013 Report Share Posted April 28, 2013 I have wondered the same thing. The first picture (new after market) looks to have a cast aluminum impeller. The second (remanufactured) the steel impeller. The pump i bought new from Mitsu for an 88 had the steel impeller. I would have to double check the parts #'s. There once was a local guy who said he solved an over heat problem by replacing the water pump. But i know no details on that. Link to comment Share on other sites More sharing options...
Dad Posted April 28, 2013 Report Share Posted April 28, 2013 I would think that thermostat will regulate the water flow regardless, unless the impeller is so small that it can't flow enough volume. Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted April 28, 2013 Author Report Share Posted April 28, 2013 the impellers look about the same size a round but the width of the capped one is a bit less because of the cap and the blade pitch looks the same but its hard to see because of the cap Link to comment Share on other sites More sharing options...
Shelby Posted April 28, 2013 Report Share Posted April 28, 2013 the uncap'd blade uses the frt of the block as the reaction plate , the cover'd plate not so muchof the two i'd say the cover'd blade may push more coolant at a lower rpm,, along these lines back in the ol school days a hi perf water pump actualy pump'd less water then the stock one . same with a/c and non a/c engines ,m a/c pumps push'd a bit more coolant at low rpms Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted April 28, 2013 Author Report Share Posted April 28, 2013 ok so it will hold up at high revs but will this be a problem in the lows Link to comment Share on other sites More sharing options...
Shelby Posted April 28, 2013 Report Share Posted April 28, 2013 eather will work just fine Link to comment Share on other sites More sharing options...
importwarrior Posted April 28, 2013 Report Share Posted April 28, 2013 i have always read that the capped flows better.1st always get the proper year if capped or uncapped is an option i would get the capped. Link to comment Share on other sites More sharing options...
88-cnqst-tsi Posted April 29, 2013 Author Report Share Posted April 29, 2013 i have always read that the capped flows better.1st always get the proper year if capped or uncapped is an option i would get the capped.I ordered the capped one from napa but it was shipped from texas and it was uncapped Link to comment Share on other sites More sharing options...
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