Water pump and thermostat questions

Rotary#10 · 08-12-2009, 12:28 AM

Hey folks the waterpump on my FC 90 gtus resently started rattling at the pulley and i knew it was bad. ( Haynes manual said it was the bearing) so i pulled it and put in the other one from my 91 couple only to find out that it was frozen or seized. So now im buying new water pump but i'd also like to know if i should also buy a thermostat while im in that area. So would ya'll recommend I buy a theromstat? I think its a good idea though. Thanks for your imput.

speedjunkie · 08-12-2009, 12:48 AM

I would have to vote for absolutely. I mean, you might as well since you'll already be working in that same arena, and that way you'll know it's new and later on, how many miles are on it. Just my opinion, but absolutely.

Rotary#10 · 08-12-2009, 01:04 AM

its just turned over 75,000 miles.

speedjunkie · 08-12-2009, 08:52 AM

No, I mean you'll know how many miles are on the thermostat. I don't know the mx schedule for the thermostat but I'd say 75k miles is enough haha. Nothing like peace of mind.

rx4ur7 · 08-12-2009, 11:35 AM

Yes, replace it. Make sure that is for a rotary and matches the one you take out. Clean the surfaces carefully. Do not use power tools. The safest is to use a chemical gasket remover and a plastic scrapper. But if you are carefull you can do it by hand with new razors. But if you have not done a few cleanings on aluminum I recommend chemical.
Make sure all the surfaces are clean. I do not recommend using any RTV or sealant - see my forum on gaskets and RTV. If your surfaces are properly clean the gasket itself will work. Excess RTV that breaks off internally from either replacement has caused many overheating issues and engine failure due to it. I have had to do too many motors because of it.

Not trying to scare you, just save you some grief.

If you think you really have to use any gasket sealant, use a very, very thin film and try to keep it away from the inner surface.

On the FC you do have to be carefull about the main W/P Thermo housing to motor gasket leaking if you do not remove the whole assembly.

If you use an aftermarket pump, make sure of clearance for the impeller. Do not go rebuilt if you can. If you do not go to Ray at Malloy Mazda which I recommend, try autoparts warehouse they sell the NPW brand. Stant does make the proper thermostat.

Do not try to go cheap on these two items. It is a pay me now or pay me alot more later area.

Rotary#10 · 08-12-2009, 12:23 PM

i'd usually buy this stuff from Atkinsrotary.com

FCTII · 08-12-2009, 09:48 PM

yeah haha dont use rtv when i got my car one of the cooling ports was clogged with some nasty ald rtv

Quote:

Originally Posted by rx4ur7

Yes, replace it. Make sure that is for a rotary and matches the one you take out. Clean the surfaces carefully. Do not use power tools. The safest is to use a chemical gasket remover and a plastic scrapper. But if you are carefull you can do it by hand with new razors. But if you have not done a few cleanings on aluminum I recommend chemical.
Make sure all the surfaces are clean. I do not recommend using any RTV or sealant - see my forum on gaskets and RTV. If your surfaces are properly clean the gasket itself will work. Excess RTV that breaks off internally from either replacement has caused many overheating issues and engine failure due to it. I have had to do too many motors because of it.

Not trying to scare you, just save you some grief.

If you think you really have to use any gasket sealant, use a very, very thin film and try to keep it away from the inner surface.

On the FC you do have to be carefull about the main W/P Thermo housing to motor gasket leaking if you do not remove the whole assembly.

If you use an aftermarket pump, make sure of clearance for the impeller. Do not go rebuilt if you can. If you do not go to Ray at Malloy Mazda which I recommend, try autoparts warehouse they sell the NPW brand. Stant does make the proper thermostat.

Do not try to go cheap on these two items. It is a pay me now or pay me alot more later area.

08-12-2009, 01:04 AM	#3
Rotary#10 Rotorhead Join Date: Sep 2008 Location: "the town " Oakland Posts: 219 Rep Power: 18	its just turned over 75,000 miles. __________________ Currently running: 90 GTUs converted to S5 TurboII. Track car. 90 N/A GTUs.. Running project car 89 N/A GTUs in Black #2 10/6/18 Blown coolant seal undergoing rebuild and restomod.

08-12-2009, 12:23 PM	#6
Rotary#10 Rotorhead Join Date: Sep 2008 Location: "the town " Oakland Posts: 219 Rep Power: 18	i'd usually buy this stuff from Atkinsrotary.com __________________ Currently running: 90 GTUs converted to S5 TurboII. Track car. 90 N/A GTUs.. Running project car 89 N/A GTUs in Black #2 10/6/18 Blown coolant seal undergoing rebuild and restomod.

08-12-2009, 12:28 AM	#1
Rotary#10 Rotorhead Join Date: Sep 2008 Location: "the town " Oakland Posts: 219 Rep Power: 18	Water pump and thermostat questions Hey folks the waterpump on my FC 90 gtus resently started rattling at the pulley and i knew it was bad. ( Haynes manual said it was the bearing) so i pulled it and put in the other one from my 91 couple only to find out that it was frozen or seized. So now im buying new water pump but i'd also like to know if i should also buy a thermostat while im in that area. So would ya'll recommend I buy a theromstat? I think its a good idea though. Thanks for your imput. __________________ Currently running: 90 GTUs converted to S5 TurboII. Track car. 90 N/A GTUs.. Running project car 89 N/A GTUs in Black #2 10/6/18 Blown coolant seal undergoing rebuild and restomod.

08-12-2009, 12:48 AM	#2
speedjunkie RCC Loves Me Not You Join Date: Mar 2008 Location: Colorado Springs, CO Posts: 2,089 Rep Power: 20	I would have to vote for absolutely. I mean, you might as well since you'll already be working in that same arena, and that way you'll know it's new and later on, how many miles are on it. Just my opinion, but absolutely.

08-12-2009, 08:52 AM	#4
speedjunkie RCC Loves Me Not You Join Date: Mar 2008 Location: Colorado Springs, CO Posts: 2,089 Rep Power: 20	No, I mean you'll know how many miles are on the thermostat. I don't know the mx schedule for the thermostat but I'd say 75k miles is enough haha. Nothing like peace of mind.

08-12-2009, 11:35 AM	#5
rx4ur7 Rotary since 1972 Join Date: Nov 2008 Location: Tucson Posts: 231 Rep Power: 17	Yes, replace it. Make sure that is for a rotary and matches the one you take out. Clean the surfaces carefully. Do not use power tools. The safest is to use a chemical gasket remover and a plastic scrapper. But if you are carefull you can do it by hand with new razors. But if you have not done a few cleanings on aluminum I recommend chemical. Make sure all the surfaces are clean. I do not recommend using any RTV or sealant - see my forum on gaskets and RTV. If your surfaces are properly clean the gasket itself will work. Excess RTV that breaks off internally from either replacement has caused many overheating issues and engine failure due to it. I have had to do too many motors because of it. Not trying to scare you, just save you some grief. If you think you really have to use any gasket sealant, use a very, very thin film and try to keep it away from the inner surface. On the FC you do have to be carefull about the main W/P Thermo housing to motor gasket leaking if you do not remove the whole assembly. If you use an aftermarket pump, make sure of clearance for the impeller. Do not go rebuilt if you can. If you do not go to Ray at Malloy Mazda which I recommend, try autoparts warehouse they sell the NPW brand. Stant does make the proper thermostat. Do not try to go cheap on these two items. It is a pay me now or pay me alot more later area.