Thermostat modifications

[NitroDann]

Okay so I bought a new thermostat recently and now my car can warm up...but, it runs too hot and I can heat the car up if I want to..

If I drill a hole in the thermostat it will always allow a little flow and the engine will definately run cooler when the thermostat is closed, but this will only keep the thermostat closed for longer and it will not affect the thermostats operation when warm... Is this correct.

So I drill the hole, The car runs slightly cooler, so because its cooler the thermostat will just not open as far, result, no difference. Right?

Where can I buy a thermostat that will keep my engine at 85c in all conditions (the radiator can keep it at 60). Mazda right? How much do they want?

Dann

[aviper4u]

try this guy
http://stores.ebay.com/Miatamecca

parts in the us are at least have the price from what iv seen eg: aftermarket stuff is same price as genuine in the US? add a touch for shipping, though for small items might be an idea?

see how u go champ

[project.r.racing]

don't bother modifying the one you have, purchase a low temp one. if you search miata thermostat on ebay, it comes up with a few options.

[manga_blue]

If I drill a hole in the thermostat it will always allow a little flow and the engine will definately run cooler when the thermostat is closed, but this will only keep the thermostat closed for longer and it will not affect the thermostats operation when warm... Is this correct.

Any thermostat must have a small hole to let some water through, even when cold. Otherwise there's a risk of not enough hot coolant ever travelling from the engine to the thermostat, so you can fry the engine while the thermostat sits twiddling its wax waiting for heat. If the thermostat has a jiggly thing in the hole then make sure that it always allows flow in the right direction. Some of those things can work like one way valves. It took me ages of sorting out a boiling engine with a new thermostat before I worked out what the hole and the jiggler were for.

[Basho]

I just replaced mine , this one appears to work fine and runs my car with the temp gauge registering just under centre.(92 NA6)

Dayco- Part No is DT27A-BP.
It's a 52mm with 82c opening. it has a jiggle pin and has an offset centre.
Repco, sale on, so only $16.89,

The OE gasket is stainless steel with what looks like a black sealant though it could have been a coating, it also appears to play a part in keeping the thermostat seated.

I cleaned and reused this with a thin layer of hi temp silicon sealer on each side .

Two things to note:
One/ The OE aperture is 30mm and the Dayco one is 27mm so I will be keeping a close eye on the temp gauge.
Two/ The construction of the OE one I removed was more sturdy than the Dayco replacement.

[Steampunk]

... I worked out what the hole and the jiggler were for.

It's a pressure release doobie and should be placed at the highest point.

What does the B6 thermostat look like? If it's anything like the BP, then it's quite a complex design:



Beck-Arnley and Stant over in the US make OEM-looking ones for around $15USD.
Mishimoto also make them, but they open at 62deg C.

[project.r.racing]

... I worked out what the hole and the jiggler were for.

It's a pressure release doobie and should be placed at the highest point.

What does the B6 thermostat look like? If it's anything like the BP, then it's quite a complex design:



Beck-Arnley and Stant over in the US make OEM-looking ones for around $15USD.
Mishimoto also make them, but they open at 62deg C.

that one in the pic is an aftermarket performance low temp one.

the DT27A one has the small jiggle pin amd the regular wax inner thermostat. so same as the pic, minus the lower temp mini openner.

[Steampunk]

*sigh*

Miata OEM thermostat

Are you now going to say that it's only for a USDM Miata?

http://www.mx5parts.co.uk/thermostat-genuine-mazda-p-757.html

[project.r.racing]

I don't think you can presume what I am gonna say next. It ain't a teenage girl facebook battle royal. But what I can say is, I have never seen a dual stage thermostat in a 90s model Mazda. As I said, "I have never seen." Doesn't mean there isn't or I'm correct. All the BP ones I have seen (I've only been playing with 323s/Lasers/MX5s for a little over 10 year, so my knowledge ins't huge) just have a single valve and a jiggle pin.

[manga_blue]

Thanks for that link to the OEM, Andrew, I'd been looking for one with reasonable price and postage for quite a while.

2 stage were standard for all NAs.

[Basho]

Thanks for that link to the OEM, Andrew, I'd been looking for one with reasonable price and postage for quite a while.

2 stage were standard for all NAs.

Interesting, this caused me to have a look at the one I've just replaced with a DAYCO and it's actualy an NTC with a code No of HE41 82C , it's a single apperture, I took this to be the origional as the gasket appeared to never have been moved .

Mazda Gold Coast quoted me $40 for the OE replacement I'll call them and see if it's a dual apperture and post if it is , it may save you going offshore

I do wonder why the twin apperture though, it would seem to complicate a simple requirement .

[Basho]

I've just recieved more information regarding these pesky items from the incredibly patient and helpfull Jason at MX5 PLUS and aparantly the brand for the NA6 was MOTORAD heres a link.

http://www.motoradusa.com/catalog.php?C ... c+GAS+FI+N

The least of issues in my previous vehicles , of which there have been many , has been thermostats , why would the MX5 be any different ?

Is the car a thermostat eater ?

[manga_blue]

Is the car a thermostat eater ?

No, the cars are not thermostat eaters. The issue is that many of us have bought cars with non-original thermostats when the original ones probably never needed replacement in the first place. Often the replacements simple don't work as well as originals.

[Steampunk]

Thanks for that link to the OEM, Andrew, I'd been looking for one with reasonable price and postage for quite a while..

You're most welcome Phil, I hope the seller ships here.
With all your track-work though, you wouldn't consider a Mishimoto one?

As an aside, just in case anyone considers getting a "Superstat" from Stant, don't.
Apparently they are designed that when it fails for one reason or another, it remains shut whereas most remain open.

... the brand for the NA6 was MOTORAD heres a link.

The least of issues in my previous vehicles , of which there have been many , has been thermostats , why would the MX5 be any different ?

Motorad shares same part#s as Tridon, so I'd say they come from the same factory.

Have a look at the coolant flow of NA & NB MX-5's to answer your question.

[Basho]

It would appear that the Motorad have 3 types in two temp ranges all of which are to OE specifications .

I can only assume that geography plays some part with the 'higher temp' openers possibly used in colder climates , 'high flow' for performance use , and the 'fail safe' model for the paranoid.

As they're part and parcel of Tridon about whom some indiferent comments have been made I wonder at thier quality but pass no personal opinion other than I am not inclined to change out my newly installed DAYCO one.

After further questions it has been indicated to me that incorrect and/or old coolant/glycol mixes play a not inconsiderable part in thermostat fails which in the main sieze open and further that a themostat change is not untoward when any work that involves coolant replacement is done. .

I had my timing belt , water pump etc etc etc done just prior to Xmas.

But not the themostat replaced .