A/C and Overheating Question

[EVOrange]

I've been in the Miata.net forum and someone said I should check to see if anyone was having a tech day around DFW. I would just like someone to look at my cooling system to see if my water pump or thermostat could be the problem. The car gets extremely hot on the highway with the a/c on, but I had the radiator replaced about a year ago with a metal one at the dealer. It doesn't overheat, but comes very close. A lot of simple fixes have been recommended, but I don't know where to look for them or how to try them. I hate going to the shop with no knowledge of the problem because it always seems to result in a huge bill. If no one is doing a tech day, or doesn't want to mess with someone else's car, could you recommend an honest mechanic or shop. I live in Denton, but would take the car to Dallas if the work is honest.

Thanks for your time

Grant

[altiain]

Welcome to the board, Grant.

Chances are it's a simple and inexpensive fix. The t-stats and radiator caps on these cars really ought to be replaced every spring, imho. It's not hard to do yourself, and the parts should cost you less than $20 total at your local Autozone or the like.

Keep your eyes and ears posted, as we have a tech day coming up in the next couple of weeks. Either that, or one of us might be able to help you fix the problem one afternoon or evening - it doesn't take long to do.

[EVOrange]

Thanks for the reply.

I live in Denton. Is there an email list I can join for the tech day or should I just check back on here?

[POS Racing]

Is there an email list I can join for the tech day or should I just check back on here?

Just check back here! :cool:

What have you replaced so far in your efforts to get it to cool down, I know you said you got a new radiator, but what else have you done??

[sammm]

Is there an email list I can join for the tech day or should I just check back on here?

No email list to join. You'll soon find a lot of the members on our forum like to AutoCross! The season is winding down and Tech Days are bound to pop-up once the season is over. Welcome aboard!

Like altiain stated, replace your t-stat and radiator cap for starters...that may be all you need. Keep us posted.

[EVOrange]

The car has 63,000 miles. Things replaced so far:

Brakes
Radiator
Belts
Plugs and Coil Pack

Everything on the car is stock. All work thus far has been done by the dealer. I bought the car used in 2000 with 8,000 miles on it. I'd like to keep the car stock, I'm not really into aftermarket modifications. Before this Miata, I had a 1990 Miata that I bought in 1997 when I was 17. I traded it with 142,000 miles for the 2000. Except for my first year driving, I've only driven Miatas. My step-dad did all the work, or at least the pre-shop consultation, but he passed on in 2003. Since then, I've been trying to figure out the problems on my own. I'd like to come to the tech day, so I'll keep an eye on the site.

Thanks

[Majik]

The tech day is something that is really helpful here. Especially for someone like you who seems to have little knowledge of working on cars. (Not a bad thing, no one knows before they start) The reason, is that it gives you an opertunity to get your hands dirty and learn what you are doing, while experienced people help. Like Altiain said, the thermostat and radiator cap are easiest and cheapest. They are also very likely to solve the problem. Why was the radiator replaced? To solve this problem? I would recommend the radiator cap first, since that might take 30 seconds if you count raising the hood. You need no tools, and it is about like opening a coke bottle.

[POS Racing]

I would recommend the radiator cap first, since that might take 30 seconds if you count raising the hood. You need no tools, and it is about like opening a coke bottle.

Yep that would be a good starting point!

Another question has the car been loosing any antifreeze out of the overflow bottle?

[EVOrange]

When I took the car in for the brake job, I was told that the radiator had a crack in it. My first Miata left me stranded from a cracked radiator, so I felt that this was a legitimate problem. I asked for a metal one instead of the plastic, because they seem to have cracking problems. I'll replace the cap, but I think I'll wait for the tech day to look at the thermostat. The car does fine around town, it's just highway drives longer than 30 mins that seem to raise the temp. Thanks for all the advice.

[EVOrange]

Also, fluid levels have remained the same.

[POS Racing]

Also, fluid levels have remained the same.

I noticed today on our '02 the level had dropped down a touch, upon further review it looks like the Radiator Cap may have a slight leak! But it's past time since for it since it is the original cap!

Hey does anyone happen to know the Mazda P/N for the NB's radiator cap? I notice it has a 1.1 rating where the one on my '92 has a 0.9 rating!

[Majik]

Quick question, where is your liscense plate? Billy Blaze had a problem like yours a few months ago. I think his front plate was actually in the grill and not on a bracket on the nose.

Edit: Here is the thread about that. I think we gave some good clues as to what you can change.

[blackzx3_13]

Does he need a "stiffy"?

[Majik]

I noticed today on our '02 the level had dropped down a touch, upon further review it looks like the Radiator Cap may have a slight leak! But it's past time since for it since it is the original cap!

Hey does anyone happen to know the Mazda P/N for the NB's radiator cap? I notice it has a 1.1 rating where the one on my '92 has a 0.9 rating!

KL01-15-205

Mazdastuff.com has it for 10.04
Mazdamotorsports for 7.60

[Majik]

Does he need a "stiffy"?

I would have to say that isnt my business!

[Sharpie]

Grant, you and I met awhile back where you worked. I'm still in Denton. I have some suggestions too. The first one is what is the ratio of water to antifreeze. I'll help you if I can. Shoot me a PM with your phone #.

[Billy Blaze]

Hi EV!, I was having the same problem earlier this Summer.
Everyone was real helpful in getting mine back to good.
Here's what I did....
1.) Bought a New Radiator Cap
2.) Bought a New Thermostat
3.) Bought some 50/50 (distilled water/coolant).
4.) you will more than likely need a new thermostat housing gasket, I had to scrape mine off with a pocket knife.

I replaced all this and ran a couple of gallons of Distilled water through the radiator to flush it out.

After I put the new T-Stat in and new gasket on, flushed and filled the radiator with new coolant the problem stopped.
Many people have commented at how well the Miata's cooling system is Stock, after I did the above procedure mine was working well with or without the A/C running.
tip: Whatever you do, don't lose or over tighten the plastic Radiator bolt.
also make sure your license plate isn't obstructing your radiator, that was a problem with mine as well.

Later this Summer and just recently I replaced the Radiator with a PWR double core Radiator, it is for HOT Climates, and running forced induction...if you want added insurance that may be an option for you.
However I beleve that doing the above will cure your problem as it did mine.

Hope this helps, feel free to IM me if I can help with any further questions.

[EVOrange]

I'm going to buy a new radiator cap tomorrow. I'll have to see about replacing the t-stat. Not sure how to do that. Not sure where it is. :)

I'll keep you posted.

Grant

[POS Racing]

Let us know we are here to help! :cool:

[channelmaniac]

Grant,

If you want to drive down to Lewisville, I'll be happy to help ya with it... I've done several thermostats...

You'll need a new thermostat & a gasket... and while you're at it, get a gallon of pre-mix antifreeze.

If you want to do a flush/fill on the antifreeze, you'll want to get two... probably only need one, but it's best to be prepared...
RJ