Project: 1995 Miata

[Evan]

at track speeds in open air, even an original miata cooling system should keep the car nice and cool.
Going 70/30/WW may band aid the problem but it sounds to me like there is something else going on.

Thermostat is cheap to replace but they are designed to fail open, i doubt thats it. (and if it failed closed it would have pegged the temp)

Was the engine detonating at all? Rocks in a can?

can you check/set timing on the 99 engine?

[Jake]

at track speeds in open air, even an original miata cooling system should keep the car nice and cool.
Going 70/30/WW may band aid the problem but it sounds to me like there is something else going on.

Thermostat is cheap to replace but they are designed to fail open, i doubt thats it. (and if it failed closed it would have pegged the temp)

Was the engine detonating at all? Rocks in a can?

can you check/set timing on the 99 engine?

Hrmm. That was my thought too. My old motor never ran hot like this.

Engine did not sound weird at all, just didn't make as much power.

I'm using the 95's Cam Angle Sensor - someone said the 99 motor should set timing automatically (versus the NA's motors where you can advance it manually) but I don't know for certain.

[PDenbigh]

Check the ignition timing (and all the things that affect it). If it's off or erratic, it could cause you to lose power and cause the temps to go up. I assume you checked your coolant level after all of that, right? Don't want that to boil and get low.

Are miata temp gauges "accurate" or are they more binary? Most modern gauges are either "in the middle" or "high" by design, and don't really accurately display medium-to-minor changes in temp. ("accuracy" freaks common drivers out, ("it's always moving!!!") so they took out the fidelity. On a RX8, for example, I've heard that if the water temp shows "high," it's already too late. Just something to be aware of.

I finally fixed the cooling issue on the XR this weekend - with a higher pressure cap. 28-32psi rated cap, up from 22psi. Temps never got above 200 at full boost Saturday or Sunday, and would quickly fall back down to 180 as I came off the track into pits. My trouble symptom was that it was boiling all of the water out, which doesn't seem to be your issue.

[JPolen01]

You've now made NASIOC twice in non Subarus. You are internet famous. <!-- m --><a class="postlink" href="http://forums.nasioc.com/forums/showthread.php?t=2531160">http://forums.nasioc.com/forums/showthr ... ?t=2531160</a><!-- m --> ...Beware of OT.

[Jake]

Check the ignition timing (and all the things that affect it). If it's off or erratic, it could cause you to lose power and cause the temps to go up. I assume you checked your coolant level after all of that, right? Don't want that to boil and get low.

Are miata temp gauges "accurate" or are they more binary? Most modern gauges are either "in the middle" or "high" by design, and don't really accurately display medium-to-minor changes in temp. ("accuracy" freaks common drivers out, ("it's always moving!!!") so they took out the fidelity. On a RX8, for example, I've heard that if the water temp shows "high," it's already too late. Just something to be aware of.

I finally fixed the cooling issue on the XR this weekend - with a higher pressure cap. 28-32psi rated cap, up from 22psi. Temps never got above 200 at full boost Saturday or Sunday, and would quickly fall back down to 180 as I came off the track into pits. My trouble symptom was that it was boiling all of the water out, which doesn't seem to be your issue.

The temp gauge is only accurate to a point. According to Miata net...

The stock water temp gauge on the Miata in a way is linear. It's just that between 180°-210°F, it will stick to that 11AM position. If you ever climb over 210°F, you will notice the needle will climb up slowly. At about 210°-220°F, it will sit at the 12 oclock position. At 230°F, you can see the gauge start to move to the 1 or 2 oclock position.

So I guess it got up to like 215°.

You've now made NASIOC twice in non Subarus. You are internet famous. <!-- m --><a class="postlink" href="http://forums.nasioc.com/forums/showthread.php?t=2531160">http://forums.nasioc.com/forums/showthr ... ?t=2531160</a><!-- m --> ...Beware of OT.

[Evan]

I'm using the 95's Cam Angle Sensor - someone said the 99 motor should set timing automatically (versus the NA's motors where you can advance it manually) but I don't know for certain.

yeah thats what I thought but wasnt sure.
Maybe recheck the timing belt alignment? Id imagine the car wouldnt idle or drive well cold either. If its off a tooth its the same as having way off timing. And as you know its a motherF**er to get the belt aligned.

Nothing else I can think of off the top of my head.

[Evan]

Are miata temp gauges "accurate" or are they more binary? Most modern gauges are either "in the middle" or "high" by design, and don't really accurately display medium-to-minor changes in temp.

its linear, but if it starts moving past center its too hot.

[Jake]

Stock radiator? If so I had the same type of overheating in the Civic with a dual-core OEM radiator, swapped out to a blingy aluminum one and it cools just fine now.

You can pick up the cheapo ones on ebay and they work just fine, Mishimoto or whatever. I never had much luck with the water-wetter combo to be honest, car still over heated.

It's got a blingy no-name aluminum one in there already.

[ScottyB]

so it sounds like the cooling system isn't the problem, but maybe a symptom...good rad, good coolant, thermostats fail open, and you're making stock power. i wonder if it isn't something weird like a clogged cat. did you notice any weird smells (like metal cooking) or any really intense heat coming up from the floorboard? when you first ran the car after the swap, was it running over-rich or anything like that?

if the cat was clogged up it would certainly prevent you from making power (either through the physical breathing problem or the ECU retarding timing like whoa) while also keeping the engine from evacuating a lot of hot spent gases - i wonder if that in turn would cause a heat soak of the entire engine, ultimately leading to the cooling system struggling to keep up.

new water pump went in with the swap, yes? metal impeller or plastic? if you lost an impeller fin i wonder if that would hinder circulation.

[Jake]

so it sounds like the cooling system isn't the problem, but maybe a symptom...good rad, good coolant, thermostats fail open, and you're making stock power. i wonder if it isn't something weird like a clogged cat. did you notice any weird smells (like metal cooking) or any really intense heat coming up from the floorboard? when you first ran the car after the swap, was it running over-rich or anything like that?

if the cat was clogged up it would certainly prevent you from making power (either through the physical breathing problem or the ECU retarding timing like whoa) while also keeping the engine from evacuating a lot of hot spent gases - i wonder if that in turn would cause a heat soak of the entire engine, ultimately leading to the cooling system struggling to keep up.

new water pump went in with the swap, yes? metal impeller or plastic? if you lost an impeller fin i wonder if that would hinder circulation.

The car has stunk here and there. Keep in mind, the old motor was shooting oil through the exhaust so the cat is likely saturated. It still spits some residual oil out the back from time to time. I wonder if a new cat + catback is part of the answer, just for piece of mind.

Yes, new water pump went in with the swap. I think they are metal impellers, it's just a stock Mazda WP but they are fairly hardy.

[Jake]

I was getting a CEL for the EGR valve. A lot of people take the valve off and de-gunk all the carbon, but a new one was "only" $85 so I figured I would just do that. Joey and I replaced it yesterday. This is the old one:



Yep, nasty. A lot of people who do this 95 --> 99 swap have issues because you need the NA EGR, but it doesn't fit properly on the NB intake manifold due to clearance issues. Well, I got lucky with my AutoZone parts run and this EGR is for the '95 but fit right on. Sadly, the CEL didn't go away. One of us, however, had the thought to check the myriad of vacuum hoses to make sure they were all plugged in right.

Some quick Googling and we figured out that the EGR vacuum lines were in fact plugged in all wrong. Got most of the lines sorted out (I hesitate to say "all" because I'm sure something is wrong, given my luck) and hooray, the light went out. It seems to idle/run a bit smoother -- hopefully a given, considering I had all those lines in the wrong order.

Who knew following the vacuum diagram under the hood would have benefits?!

Also, I took my old boxspring to the dump. It wouldn't fit in the ST or the GTI, and their paint is too pretty to throw it on the roof. So, Miata to the rescue.

[Feersty]

Can we please start it off with a picture of Feersty's chrome hubcaps?

Or his Krylon fog lights

...how about we start with get a life. :evileye:

[CaptainHenreh]

He said, four months later.

[JPolen01]

Lol. Nothing but comedy gold every time he stops by.

[Jake]

Post-Summit Point Update -- 119,500 miles

Well, the car still runs great on the street and like crap on the track. And now the new motor is starting to burn oil. Frankly, I'm burned-out on it. Adding the roll bar, seats, and harnesses transformed it from a cheap, fun roadster that I loved driving, into a track rat that happened to have no roof. I don't fit in it well, and I would have to modify the floor to make everything fit better. And that still doesn't help the fact that I'd rather my daily driver have a removable top. The car sat for a year while it awaited the motor swap, and I think in that time of me not driving it, I kinda lost the love for it.

It pains me to type this all out, but after next Wednesday, she'll be living in someone else's garage. She's staying in the NASA-MA family, but one of the other officials with interest in a new project will be taking the reins. I will still be at the track and plan on starting Time Trials in October -- but I'll be in a different car. Looks like this project thread is winding down after five or so years. It's been a good effin' run.

[JustinG]

Spill the beans, what busted e36 are you buying?

[Evan]

[D_Eclipse9916]

Again, sorry to hear. I got tons of E36 stuff, although I am probably out of any spare front end body panels .

[Goodspeed]

Sad to see it go, but I can't really fault the decision. I know it was always a "tall guy in a little car" situation for you, never a problem I had, but TBH the whole going-full-retard trak car is what helped push me to sell mine after the dust settled, as you're left with a car that suuuucks to drive on the street after a while.

Looking forward to seeing what you will accomplish with another E36

[V1GiLaNtE]

Wow. It will be sad to see it go. But then again you have to admit you had a pretty good ride with the little 'otter.. Pun intended.