So I was cruising down the highway today and noticed that the temperature guage was slightly higher than I thought was normal. The coolant reservoir is full to the 'max' line. It never got higher than was shown on the picture and cooled down a little bit as I moved onto some more hilly and windy 50-60mph county roads. See the pic below. Also, is that normal for the oil pressure and voltmeter? There's not an e-fan or anything, just the normal fan (which works just fine) with all the proper shrouding, etc.



And yes, I always keep a camera with me in the car. More than once have I been able to get a nice shot that I would have otherwise missed.

Thanks.

 

Hi, I'm Ian too.
That's not normal for the temp guage, I'd check your thermostat, it might be time for a new one, also check you tranny fluid. After my engine did that, my tranny blew up. I put a new one in, along with a new thermostat, and everything was fine.

 

dude i'm in new york too, and my car was pretty much the same when i was crusin around at around 80
i'm gonna have to disagree with what molotovman said, but it wouldn't hurt to check it

i'd just blame the increased temp on the disgusting heat and humidity we've been having in NY the last few days
i'm not worrying about it...

edit; if you were off the accelerator at the time, the oil pressure loosk good
the voltmeter is a little low though, unless you had your headlights on and aftermarket stereo bumping?

when all of that stuff is on in my car it looks like that, but once at around 3000 rpm it'll go to a shade under 14v
during the day it stays at 14.4, though
if that was during the day with no heavy electrical loads on your car, you should check your alternator and battery

 

I had cruise control on, nothing extra electrical on (lights, stereo, etc., all off).

How would the transmission fluid relate? It's Redline synthetic, no more than 6000 miles on it.

 

I'm in Milwaukee, and my temp gauge has been running around there after some hard driving (88 SE NA). It makes me uncomfortable, and usually results in me blasting the defroster heat at max (with the windows & sunroof open, it doesn't really bother me) for a while.

I'm ordering a new thermostat from MazdaTrix (actually, ordered) and am going to be flushing my coolant system this weekend, installing a new thermostat, and some other stuff before heading up north to Michigan for a week. The temperature is slightly erratic, and I suspect a sticking thermostat.

Also, your voltage looks low. It should be at 14 or so running. Check it with a voltmeter at the battery, it may just be a meter calibration issue.

-=Russ=-

 

I'll check the voltage with a voltmeter when it's running; hopefully it's just a calibration issue. Also with the oil pressure, what sort of things can I look for that would cause lower-than-should-be oil pressure? The car doesn't leak at all, and the oil level was just slightly (one or two mm) below the full mark when I checked it in the morning. Perhaps too much oil going to the oil injectors? FWIW, I'm running 400:1 premix with the OMP still connected.

I've ordered a new thermostat from Mazdatrix along with the LSD additive to cure the annoying chatter from the LSD while pulling away from a standstill into a curve (i.e. turn at stoplight).

 

no, he is right.. chack the thermostat... even though i can't see the picture, i'm guessing it's above the half mark? i also don't think our stock gauges are accurate, but nonetheless, it's stiil a good sign that you need to do something about it. also don't blame the weather, i'm in texas.... TEXAS, i NEVER overheat or show signs of it. even when i dog it. don't try to hide the problem, do something about it.

 

Also, would it make sense that the engine would cool better at higher RPMs (water pump moving more coolant?) -- when I'm driving the hilly windy county roads, the temperature guage reads around 1/3, and RPMs are between 2000 and 5000, varying a lot. I wouldn't quite call it "spirited" driving, but certainly more entertaining. I absolutely love the handling of the car, and the passive rear steering is pretty nifty too (the 86 GXL has it, right?).

 

To clarify: in the picture, the temp gauge is about exactly at 1/2, the voltmeter is somewhere around 12.5 or 12.8, and the oil pressure is at 50 psi. All this is at 3000 RPM and an indicated 70 mph with cruise control on but no electrical extras (stereo, lights, etc.) on.



Now that I think about it, I've used the stereo twice. Ever.

 

low oil pressure could be caused by a failing thermal bypass valve in the eccentric shaft. If this is the deal, you have a very little time to deal with it. Adkins sells thermal pellet replacements that work fine. If you choose to fix this yourself, if it is the problem, be sure to read ALL directions with the kit and on Mazdatrix's website about e-shaft thrust bearings and the pully/belts assembly in their FAQ section. The sending unit could be bad, or the guage also. my guage is bad and others have had problems with it also. The things I can think of that would effect oil pressure would be as follows, oil pump, front and rear oil pressure regulators, thermal bypass valve, and maybe oil filter/viscosity of oil used.

 

i'm pretty sure the half mark is normal for s4's..

 

Is there another way to test oil pressure?

 

my s4 ran under normal conditions at that temp when I bought it, then I balanced out the coolant/water mixture and now it runs at 1/4.

 

my s4 usually runs at 1/4-1/3. But in this hot weather, i've been seeing close to 1/2. And when i use a/c on the highway, it's even gone slightly over 1/2. The S4 temp gauges are more analoguous(sp) than the S5 ones, so i don't think you have to worry much unless it starts rising to 3/4 or so. My .02

 

Those dont look like terribly bad readings to me... I would get excited when I got aroung 3/4 on the gauge.

 

Guys ever had the tranny overheat the engine? I was losing bands in teh auto tranny a couple years ago. Got to the point where a drive on the interstate would overheat the tranny fluid, overheat the radiator, overheat the coolant, overheat the engine. It ended up getting so hot that the tranny fluid boiled (fortuantely not igniting) and overflowing out the tranny pan, hitting the exhaust in the interstate. Talk about a ******* mess. stopped traffic in two lanes cause of the smoke, and had to have HP come out with crap to throw on the oil

 

That would suck. Big time.

 

That is NORMAL if you have the a/c on. It is slightly lower without a/c. Don't worry about it.

 

I don't have working A/C.

 

Now I ahve someone to back me up when I said Check the tranny. But if you have 6k miles on the tranny fluid its good. thermostats are abotu$20 shipped from mazdatrix, it's well worth it to gett the right one.

 

Mine showed the same thing half way up on my s4 and I had popped a coolant seal. Slowly it will get worse then you will not be able to start the motor because the spark plugs will get wet. Time for a build if you ask me. Best thing you can do is get a aftermarker temp guage and see actually what the temps are because I have a FMIC and my stock guage says 1/3rd and the aftermarket guage says 205 on the highway. That tells you how hot 1/2 is on a stock guage. Like 250 on a aftermarket one and that equals rebuild

I got my guage at www.rpmoutlet.com it was the ultra lite and the entire kits was 40 bucks shipped

 

Halfway on an S4 temp gauge is BAD. It's not going to pop your motor but something is wrong. Voltage is bad as well, check your alternator and/or make sure the belt is good and tensioned enough. Oil pressure should be 60 psi @ 3000rpm.

Does that speed look funny to anyone else? When my car is @ 3000 I'm goin like 79 mph

 

When I reach halfway on the stock gauge I see between 185-190 on an aftermarket gauge and that happens on hot humid days and on the gas. I say about the 3/4 mark or higher I would worry.

Get an aftermarket temp gauge so you know for sure.

 

For a series four the temp looks a bit high. The oil pressure looks low but the sender is probably not accurate. Get a aftermarket, cheap, oil pressure gauge and install it where your stock sender is and go for a similar ride. The reading should be sixty and preferably a touch higher........and yours probably is. It's probably the gauge. Same with the voltage. Get a meter out and read off the battery posts and compare to the cars gauge.

 

Battery voltage with car off is 13.5v or so measured with a voltmeter. At idle it's about 14.5v measured at the battery. Then when I was driving it today (just backroads) the dash voltmeter said 14v at some times, and 13v at others. So it looks like the gauges are just screwy. I'll assume for now that that's the case until it something else says otherwise. In other news, my clock worked today for about 5 minutes for the first time since I've owned the car. Then it died again. Annoying but not worth the effort to get it out of the dash and resolder. I have ordered a new thermostat from Mazdatrix just in case.

Thanks for your help.