Coochas

Hi Everyone,
I tried a search but couldn't come up with an answer for my model 986.
My coolant temp seems to be running around 200-210 on the gauge (72 degree day here). I've only been driving this car for a few months so I don't know where it should be running.
My 997s both ran coolant at 180 on the dot regardless of driving conditions.

Silver Box

My '99 always pegs right between the 8 and 0. Doesn't seem to matter if it's hot or cold out. That's just where it settles.

Macster

is almost certainly not 180F.

The in-dash temp gage is just one step above idiot light.

(The 987s are even worse. My Cayman's coolant gage doesn't move off that tiny black rectangle located at the 175F mark no matter if coolant temp 175 or 215 and I've checked it against the actual coolant temp. Only way I know coolant "hot" is when I hear radiator fans come on.)

Years ago in my Boxster ran into some very hot weather down in southern AZ. 116F. Coolant gage needle went very high. Actual coolant temp (I was monitoring it with a scan tool) climbed to 226F. Fans on all the time. Engine compartment fan on I think all the time too, but I could only hear it when car slowed down some from freeway speeds.

I was worried but engine seemed to be ok and no coolant spilled and there was no overheating.

When I got back home I checked in with my service manager and detailed the circumstances. He contacted factory and factory said if the coolant light not on or flashing there was nothing to worry about.

I believe factory cause that has been nearly at least 150,000 miles ago...

My 02 Boxster's coolant gage needle ranges from the 180 mark to several needle widths above it even in milder (less than 116F) temps. If A/C not on cooloant temp will climb to 212F and fans come on low speed and shut off when coolant temp drops to 205F. If coolant climbs higher with fans on low speed they are switched to high speed and then shut off when coolant temp drops to 205F.

In these cases I see gage needle rise until fans come on then needle drops a bit and stays down until slow driving raises coolant temp again and the process repeats. At slower speeds not much air flows through these car's radiator ducts. That's what the fans are for.

About all you can do is verify -- and this is most important -- the cooling system is leak free -- that it can and does hold pressure without fail and it does not loose coolant and that coolant is fresh (4 years old or less) and mixed with distilled water to proper ratio.

And for corrosion concerns more than cooling concerns the radiator ducts are clean of plant debris and trash.

These cars when radiator fans are on act as vacuum cleaner sucking up all sorts of trash. This trash not only collects at bottom of ducting at bottom of A/C condensor but gets pulled around *behind* the A/C condenser between the consdensor and radiator. The radiator sits behind the condensor.

I've cleaned my '02's radiator ducts out several times now and you would not believe the amount of trash that collects, but I can see no difference in cooling. Car/engine ran ok before, no overheating symptoms at all, and ran ok after.

Sincerely,

Macster.

Coochas

Thanks for the input guys.
150,000 miles? Wow!

Macster

the 1st July after I bought car in Jan. of '02. Started near KC Mo and went west to Denver then up and over into Utah and Idaho. Across Idaho into Oregon and across Oregon to Bend and then Euguene where I picked up a folding bicycle that fit in front trunk of Boxster.

Down I-5 to Sacramento where I stopped and had oil changed. Bend dealer couldn't do the job.

Made way through bay area to visit family and friends then down into southern AZ (in July...that'll teach me) and eventually back to the KC Mo area. 8000+ miles and around 2 weeks on the road.

Still have Boxster. Getting ready for another road trip in a week or so, but this time taking new Cayman S.

Sincerely,

Macster.

sjfehr

So the temp gauge is only about as accurate as the speedometer? Good to know, thanks!

dallison28

my 02 sits just above 180

designman

Same here.

Macster

the warm fuzzies.

For my car's gage I tried to characterize the needle position based on actual coolant temp by observation and managed at one point to have a pretty good handle on actual coolant temp based on needle position -- mainly so many needle widths away from the 180 mark meant the coolant was at a particular temperature -- but it does not apply to other cars. At least not that accurately. There's just enough variation to make the behavior of one gage in trying to establish some base line useless.

It really boils (no pun) down to as the factory said as it was relayed to me and that is if no warning lights on/flashing there's no problem.

The only times the coolant light has been on, it has come on twice, there has been a problem. Once after I hit some road debris and busted the driver's side radiator and the radiator was leaking coolant. I saw the coolant cloud in the rear view mirrors and hoped it wasn't too bad (hah!) but about that time the dash light went on. Tranny in neutral and let car coast down from highway speed at idle hoping to cool engine enough it didn't suffer being shut off with a big coolant leak.

(No after effects but I don't know if my action helped or made no difference but at the time it seemed the right thing to do.)

And another time the light came on due to a low coolant level and I traced this to a leaking radiator cap.

Can't stress enough though that just because gage not that real doesn't mean you can ignore rest of cooling system. These engines need good clean coolant properly mixed and maintained under pressure to keep the engine from overheating.

As a car and engine age overheating starts accounting for taking older cars off the road, permanently.

A small leak is ignored until one day engine severely overheats cause of a real warm day. That small leak has now probably resulted in a blown/leaking head gasket, at best. Owner facing big repair bill and a big bill to renew/refresh other cooling system components. Say head gasket needs doing but also cooling system needs flushing/refilling and since overheating due to a leaking water hose all water hoses need replacing.

Owner could be looking at nearly $4000 worth of work.

Sincerely,

Macster.

Macster

except when driving in heavy traffic or waiting in drive through line at local fast food joint.

Then I see gage needle creep up until -- if the wait's long enough and the day's warm enough (and 70-ish deg. temp warm enough) -- until I hear the radiator fans kick on. Then I know coolant temp 212F or so. When the fans shut off I know coolant temp down to 205F.

Now in this same warm day I'm driving car down freeway at cruising speed needle doesn't move much if any from the 180 mark and I know from direct observation coolant temp stays in the 185 to 196 temp range.

If I happen to have the A/C on -- auto climate control -- though the temp gage needle remains even more steady on or near the 180 mark. When A/C compressor on radiator fans on low speed and all the time and this works to really keep the coolant temp. steady. Hardly ever see temp rise above 196 unless pretty warm day then it will climb to just over 200F. Even when sitting in drive through line with A/C on fans keep coolant temp down.

Sincerely,

Macster.