Temp gauge buried at 0 and no heat inside boxster

[zappbranigan]

I've visited several threads and after eliminating almost all other solutions, I still have the same problem.

When I turn on my 2001 Boxster, the temperature gauge is buried at 0 and will sometimes rise to 180 and back down after 20+ minutes of idling or driving. It never stays at 180 though. When the weather got down to the teens here recently, I never got the temp gauge to rise above 0.

The heat inside the boxster never gets any hotter than "barely" warm. And that too is only after the above mentioned time lapse.

I've ruled out the following so far:

Air mix flap is working (under passenger footwell dash area)

No coolant leak

Recently investigated the door flap inside heater core for missing foam. All is good.

There's no signs of leakage anywhere or obvious signs of hose damage.

I'm really hating to take this to the stealership as I've read many people's experiences with taking their car in and getting everything including the kitchen sink completely replaced.....and still not getting the problem solved.

Also, as long as I have the heater core pulled, any advice on how to tell if you have a bad heater core?

Joe

St. Louis

[rsfeller]

You have not listed the #1 reason for such symptoms...a stuck open thermostat. Has this been checked?

Running a vehicle under temp any length of time is very bad for it!

I doubt you have any concern with the heater core as this should not affect operating temps. Maybe someone could comment on the location of the temp sensor too to make sure a blockage would not prevent heat and proper temps even knowing the vehicle is operating at proper temps. I am sure nobody has built cars that way since the 80s :rolleyes:

[1schoir]

...

Also, as long as I have the heater core pulled, any advice on how to tell if you have a bad heater core?

...

Joe

St. Louis

Joe:

Best way to proceed if you suspect your heater core is to take it to a shop that specializes in radiators. They can pressure test it, and they can also "boil it out" to remove deposits that build up inside the tubes. If there is a severe buildup of mineral deposits inside the core, that will prevent efficient heat transfer when the fan blows air over the heater core.

A buildup that would have that kind of effect would normally occur gradually, over a long period of time. So, if your situation happened fairly suddenly, that is probably not your problem.

Have you looked into the possibility that your thermostat may be defective (stuck on "open"). That would allow coolant to flow throughout the whole system continuously and not allow it to warm up properly.

Regards, Maurice.

[zappbranigan]

It sounds like the root of my heat/temp gauge problem has gotten a little narrower....

Now, the thermostat that's possibly "stuck" open. Can someone point me to where I might find that? And what to look for?

I know I need to buy a Bentley manual in the worst way. My next expenditure on this car (only owned it since last summer) may be the manual.

Thanks for the help so far!

[1schoir]

It sounds like the root of my heat/temp gauge problem has gotten a little narrower....

Now, the thermostat that's possibly "stuck" open. Can someone point me to where I might find that? And what to look for?

I know I need to buy a Bentley manual in the worst way. My next expenditure on this car (only owned it since last summer) may be the manual.

Thanks for the help so far!

Zapp:

Here is a photo of the thermostat housing, circled in red (courtesy of TxHokieforlife):

(click on the photo to blow it up for a clear view)

There are four bolts holding it in place, 7 ft lbs tightening torque. You can access it from underneath the car.

Regards, Maurice.

[zappbranigan]

Maurice,

Great photo. Now I know what I'll be doing when I wake up tomorrow morning. I appreciate the help.

I hate to go back to the well too many times here, but can you or anybody tell me if the thermostat is "stuck"....can I repair or do a quick-fix to it? Or does the whole flippin' thing need to be replaced?

Very greatfully,

Joe

St. Louis, MO

[rsfeller]

Joe, I know you are very concerned about this project and went to the dark side of considering my complicated concerns, but this job is silly easy and cheap. Although failed thermostats are rare (in my oppinion) on late model cars they were very common in the 70s and 80s from my experience. I have yet to truly have one fail in 20 years but I still replace them from time to time.

The stat is easy to get to on the bottom of the car in the front as you can see from Maurice's photo. I did mine on a small lift but you can get at it with secure jack stands. The part has to be cheap, I think I got mine from the site sponsors.

Google the topic on how to test a thermostat and 1001 write-ups are sure to come up. I will not go into details as this is car 101 stuff that I am sure is well covered. They can stick open or stick closed and I've read of the spring breaking in rare occasions.

Now go by the Bentley from site sponsors as well as the Durametric software and a $30 thermostat. You have most likely saved yourself $1000 bucks from going to the stealer over what is a automotive hang nail.

Quite driving the car until you get this figured out. Low temps are bad for your engine and emissions!

[zappbranigan]

rsfeller, done, done and done. I feel much better about this "project" now.

I'll report back after getting the new thermostat in. And just FYI, I've kept the car garaged since the problem arose so I hope what little driving I've done hasn't caused yet more problems.

Much appreciation to everyone who chimed in to help an up-and-coming DIY'er!

Joe

St. Louis, MO

[zappbranigan]

Uhhh...can someone please verify what I think I have..or haven't found once I removed the thermostat housing? After searching for a new thermostat and seeing several pictures of what they look like, I was very surprised when I removed the housing and found nothing inside...[pictured below]

And nothing was inside the engine either.

:huh: This is gonna sound a like a total Noob question, but based on the parts for order I've seen....shouldn't there be an actual thermostat somewhere in housing? Have I been driving without a thermostat? And if so, what kind of damage has been done in anyone's estimate?

[Bill_SoCal]

Not a total Noob question at all...I don't see your :censored: thermostat.

Here is what you should be looking at as shown from Section 19-9 of the Bentley Manual:

Click on the picture to enlarge your view.

It looks as though you're running without a thermostat...the good news is you don't need the special Porsche tool to remove it. Unbelievable.

Best of luck here. You may have found the root cause of your problem. :clapping:

Bill B)

[1schoir]

Uhhh...can someone please verify what I think I have..or haven't found once I removed the thermostat housing? After searching for a new thermostat and seeing several pictures of what they look like, I was very surprised when I removed the housing and found nothing inside...[pictured below]

And nothing was inside the engine either.

:huh: This is gonna sound a like a total Noob question, but based on the parts for order I've seen....shouldn't there be an actual thermostat somewhere in housing? Have I been driving without a thermostat? And if so, what kind of damage has been done in anyone's estimate?

Zapp:

Running without a thermostat does not in and of itself cause any damage.

The only problem is that until your engine gets up to 180 degrees and is thoroughly warmed up, you are supposed to keep the revs low (below 3,000 or 4,000 depending on who you believe).

The previous owner may have taken the thermostat out to deal with an overheating situation, who knows?

In any case, it definitely looks like you found the answer to your issue, so put in the thermostat insert and put the housing back on and tighten the four bolts to 7 foot pounds, top up the coolant and take it for a ride. If you haven't lost much coolant, you can probably get away with just adding distilled water.

Keep an eye on your temperature gauge and be sure to top up the coolant tank as needed. It might be a good idea to pull up the lever on the bleeder valve to bleed the coolant system. That lever is located on top of the bleeder valve, on top of the coolant tank, underneath that little thin black plastic cover that you can remove by taking off the coolant cap and the oil filler cap. You can ride around with that lever straigt up for a few days until you are convinced that you don't need to add any more coolant.

Your temp gauge should now read roughly between the 8 and the 0 on the "180" mark and you should finally get some heat!

Regards, Maurice.

[zappbranigan]

I can only wonder how much I would've paid the "stealer" for this problem. Just goes to show how this forum, and everyone with porsche "know how" who contributes, really helps out us little guys.

Thanks again to 1schoir, rsfeller, Bill_SoCal, and Maurice, who walked me through this issue! You guys saved me a ton of cash!

After I get her put back together, I'll report my results and bring this mystery to an end!

Edited February 16, 2009 by zappbranigan

[wvicary]

Best check the impeller on the water pump as they have been known to fail.

[rsfeller]

My comments are stickly hypothetical about running w/o proper operating temps as things really have to do with the tollerance of items in the engine.

The only concern of running w/o the stat is you NEVER got up to temp unless you road it hard and then sat it traffic on a hot day.

the primary concern is that internals never got to temp to expand to their proper tollerances for hot and spirted driving (as stated previously, high revs).

It also effects emissions but most likly has done little if any damage. It's just a rule of thumb to NOT do this with modern cars, but it doesn't mean any sure or serious damage was done.

[zappbranigan]

This car really has been a mystery as so many things have needed repair when I bought it (motor mount, ignition switch, radio wiring, wheel bearing, control arm, new carpeting due to previous coolant leak, etc).

The fact the thermostat was missing almost leads me to believe there is yet another issue awaiting me...like the overheating mentioned earlier. Would an educated guess into the reasoning behind removing the thermostat, lead one to believe there may be a water pump problem too as wvicary suggests?

I'm guessing once I get the thermostat installed, coolant levels checked, etc, a first sign of a bad water pump would be overheating?

Edited February 16, 2009 by zappbranigan

[rsfeller]

Although they may have removed it for a reason, it may well have simply been the stat was bad and they didn't want to replace it before selling/dumping the car. I wouldn't assume the worst.

Although I have not had issues with my water pump and thus have not researched it they usually fail with bearing concerns, so I doubt you have a problem. If they do in fact have an issue with the vanes falling apart (you should search the board to find the topic). Water pumps are an easy check and repair for someone who has done as much as you.

Personally, I would throw the stat in and start driving. If you see overheating and suspect water flow due to a faulty pump, deal with it then.

Don't stress to much. It's nice you are looking ahead to failure points but you'll drive yourself nuts. I know, as I used to be more that way with my other cars! I'd get a vibration in the wheel and assume a bad inner driver rather then a worn tire!

[zappbranigan]

Part should be in tomorrow. We'll know for sure then!

Thanks again to all!!

************************UDPATE************************************

Got the thermostat installed today. What an easy process! Thanks again for everyone's guidance! Temperature rose to 180 and stayed with some pretty decent cabin heat.

After a quick test run, however the engine temperature stayed at 180 with the engine temperature light flashing. I know there's a thread somewhere where Loren pointed out the 4 reasons the temperature light comes on. Seems like all arrows are pointing to the coolant sensor now.

*************** FINAL UPDATE ***********************

Added more coolant (to the max fill line) and all is well now. No more flashing light. No overheating either. Still not sure why the thermostat was totally gone, but I'm not complaining. Thanks again to everyone for their input!

Edited March 2, 2009 by zappbranigan