bc1

I am having trouble re-starting my 1999 996 after it heats up(200), its starts to turn over but it seems like there is almost a hydraulic lock and it wont start. It starts fine cold, and will start fine after cooling down as well. The battery is less than a year old, and the alternator is charging fine.

Has anyone else experienced this? Any help would be appreciated.

Thanks,

Brett

Riad

I haven't, but it's odd that the car even gets that hot... I would be concerned about that. It should never really go about 180.

programmatore

I had a similar problem about 2 years ago. The car won't start (you could hear the starter clicking but the engine won't turn over) once the car got warm. I ended up having to replace the starter.

Tippy

These two dont go together, trust me, did it twice.

Unfortunately to load test the starter, it would requiring removing it which would be a PITA. You can load test the battery at Autozone for free, it will tell you if a cell has failed.

BruceP

I don't think Porsche would agree with that. I know some here have strong feelings about whether this is good or not, but the fact is that these cars routinely run at 90 degrees Celcius (194 F) or higher fully warmed up, and in traffic and hot weather, well above 100 (212F), as read from the OBD display.

pat056

riad
180 degrees?! Mine levels out over the 180 degree mark (just over). Is that a 1999 thing with the 2 radiators? I thought 180-200 was the norm.
I need to do a search and change my outside temp to water temp, I guess so I can talk "digitally" and not "analogically" (probably not a word, but sounds good).

Tippy

The heat is not good for the engine but good for reducing emissions, the sole reason they let the motors temp raise.

BruceP

The Mk 2 cars show cooler operating temps. Some say that cooling system improvements were made, but I don't know what. What I do know is that the coolant temp sensors are different on the two cars. 99-01, there's one sensor at the engine. After that, there were two, the other one I think at the rad. The readout showed an average, so was always lower than typical for the 99-01, notwithstanding other changes.

You can push some buttons on your climate control to get the OBD to give up the real operating temperature. Do a search.

EDIT: Here it is, courtesy of 1999Porsche911
"Press and hold in the recirculate and the top (arrow up) buttons on the right side of the panel for a few seconds. The left screen will change. Using the + key below that screen, advance so the display reads 6c. Then press the center vent button once. The display will show you your coolant temp.

To go back to normal, simply press AUTO."

Once you've done this, it will default to this mode just by following the first step. If you check it more than once while the engine's running, only the first check will require you to wait. The readout is instant after that.

1999Porsche911

Forget the temp gauge. It is not even close to being accurate. Your 996 CANNOT run at a coolant temperature of 180F. Even the thermostat is not oipen at that temperature.

BruceP

Confused. Mine runs above that temperature all the time. At that temperature, it's not even really warmed up (that's just 82 degrees C). Keystroke error, maybe?

1999Porsche911

The thermostat opens at 183F. Your minimum, fully warmed up engine coolant temp on a stock 996 or 997 is 190F in the best of conditions. Once warmed up, you the coolant temperature willnever fall even close to 180F, regardless of what the gauge says.

Clearer?

BruceP

Much.

Riad

Both my 01 and my 04 will settle with the needle between the "8" and the "0" of 180 and rarely if ever go much higher. And keep in mind that I mostly drive in bumper to bumper NYC traffic and it gets hot here.

Never tracked the cars but I would expect the temp to rise on the track.

BruceP

Try that climate control OBD readout thingie.

1999Porsche911

Like I said above, your gauge is wrong. On the 3.4, you will most always be between 200F and 220 F driving around town in warmer climates. Your engine CANNOT maintain a coolant temperature of 180 even in ZERO degree temps.

When your gauge needle is spltting the "0" in 180, your coolant temp is approximately 215F.