Temp gauge blinking & Car Overheating

[Speedy164]

I'm about to go insane..... So i have a 1998 Porsche Boxster and at start up the Temperature Gauge is already Blinking once every second and i drove just 80 NYC street blocks and the needle was near the 250 F and it was only 62 f degrees that day i immediately pulled over and turned off the car. I added a gallon of Porsche Coolant and a Gallon of water since has to be premixed 50/50 and the coolant reservoir isn't even at minimum level.

I don't see any leaking under the car and i checked under the carpet by the coolant reservoir and no leak. I turned on the A/C while i was parked and i could hear the fan come on at high speed. Any ideas or help?

[peterbrown77]

I blew a ton of coolant out this spring, it was a bad cap. It runs down the drain so you may not see it but you sure should see condensation on the underside of the trunk lid where the reservoir gasket seals.

[bar10dah]

You drove 80 NYC blocks, even after seeing the coolant light flash, warning you that your coolant was low??

If I recall correctly from reading on these forums, if your coolant is low, you could have air pockets develop in your cooling system. So even if your gauge reads <250F, parts of your engine could well exceed it.

[Joel-Box-ster]

Clearly you're low on coolant level bring it to proper level and drive it a few blocks.

[Speedy164]

at bar10dah i had added 75% of a gallon and 75% water the day before and it was full so didn't think it was low even though i was already driving...

Looked under carpet no leak or condensation

[bar10dah]

"If the coolant level is too low, the warning light flashes." - Owner's Manual

I'd say any time a light is flashing, find out what caused it, before continuing on.

Hopefully you caught it in time. Like I said, through these threads, I've read that air pockets can form and block the normal flow of coolant. So even though the thermostat is reading temps of <250F, other areas of your engine may well be seeing temps >250F.

First thing's first. Try to ascertain the cause of your leak. Losing that much coolant, especially in one day, is pretty bad. Get up under your car and check of the obvious 'wet' spots. But also look for the chalky type residue. That's dried up coolant. From radiators on back. Check everything. Within the engine, check to see that the coolant and oil hasn't mixed. Check the coolant tank for a milky substance. Check the oil (not sure what the coolant will look like in the oil, but I'm sure a search of these threads will find you the answer). Maybe now's a good time for an oil change to see if there's any coolant in it. Has your exhaust been blowing any smoke lately? Also, since you're not seeing any condensation under the rear lid, your coolant cap may be okay. But, it's a cheap part, around $20-25 online. You should look at replacing it especially if the part number on it does NOT end in 04. I can't think what else to check. Other members will surely chime in and attempt to help. Hopefully we'll put you on the right track.

[Speedy164]

Originally Posted by bar10dah

"If the coolant level is too low, the warning light flashes." - Owner's Manual

I'd say any time a light is flashing, find out what caused it, before continuing on.

Hopefully you caught it in time. Like I said, through these threads, I've read that air pockets can form and block the normal flow of coolant. So even though the thermostat is reading temps of <250F, other areas of your engine may well be seeing temps >250F.

First thing's first. Try to ascertain the cause of your leak. Losing that much coolant, especially in one day, is pretty bad. Get up under your car and check of the obvious 'wet' spots. But also look for the chalky type residue. That's dried up coolant. From radiators on back. Check everything. Within the engine, check to see that the coolant and oil hasn't mixed. Check the coolant tank for a milky substance. Check the oil (not sure what the coolant will look like in the oil, but I'm sure a search of these threads will find you the answer). Maybe now's a good time for an oil change to see if there's any coolant in it. Has your exhaust been blowing any smoke lately? Also, since you're not seeing any condensation under the rear lid, your coolant cap may be okay. But, it's a cheap part, around $20-25 online. You should look at replacing it especially if the part number on it does NOT end in 04. I can't think what else to check. Other members will surely chime in and attempt to help. Hopefully we'll put you on the right track.

I will definitely get under the car and check so far no chalky or milky substance on the coolant tank, i checked the oil and no mixture. No smoke from the exhaust and yeah i thought that myself no condensation so coolant cap is ok. Im going to have to remove the bumper and check the radiators and look under the car also check if the fans are working at low speed i do hear them come on when i turn on the A/C at high speed.

I will top off the tank and see if it does leak anywhere also try opening the bleeder valve and see if thats the case because coolant wasn't low and light was still flashing and it was reaching the 250 F mark while driving before pulling over. thanks for the insight

[san rensho]

Don't drive the car if its overheating. Even a brief overheating can completely grenade your motor.

If you are not comfortable with filling and bleeding the cooling system, take it to a professional that knows how to do it. You are playing with fire.

[Joel-Box-ster]

If overheating still occurs you probably have a worn out waterpump impeller or a stuck thermostat, its time to replace them if you have'nt so. Also have your cooling system pressure checked to find out if there's a leak somewhere.

[Speedy164]

I can't sleep trying to get this fixed so i just went outside topped off the reservoir tank turned on the car and opened the bleeder valve, you can hear air coming out of the bleeder valve. The coolant went completely down only thing left in the reservoir is about a finger left of coolant and waited till the car got hot enough sometimes i gave it gas to 2,000 Rpm. Should i put more coolant & water mixture? i checked under the car for leaks with the bleeder valve open couple drops and that's it no more after that. maybe i need to drive it but so far didn't pass this mark on the temp gauge.

[tonycarreon]

Originally Posted by Speedy164

Should i put more coolant & water mixture?

no! You can not figure out where the coolant is going, so you should call a truck and get it to a shop. Do not start it, do not drive it. Get it flatbeded to a shop before putting the key in the ignition again. continually adding coolant will not solve anything.

[Speedy164]

Originally Posted by tonycarreon

no! You can not figure out where the coolant is going, so you should call a truck and get it to a shop. Do not start it, do not drive it. Get it flatbeded to a shop before putting the key in the ignition again. continually adding coolant will not solve anything.

Thanks for the heads up....A woman owned it before and she said she has never put coolant in the car everything done at the dealership but so far i have just put 2 gallons in total 50/50...

[white99c2]

If it is not leaking and keeps disappearing from the expansion tank you better check the oil dip stick. If it looks milky you have intermix. Your car may have overheated so bad that the head gasket or even worse a cracked head is causing the coolant to mix with the oil. Best of luck, do not start the car any more. Get it towed to a shop fast

[deptotpr]

thermostat needs replaced

[Olin]

Originally Posted by Speedy164

Thanks for the heads up....A woman owned it before and she said she has never put coolant in the car everything done at the dealership but so far i have just put 2 gallons in total 50/50...

Interested in how you ended up, what was the result please Speedy?