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-   -   Coolant Light Blinking (http://986forum.com/forums/boxster-general-discussions/59889-coolant-light-blinking.html)

Seadweller 12-21-2015 06:32 AM

Coolant Light Blinking
 
Greetings,

About 6 weeks ago, I had my Indy do a coolant change/flush, along with a bunch of other standard service items, on my recently acquired '98. Drove the car home and put it away with nary an issue. Took it out a week later to find the coolant light flashing. I called my Indy, and he said bring it right in. The coolant level was evidently perfect, and they pressure tested the system and found everything to be 100%. I drove it for the rest of the day without an issue.

Took it out the next weekend, and drove it all day without issue. Fast forward to yesterday, I took it out to stretch its legs on a couple of errands, to find the coolant light was blinking again. Arrived at my first stop, popped the lid, and opened the coolant reservoir and it was like slowing removing the lid off a bottle of tonic water. Checked the level and it was fine, replaced the cap, started the car, and the light was no longer blinking.

Any idea what might be causing this intermittent issue? The coolant light never came on until the coolant change/flush.

Thanks!

Retroman1969 12-21-2015 07:14 AM

From my experience, these cooling systems need to be carefully and thoroughly bled after a flush, and are incredibly fussy about it. The low coolant flashing light is also unpredictable, as sometimes it will flash while the level is above the mark and not flash when the level is well below the mark.
I had a similar issue after a flush on my '99.
Every few days the light would start flashing and I had to top up the level. I took the car back to the shop several times over this period where the whole system was throughly checked and no leaks or compression issues were found. I replaced the coolant cap for good measure, but it didn't change the behavior.
So I just resolved myself to topping up a couple of times a week until it finally stopped flashing and the coolant level stopped mysteriously dropping. It took about 4 months and went through about a gallon of coolant. That was 6 months ago. Have had no issue since.

paulofto 12-21-2015 07:22 AM

With the engine behind you and the rads up front there are a lot of hoses with nooks and crannies where air can be trapped after a flush and fill and it may take a while for all the air to make it's way to the recovery tank. I went through a similar issue and it took a few weeks to get settled down. Also, as Retroman said, make sure you have the newest coolant cap to ensure a proper seal and pressure vent.

JFP in PA 12-21-2015 08:08 AM

Four functions of the coolant warning light:

1. Engine coolant level too low
— light flashes slowly (0.5 Hz)
2. Engine compartment temperature too high
— light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)
3. Engine coolant temperature too high
— light is lit; pointer on the right
4. Temperature sensor at water outlet faulty
— light flashes rapidly (1 Hz); pointer on the right

Note
The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously
(1Hz = 1 flash per second. 0.5Hz = 2 seconds per flash)

Seadweller 12-21-2015 12:20 PM

Thanks guys...I suspected air in the system, so that's probably what it is...

It's a slow blink, and appears immediately after the car was started from cold, so I think I can discount an engine compartment temperature issue...

Funny though, I don't know that I hear a fan in the engine compartment, however I do hear a fan running in the front of the car. The engine compartment fan comes on at a certain temperature, I would assume? I have a low-temperature thermostat in the car, and it seems to run around the 185-190 range.

Steve Tinker 12-21-2015 12:50 PM

Open the pressure vent valve for a few heat cycles - I'll bet you see the coolant level drop if air is in the system.
The valve's D ring needs to be flipped up & is located under the plastic cover between the coolant fill and oil fill caps in the rear boot (trunk).

jb92563 12-21-2015 01:03 PM

I agree that its probably air in the system, and needs to be burped via the Burp/Pressure release next to the Oil/Coolant caps in the trunk, under the plastic cover.

The quickest way to do a proper coolant refill would need to be done with one of those vacuum coolant fillers.

It creates a partial vacuum in the system and then allows the coolant to be sucked back in excluding any air.

I have one (~$80) but have not tried it yet. I bought it thinking I had that issue as the car would barf out a few cups of coolant after stopping. Turns out I was over filling the coolant tank and it was expelling the excess....but I digress.

Ray

Perfectlap 12-21-2015 03:08 PM

coolant flush should be done with a brand new coolant cap. If the cap is old it holds less pressure each time its removed and air will get in. if Too much air gets in and the old and probably brittle plastic coolant tank will split open and dump all your coolant on the road.

mikesz 12-22-2015 02:39 AM

I have replaced coolant in my 99 and found the burping method to work just fine. I had similar problem, replaced the coolant cap and make sure its on tight. Also, my engine bay fan was not working. Replaced the fan and no more light. You can check if its working by removing the relay in the trunk and using a wire jumper to test. Replacing is not that difficult one nut and unplug the wires.

Seadweller 12-22-2015 04:18 AM

Thanks gang...I didn't know there was a pressure release valve, so I'll try that the next few times I drive it, while keeping an eye on the level. I'll also test the engine bay fan. It's likely that the engine compartment hasn't gotten hot enough to activate the fan, which seems to fire up when the compartment gets to 150 degrees, or the coolant temp gets to 210 degrees.

jb92563 12-22-2015 05:33 AM

I hope you haven't seen 210 on the coolant temp gauge.
Normally the needle never quite touches the Zero on the "180" mark on the gauge, Just a bit over middle needle position.

If it goes past the Zero then something isn't quite right and if it goes to the next marker bar you have a problem that needs resolving quickly to avoid a potentially serious disaster.

Blinking lights on the gauge cluster also indicates a serious issue needing immediate attention.

cas951 12-22-2015 06:35 AM

I just had this problem and I'm still trying to sort this out myself with a little drama to go with it. A few weeks ago eng temp light flashing at the corner. I pulled over as soon as I could and checked under the car to see if there was any leaks. I didn't check the coolant level because it was hot. I restarted the car and the light was not flashing. I drove the car home and waited till it cooled down and I had to add about 1/2 quart of coolant. I checked the coolant level again the next day and I had to add about 2 cups. I took the car for a drive of about 25 minutes, the flashing light never came on, no leaks under the car just from bending down to look. I placed the car on jack stands and removed some of the under trays I couldn't find any leaks under the engine.

I left the car on jack stand and ordered a mighty vac cooling systems pressure tester. Turns out none of their adapters fit a Porsche. I call the dealer to see what a new cap would cost. $47.00 plus tax. I checked Pelican parts and it was only $27.00. So I order from Pelican and also ordered brake fluid, two oil filters along with the coolant cap for a total cost of $58 plus tax. 3 days later the package arrive and some ass wipe steals the package right from my front door. Luckily Pelican comes through and ships a new shipment at no charge. Thumbs up for Pelican. Now that I have the coolant cap I haven't had a chance to go for a drive. It's been raining too much lately here in the Bay Area. Once I confirm the new cap is a good cap I'll convert the old cap into a cooling system pressure adapter. I have the old type of pressure tester.

Well. This was my drama. Forgive me for hijacking.

Seadweller 12-22-2015 07:47 AM

Quote:

Originally Posted by jb92563 (Post 477340)
I hope you haven't seen 210 on the coolant temp gauge.
Normally the needle never quite touches the Zero on the "180" mark on the gauge, Just a bit over middle needle position.

If it goes past the Zero then something isn't quite right and if it goes to the next marker bar you have a problem that needs resolving quickly to avoid a potentially serious disaster.

Blinking lights on the gauge cluster also indicates a serious issue needing immediate attention.

No, the gauge sits rock solid around the "0" on the "180" mark...I'm assuming the engine compartment has never heated to the point that the fan has activated, because I've never heard it run...This is a weekend car that doesn't see an overabundance of stress, and I've yet to really put it through its paces since I bought it...


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