"Add Coolant" warning + buzzer, even though coolant reservoir is full...?
 

Hi guys

I read some thread of people that have coolant leaks and etc. but nobody with my exact problem, that's why i'm still creating a new thread.

So, when I started my car today ('86 gxl rx7) , the "ADD COOLANT" light on my dash appeared and a really annoying buzzer came on. I check my coolant reservoir and it's full (the engine was cold). I also removed the coolant filler cap (the one next to the upper radiator hose) and it's full too, plus the fluid got a nice green color...

I also unpluged and repluged the coolant level sensor and the wire and connection seems ok.

Also, last time I drove my rx7 the warning buzzer from my aftermarker oil pressure gauge was going on from time to time. The buzzer comes on whenever oil pressure goes over 55-60 psi (which happened whenever the engine was reving higher than about 3000 rpm). I never heard the buzzer before and I was often reving higher than 3000 rpm...so, even though I wasn't looking at the gauge often, I guess it never went higher than 55-60 before... Oil temp however was normal (165-175).

maybe my 2 problems are linked together ?

thanks

Bleed the cooling system of any air that may be trapped within. Open the bleeder screw on the radiator slightly, and allow air to escape until coolant starts to come out. Tighten the screw and top off the system with a little coolant. If you want to be extra thorough, you can also do this while the engine is running (but only when cold obviously), and the heater can be turned on to open the path through the heater core.

Oil pressure is supposed to exceed 60 psi at 3000+ RPM, so your aftermarket gauge needs the buzzer adjusted or removed. Factory oil pressure specs are in the free FSM. Links can be found in the 2nd gen FAQ.

Alright ! I'll try that thank you :)

just a little question, where is located the bleeder screw exactly ?

thanks :blush:

Top of the radiator where the upper hose connects.

okay! thanks a lot,

last question, you said : "Tighten the screw and top off the system with a little coolant. "

but, since I don't know what brand of antifreeze and ratio the last owner used (I bought the car about 1 month ago), is it better if I flush all the coolant and add new one ? or mixing them won't matter ?

Mixing doesn't matter as long as it's green (or compatible w/ green). Just make sure you're not buying something like dex-cool, which is orange. Add some 50:50 for now, and if you want to flush the whole system, there's a drain plug on the bottom of the radiator.

i don't have any advice for you but i also had the exact same problem with my old fc that i sold. the way i would shut of the buzzer was revving a little past 3rpm although it would come back after a while. Do you have any flooding problems or does your car smoke ALOT after it hasn't run for a week or so (mine did)

the car im looking at buying has the same problem.....did this work?

the LOW oil Sensor and the Add coolant sensor are both hooked up to the Buzzer.
If you have low oil,what will happen is the buzzer will go off if you go around a corner a little faster than normal.(or if the engine gets too high Oil pressure).
The Low Coolant sensor will activate the Buzzer if the Cooling system is not Full,or has an air pocket in it,preventing coolant from hitting the sender.(that would cause it to go off).
The Warning sound should be Present IF you Disconnect the Sender( take and disconnect the one wire going to it..the Buzzer should go off).
NOW,if the coolant is FULL and the Buzzer is going off,try taking the Wire From the Harness and Ground it out( to Chassis) .That will alleviate the warning buzzer.,and Tell you that your Sender is Bad.
BUT,the best thing to do in a case Like the Latter,is to replace the sender.
You "can" drive the car with the Sender grounded out,BUT If you have a Low coolant Situation,it will not Tell you of any problem,and could end up costing you Big Bananas.

The problem is solved.

Basically, I think that the coolant reservoir was too full. I removed the radiator cap and revved the engine for 30-45 seconds, letting coolant come out of it and then, the warning+buzzer stopped. Haven't had any problem ever since .

thanks for the help :)

1993 fd
 

Hello I have a 93 with the same problem

Hate to be the one to resurrect this thread, but this same problem is driving me crazy and I've been searching for two days for the answer. I have it narrowed down to air in the system, but everything I see about bleeding the system says to loosen the screw on the radiator neck and fill from the filler cap at the thermostat housing. The problem is I don't have a bleed screw or a filler cap at the thermostat housing. It looks like most other cars, with the pressure cap on the radiator and the overflow in front. I discovered that the hose from the block to the heater core was frayed and leaking a little so I replaced that but now I'm not sure if I need to bleed or the right way to do it. I was told that this motor was installed new about 15,000 miles ago from Atkins Rotary so I dont' know if that makes a difference. Hope somebody can help and I haven't left anything out...

Post a pic of your setup..
That will give is some info on what you are working on!.Thanks.

Attachment 712899
Attachment 712900
Attachment 712901

Hopefully I did that right...I took one of the whole motor, then the upper rad neck, and the thermostat housing.

Oops sorry those came out so big. At least they're easy to see...

If that's the original radiator there should be a bleeding screw on the left side corner....

Atleast for european models, not sure about the us models.

Yeah that's what I've heard everywhere I've looked, which makes me think it might not be the original radiator since its not the original motor. There's definitely no bleed screw anywhere on the radiator. I'm thinking about just doing this the old fashioned way and seeing what happens

It looks like an OEM S5 radiator, which has that extended filler neck near the battery. The plastic end tanks give it away. Only S4s had the filler on the thermostat housing, but I thought the S5s still had the bleeder screw. It's next to the air filter on S4s and on most aftermarket replacements.

If it's not on the S5 rad, you can remove the cap with the engine running (cold only!), and turn the heater on to try to force any bubbles out (opens the passage to the heater core).

Sweet thats what I'm gonna try as soon as I get home. Been out of town all weekend.

I have a question. In the last pic he posted it shows the cap and the battery just to the right. Coming off the side of the cap is a hose that runs across the top of the fan shroud and out of the picture. On my s5 I have a little neck but not the hose off the side like that. It looks like the hose on mine was pulled off leaving just a little spout piece where the hose should attach. Any idea what that hose is for and if it's important?

That hose goes over to the overflow tank and should probably be replaced. I'd imagine you would start losing coolant when the motors hot because instead of running into the overflow it would just shoot out all over the place.

Thanks. Can anyone take a pic of
The hose showing where it starts
And ends for me please? I know from
That pic where the hose mounts
To the neck but not exactly where on
The overflow it connects. Sorry if my
Post is weird looking I'm typing it on
My phone. Thanks.

Attachment 712904


I suck at uploading pictures so hopefully that was right...The hose comes off the side of the rad neck and goes over the fan shroud, like you saw in the other pic. Then it goes under the upper rad hose and through a hole next to the radiator to the left side of the overflow cap. There should be that hose going in the left side and a short hose coming out the right side that goes down a couple inches and stops.Hope that made sense.

Well I have a Fd and when the cooling light comes on I just turn the air on full blast! I also drive with the fan on and dill on the cool side it works for me hope it helps.

I have the same problem on my s5 but the wire on the top of my radiator has been pulled from the engine bay and not the sensor. So now I do not know where the wire came from and need to find where i can splice it back 2. Any Ideas?