mehtavick

I have a 1993 RX7 and after I am done driving it regardless of whether it is Hot or Cold weather the coolant is boiling.

Has anyone had the same issue? Does this signify a problem with Motor, Seals etc that I need to know about before I go to shop to have them check it out?

Thanks
Vick

FormerPorscheGuy

Your coolant should never "boil"

Is this happening in your coolant overflow reservoir or are you opening up your filler neck after a drive?

scratchjunkie

how do you know its boiling? are you hearing a gurgle sound from the turbo side when you shut off?

tester1977

What psi is your Radiator Cap? The perculating sound is common with the .9 bar cap. Try the 1.1 bar cap. That worked for me.

FormerPorscheGuy

Thats a negative ghost ryder. A higher preasure cap can cause things to break, if not explode out right.

tester1977

Mazda originally put on the 1.1 bar cap but through a recall they replaced it with the .9 bar cap. The difference in pressure is minimal and if your radiator is in otherwise good shape it should cause no problems. Thats why I suggested trying the 1.1 bar but you are right if there are other problems with the cooling system a higher presure cap should not be used.

wrankin

Vick -

You coolant should not "boil". When are you hearing/seeing this behavior? Is it after the car is parked and cooling down? I had this behavior for a while. It was caused by turbo heat soak combined with a bad radiator cap.

How much water are you running in your coolant mix? 60%? 70%?

1) Get a new radiator cap. Get the stock 0.9 bar cap - you don't want to "hide" a problem by going to a higher pressure cap.

2) Make sure that you are keeping the coolant level topped off. Did you drain your radiator recently? It may take a while to get all the air out of the system.

3) You may consider installing an aftermarket temp sensor and gauge.

4) Check for symptoms of coolant O-ring failure (do a search for the FAQ).

Hope this helps,

-bill

PVerdieck

Did you refill the coolant without repeatedly topping off later?

ROTORHP

Mine used to do that as well... then one day I took off my airbox and seen my upper rad hose had collapsed. I think the ast finally pulled all the air out of the system then left a void in the system so I pulled off the rad cap and topped it up.... hasn't gurgled since.

mehtavick

You guys are all great. That is why owning an 3rd gen RX7 is being part of family.

When are you hearing/seeing this behavior? Is it after the car is parked and cooling down?are you hearing a gurgle sound from the turbo side when you shut off?

YES

How much water are you running in your coolant mix? 60%? 70%?

60%

2) Make sure that you are keeping the coolant level topped off. Did you drain your radiator recently? It may take a while to get all the air out of the system.

Did Not Drain the Radiator This Year. As everyone suggests I will try topping off in reservoir. Though when I checked the radiator is full.

1) Get a new radiator cap. Get the stock 0.9 bar cap - you don't want to "hide" a problem by going to a higher pressure cap.

Okay I will try this as well.

Mine used to do that as well... then one day I took off my airbox and seen my upper rad hose had collapsed. I think the ast finally pulled all the air out of the system then left a void in the system so I pulled off the rad cap and topped it up.... hasn't gurgled since

I will check this as well.

Thanks guys if you think of something else let me know. I will try this stuff this weekend and get back to you all.

FormerPorscheGuy

Ok, If this is was my car this is what I would do next.

1) Buy a new cap.

2) Do the Champaign bubble test. (this is only to eliminate possibilities, others might not agree)

If this came back negative, then.....

3) You have a hose leak. Check and possibly replace the turbo coolant hoses.

4) Start checking other places where leaks could occur (i.e., TB coolant hoses, exc.)

mehtavick

2) Do the Champaign bubble test. (this is only to eliminate possibilities, others might not agree)

What is this?

BTW Whose *** Pic is that?

Vick

EKTwin93

A little gurgling noise after shut off usually isn't anything too serious or hard to fix. I had the same problem, and I ended up moving my AST (to a higher point) Absolutely NONE now. The higher up it is compared to the filler neck the more effective it is. If all else fails try that, but I think some new caps should fix it.
Evan

zullo

Why the suggestion of a new cap? What is the theory behind the cap causing the gurgling? I assume if the cap leaked the system would not hold pressure and he would have more serious cooling issues than gurgling at shutdown.

FormerPorscheGuy

This is when you start the car up from cold with the filler neck off. You look in the filler neck to determine if their are any bubbles coming up out of the coolant. If their are then you coolant seals are failing.

A friend of mine, like it?

Caps fail and leak. I go through one a year.

areXseven

iTrader: (1)

Bad Thermostat??