SWAT81

iTrader: (14)

I have burped the system so many times yet I still here it on lower gears at times. Could this be cuz I have a air leak somewhere on the coolant lines? Or perhaps the caps for the coolant resevior and AST cap?

RonKMiller

Ummm, I loathe to say this, but - get out the checkbook.

It be rebuild time!

But, before you throw in the towel, check for "champagne bubbles" in your coolant filler neck.

It is THE definitive test.

SWAT81

iTrader: (14)

can;t be time for a rebuild I just bought this 6k miles ago from Malloy's, I think its rather time to change the filler caps on my block and AST. Dont scare people like that

93MB

Get a block test done! I had the same sound with mine and got a block test and found out that its rebuild time for me. Hope you get it figured out!

BigIslandSevens

iTrader: (4)

Calm down everyone...It's not time to get the check book out just yet.. The problem( or noise) you here is most likely the coolant being transfered thru the heater core under the glove box area. I have a 93 in the shop rite now that does the same noise at low gear and speed( parking lot/driveway speeds)And it's engine is fine! The AST also bubbles some depending on how hot your car runs...This is not a good thing.. It should not be boiling the coolant. If you here it when you open the hood and can feel the bubbles in the hoses at the AST, You need to cool that beast down.... My personal opinion ( without seeing or hearing your car) is that it is just the heater core flowing coolant. EDIT: This noise is very hard to hear on the car here. I have to almost lean over towards the passenger side to hear it. A pressure test on the system will never hurt ( as it will give piece of mind that your engine is safe)

red 7

i heard this noise everytime after i shut the car off.
It went away when i got a single turbo, so i just figured it was coolant boiling inside my POS stock turbos

clayne

It's not always time for a rebuild just because you hear gurgling from the passenger-side, by any means.

If anything get out the checkbook and go single-turbo to move away from the large HEAT-SINK of turbos crammed against the exhaust side of your engine. After driving they cause localized coolant boiling and this is what the gurgling sound is.

A cheaper solution is an auxillary electric water pump to run after the engine has shut down.

An even cheaper cheaper one is fan mod + shut car down for a minute then turn car back on again to have water pump circulate for another minute, then shut car off.

clayne

Correct.

A right answer for once.

SWAT81

iTrader: (14)

I got turbo timer so it runs eve after shut down for 3 minutes so I think I'll be fine, also confirmed that one of my other friend's with FD has the same sound ever since new engine like me.

InsaneGideon

I've heard this a couple of times after letting the car sit for a week and starting it. After a minute or so it goes completely away and doesn't return unless I let the car sit another week.

RonKMiller

No one wants to hear that their 6K motor is toasted.

Eliminate the most likely and expensive cause first.

Instead of everyone SPECULATING here's the test:

1. Open hood.
2. Unscrew cap from filler neck above water pump.
3. Fill neck to top with distilled water, CAREFULLY wrap
a towel around the TOP of the neck to absorb any
overflow - there will be a little.
4. Start engine, let idle for 10 - 15 minutes until warm.
5. Look for a stream of "champagne " bubbles rising to
surface of coolant. Bubbles will increase as car
warms up. A bright flashlight held at a 45 degree
angle will illuminate them even better. If you've got a
good nose you can even smell them - they're
stinky hydrocarbons.
6. If bubbles are tiny, do the Block Weld thing.
7. If bubbles are large, get checkbook out for
another rebuild.

There are a multitude of other places where AIR - not exhuast gas - can get into the system. The next test would be to pressure check the caps. If they pass pressurize the cooling system continously for 12 to 24 hours and look under the car with the belly pan removed. Listen for leaks with a mechanic's stethescope and extension - some of them are VERY difficult to track down.

A gurgling or whooshing sound is NOT NORMAL if your cooling system is functioning correctly. It has absolutely NOTHING to with the stock turbos or transient heat!
(Unless of course you have leaks at the clamps at the two coolant hoses going to the turbos - which is a VERY likely culprit unless the hoses have been replaced and the OEM spring clamps used to secure them.)

"When you hear hoofbeats don't go looking for Zebras."

TwinTurbo93

My car has been doing that forever, even before I got a new motor, I have about 28K miles on my new one and I allways heard the little bubling sound once in a while even on a brand new motor.
Is got to be heater box related problem in my and SWAT81 case.

XSTransAm

I had this exact problem, It turned out the coolent lines to the turbo were cracking and bubbeling out coolant, finally one let go so i replaced them with steel braided lines. best mod ive ever done

TwinTurbo93

Hmmm,,, I also recently changed all the coolant hoses with braded ones including turbo, heater and radiator.
I didn't pay close attention to the sound since my myffler is pretty loud but I'm gonna keep that in mind to see if the bubling sound is still there...

PandazRx-7

iTrader: (18)

My Fd is doing the same thing right now...I only have 12,000 miles on it. I can hear it the most when I just start the car when it's cold, then it seems to go away when it warms up. To me it sounds like air bubbles in the heater core or something. Highly doubt it's the engine, but I'm gonna check it out this weekend, maybe flush the whole system as well...any suggestions on which coolant to use, and percentage of coolant/distilled water.

Have Fluidyne and TP AST...

DaedelGT

I had the same noises at one point, and after posting on the forum, I was about to get out the check book. It turned out to be the turbo coolant lines, and when I replaced them, and my coolant leak stopped, I haven't heard the bubbles since.

RonKMiller

The only thing that can wrong with your "heater box" is a puncture/crack which is highly unlikely. You'll usually have wet carpet if it is.

Just because a motor is new does not mean that it was rebuilt properly. There are tons of motors that leak right after the rebuild. It's usually due to the grooves not being completely cleaned, improper torque sequencing or re-using a housing that should have been replaced. Very few housings are reusable.

clayne

Hah dude. Myself and plenty of others completely pass the champagne test, NEVER have changing coolant levels, or other symptoms of blown o-rings and STILL have the gurgling happening.

It's from the turbo manifold. What does it take to convince you of this?

You just had one other guy also post on here that when he went single turbo the sound WENT AWAY. So either he had coolant leaks all around his stock turbos which he didn't notice, his engine magically fixed his "o-ring problem" when he changed turbos, or perhaps the stock manifold was causing localized boiling maybe? Or maybe the majority of people are suffering from coolant line issues to the turbos, but mysteriously their coolant levels never change?

Are you telling us that you cannot boil the coolant in a hermetic system?

RonKMiller

You would have been better off covering the OEM ones with a woven fiberglass heat sleeve to insulate them from the heat of the turbos. The steel braided lines will conduct heat and cause the rubber underneath to fail prematurely. They are also especially difficult to evenly clamp on an outlet.

About the only time steel braided lines are used is for an application with a chafing/vibration issue, or for certain extremely high pressure situations.

RCCAZ 1

iTrader: (10)

I can hardly believe what I'm reading.

Gurgling in the heater core has EVERYTHING to do with air in the system and little if NOTHING to do with the turbo manifold. I had the same gurgling in my system and I can tell you that its AIR your hearing, not BOILING. Since his motor is fairly new I've got to believe that a small amount of air is still trapped in his motor and it has not been properly bled.

If both your AST and fill caps are new and your system holds pressure, the proper fill procedure is to start at the lowest point in the motor (i.e., usually your AST) and work towards the highest point (TB coolant hose). Knowing this, with the AST cap off, add coolant from the fill port until the AST begins to overflow. Install AST cap and begin to fill the filler neck until coolant is barely visible in the bottom of the neck. Then, remove the coolant hose from the back of your throttle body (highest point in the engine) and fill with coolant until the fill neck overflows. Cap off your fill neck and continue to add coolant to the TB hose til it overflows, then quickly reattach (NOTE: you may have to do repeat this procedure several times to get ALL of the air out) .

Most guys on this list don't fill from the TB hose and the air gap between the TB hose and the filler neck never gets filled, consequently a small amount of air constantly moves around inside the coolant system. Careful attention to remove this tiny bit of remaining air will eliminate the gurgling (air) sound that you're hearing in your heater core.

Ron may be right... you could have gotten a bad engine, but my bet is that you still have some air in your system. Removal of as much air as possible decreases the amount of internal boiling in your rotor housings (i.e., localized hot spots), thus lengthening O-ring and engine life! Those of you who are still hearing heater core gurgling need to work harder at getting the remaining air out of your systems.

RonKMiller

His problem went away simply because he put in new coolant lines that sealed properly or eliminated them since they were not neccessary in the new application.

Sure, you can boil the coolant, if you want to

I prefer not to by making sure there is no air/exhaust gas in the system, and alot of FD3S's have coolant system leaks. Most are so small they are almost undectable since they cook off when the engine is running.

They come from any of the myriad hoses in the system, and are aggravated by using cheap aftermarket hose and worm clamps (usually grossly overtightened). The worm clamps "chew" into the rubber over time, instead of the OEM spring clamps which are designed to expand and contract yet maintain even clamping pressure throughout a large temperature range.

If you have a gurgling sound - anywhere - you have air in the system which will AGGRAVATE localized boiling in the coolant jacket - a very bad omen for rotaries. The only question is how much and where it is coming from.

The next question is how much longer your engine will last unless you figure out how to stop it.

About the only sure fire way to eliminate it is to:

A. Do a rebuild if it IS exhaust gas.

B. Install all new coolant line hoses and OEM clamps -
and there is a BUNCH of them - and then perfrom a
pressure "leak down" test over time.

C. Block Weld it, but this is only a bandaid approach, and
only works if you catch it at the beginning.

It ain't CAUSED by the turbos. Period. Dude.

RonKMiller

...just trying to help out the newbs...

clayne

Thanks for the long-winded contribution, it may help some people out (honestly).

Just to let you know though, I bypassed this hose ages ago and I can still duplicate the sound based on how long I let the car cool down for and what other voodoo methods I use to cycle the coolant away from the manifold after shutdown.

clayne

If someone wants to tee in a thermo-sensor right into the turbo coolant lines we could have more visibility on this.

RCCAZ 1

iTrader: (10)

I don't doubt your honesty Clay, and since I'm still running stock sequentials with my TB coolant line connected I can't compare my setup to yours.

What I'd really like to get my hands on is a tall funnel with a sealed fill cap on the end of it. I've seen a few at dealerships, but when I asked the local Snap on man about one he looked at me like I was an alien.

Anyway, this funnel allows you to attach it to the fill port and fill it up about a third of the way with coolant. Then you start you car and as it warms up and expands it rises in the funnel. With the car fully warmed up, you shut the vehicle down and leave the funnel there until the next morning. Then just simple detach, put your fill cap on, and you're done. Sure would make life simpler for us FD owners. Anyone seen one of these or know where I can purchase one? I've seen lots of pics in Japanese tuner mags where they are in use to bleed air out of cooling systems. Sure would be nice to have!!