T@L0n

Hey there folks, I've got a bit of a strange one for you.

My 96 RS occasionally comes up with the coolant warning on or just after I start. I've checked the water levels a couple of times so far & I don't appear to be losing much, if any water from the coolant system OR the overflow. (Obviously the overflow does change a bit according to the heat of the car But I've checked 1st thing in the morning & it's still pretty much the same.

Apparently I might have a water jacket leak (which is sounding expensive) But how much water loss does there need to be to actually be a leak?

Here's hoping there's some known issues with the water sensor on these things!!!

HELP!!!!

ricola555

If you are not seeing a drop in your coolant level but your coolant light comes on you probably have air in your system...Just burp the cooling system and you should be fine.

T@L0n

Thanks for the fast reply...

I guess it could be... it was just serviced a few weeks back & has been happening once or twice a week since then.

Now to show my relative ignorance... How would I "burp" the system to clear the air???

(Yeah I know noob kinda question but I'm a noob so I've been paying people who should know how to do things while I try to learn )

David Beale

I burp mine by removing the engine filler cap and gently sqeezing the rad hose. Repeat each morning (when the engine is cold and not running) for a few days and that should do it.

You could also have a damaged coolant level sensor wire or bad sensor. If it started after service they may have pulled the connector almost all the way off, or damaged the wire. It's by the water pump.

T@L0n

Just went down to have a quick look at the water sensor wiring. When I opened the hood I hear this wierd sound. Like water slopping around in a 40 gallon drum or something. Had a quick look at the wire (burnt myself aa couple of times) Then closed the hood & closed the door, & wot do you know I hear it again!?!?!

I'm not sure of the way these cars usually cool down seeing as I've never sat beside one for the 2 hours or so it appears to take but is that NORMAL!?!? I gotta admit I'm wondering if there's a blockage somewhere to the reserve/overflo tank that clears when the pressure changes a bit i.e. water cools & compresses or heats & expands. Could that be a possible cause? A blockage in the overflow??

I'll double-check the wires tomorrow morning when it's cold & give it a burp & see what happens.

Thanks again for the assist guys.

PVerdieck

One other thing to check. I don't know if they replaced it, but the line going to the overflow tank is stupid. It has a junction or two where the hose ends, there is a plastic connector, then another line starts. I don't remember if the line is in 2 or 3 pieces, but it is a good idea to replace it with a solid/continual line.

T@L0n

This morning I checked/burped the car. The water level is definitely down in the radiator but the overflo tank seesm VERY full.

STILL don't know what that noise was last night.

Kento

The gurgling noise you're hearing is coolant near the turbos suffering localized boiling on shutdown. There is probably still a bit of air in your system that needs to be bled out. Look up "throttle body coolant line" in the search function, and see the procedure on burping your coolant system through that hose. It's the highest point in the system, and you'll be able to bleed out air that you can't get by squeezing the rad hoses.

rx7raca

I think you are talking about, the coolent seals. from what you are saying this might be ture. what happens is those seals get old, from not changing the coolent every 1.5 years or so. this will make the seals not seal anymore. do you notice a good amount of white smoke sometimes?

also a good test for the coolent seals is, when the engine is cold, take off the filler neck cap. have someone turn the engine over, letting it start. if alot of coolent comes out and is bubbling out as if pushed from compression. then your seals are toast.

this can be expensive if your apex seals are old, other wise you can just have the engine pulled apart an have all the seals on the block replaced, and not the rotor seals, which are the expensive ones. good luck.

widebody2

Rob Robinette's site actually describes what you are hearing to a T. A gurgling noise after shut down. That is a symtom of air in your coolant system that needs to be burped out as others early in this post pointed out.

mad_7tist

has the coolant resv tank overflowed? i would check the caps. the vac part may be bad. what ast do you have? does the car smoke ? what does it smell like if it does? have you gone under the car and looked for any leaks? it would be easiest to have the coolant sys and the caps tested somewhere.

T@L0n

Reserve hasn't overflowed but gets over the "full" mark when hot. Which part is the vac part & what is an ast?? Car doesn't smoke (cept for cold start on coldish mornings) As for smell I'll have a sniff tonight & report back. NO visible leaks under the car... (kinda wish there were it sounds less expensive ;o)

As for the test I'll have to see about getting the pressure test done soon.

Thanks again to everyone for helping.

T@L0n

OK, here goes tonight I did the test rx7raca recommended, water just moved with the engine, no bubbles at all.

Here's the run down from the beginning with all the info I remember.

Took the car in for it's service & a check of the turbos. The guys at the garage re-connected the wiring for my emissions/air pump did the service & sent it off to the turbo mechanics who disassembled the front turbo & said it had a little play but was otherwise fine. Since then...

1.) Within a week or so I got the coolant ligh (&annoying buzzer) come up on startup of approx 30 secs after this stayed on for between 15 sec & 1 minute.
2.) Began checking the water levels on both caps & the overflow. these initially seemed OK, but the level on the main cap has been down about 10-15 cm over the last 2 days.
3.)No extraneous smoke. I've taken it up to about 7000 rpm once or twice to check.
4.) Exhaust smells pretty much normal (Strong smell of unburnt fuel, kinda sweet)

I've burped the system as recommended by David Beale, NO bubbles. I've also taken off the main cap (not the pressure one) & started the engine, NO bubbles. Haven't checked the lines as recommended by PVerdieck, but as everything else is standard I'd suspect that those are too.

Kento I've tried looking up "throttle body coolant line" But after reading through a few posts haven't found anything about a procedure for burping the system through that hose yet. (If you can give me some more info maybe I'll find it quicker but I'll keep looking tonight.)

All in all I'm hoping against hope that it's not an issue with the seals as the car is pretty new (at least to me) & the possibility of spending up to $8K (New Zealand dollars) REALLY isn't very appealing.

Thanks again to EVERYONE who's submitted some info on this post & thaks in advance to anyone who continues to contribute. YOU GUYS ROCK!!

T@L0n

Bugger, just remembered something else I forgot earlier... When I was checking it earlier a mate of mine noticed the water in the radiator filler seemed a little oily. Does this ring any bells for anyone???

mad_7tist

little oily? prob ok the sweet smell is what has my attention. it may be coolant burning.

T@L0n

Today I've had a few guys have a "sniff at my rear end" & All they smell is unburnt gas still not sure on this but there's no smoke that I can see. (Not that I'm ruling it out by ANY measure)

Just got a new filler & AST cap (Mazda not 3rd party) & am waiting on the car to cool before I go through the whole removal & re-fill process again. I'm wondering about the pressure cap on the AST &/or the AST itself as I've read on a few posts that it's a weak-point on these wagons & can cause this type of issue. Would this be the case on a 96?? Any thoughts??

BTW Thanx again to everyone for the help. This place makes me feel glad I bought rotary!!

mad_7tist

the ast is plastic and cracks with time. press should be at 13 lbs i think that is the "new" cap press. check the line from the ast to the overflow tank also

T@L0n

OK replaced the caps, topped off the radiator & over-filled the catch-tank (Probably **** extra coolant tomorrow but at least I'm sure it's full & not sucking air back in)
As for the overflow line from the AST how do I get to that?? Just in from the top or from underneath?? What's the best method of attack??

T@L0n

OK, levels down again this morning so I had a look at the AST (Air separation tank for the rest of the newbies like me) Found the line fron the filler was loose. Then what do you know, it came off in my HAND?!?! with about 1 inch of the plastic nipple still in the pipe!! REALLY bloody annoying.

I'm hoping that's what's been sucking air into my system BUT, the problem is that NO ONE down here appears to import aftermarket versions of these. I've read in a few other posts that some of you use a petite replacement (which I'll have to get down here) I'll probably have to go with a Mazda spare in the mea-time but what would you recommend to replace it later, Stick with Petite or is there something better??