Hey guys... I've spent the last couple of hours on the forum trying to find out the solution to the problem using the search feature in this forum... and DAMN, rx7's seem to have quite a few of these!

My leak only occurs after the car is shut off after its been driven. THe leak seems like a half cup of fluid right under the coolant resevoir tank (underneathe the passenger side headlight). That resevoir tank is full and yet after cool down, I need to add about a half a cup of water to the filler neck.

Is this a symptom of failed water seals? (please say no, please say no!!!!) I just find it funny that coolant is not being sucked back into the cooling system.

Your help is GREATLY appreciated... thank you thank you!

 

Yes, it is most likely your seals. Does it start hard in the morning and blow any white smoke at startup? You'll also smell the coolant as it comes out your exhaust. A litlle puff of blue/grey smoke is normal.
Sorry to be the grim reaper. There is a possible cure
with CRC Copper Block Weld if this IS the problem and IF it is a small leak. Don't give up hope yet!

 

shiet!!! Well, I don't smell coolant from the exhaust yet... but I don't want to push my luck. How does the CRC stuff work? And I would say I'd lose about a cup of coolant a day... I'm not sure if that's considered small or not... I really am hoping that it's something else, I can't afford the down time... might have to pick up a commuter car or something. What are the chances it could be a faulty radiator cap?

 

Sure it could be a bad cap, and about 15 other things. I need to know the symptoms first. So - hard starts and white smoke?
If not then we'll work backward and forget about the CRC for the time being. One thing you'll have to get is a radiator pressure tester which can be rented from AutoZone or another parts store.

 

I don't think that it is your seals. I would lean closer to the pressure cap going bad. You are spilling the 1/2 cup you put in the day before each time you turn you motor off. While you are moving the temps are lower and there is not as much pressure under the cap as when you are parked and not circulating the coolant. A bad cap, or too low a pressure cap would allow for the coolant to exit and not return at the same level. Replace the cap first before you worry about the seals. Replace you AST if you havn't already. They are not getting any younger and you are chancing a melt down if it cracks open.

 

$10 says it's your cap.

 

I'm with Ron, it's leaning towards your motor. At least that's one of the symptoms of a bad motor. But check for all the obvious first.


good luck,

car 53

 

I guess I'm hung up on the fact that my motor sounds and runs very good. No smoke, no smell of coolant from the exhaust (at least not yet)... but I think I'm in denial of the inevitable. In the mornings, the car starts as usual... the only thing odd is the coolant on the floor after I shut off the engine after a drive. And it's not a constant leak. It will leak until the engine is cool, and then stop.

I suppose I will purchase a $15 dollar radiator cap in hopes that it will solve the problem... but I'm getting more and more doubtful.
II've been reading too many posts of people blowing their water seals with the same symptoms as me.

So, if it is the seals... how much longer do I have? And how effective is that CRC stuff? Thanks guys, for all your input... much appreciated!

Brian

 

if you're not getting the white smoke then its probably not your seals. i had the same exact problem and you know what it was? when a new water pump was installed someone forgot to put sealant on one of the bolts. leaked all to hell...

 

A quick test is to remove the filler neck cap(with pressure released), start the car(some fluid may surge out), when it levels off, see if there are any bubbles coming from the coolant. If so, exhaust gas is getting through the engine seal into the coolant. Only fix then is an engine rebuild. Another symptom is oil in the coolant. You would see this at the top of the filler neck.

The theory of all this is that the exhaust gas overpressurizes the coolant which forces it into the overflow tank. When the car cools, there's not enough reverse pressure to return all the coolant back into the system. So, overtank overflows and filler neck is low.

However it could also be as simple as your filler neck cap or pressure cap. They are cheap to replace. Hopefully the caps are your problem, it was the cause of my coolant problems.

Arc Welder

 

It's the motor... it's going. I've had two go in 18,000 miles. I know how it goes.

 

Ok guys, what if I AM getting white smoke at startup and NOT losing coolant. Should I be worried about white smoke if I'm not losing coolant? Is it just condensation from the colder weather or something else I should look into? Recently my car has been producing a lot of white smoke from the exhaust for a couple of minutes in when I first start up the car in the mornings but one morning when I woke up late for work and it was already warm outside... no smoke. My exhaust doesn't smell like coolant either... more like fuel actually. I know my cooling system is pressurizing because every morning I check the AST cap and the radiator cap and both are pressurized and full of coolant. Someone had mentioned that it could be poor compression and that air is going into the motor and then condensating when I start up the car? I've never heard that before but my vacuum is around 16-17 at idle... Any advice/comments?

 

MILD 7 how many miles are on you engine. My waterseals are blown hence it sits in my driveway. I never smelled coolant in the exaust but the one problem was that I couldn't get the coolant to level off in the resivour no matter how many times I tried to bleed it. As a result it would push the excess coolant that was being displaced in to the overflow in pass. fender. The way in which I was able to be clear that it was the seal was to use my coolant pressure tester pressurize to 15lbs and maintain, and let it sit for an hour. While waiting remove the 2 spark plugs from motor. Be sure to watch pressure so that it doesn't drop, that could be a leak from a hose or a coolant seal. After an hour rotate the motor slowly and then look for coolant to come out of the sparkplug holes. If no coolant probably either one of the caps.
Good Luck

 

Chad, my motor has about 80,000 on it. I'm going to see if there's bubbles in the coolant at the filler neck as soon as my car cools down. I won't have time to investigate further until later this weekend. I'm very worried now. If worst case senario = blown seals... anyone know a good place in Socal to quickly and reasonable drop in a reman. engine? This is my only car, and use it daily to commute... this sucks!!!

 

Hi Brian, I'm back.

First, take a deep breath and relax a little bit. We're all totally stressed out right now and suffering from Post Traumatic Stress Syndrome - whether you know it or not.

The bubbles in the filler neck are for sure one of the signs of a "blown seal". So, you can check that easily on cold startup. Make sure you take a towel and make a "collar" around the neck to keep coolant off your belts and engine since a little will spill over. Make sure it does not hang down in your belts! Fill it to the top with DISTILLED WATER ONLY. Get a bright flashlight. When you start the engine cold, if you have "blown seals" you will see lots of little bubbles percolating up to the top - kind of like champagne bubbles. As it warms up you will probably see more. If they are small and kind of fizzy you have a small leak and one that can be repaired - MAYBE - with the CRC product. If you have big bubbles - probably not. The point is that a "blown seal" may not be a death sentence after all. But at $7.00 a bottle (and you might go through a few), some time and distilled water you have absolutely nothing to lose! The CRC product "Copper Block Weld" DOES work on small leaks. I've got over 5,000 miles on my engine with 71,000 miles on it and it does not burn any coolant since my treatment.
I was lucky since I caught mine right when it happened. If you ignore it or beat on the engine it will get worse and worse until the only cure is a rebuild. Now, if you're racing or running high boost there is no question you are just buying time - but it sounds like yours is a daily driver - and this is a relatively low stress situation compared to the way most guys on this forum drive!!

The fact that it starts easily and you are not smelling any coolant is good! Hopefully it is just a small leak. So..........check out the bubbles and report back! We're with you 100% dood, and the guys on this forum are THE BEST - they are total fanatics.
(and I mean that in a GOOD way)

Let's figure this out logically and not start guessing and throwing parts and money at it....

Ron

 

get a 20oz bottle and cut it in half. then hold it tightly upside down and look in. it wont spill.

 

Ok guys.... my worst fear has come true... started the engine with the filler cap off... and low and behold... bubbles. Here's the run down. When I first started the car (wasn't too cold... no 3,000 rpm warm up mode) and a steady flow of bubbles similar when you just open a soda. The stream of bubbles was constantly flowing for the first 30 seconds, and then began to slow. After about a minute, I counted about 5 bubbles per second. So it seems to me that my leak isn't too big.

So, now that I know that it's a water seal(s) how does this CRC stuff work? And where can I get it (autozone, etc?). Yes I do plan on replacing the motor soon, as soon as I can save up enough cash. I'm thinking the most cost effecient solution is a Mazda reman. Anyone know any qualified shops in the Socal area that could drop it in without too much down time and at a reasonable price (tri point is too pricey). Thinking about the rotary shop in Gardena. How much does labor usually cost. Not planning on doing anything else than a straight forward swap. Hoping not to spend more than 3 grand.

I really do appreciate all the help and support I 'm getting from you guys... it makes my situation easier to swallow knowing that I have fellow brothers who feel my pain.. and know what I'm gonig through. Thanks a million... you guys are the best!!!

Brian

 

Hey Brian...
I feel your pain... gone thru a engine/rear turbo/Diff as well all this year. Ouch!!! And my car is still not up to par and running
right.
However... I had leaks from the front overflow tanks area as well. It turned out to be a overfull overflow. Then bleeds out excess somewhere underneath.
If your car is not blowing white smoke in the mornings. This is a very good sign. You might have
air bubbles in your coolling system. When cold remove the rubber coolant hose on the throdle body and fill with distilled
water til you get some that flows from that disconnected hose.
Also squeeze the main rad-hose a few times to get the sir bubbles out.
Re-hook up hose to throdle body and make sure coolant is full.
I would check the AST for proper operation as well.

Best wishes.... jc.

 

couldn't this problem be easily decided by bringing the car to someone who can run a compression test on the engine? correct me if I am worng but a compression test can tell you if your seal are bad- correct?
-Jon
94 base

 

I don't know if this is it, but my friend was having a similar problem. He would shut the car off and coolant would "spill". What it ended up being was that there was a clog in the system and the coolant was backed up. So I did a hella fluch on his car for him. I took the thermostat housing off after I cleaned the entire radiator. I sprayed water in the block and ran the motor with a hose attached to it to clean it out. The water would enter through where the thermostat was and exit through the bottom of the radiator. Then I put it all back together, and it worked great. The other thing that I have heard on forum is that the cap could be bad. I would try those two things first.

 

I had the same problem - coolent leaking after shutdown in the same place.

I replaced the caps & it completely dissappeared. Pls do as the others on the Forum have suggested - replace the caps - its cheap & "may" fix your problem as it has with other owners.

The bubbles you refer too can be trapped air in your coolent system that gets in because there is not a strong seal - coolent leaks & air gets in.

Don't be ready to think its your seals - doubt it - do the cheap/logical fixes first & then worry about seals if its still present.

Good luck pal.

-Matt

 

When you use a pressure tester, how long should you leave it pressurized? Since changing to the SR Ultimate Rad last month, I have been pushing coolant out but not sucking it back in. But it is not always consistent - seems worse in stop and go driving than highway driving. It doesn't boil over either, just overflows the tank if you let it go on too long with out sucking some out of the tank & usually this is the same amount that I have to add back to the filler neck to top it off. No hard start or smoke or burning coolant smell and no overheating that ever saw on the guage.

I borrowed a pressure tester last week and put it on the filler cap first and pumped it up to about 16 psi, a second later the AST cap vented and let pressure down to 13 psi. So to do the 20 psi test per the FSM I put the tester on the AST and pumped it up to about 19 psi. Then left it for over 40 min. while looking around at every hose to see a leak - nothing. So I tried putting it back on the filler neck, pumped it to 16 then it vented to 13 psi and held for a while. When I started looking this time I could see coolant weeping not dripping from the lower radiator hose.

Alas, as suspected I should not have reused the Mazda spring clamps. No problem since I already had the worm clamps and new rad hoses in stock. So I replaced them and still have the same problem but now it will sometimes pull the coolant back in from the overflow tank. Last night I finally saw a coolant drip on the rad pan right below the water pump housing connections but couldn't feel around too good since it was so hot but I did feel a trace wet spot by the lower rad hose to water pump housing. Will try to tighten that clamp this evening. The only other place I suspect is the long hose than I have by-passed from the throttle body, it's been on and off a few times but I have reused the Mazda spring clamp - perhaps that one is weeping and not showing a leak.

I will try the running it with the cap off to check for bubbles just to be sure but since it sometimes pulls coolant back in now and doesn't consistently overflow I think/pray the motor is ok.

Do I need to leave the pressure tester on the system for an extended time like overnight to find these weeping type leaks since they don't spew coolant?
Help is appreciated,
Jack

 

whoa whoa whoa whoa!! Hang on a cotton picking second.

Ok, depending on how hot your engine was, keep this in mind - water boils. What is your water/coolant ratio? When you take off the radiator cap, you've lowered the pressure in your cooling system, thus, lowering the boiling temperature of your water/coolant. It's possible that you're just seeing the result of boiling. Were the bubbles big or were they small and foamy? Mine was doing this too - big bubbles - result of boiling because the engine wasn't COMPLETELY COLD when I was checking.

Now, take a look at a much more common problem on the 7.... the radiator. Is yours still stock? When your engine bay gets hot, everything expands. Lots of stuff in there is made out of different materials and expands at different rates. One such thing is the radiator, being that it's made out of aluminim and plastic (what were they thinking??). If your radiator's plastic tanks get small cracks, they may not leak until the aluminum core expands and makes the cracks wider.

To see if it's your radiator - take off the mazda fresh air duct if you still have it on... remove the fuse panel just below that (just move it to the side). That should be enough to see the top of your radiator. Take a flashlight and shine it down on the radiator. See any sign of liquid on it? Take a paper towel and wipe it along the plastic tank where it meets the core... any sign of coolant or water? Do the same wipe on both sides of the top and bottom tanks - right where they meet the radiator. If you find any sign of coolant in these places, there's a VERY good chance that you just need to replace your radiator.

I had the SAME THING happen to me - leaking only after shutdown when hot. Everyone told me my seals were gone too, but before jumping on a rebuild, I had the radiator checked. low and behold, my problem was fix and the car was upgraded with a $412 Fluidyne radiator as opposed to a $3K rebuild. Let's hope this is your case too.

 

Please check my above post before getting a rebuild started.

However, IF you end up needing a rebuild, I HIGHLY recommend Rotary Power in Gardena. The number is 310-516-9959. Don't get a reman, have them do a rebuild, especially if your housings aren't damaged from a blown out apex seal. I was asking him about his prices - he said that a straight rebuild with 2mm apex seals and no porting or performance mods will cost just over $2K.

Coincidently - it was Rotary Power that found my coolant leak and told me it was just the radiator, so at least you know they're honest about this sort of thing.

Good luck!