crcleofdst

Ok, I have been troubleshooting this problem for a while now, and I cant seem to figure it out.


Problem: A few months ago, I got a low coolant light. I topped off the coolant (about a drinking glass worth), and went on my way making sure my temps stayed in check. All was well, and I parked the car for a week. The next week, I had the low coolant light again. It took much less water this time. I drove the car, keeping an eye on the temps, and all was well again. This was the last time I got a low coolant light, but shortly thereafter I noticed that my greddy water temp gauge acting funny. The gauge is installed in the TB coolant line. (I followed the Dale Clark method with the lowes fittings). I started noticing that the gauge would stick at around 40c, and wouldn't move unless I blipped the throttle. After blipping the throttle, the guage would quickly shoot up to whatever temp the coolant was, then hang until I blipped the throttle again. Normally, I slowly drive away once it reaches around 60c (keeping the rpms below 3k). The car normally reaches 85c by the time I get to the end of my street. I figured that I had some air in the system, so I purchased the lisle funnel. I put the funnel in the first time, filled about a 1/4 of it with water and fired up the engine (heater on full blast). I didnt notice any bubbles until the thermostat opened, but when it did, there was a lot. I let the car idle a bit, and after a few minutes, the coolant started to boil. I shut the car down to cool, and draw the coolant back into the system. After a few hours, only some of the coolant had been drawn back into the system. I put the plug into the funnel, and transfered the remaining coolant to the over flow tank. I let it cool down completely, and then fired up the engine again to see if the gauge was working correctly. Unfortunately, the problem didnt go away. I did this several times with the same result. I have removed the temp sensor probe, and inspected it. There does not seem to be anything wrong with it. I have removed the TB line to add coolant at the filler neck, but I never seem to get coolant to come out that way. I have used my mighty vac to draw the coolant through the TB line, and it flows freely without any air bubbles.

So basically what I have is this: The car does not overheat as far as I can tell (although I dont completely trust the gauge at this point). It does not boil over with the caps on. I don't have any smoking or starting issues, and my idle seems to hover between 1k and 1500. ( I am assuming this is because coolant is not reaching the TB, and it is perpetually warming up). I dont see any leaks, but after a session with the lisle funnel, I almost always have to add a little coolant to the filler neck. A couple of times when I opened the filler cap (after cooldown), there was some air pressure released. I also noticed that the system doesnt seem to draw coolant from the overflow tank. There is no coolant in my oil, and no oil in my coolant as far as I can tell. I dont smell coolant in the exhaust either (although sometimes, it will make your eyes water).

I am thinking that I either have a leak that I cant see, and its allowing air into the system somewhere before the TB. Or I have a waterpump issue. What do you guys think?


My only engine mods are a downpipe, boost controller, and an oil pedestal for my oil pressure/temp gauges.

car hugger

iTrader: (1)

Do you ever get a whiff of coolant while driving the car? I've had hoses start to go, I never saw any coolant on the ground, but I would occasionally smell coolant during or just after driving.

These leaks never showed while cool and when the hose would finally give out it was a pin hole that continued to leak until the pressure gave up.

Something you can do is pressure test the system, after letting the car cool but while the hoses still retain some heat and are more pliable.

It's always dangerous to remove the coolant cap while warm but I have used a folded over beach towel to remove the cap when the system was still warm.

Good luck.

DaveW

You either have a problem with the coolant-recovery system not drawing coolant back, or you have a slight o-ring leak, letting a small amount of combustion gas into the coolant system, causing the air pockets.

Common coolant recovery problems:
1. bad AST cap (not sealing, allowing air to be drawn back to the engine instead of coolant)
2. leak in coolant-recovery line, again allowing air to be drawn back to the engine instead of coolant
3. pinhole leak in some hose, like the turbo coolant hoses, where coolant evaporates quickly, and air can be drawn into system on cooldown

The add-on gauge is flaky because it doesn't have water in contact with its sender all the time.

crcleofdst

I actually purchased a pressure test kit from sears a month ago. I could never get the tester to seat right on the filler cap though. Admittedly, I didn't spend as much time on it as I should have. Also, sometimes I do smell coolant, although its very rare. I guess I will re-visit this later today.



Thanks for the responses guys. I just got off the phone with Ray at malloy. I went ahead and picked up the hose kit, both rad caps, and a thermostat. Grand total was just over $200.00. I figure that I might as well replace these items, as it is probably time for it anyway.

crcleofdst

*update*


I got the pressure tester figured out finally. I am able to hold pressure somewhere between 10 and 12 psi before it dumps into the overflow tank (which, as I understand it, is exactly what it is supposed to do). I am letting it sit now, to see if I lose pressure. My understanding is that a loss in pressure doesn't absolutely indicate a blown coolant seal, it could also be a leaky hose (TB hose, turbo coolant hoses, etc..). So I guess that I should be seeing a drop in pressure, no matter what. If I don't see a drop, then I would assume that the rad cap is to blame. Does this theory track?

Also, I am noticing that after driving the car for an hour or so today that I am losing far more coolant than I thought. almost 2 to 3 drinking glasses of water (maybe more). I still have no starting issues, smoke, overheating, etc... How much coolant would one have to lose via a compromised seal before seeing smoke at startup?

thanks for the help so far.

crcleofdst

*update, and bump*


Got my coolant hoses, thermostat, and caps in the mail this morning. Ray is THE MAN! I honestly didnt expect to see this stuff until monday. I cant even get the local mazda dealer to talk to me unless they have my damn vin number... then they wont place an order over the phone! Thank god for guys like Ray.




Anyway, does anyone have any insight on my other questions?

Copeland

iTrader: (42)

Install your hoses, tstat and caps and I think you're problem will disappear. If not then you have to worry. I think your turbo coolant lines are damaged.

BTW: How much did the T-stat run you?

crcleofdst

I'll have to check and see exactly how much I paid for the thermostat itself, but all together it was like $202. That was for all of the hoses, both rad caps, and a thermostat.

thanks for the reply.

crcleofdst

Ok gents, looks like I have a leak between the thermostat housing, and the block. Hopefully it is just a gasket, although I didn't order one. I can definitely see coolant running down behind it.



On another note- The more I look at my engine bay with all of the airbox/intercooler **** out of the way, the more I want to go single......




*edit*

that thermostat was $13.63 from Malloy. List is $25.07.

crcleofdst

Ok guys, I finally have had some time to work on the car. I believe that I have found the problem. The gasket that goes around the thermostat had some kind of hard deposit wedged between the housing and the gasket. I very lightly sanded the housing to get rid of any crap, and I noticed that the housing is slightly scored in the exact same place I had the deposit. Its deep enough that it catches my fingernail, but its really tiny. Unfortunately, my wife has the camera right now, so I wont be able to take pics until later tonight or tomorrow. Should I be worried about this? If so, what is my course of action? I am almost 100% sure that this is exactly where my leak started.


Also, I just realized that my new thermostat doesnt have the jiggle pin. I'm gonna search on this right now, but I figured that I would mention it just in case someone wants to save me some time...

thanks

crcleofdst

Bump

crcleofdst

I guess I will just put it back together then............

DaveW

I had a thermostat leak due to the same cause, but mine did not cause a pit in the metal. The hard deposit was corrosion "salts" (coolant not changed often enough, etc.). The pit is where the corrosion ate away the metal. You could probably get away without it, but I would use a bit of silicone seal (ultra-black, etc.) on the thermostat gasket or in the groove to help seal where the pit is.

Apparently, the later thermostats don't have jiggle pins (others have commented on this). The one I got in 2004 for the above leak did.

ITR

iTrader: (1)

crcleofdst any news? Did you solve the problem ?

adam c

iTrader: (2)

I recently started having a similar problem: Overflow tank overfilling after shutdown, and then not flowing back into the system. This is giving me a low coolant light/buzzer the next time I drive the car. I just put on a new 13 psi AST cap. The old one had a tiny leak. The leak only seemed to be leaking off a tiny bit of air pressure, so I wasn't losing any coolant.

I believe that my coolant overflow tank has sediment/crap in the bottom, and won't allow coolant to flow freely back into the system. I wonder when the last time was that anyone cleaned out their overflow tank?????

I'm planning to clean it out this afternoon. The FSM doesn't list how to do this. From what I have read, it looks like I need to remove the passenger side tire & fender liner to get the overflow tank out. Any experienced comments would be appreciated

Thanks, Adam

CantGoStraight

I was able to remove the recovery tank by removing the small plastic panel below it and working through the hole in the front bumper, removing the wheel and plastic fender liner will make it much easier to work with.

crcleofdst

Well, I'm not 100% sure that it is fixed yet. My temp gauge still seems a bit sluggish when the car is cold, but once the car warms up, it seems to react as it should (at idle). I let it heat cycle about 5 times tonight, and the temp stays between 92c and 98/99c.

I haven't driven the car more than a few miles since I finished replacing the hoses, and I have only burped the system twice (once tonight). I have noticed some extra crap floating in my coolant since I re-filled the system, and I don't think coolant is flowing into or out of the tank. Because of this, I may follow adam c's lead and clean out the overflow tank.

Here is what I have replaced/installed so far:

Upper rad hose, both turbo coolant lines, ast to filler neck hose, TB hose, both rad caps, thermostat and gasket, FC thermoswitch, and some other items (belts, plugs, etc...)

I did buy all of the hoses, but I decided not to install all of them after I found the leak at the thermostat housing. I may go back and install the last few hoses for ***** and giggles, and do a complete flush.

CantGoStraight

If you have loose stuff floating around in your system and some of this stuff gets trapped on the seal of your radiator cap (the one on the AST, bottom seal) then it will cause two problems (prevent the system form building pressure and or not pull coolant back from the recovery tank when cooling.

Copeland

iTrader: (42)

Hows it coming along?

crcleofdst

Well,

I don't think the prognosis is good. The car has been sitting for a couple of days since the last time I drove it. When I went to check on it tonight, the coolant was under a shitload of pressure. It sprayed all over the place. I fired it up, and it was running like crap. I didn't notice a lot of smoke, maybe just a tiny bit. It is getting a little colder at night, so I figured that it was just condensation.

I'm doing a pressure test as we speak. I was able to build the pressure to about 14 psi (my ast cap is a .09 bar).

What I need to know is how long should it hold the pressure? Also, should the system spew coolant out of the rad cap cold like that?

I'll be pissed if the seals let go. I was supposed to bring the car to a show next sunday......

crcleofdst

Ok, I now have a continuous stream of air bubbles in the cooling system. I can't seem to get all of the air out of it. The coolant will boil over with the lisle funnel before all of the air is gone. Now when I open the radiator cap, the coolant is under a hell of a lot of pressure. Even when cold. I also noticed what seems to be oil droplets in the coolant.

Bottom line: Me thinks its rebuild time.

I am going with the atkins overhaul kit, and I plan on replacing the omp lines, the fpd, and getting the injectors cleaned. I am still undecided if I want to do a streetport or not. I think I want to stick as close to stock as possible, as this will be my first r&r. My budget isn't unlimited, but I obviously don't want to spend more than I have to. Assuming the rotors and housings are re-useable, and besides what I have already mentioned, are there any other items that should be replaced or serviced?

CYD

Ah crap, I was hoping for a happy ending. Ya know when you read of someone with similar issues...and you hope it's something minor...and it turns out to be major (or just $$$).

crcleofdst

Well, the good news is that I am learning a lot more about my car, and I am slowly but surely getting things back together. I seem to have gotten lucky with my housings/irons, and I haven't hit any major snags yet. I am almost done with my port job (pineapple med street port), and hopefully I will be painting the housings and irons this weekend.


All in all, it has been a good (although expensive) experience, so I consider it a happy ending..

rotaryrotary

wow , this really reflected with the problems i used to have on my FD, i used to think it was my coolant reservoir cause mine was cracked but no . . lol