Leaking Coolant
 

About two days after posting that my FD is running well.... :)

Hahaha aint that the way.

I've owned my FD for about 8 weeks now, haven't had a problem. I had a major service about 3 or so weeks ago, changed all the oils, drive belts, filters and flushed and replaced the coolant.

One week ago I had the pre-cat whipped out and a downpipe put in (stock downpipe from a series VIII). I asked them to check the cooling system for me (some gurgling after shut down) and they gave it the all clear, just some air that needed burping.

I noticed the overflow tank was a bit low so I topped it up with about 3/4 of a litre 3 or 4 days ago.

Anyway today it was quite warm, and I drove it for about 30 minutes and parked in town. Came back 2ish hours later, went to start the car and the low coolant buzzer went off. A fair bit had leaked out. Opened the filler neck and couldn't see any coolant, but the overflow bottle was full (above the F).

Called the mobile mechanic dudes who came, topped up with water, and noted bubbles in the cooling system with the engine running (so called champagne test). He thinks my coolant seals might be stuffed but I don't reckon that's the problem. The system was pressure tested 8 weeks ago before I bought the car and it was all good.

I haven't had a look at it yet, we are going to take it to the rotary mechanic in the morning and get them to look over it. I just want to get an idea for how long it takes a coolant seal to wear down. Could they begin leaking within 8 weeks of a pressure test? Or is it more likely to be something as simple as the return from the overflow bottle not working correctly.

Will post again once I've heard from the mechanics.

Sounds like the water jacket seals have a small hole in them somewhere.You can check this by starting the car and then shut it off and see if the upper radiator hose has pressure if it does then the engine is pushing the compression thru the coolant system but when you do a pressure test it shows good probably because the compression can come out but when you dothe pressure test the pressure is pushing in and the seal actually seals when pushed in but wont seal when pressure is pushing out. I have fixed two 3rd gens like this with out breaking down the engine. The gurgle noise just means that the water is probably boiling in the its to hot man. this might be it but I will wait on your next post. Where are you located? We are in GA

That could make sense. I'll have a crack at that in the morning when it's cooled down.

The thing is the car has only been doing this as of today. For the last 8 weeks I haven't had any problems, every time I check the coolant level at the filler neck it's within an inch or so of the top. Now the level is low and it's nowhere to be seen in the filler neck, but the overflow bottle is still full. The pressure cap on the AST seems OK, as does the AST (which is stock plastic). The cap is rated at 0.9 bar as seems to be the norm. I have had minimal whitish smoking on cold starts that clears within 2 or so minutes. Mind you that's the general story from the last 8 weeks, and this problem has only developed today.

Try replacing the pressure cap on the AST first. Use an OEM 0.9bar cap. My old one "looked fine" but was leaking air into the system on the suckback from the reservoir. Also check the seal on the filler neck cap.

-bill

Hmmm well it's really late at night so I still haven't checked the car myself yet. Well short of looking in at the overflow reservoir - it doesn't look like the coolant has overflowed out of that. The coolant is leaking out from a small hole in the middle of the cover thingy (sorry too late at night for me to remember it's real name). It's not leaking now when the engine is off and cooled down.

It's got to be a hose somewhere in there. I guess that air would enter through a busted hose, hence the overflow reservoir remains full. Think positive untill I have it pressure tested tomorrow and get the dudes at rotomotion to find the leak.

About to go pick her up from the rotary shop. Turns out it was just a cracked drain plug. Something I could fix at home if I had the right tools, I think I'm going to invest in some. I want to get in and dirty rather than running to the specialists at every opportunity.

Moral of the story: When a mobile mechanic tells you that your head gasket (haha)is shot check the radiator drain plug.

I'd go flog whoever did your coolant flush. They cracked your plug. They should pay for it.

I seems that I have the same pressure problem that you decribed. There's bubbles in the antifreeze. How can I fix it>

thanks,
Wayner

Give us more info about your pressure problem. Are you leaking? Are you overflowing out the overflow tank? Is your overflow tank full but filler neck appears empty?

Best advice I can give is to take it to a shop and ask them to pressure test the cooling system. If that's not feasible, jack the car up yourself, remove the undertray and see if you can find where the leak is coming from. Obviously be careful, you don't want to get squashed if the jacks fail.

I took the car to a Mazda dealership and told them that the add coolant buzzer kept coming on. The said they would burp it and had a funnel shaped contraption hooked to the filler on top of the motor. This is when they noticed that there were bubbles in the coolant. He said that pressure was escaping from the motor into the coolant and was building up pressure which pops the radiator cap and spills over into the overflow tank. He said that I would have to pull the motor and replace the seals but I thought I saw on one of the threads that this could be fixed without removing the motor. I sure hope so because he said it would be about $4000 Canadian to replace the motor.
:confused:

Just be aware that not everyone knows what their talking about. I had a guy tell me my o-rings were completely shot when I simply had some air in my system and a leaking radiator drain plug.

Are you losing coolant but not seeing any leaks? Are you having difficulty starting the motor, blowing a lot of white smoke (at startup)? If you are then your o-rings could be failing.

Search the forum for o-ring failure to find out all the symptoms. Keep a close eye on your cooling system, see if your exhibiting any of them.

There are a number of things you can try, like replacing the caps (pressure cap on AST if u got it) and the filler neck cap. Check all your hoses for leaks. Pressure test your system, it might help you spot any leaks, and help indicate it it's your o-rings that are going. Some might even suggest this block weld stuff (I know nothing of it so can't really help with that).

Don't just jump in for a rebuild. It's the most expensive and should be the last option, after you've tried pretty much everything, and proved to yourself in the process that your o-rings are toast.

WAYNER1, it sounds like you've got a classic coolant seal failure. The test they did is known as a 'champagne bubble' test. The engine either needs a rebuild now, or soon. There is a trick involving block weld that might reseal it from the coolant side of the seal, but it's a half-assed way to borrow time.

$4k Cdn sounds about right, too. Maybe you can get one of the new remans at Malloy which supposedly look to be well-built.

How long have you had the car? How did you determine the health of the engine before making the purchase?

Dave

I've had the car for about 7 years but I haven't driven it for the last three years.The body and interior are in great shape and there is just over 200,000 km on the car. I replaced the radiator 3 years ago and the new radiator had a cap on it so I blocked of the one on top of the motor and use the one on the radiator which send to the overflow. Other minor problems are a bad heater control motor and an auto transmission that sometime slips or is slow going into gear. All added up, maybe this car might not be worth fixing. What do you think.