Took the car out today, drove hard for about 5-10 minutes (lots of WOT runs) and brought it back to the shop. Upon stopping I smelled coolant, but saw no steam. Smelled the exhaust...it seemed like the exhaust had a coolant smell to it. Asolutely no steam coming out of the tailpipes and no condensation in them at all. Ok so a few minutes later the add coolant light came on. Wierd thing is the car never makes a cloud of smoke (sometimes only the normal tiny 1/2 second puff whent he engine first fires), and NEVER takes more than 2 seconds to start, even after its hot. So the coolant disappearing and coolant smell in the exhaust seems like a coolant seal in the engine. The fact that there is no hard start, excellent compression, and no smoke from the exhaust makes me wonder what the hell could be going on. Any idea's what this could be?

-Joe


BTW...I can let it idle all day long and never get a hint of coolant smell. Only when you romp on it for a while does it happen.

 

what ever the problem is,,,,,,it sure isnt going to have a good outcome.

 

Errrrr....ok. And what makes you say that? If it turns out to not be an internal coolant seal, then I'm not too worried about it. If it is a seal, then its big streetport time.

-Joe

 

streetport,,,,,whats that (porting out the intake??)

by saying not good i just meant,,,teardown time,,,,less time to drive.

 

Any ideas from anyone? I'm going to check for other possible causes besides the coolant seals tomorrow...any tips for then would be much appreciated.

-Joe

 

pop the cap on the filler neck SLOWLY and with gloves after you get bakc in next time. see if the coolant really is low.
the snsor could just be iffy

 

I'll definatly do that. I checked it about a week ago and noticed it needed about 1 cup of coolant, so I'm pretty sure its consuming it. I would be interested to see how much is gone now though...it was just too hot after running it today to check it. I also wonder if the aftermarket radiator cap could be the problem. Something else I noticed is that the top big radiator hose gets ROCK hard while its running. Could the cap be causing too much pressure in the coolant system, thus pushing coolant past the coolant seals in the engine? I have no idea how much pressure that would take.

-Joe

 

It is very feasible you could have a small pinhole or crack along a housing coolant seal wall somewhere. I think Mazdatrix has a good writeup on this topic in their FAQ section...

 

OK heres a little update:

After looking carefully for leaks, I found that water is seeping out of the water pump's weep hole. I have one on order and should have it to put on today. Now my only other problem is that I am getting coolant in the overflow. It isn't spitting out of it, but it won't suck it back in so the level keeps increasing. I'm guessing this is because of the leak in the water pump. So my question is...how much overflow into the overflow tank is normal under normal driving conditions?

-Joe

 

OverDriven - my car was doing the SAME EXACT Thing.. eating water very slowly, no smoke, no steam, high pressure. I was attributing it to a very minor leak near my radiator... I was wrong. nothing too serious for me, though.. . mine was the hose that connects from the block to the UIM that burst, and the cause was a defective thermostat (as far as I can tell). Here's my thread on it: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/any-danger-running-too-cold-thermostat-removal-story-336573/

 

I'm bumping this up because i need to print it tomorrow. I'm having the same kind of symptoms.

 

Ok update...I got the water pump for around $42 and installed it. Took about an hour and a half to finish the install. I gave it a good run and as far as I can see, the problem is solved. I'm not getting a low coolant light, and not losing a noticable amount of coolant. I'm taking it for another test today and will see how it does. Another quiestion...how much overflow into the resevoir is normal while the car is at full operating temp?

-Joe

 

Maybe 1 1/2 to 2" up the bottle is normal for me after a good drive...

 

My problem wasn't completely solved by replacing that one line, after a (shorter) hard run, my temp shot up, and my water pressure was crazy. It ended up blowing the top radiator hose, and all my coolant leaked out of it. I was watching for it (luckily!) and managed to shut off the car before it got overly-hot.

Here's the question: I'm running no Air pump right now, but with a single alternator pulley (I know, i know, bad idea, i can't afford another one right now).. . do you think it's possible that the water pump just slipped too much, didn't move enough water, and the water in the engine just expanded too much and built up pressure, or do you think that the water pump is defective?

Thanks in advance.

 

Hmm I think if the water pump belt is slipping, you would hear it squeal. You might have a bad radiator cap? If you built up enough pressure to blow that hose, I would definatly say its your cap. If you want to make sure on the belt issue, grab a yoohoo belt from a local hardware store and put that on:

http://www.1300cc.com/howto/how2/belt.htm

-Joe

 

Overdriven - You think it was all caused by my cap? I know mine is going, and I was going to pick one up tomorrow or saturday... I'll let you know what happens