charliegt

Ok, I made a new thread since my old one is getting cluttered.

My problem is with the coolant buzzer going off, and just recently the car being hard to start.

Today I pulled a spark plug from each (chamber?) and there was no sign of coolant on them - no coolant squirted out when I turned the car over either.

Compression test revealed each chamber to be the same, 90psi. I'm assuming being exactly the same is a good thing, and the low compression number is correct since the car is turbocharged.

I then started the car (took a minute and once it did start there was white smoke initially that went away). I watched with the filler cap off, no bubbles... As the car warmed up the level began to rise and I used a funnel to keep it from spilling over. The level stayed up and no bubbles. Then I had someone give the car a little bit of gas to rev it up, the level dropped instantly and then came back up once the car went back to idle. Is this normal?

Now, once we shut the car off the level went back down to a normal level and I could take the funnel off. As the car sat the level kept going up and down and there was a strange noise that sounded almost like the gravel in the vaccum cleaner sound I've heard people refer to. I waited about a minute and started the car again, started up fine and no smoke at all.

Now, I do not have an AST. I am wondering if there is a leak into the combustion chamber due to the coolant system being under pressure once the car is shut off - would having an AST eliminate some of the pressure and help decrease or eliminate this problem?

Thanks again guys,
-Charlie

BigBoosting

Well...It might be a good thing that compression numbers are the same...but really 90's isn't all that great compression. Not bad, but not good. You might want to worry about your coolant seals. How many miles are on your engine?

alberto_mg

Sounds like it might be coolant seals. Also sounds like your compression readings aere lower than normal. Search on how to do a compression test and maybe try again.

No offense, but it also doesn't sound like you know what you are doing in regards to troubleshooting. You might want to try the regional forums to find a good rotary specialist in your area so you know for sure what is going on. This forum is only so helpful.

Fritz Flynn

iTrader: (263)

Have you drained your coolant and refilled recently?

Based upon everything your saying I'd say you have air in the system and not bad coolant seals.

Each night take the top off the filler neck and when you wake up top if off. Should take a few days. Also if it's just air in the system the buzzer will come on then go off over and over not just stay on.

If the system was not drained and this happened out of the blue then you could have a coolant leak. Look for leaks around the turbo lines and the lines in front and behind the manifold. Basically check all the coolant lines by pressurizing the system if you have the proper equipment. Don't over pressurize it or you could actually blow out good coolant seals.

Anyway good luck and 90 psi is fine if its even on all the faces. 70 is rebuild time so right know just pretend you have some nice low compression rotors

charliegt

All of the troubleshooting techniques listed above were based on advice members of the forum gave.

My main questions are :

1. Is the level of coolant dropping when gas is applied normal, and if not what would cause that? Maybe a clogged/kinked coolant hose somewhere in the system?

2. Would having an AST reduce the pressure in the coolant system.

3. What could that suction noise be that I am hearing after the engine is shut off (it coinsides with the coolant level going up and down repeatedly).

Thanks again guys,
-Charlie

Fritz Flynn

iTrader: (263)

PRESSURE and water pump.


How much coolant are you putting in?

How often?

Does the buzzer come on and stay on?

Do you have a shop manual?

If not I'll sell you one LOL

skunks

i dont think that you have broken any of your water seals becuase if so, coolant should be shooting out as you start your car and watch for bubbles (as the rotor compresses air, it should force a bit past the leak and cause coolant to shoot out)

Mahjik

iTrader: (1)

Unless it's an outter seal and going into the oil.

skunks

ahhh true, although i assumed that he does change his oil regularly/quite frequently and should have seen the coolant in his oil. your right though, i never really though of that situation happening to tell you the truth.

charliegt

I changed the oil today and it looked normal.

The coolant buzzer was coming on once a week (just during warm up and then going off). Now it comes on just about every time I drive it even after a fresh top-off of coolant (again it only comes on for 1-2 minutes at a time and then shuts off - once the car is fully warmed up it is not a problem). I have found leaks, several leaks over the past year or so, and fixed all of them. At this point I see no visable evidence of a leak - or any smell of coolant under the hood. Today when I was under the car I checked the upper and lower radiator hose and looked around the engine bay (top and bottom) for any sign of a leak - no dice. There is no smell of coolant in the car and the windows don't fog with the defroster so I doubt the heater core is leaking.

My overflow tank is FULL, or close to it. It begins to spill over onto the drive if I add more directly to the tank (even though there is room for coolant in the filler cap as well). I am wondering if an AST would help with any of these problems?

When I add coolant it doesn't take very much to top off (maybe between 4-6 shot glasses worth), but I can get the level to go down by squeezing the upper radiator hose a few times - then top it off and repeat. This would make me think that there is a leak near by, by the amount I'm squeezing the hose doesn't justify the sharp drop in coolant level - its more like I'm just working bubbles up.

I have a shop manual on my computer, and yes Fritz you seem to have every RX-7 related part imaginable - I purchased quite a few parts for you a year or so ago and was very satisfied with the parts and your fast shipping.

And to answer the question from your first post Fritz. No I have not drained the coolant recently. However about a year ago I had a problem with a leak that I fixed (in order to fix it I replaced the upper radiator hose and the coolant level sensor). Ever since then I have had no leaks but about a week afterwards the buzzer started acting up. I treated it like air bubbles at first (tried burping and just topping off every now and then) but it has continued until now. At this point it is worse, plus now that the car has acted up not wanting to start a few times I am starting to think it may be serious.
-Charlie

Gadd

Ok,, To answer your questions

1; Yes, Increasing the rpm of the water pump will cause surging and/or changes in water level at the filler neck.
2; NO, the pressure of the cooling system is controlled by the cap that was on the AST .09 bar
3; suction noise..... Hmm could it be described as a boiling noise? You have air in the cooling system.


The AST was there to help remove air from the system ( hence the name ) Once the system is purged of air it becomes ineffectual.

Rent a cooling system pressure tester from the auto parts store and pressurize to about 20psi overnight. It should hold pressure indefinitely. If you lose pressure, you have a leak or leaks somewhere, pull the leading plugs ck for coolant. (Bummer for you if you find coolant here)

It sounds to me that coolant is not being drawn back from the overflow tank. Check or replace the hose running from the overflow tank to the cooling system, replace the pressure cap. If there is the smallest of leaks in ether, air will be draw back into the system instead of coolant from the overflow when the engine cools. (I’ll bet ya this is the problem)