Is ther an easy way to check the AST cap, besides visually for good rubber?

 

Just buy a new one. It's a cheap part.

 

fyi - you can rent a truck and car tower thing from UPS at a decent price. You might want to get in touch with the local UPS place and just tow the thing home. I paid something like $600 to rent both and get it back to NY from IA over the course of 2 days. At least you won't be stranded and can deal with it once you get home.

 

Same goes for UHaul, Penske, and Budget.

If the o-ring has failed it's rebuild/replacement time because you're not going to be able to keep the coolant in the system and therefore overheat.
I can't think of a good way to run the cooling system open (unpressurized) if you indeed have an o-ring failure introducing exhaust gasses into the cooling system. I know the guys who run Evans coolant do it but I don't that will work with an o-ring failure.

 

i"m about an hour away from you (in suburbs of Detroit)- but you are already gone?

Hey guys isn't there a shade-tree method of fixing a blown coolant seal? Using Bars-leak or pepper or something? maybe he could try that?

call me on my cell if you are still in the area -I'm no expert but I have a garage and we could look at it - good thing you picked the hottest weekend of the year...

I'll PM my cell # to you

Jim

 

well - I found a thread - but it ain't a pretty solution...

https://www.rx7club.com/showthread.p...olant+seal+fix

 

it does sound like a coolant seal may be blown...

What about using some radiator sealer/copper block weld stuff? I know it has worked for some people and extended the life of their motors after coolant seal failure.

 

here's the link to the original o-ring fix - no mention of bypassing the radiator or heater core

http://www.scuderiaciriani.com/rx7/o-ring_fix.html

but you have to leave it overnight to dry - maybe not an option for you...

 

As an engine rebuilder, I can tell you that this problem is common with the 93+ rotaries due to the heat and stress they endure. Also, the problem sounds dead-on like an internal coolant seal failure...look nowhere else. Besides...even if it didn't START out with that (it did, but just playing devil's advocate), then the overheating episodes have flattened the seals and you NOW have the problem regardless.

IT will not get better, it will get worse. Apparently yours is getting worse quickly. I do not advise that you drive it any further, or you will DESTROY the entire engine block, and have nothing left to rebuild. Excess heat can warp irons, and even rotorhousings, and the excess heat can transfer into the oiling system (which does much of the cooling in a rotary engine) and cause high oil temps, which can break down the oil and cause bearing/iron/rotor damage. I've seen this all before. Most all rotary engine rebuilders base the cost of the rebuild upon your core in one way or another, i.e. evaluate your core and refund/charge the core charge based upon what's useable. Driving this thing home is a good way to cost yourself another grand or more. Not to mention that it might very well NOT get you home in it's current condition.

Bottom line, you need to tow this thing home. You can rent a pickup at enterprise for around $300, and rent a tow dolly (assuming this is a manual trans car, this is okay) from uhaul for $55 per day (more for one-way).

 

Oh, and you can try the procedure outlined on my site, but it usualy won't work with an advanced seal failure like yours, from what I hear anyway. I guess you have nothing but a few hours and a few dollars to lose at this point though, so go for it. Hell, dump all the stop leak you want into the thing, just be prepared to swap radiators and flush your heatercore later on...

www.rotaryresurrection.com ---> tech ---> coolant seal fix

 

He sent me a PM about 3 PM today - he was back in Minn.

he tried a 16 psi AST cap - that worked for 6 hours - then started blowing coolant again - they stopped every hour and added water. drove at night and in the rain

Lets hope his engine isn't completely toast.

 

If you want to be sure that you have a blown coolant seal, the best way is with an exhaust analyzer. Take it to a place and have them check for Hydrocarbons coming from the filler neck. If you have any HC's, CO's, CO2's, O2's, or NoX in the cooling system, than it is sure to be a bad coolant seal.

 

you just bought it and broke down 600 miles later??? RETURN IT!!!!!! GET YOUR MONEY BACK!!!

 

yeah, because that would go over real easy Congratulations for the dumbest post in this thread.

 

Wow, I'm simply amazed at some of the misinfo some of you guys were giving. I know it's always best to check EVERYTHING that could possibly go wrong, but when a pressurized test has been done on the system, some things should automatically be eliminated. I hate to see this guy run ragged because everyone's telling him to do everything under the sun to fix his problem. Rotary4tw stated it was an overflow issue, not a leak, but most of you still insist it's a hose, a cap, the AST. I'm sure the mechanic that checked his car knew what he was doing even thought most of you may feel dealerships have no clue when it comes to rotary engines... cooling systems basically work the same on all engines. If the test was done correctly there should have been no questions as to what the issue was. mgoddard1 was right on the money with the method of checking for air bubbles if there was any doubt about the prognosis.

 

I say he should drain and flush out his entire coolant system, replace the thermostat, and properly add back coolant to the motor;1 making sure that all the air is out, the AST is filled and overflow is filled to the correct amount of the overflow dipstick. After which run the motor for about 15mins with the hood up and the plastic cover, above the IC/radiator/condenser/fuse box by the hood latch, unbolted from the car to expose the 2 fans.

When I got my FD, my radiator fan motor was shot, only the A/C fan worked. I replaced the fan motor, and came to realize that all the over-boiling of my coolant overflow (and the age of the car) melted some of the wires by the relay and the fans worked whenever it rubbed a certain way, which caused all the overheating issues. During cool driving, the car was fine; during hot drives or at idle (cold or hot outside) the levels soared.
I've replaced my thermostat (drilled out), new rad fan motor, replace harness; now pretty much everything works fine except the fact my car is apart in my garage being worked on.

This is pretty much my advise and my experience with my 94, I'm no expert at FD (hell, I just got mine last month), but I've worked on plenty of cars in the past

 

I just wanted to thank everybody for their help over the last few days. Again, this was my first FD, so I was running on alot of excitment and not as much sleep. I'm finally home...

I'm convinced that the increased preasure in the coolant system, like many of you have said, is due to an internal problem with the engine, likely an O-ring failure. I called a local "Rx-7 Heaven" shop in town, and he also confirmed that was likely the issue, and it happens quite a bit.

We ended up driving the car home... for the first 6 hours, we had no coolant problems, and lost just a little bit when we stopped to check it out. We had thought that possibly the AST cap was busted, and it was allowing overflow to come out at too low of a preasure, causing the overflow. When we replaced it with a 16 psi cap, and didn't have any problems... we thought we were home free... big *** grins our whole way through Michigan.

And then, in the middle of the night, we started to notice more and more coolant going... we probably put 10 gallons of coolant in for the last 6 hours of the trip. Luckily for us, the temperature was very cool on Friday night (we drove with no sun out) it rained quite a bit, and when she had coolant, it the car was not overheating.

We finally made it back to Minnesota late sat morning, taking about 30 mins every hour and a half to let the car cool. Each time we would add more coolant.

At this point, the car is running very strong. I know that it can still have a warped motor, but there was nothing I could really do about it. I was not about to leave the car there, and the my father was so impressed with the car he said he would "make it work" if we needed to get a new engine.

That is likely what we are going to need to do. I'm going to consider some of the temp fixes that have been addressed in this thread, but am aware that I may need a new engine.

I plan on being a rotary man for many many years to come. I have two 2nd gens that are both on the market to help pay for the FD. Last night, 3 hours after I got back, somebody showed up with cash in hand to purchase one of them. I have a feeling things are going to really work out.

I just wanted to thank everybody for their comments and help. This forum is truely amazing. When you think about the wealth of knowledge and support that this community has... it's just simply incredible. To each and everyone of you, I want you to know your comments and help was greatly appreciated.

I'll likely be posting in a few days once I get things figured out here about what my options are for a new engine/rebuild. I just have to say, Rx7.com spent about 30 mins on the phone trying to cross diagnose the problem with me while we were at the dealers in Port Huron, and I thought that was almost as cool as all of the help I recevied from this forum!

Be safe and well everyone!

-Ben Tarnowski

 

If the coolant exploded out of the filler neck of the over flow...then yes, you pressurized your system. You will see the coolant all over the hood.

If this did not happen.... keep in mind that the over flow tank is split in the middle. Filling up the overflow above this line will cause it to leak out as the coolant expands into the tank. If you pull back the wheel liner you will see the split line and you can determin if this is where the leak is coming from. Mine leaked from here after a flush and fill as they fully added coolant to the system and then filled the overflow tank while it was cold. Car heated up and bam...lots of coolant on the ground.

Lets assume you presssurized the system and blew the coolant out.

A...you have a bad coolant seal which you can confim by a pressure test or by starting the car cold with cap off and looking for many little tiny bubbles to constantly fizz up out of the radiator fill cap. Mind you there is air in your system now so You need to make sure you have many bubbles constantly fizzing not random bubbles escaping due to air in the system. If it is a bad seal...if the car sits cool for a while (overnight)...you will most likely blow a lot of white smoke out the back (depending on how bad the coolant seal leak is.)

B... you sucked air into the system. A faulty hose or a pin hole leak will drain out the coolant until the coooling system sucks air. The air super heats casing the system to super heat which in turn caused the coolant to blow out the over flow tank.

How to proceed---- cool the car off. Open the cap and add coolant or distilled water. Run the car cap off until the thermostat opens and then add as much water as it will take as fast as it will take it. Cool the car off and then do it again. After 4 cycles of this you will have gotten as much air out of the system as you can. If the amount of coolant you need to add goes down each time...then you might not have a bad seal. Once you fill it fully, drive it for 20 minutes or so. FYI a new coolant seal leak will most likely be small, burning the coolant fairly slowly. most folks with bad coolant seals around me could still drive their car for approx 20 minutes at a time as long as tehy added more water each time. Stop the car...cool it off. Open the cap and see how much you lost. If you are lucky...you lost little and a pin hole leak is likely the culprit.

If the amount of coolant you need to add each time during the cool and fill is the same...then you know you are loosing it somewhere. If you have bubbles and white smoke..then a bad seal is most likely. If you see leaking, then you have a bad hose. If you still loose coolant but have no bubbles or smoke...you could have a pin hole leak in a hose.



i went through this exact thing last week stranded in wisconsin. I had a pin hole leak.
GL

 

Replace the radiator caps with 16 psi caps on both the goose neck and overflow. There is also a double nipple that connects the overflow coolant live under the intake filter box. Check the hose and put double clamps on the lines (each side).

Once you over heat an rotary it's bad news. I have seen them run for a while afterwords but they fail sooner rather than later.

 

it may not be easy, may need a lawyer but that's what I would pursue if it happened to me

I once sued a dealership when the used FC I bought from them caught on fire 37 days and about 1500 miles after buying it. I got my money back

 

My .02 cents worth.......remove the radiator (its pretty painless) and take it to a shop to have it pressure checked by itself.......my plastic piece of crap cracked once and would allow coolant to leak out without being obvious. This caused the same symtoms you are describing and caused the engine to overheat. I replaced the radiator and average 400 miles a week with no major problems since then.....
Just a thought before you assume you need a 3000 dollar engine replacement...
Allen

 

but that was new and from a dealer

 

He said it was used...

 

i know but it was still checked out (should have been anyway) from the dealer and to a lawyer thats more"new" then buying a used car from a private sale... I dunno if that makes sense or not but I think it would be easier to sue a dealer than a private sale.

 

Glad to hear that you made it home OK. At least you can take your time now, to find out the true problem, and get it fixed correctly.