Has anyone seen this before?

Started with an intermittent "add coolant" alarm. Coolant levels were normal. Temperature gauge normal until recently. Temperature went to "H" and dumped most of the water. Refilled the coolant system and found that I had to run the starter with gas pedal near the floor to start engine. White smoke out the tail pipes at first but then cleared after 5 minutes. Might have been water or excessive fuel in the cat. Now engine runs fine but Radiator overflow tank constantly bubbles. Are these two problems or the original getting worse?l

 

Did you replace the coolant recently? There could be bubbles in the cooling system.

 

no I haven't recently changed it. I have been adding coolant to keep the system running to get it home from work, 37 miles on the freeway. I don't have any reason to believe there were bubbles in the cooling system; it ran fine for the last two years.

bubbles are coming out of the radiator into the overflow. temp gauge is showing regular temperature. Curious if a jacket bursted in the engine and is pressurizing the cooling system too much.

 

bad coolant seals maybe. your radiator cap might just be scrap and keepin it open. is it a s4 or a s5 radiator? you need to get a new radiator cap im thinking.

 

what does s4/s5 stand for? how would I find this out. noob question hehe.
I was thinking it may be the cap/thermostat at first, but cap sounds right.

 

https://www.rx7club.com/showthread.p...light=radiator
still not sure of the differences though.
https://www.rx7club.com/showthread.p...ubbles+coolant

 

This radiator has the fill neck on the drivers side, extended back towards the firewall, just left of the battery. Checked the overflow tank after the engine cooled and found the tank contents had been drawn into the radiator, no signs of wetness on the ground. Topped of the overflow tank up to the full mark and will run the engine back up to temp to see if the bubbling continues. Taking the motorcycle to work but will pickup a new radiator cap for good measure.

 

is this an s4/s5 radiator?

 

I don't see a bleed valve for the radiator. So how do I bleed the air out of the "sealed" cooling system? Also cap has been replaced and it is having a hard time starting.

 

From what I've read, bubbling coolant at startup = bad coolant seal. White, sweet smelling smoke is burning coolant (once you smell it once, you'll never mistake that smell again). Also, it'd be hard to start b/c of coolant in there.

Check the " Do I have a blown coolant seal" Q in the FAQ section, it'll help.

 

speak of the devil, as you posted that I was reading the faq. I am actually about to show my dad, porchedave this info. It is his car, so I let him do the fun task of reaparing it.

 

My car did the exact same thing... what happened was that a piece of the water jacket had broken off and had dissapeared somehwhere into the coolant system..

The break happened on the lower side of the housing, because this is where cumbustion takes place, coolant wasn't really being sucking into the motor while it was running, but compressions was being blown into the coolant.

the motor still ran strong, until you shut it off and tried to start it in 10 minutes. then it wouldn't start. But if you let it set overnight it sould start up in the morning, run on one rotor for a minute or two then run great.

No white smoke ever, just a slight sweet smell in the exhaust, bubbles in the overflow tank and using coolant at a mild rate.

When i took the motor apart, it was apparent why.. when the metal broke away, the seal didn;t break, but it kinda bunched up and then slid into the water passage, creating kinda a sloppy one way valve that leaked!!!!! Pressure could get out, but water had a hard time getting in while the motor was running.

If this is your problem, its new housing time, it can't be fixed (well, not nad have the motor last more than a few hundred miles anyway)

 

Thanks for all the insight. I have hard starting and white smoke, which tells me water is getting into the combustion chamber. All indications suggest a blown water seal and with almost 150,000 miles, the engine is too worn to consider anything but a rebuild. Ordered up a Remanufactured 13B with new improved apex seals and will start pulling my engine for the exchange. Should be back on the road in two weeks.

 

Cooool... good to see someone that realizes when its time to pull the motor before it lets them sit along the highway!!!!!!

Hey.. as you pull it apart, get a bunch of hefty freezer bags, and put the nuts, bolts and whatever from each part you remove in a seperate bag and label it. it makes putting the thing back together WAAAAYY easier!!! (it took three motor swaps for me to start doing that rather than rifling through a big bucket of bolts to find one that fits!!!!!!)

 

Great idea, I have everything bagged and used electrical wire labels to mark the wires and vacuum lines for re-assembly. Should pick up the rebuild tomorrow and starting the process of getting back on the road. I took the pulled engine with flywheel to the local machinist and had him pull it for resurfacing. All took 30 minutes but was well worth it. The rebuild specialist will put the flywheel on the Reman engine during the exchange.