I just got home from a long, slow commute in my '90 SE; takes about an hour, mostly inching along.

When I pulled into my driveway and turned the engine off, I noticed a strange sound. I opened the hood and saw that the coolant overflow tank was boiling.

The dash engine temp hadn't shown overheating or anywhere close.


Any suggestions? I read here in another thread that boiling coolant in the overflow tank with the engine NOT overheating meant a bad head gasket. Really? Ouch. Is that correct?

 

unfortunately it could be the headgasket, i dont think VG30E are that prone to headgaskets though but its happened to a couple people here

 

Update:

I've been monitoring it, and for several days it didn't happen again, even on a warmer day with much slower traffic; I was crawling along for just under 2 hours. When I got home, I immediately looked under the hood with the engine still running. No hint of boiling.

But today, only about half an hour into the commute, I heard the boiling. Then a couple minutes later I saw steam coming out of the hood. The dash temp gauge still showed normal; just below halfway.

So I pulled into the next side street and looked. The overflow tank was boiling like crazy, with coolant and steam spewing out of the hole in the top. I saw that the radiator fans were NOT running.

I got back inside and turned on the air conditioner. The fans immediately started up. I turned the air conditioner off; the fans turned off. I turned it back on and waited. Within a minute or so of the fans running, there was no more steam. I drove the rest of the way home with no incident.

I'm pretty sure I hadn't had the air conditioning on the other days. It seems to me that if the air conditioning is not on, then sometimes the fan goes on when the coolant gets that hot; sometimes not.

Any suggestions on what I should do to fix that?

 

The fans are supposed to have 2 speeds:
low speed (slightly hot coolant)
high speed (very hot coolant OR a/c engaged).

Fan relay #1 controls low speed, and fan relay #2 and #3 control high speed. Perhaps your low speed fan circuit is not working at all, but the high-speed fan circuit is engaging when the A/C is on?

 

When steam came out of my car, it was because one of my hoses ruptured. I don't recall have boiling issues. But check your hoses.

 

I'd say change both engine coolant temperature sensor and gauge coolant temperature sensors. I had this issue where my car would start to overheat when I was on stop and go traffic any my fans would run at low speed when I would turn on the AC.

 

I am having the same issue with my '90 SE. Did he ever resolve his issue? I am starting to really drive, and use my Maxima after having it for several years. It set for a while, so I had several issues pop up because of that.

Mine will boil over from just sitting while running, it doesn't do it all the time, and the fans come on when I turn on my AC, then immediately shut off when I turn it off.

I think it is funny, that my neice thinks i really have a nice car, compared to her mothers newish corolla.

Not to sound dumb, but what is the ecm?

 

Oops. I can't believe I mentioned to change the ECM (engine control module). I meant to say the engine coolant temperature sensor (ECTS).

If the temperature sensor is bad, it may not report the correct temperature to tell the ECM to turn on the fans. So that would be the first item to look at. Also, look at the connector for corrosion as that may affect temperature reading as well.

 

Thanks for clearing that up. I googled it, and was thinking that is the computer I might not be up to this challenge. lol I tried to look under the hood yesterday to see if I could find the Coolant temp sensor (I think that what it is called, the one that is next to throttle cables). I couldn't find it on mine, but I thought there was a chance it was under the distributor cap, but I didn't want to take it off, in case I wasn't looking in the right place. It has been a while since I have had a car for a project, so I am just getting back into the swing of things, and may need more advice than I should.

On a slightly different note, does everyone experience that these cars have a weak "passing" gear going uphill, or does my linkage need to be adjusted?

Thanks Jbbon

 

I haven't been able to get to it yet. I've been driving around with the AC on all the time. The problem has never happened with the AC on.

 

Follow the top radiator hose to the engine. Around the end of the hose, you will see two sensors attached. The one facing the firewall is the temperature sensor.

 

Did you try to fix it, or just didn't bother? Thanks for letting me know.

I called my local autozone, and they have the same one listed for each name. Are they both the same part? If not, where is the other located? Thanks, and sorry for all the questions.

 

Both are temperature sensors, but the one with the two wires/prongs is the most important one. The other one is for the gauge reading on the cluster.

 

So they are both attached to that hose? the one Facing the firewall is the ects, the one pointed towards the radiator is the temp gauge switch? Reason I am curious is I am probably going to get both, and I need to know what to ask for (because it really confused the autozone people), and where to put them.

Also thanks for putting up with my questions jbbons

 

did you do a combustion gas test? just wondering because ironically shortly after i posted last in this thread, i had the same problem on my Crown. after going on the highway, the overflow tank would be full and flooding onto the frame, yet i could crawl in rushhour traffic with no flooding. did a combustion test on the coolant, and it would pass if the car was revving under 3500rpm. after 4000rpm it failed the test, hence why the reservoir flooded on the highway. turned out the headgasket was just starting to go bad and only caused issues at high rpm

you can try a new rad cap as well, its not overly common but the valve in the cap can go bad and cause coolant to flood into the reservoir

 

It has no issues at higher revs. it is at idle when it is boiling over, and over heating(maybe). Yesterday, when I first crank the car, i had the radiator off, and I could not tell if it water was moving or not. It has a new radiator on it. Also looked at a thread about the CTS, and that gave me some other symptoms my car is having, like a weak passing gear. Still trying to figure all this out. Thanks Chrome91

Update 8-14: Replaced gauge temp switch, cts, and radiator cap. Advance auto parts has the correct size radiator cap. az/o'reillys had the part but it would be near useless. I'll let everyone know if it fixes it or doesn't. It seems to run smoother, but still a extremely weak passing gear.