Radiator cap blew today - Toyota Nation Forum : Toyota Car and Truck Forums

inzel · 07-07-2011, 02:42 PM

So Im driving to work today and notice a bit of steam coming from the passenger side of my engine compartment and then realize that my temp gauge is basically maxed out. As soon as I notice this, the light turns green so I press the gas. The gauge immediately goes back to normal. I had to go about another 200 feet to get to my work so I pulled in and popped the hood. The cap to the overflow tank was not on all the way and it was letting fluid leak out. I then let the car cool and then removed the radiator cap... it is obviously no good at all. I checked the oil and it looks fine and clean. The fluid inside the overflow tank is dirty, but doesnt seem oily at all. Im feeling ok about this, but wanted to let others know my experience. I just got a new thermostat, some coolant, and a new radiator cap. Going to put the radiator cap and fluid in first, then drive home. If all is well, then I will replace the thermo this weekend and put some more fluid in. I wanted to get your guys' opinions to see if there is anything else I should look for...

Thanks in advance

carsrus · 07-07-2011, 03:31 PM

Check the fans. What your describing sounds a lot like a non functioning fan.

inzel · 07-07-2011, 04:12 PM

Ok, so I didnt have a wrench to replace the thermo yet, so I replaced the cap and topped off the fluid. It seems like there is a little oil or something milky in the fluid itself... Is that a really bad sign??

Also, I left it running with the cap off for about 10 minutes or so and the fans never came on but the fluid did start to bubble out of the radiator where the cap was off. The car did not overheat or anything like that this time but the temp was a little higher than normal but not by much at all. The hose to the thermo did not get hot or feel pressurized, while the one from the engine to the radiator did get hot but did not seem to have too much pressure or anything.

btw it is almost 90 degrees here right now so it seems like the fans should have come on...

inzel · 07-07-2011, 05:21 PM

I went and checked my engine oil again and I dont see any water in there. It looks good imo. I am now wondering is a 98 5sfe has a transmission line that goes thru the radiator? Any thoughts on this? Im pretty scared to drive it this way. Maybe I should just flush out the system with a hose this weekend sometime and then see if more fluid gets in there somehow?

carsrus · 07-07-2011, 05:29 PM

Trans fluid very, very, very rarely will leak into the rad. Almost 0% chance.

Turn on the A/C fans should kick on. If they dont theres your problem.

No pressure will build inside the cooling system with the rad cap off. Lower pressure = lower boiling point as well.

inzel · 07-07-2011, 06:13 PM

Ok will do. If the fans dont come on, is there a way to manually start them until I can get a new set? Or are they basically dead at that point?

inzel · 07-07-2011, 07:04 PM

So it looks like the fans are no good. I cant seem to get them to come on at all. I tried it with the ac as well as letting it get hot enough, and neither worked. It was a long drive home having to stop every half mile to let it cool enough to where I felt safe to drive it further...

Do I buy the fans and the radiator at the same time? Or do they sell one separate?

inzel · 07-07-2011, 07:52 PM

OK, so I take back my last post.. the fans do work. I disconnected the sensor deal from the bottom of the radiator and they started blasting full speed. And the "oil" in the radiator turned out to be some kind of sludge... Looks like Im back in business for the time being. I will be getting a relay sensor thing and putting that in.. will post the results.

Thanks for your help guys