Hello all, You guys are pretty knowlagable I have found in the past with problems, so here is mine, I hope you can help.

So she starts steaming and hissing around the water outlet fitting and below, like down around the thermostat case. I thought it was the o-ring at the water outlet to pipe (all terms from the service manual). Replaced it, and the thermostat, new silicone gasket at all locations necessary.
New rad cap.
Fan clutch acts normal.
Radiator flushed last week, looked good.
Put in "Barrs Leak" for s**ts and giggles.
Heater blows hot.
Ran fine for me last night, I drove it all over, no problem, then this morning wife drove it to work 2.5 miles and doesn't necessarily overheat, but steams/ pushes out fluid. Then on way home home, steam around same area (front middle behind crank covers) lots of fluid coming out botton toward rear of motor, but no overheat at temp gauge.

Any thoughts?

Some ideas in order of likelihood:

1) bad radiator cap
2) bad fan clutch
3) bad water pump
4) plugged water passages in the lower intake manifold
5) plugged water passages in the heads
6) hardened sediment in the cylinder block water jackets

Since you didn't say you replaced it, my money's on #1. That's the only one I can think of that would allow coolant to boil over without showing an overheat on the gauge - but then, the gauge or gauge sender could be lying.

Frank

Out rad cap? If you replaced gaskets why did you use Barrs Leaks?

Flushed the radiator, but didn't get it rodded out? My money's there, but I'm nowhere near as qualified as the above two guys.

John B.

I edited first post after driving her tonight. So weird. Lots of steam and hissing, but can't see where.

The oring on the back of the water pump? BLown head gasket?

Go rent the radiator pressure tester from autozone so you can check it without parboiling yourself...

I see you added that you did replace the radiator cap. Assuming it's good, I'd agree that the radiator is suspect. Sometimes only cleaning one leads to a blockage from loosened deposits gathering in passages.

I also don't think it was wise to put in the Barr's junk.

I'd get a used radiator from a yard and try that - or take the radiator to someone for a good rodding out.

Frank

O-ring on the back of the water pump if leak is here. Not sure which engine you have but assuming v6? How was the old coolant looking prior to the flush? If rusty I would chage out the water pump. I've seen the impeller fins rust off to the point that the pump will fail to push water.

Don't worry too much about the radiator at this point, you've got to fix your leak first. If it's coming from behind the water pump then it's probably time to replace the water pump itself, along with any associated gaskets and seals - unless the water pump has been replaced recently it just makes sense to put a new one when you remove it. Using a stop-leak product is a bad idea, and will do more harm than good in the long run by contributing to clogging up coolant passages inside the engine and radiator - flush out your cooling system to get as much of it out as possible. Taking your radiator to a radiator shop and having it rodded out is highly recommended maintenance, especially since you've introduced a stop-leak product into the cooling system. Spending the $75-$100 to have that done is pretty cheap compared to the cost of replacing a blown head gasket due to overheating.

If you edit your signature to include your vehicle info, you'll get much more accurate replies to your questions. <img src="/forums/images/graemlins/smile.gif" alt="" />

I've recently had a similar problem with my 90 Montero. I was losing fluid through the water pump (I believe through the weep hole, but I was unable to verify). My symptoms were similar to yours, overheating quickly, steaming like crazy, and I could see radiator fluid leaking over the transmission bell housing from the front of the engine between the heads. I replaced my water pump, and have stopped that specific problem.