alistair

OK here is one for you. I took my Trans Am 350 TPI out yesterday, a hot day, did 1 hour 30 minutes at about 80 MPH, sat in the fire up lanes at the track, pulled a series of 14.6 @ 94 runs (thanks for asking) and then drove home, another 1:30 at 75-80 MPH.

I stopped off to pick my daughter up from my mother in laws and when I turned off the motor the coolant was making a rushing, gurgling, frothing noise.

I let the car stand 2 hours or so then drove home (about 8 miles) at about 40-50 MPH mostly.

Once again when I shut the motor off its gurgling and sounds to be bubbling but there is no bubbling in the header tank.

The coolant in the header tank is usually pretty clean but it is now real brown.

Some of the coolant appears to be forced past the filler cap on the header tank as there is brown staining there.

It runs quite hot on the gauge but not right to the top (190-200?)

MAC_87

iTrader: (3)

This happened to my car as well, turned out to be a bad radiator cap. - it wasn't holding pressure. Went to Autozone and shortly after resolved my issue.

the solitaire

I agree, pick up a new radiator cap, take the oppertunity to flush the radiator and the issue should be solved.

alistair

thanks, I'll let you know how I get on

sleeper84

iTrader: (1)

That is generally a sign that combustion gasses are getting into the cooling system. Usually a head gasket seeping some. GM starting having that problem in the late 70's with the introduction of the "light cast" cylinder heads and worsened with the introduction of aluminum cylinder heads on motors.

alistair

OK, the coolant appears clean in the header now...

I will see if I can test the head gaskets with a leakdown test or something.

the car smokes bad when started - it burns oil - so I think the valve stem seals are shot. I had been hoping to get the coin to replace the heads with some performance ones so if the head gasket is leaking this will cure that also!

Thanks for the tip.

Lucid

iTrader: (4)

What color is the "smoke" at startup?

My camaro does a puff of bluish smoke at startup and it smells like burnt oil. Stupid valve seals. If the smoke is white and it does a hard start, it might be burning coolant slipping past the head gasket.

alistair

bluey-white-grey smoke... Smells oily

I got this car off a long line of people who have beat it hard and I'm catching up on all their missed maintenance I think.

It only does it once its been sat for a few hours, so mornings and so forth.

It does often turn a few times before firing but I think thats because the plugs are fouled up a little, I need to change them. Have some, just the time has flown by...

RyanEricW

Mine was doing the exact same thing, down to the coolant reservoir having discolored brown fluid.
Turned out to be a failed water pump and radiator. The water pump had a small drip on the bottom through that hole which was landing on my harmonic balancer, so I never seen a leak from the ground. New radiator from pepboys 136~, and a cap @ $7. Think the water pump was like $40 for the "HD" one.

alistair

I've not long ago replaced the water pump. I would hope I don't have another one failing. I will check the radiator out, make sure coolant is passing through it OK. The coolant level stays OK (allowing for the small amount which seems to be pushed out of the cap on the header tank)

RyanEricW

Well the water pumps are easy to install, and tbh if you have your receipt for a new one, they almost always have limited lifetime warranties. There's not really a good way to check out your radiator unless you have a temp gun to check the difference of degrees on the incoming/outgoing sides.

My radiator looked great inside, but it was causing my car to overheat slowly (45min drive in city), and ultimately caused my water pump to fail.

mantaguy

iTrader: (5)

Try letting the car run while the fans are running,when the fans stop,shut the car off and see if it still happens.

camarotucker

iTrader: (2)

Its gurgling or boiling? I have a 2001 Blazer that "gurgled" for a while. When the summer temps hit triple digits it went from a gurgle to a boil. My temp gauge never went 10* over "normal" which wasnt bad for a manual fan + triple digit outside temp. I did the basic cooling matainance, thermostat, radiator cap, coolant flush. Now no more gurgle.

crabbeater

i have just installed a newly put together. 350tpi, coolant seems to be mixing with my oil. i have changed the intake gaskets. and still coolant is getting in someplace. I have the gurgling noise and brown stains in the overflow tank. motor is hard to start. I also have coolant leaking behind the motor passenger side. could this be a leaking head or head bolts? motor sounds good doesnt over heat. it idles fine then after 5 mins. it idles upto 3k rpm. any ideas? thanks

ramicio

iTrader: (-1)

So it's not normal to boil after running? Every car I've had has done this. There is still heat moving into the coolant after being shut down, but zero coolant flow. If it boils when running, then there's a problem.

Lucid

iTrader: (4)

Don't think that's normal to boil over into the overflow after running. Mine don't do this unless there is a leak, the system is low on coolant or the thermostat isn't working. My 87 boils over every once in a blue moon but I know there is a tiny leak in the lower intake gasket near the thermostat. So I make sure to top it off.

These systems are pressurized and also you are using a coolant solution. When you increase the pressure, you also increase the boiling point of the solution. The coolant (with anti-freeze) increases the boiling point as well.

Are you running dual fans? Are you running straight water? What kind of radiator are you using?

I wired both fans to come on on my 87 (green wire from ECM) and run 50/50 solution and also decreased the temperature at which the ECM energizes the fans to come on. I also run an aluminum radiator because I never had much luck with those brass radiators.

ramicio

iTrader: (-1)

Fans and radiator don't matter for boiling after shutdown. There is no more flow, and the engine is still a source of heat. It's normal to boil after shutdown. I realize the system is pressurized and that coolant also increases the boiling point. Whatever boils into the reservoir is just going to get sucked back in when it cools and contracts.

desilva

Hey, I've the same issue with my Formula 350. My coolant in the overflow jug and radiator cap is brown and kinda smells like coffee. Couple months ago I had flushed my system and replaced my radiator. I took apart my old radiator and found that my radiator had been clogged in the bottom half, restricting coolant flow. It ran nice and clear for awhile and now it is brown again though it is not as bad as before, I hope it isn't a head leak or something because there isn't water or white smoke coming from the tail pipe, and my oil is clean, not idling rough either, and there are no oil or coolant leaks from the engine. I was told that it could also be coolant additive that had broken down and had been circulating through? Idk but I've had this car for 3 years, it's my first car and I am the second owner. I hope I'll have her for the rest of my life.

84 1LE

iTrader: (9)

Boiling water evaporates & turns to steam, which will vent thru the cap once in the expansion tank.It won't be sucked back in.Boiling before/during or after can't be good.The whole point of pressurizing the system is raise the boilng point.

ramicio

iTrader: (-1)

Unless it gets cooled by the coolant sitting in the expansion reservoir and turns back into liquid... Raising the boiling point prevents it from boiling while running. Boiling after the car is shut off is really of no concern.