sempermarine29

I have just encountered a problem with my 1995 LT1. Coolent sprayed out of the catch tank towards the front of the car. My car never overheated, no codes were thrown.

A little history on the car...about 2 and a half months ago my heater control valve broke, spewing all of my coolent out. The car overheated before I could get it off the road, but not long enough to do any damage. I replaced the little plastic control valve, the thermostat (since it got so hot), the radiator cap on the surge tank by the firewall and replaced the coolent.

The car has been fine since then. Today the coolent spewed everywhere, but never came close to overheating, it was running at normall operating temp. What would have caused this??? There are no leaks in the hoses, and all caps are on correctly. PLEASE HELP!!

Slalom4me

My take on the best case scenario is that an air bubble
worked its way to the rad cap and was expelled into the
catch tank.

If the catch tank was near full, the air bubble could have
caused coolant to be expelled from the tank vent.

The worst case scenario is that by not shutting down
the engine immediately during the previous problem,
the head/gasket/block interface was compromised and
now combustion gases are leaking into the coolant.

What driving circumstances preceeded the overflow?

.

sempermarine29

I was driving in city traffic, no faster then 45 mph, a few spots that are 50 mph. Stop and go traffic. Nothing out of the ordinary. I am in Denver, so the temp outside today was about 70 degs.

Slalom4me

Well, since you don't mention hard acceleration as a precursor
and it sounds like a one-shot occurance, I'll pick door #1 and go
with the errant air bubble theory.

Going forward, you have options about what you do next:

• Make sure the coolant is topped up and then just drive it
  while watching for further symptoms like reoccurances or falling
  coolant levels
• See a pro or get a DIY kit to inspect for combustion gas in
  the coolant.
• Perform more proactive diagnostics like reading the plugs,
  performing a leakdown & so on.

Search for other threads, there are many. Some just within
the past day or so.

Keep in mind that coolant in the bottom end is bad. If at anytime
you find the engine oil is beginning to resemble a chocolate milkshake,
PARK THE CAR IMMEDIATELY.

.

sempermarine29

There were a few times that I did jump on the accelarator to move ahead of traffic. It was for a brief period, as I don't go above the speed limit, and traffic doesn't really allow for it anyway. The car is an auto also.

sempermarine29

I found out by running the car a little more, looking for a leak that the Radiator itself was actually leaking. Before, the leak was not very big, but I was driving long enough to make it look like a big deal. Tonight I found out the truth, the radiator had cracked and it is no longer just a small leak. Problem solved I guess.

Slalom4me

Sure, as long as the cracked radiator isn't a symptom of
something else. This isn't the place, but I have stories
to tell about the E39 Series BMW 540.

This is the second failure of a plastic component in the
cooling system. Might I suggest a careful examination
of all radiator, heater and oil cooler hoses with replacement
where trouble is suspected, along with watchful waiting
following installation of the radiator. A check for combustion
gas in the coolant wouldn't hurt or cost much either.

.

sempermarine29

That is still a very good idea. I will have the coolent coolant checked for the gas. Another thing that is very recent, my car doesn't ever "use" any oil. It usually stays very clean for all three thousand miles before I change it. I checked the dipstick yesterday and the oil was black, and it smells like gas. Any ideas on that one?

Slalom4me

What do the inside of the muffler tips look like? How has
the car been running lately. Any change to fuel consumption?
How quickly does it warm up, what does the operating temp
stabilize at.

Any mods? Injectors, AFPR.

I'd change the oil and filter.

.

sempermarine29

The car has been running well lately. The inside of the tips are black. Fuel consumption has dropped off since hurricane Katrina, (I think I have been getting some bad fuel for Premium price, and up here in Denver the highest pump octane is 91). The car warms up to operating temp within 5 minutes. The operating temp usually is at 200 - 220 deg.

No major mods, air foil (waste of money) K&N filter, and someone before me had installed their own exhaust system. One thing is for sure, I think the inside of my Catalytic converter is breaking apart.

Slalom4me

One thing gas in the oil suggests is an A/F ratio rich enough
that fuel is washing past the rings. You'd notice this in poor
driveability, but you say this isn't at issue. Still, sooty tail
pipes indicate a reasonably long standing rich condition. (Tan
or grey deposits are nice, white indicates it is tending toward
lean.)

Quick warm up and the operating temps you have rule out a
bad or incorrect thermostat.

Maybe a plug or wire problem. Might want to narrow it down
by inspecting the plugs for fouling.

Gas fraud or a bad cat will not contribute to fuel in the oil.