Started the IROC this morning in about 38*F weather, backed it up a couple minutes later to see a rust-colored puddle about six inches in diameter on the ground near where the driver's side of the engine would have been. Stuck my finger in it and gave it the sniffer test, smelled like exhaust condensate to me. I described the situation to my old man and he seems pretty sure it may be a blown head gasket, even though I didn't see a trace of coolant in the puddle, or so I thought. So, rust colored puddle, no greenish tint, smells like condensate to me, I think I have a leak at the exhaust manifold. My old man is sticking to the head gasket theory. What do you guys think based on this description? Also, the car has idled roughly for quite some time although it runs well in higher (2800+) RPM ranges. Could an exhaust leak at the manifold cause this as well? Thanks guys.

 

one vote for exhaust leak.

 

There are several places that could cause coolant leaks. Hoses, gaskets, block, head(s, radiator, heater core, etc.

Usually a blown head gasket will show up with a radiator pressure testor available at any of the larger auto parts stores.

Screw it on in place of the radiator cap, pressurize the system with the little hand pump and if it doesn't hold pressure, look first for leaks on the floor/ground.

Next pull the oil dipstick and if you see a milky white substance on the stick, you've found your leak and it's either the intake manifold gasket, head gasket or a cracked head or block.

Sometimes, too, a leaking head gasket will show up as bubbles in the radiator with the engine running.

Drain the oil and check it as it comes out; if it's coolant's getting in the oil, you'll see it.

Pull the plugs and examine them. If coolant is leaking into a cylinder, the plug will be exceptionally clean (steam cleaned).

The inside of the valve covers will show signs of coolant getting into the oil too. If it's really bad, it'll look like thick shaving cream.

If you do have coolant in the oil, do not run the engine because coolant will kill the bearings.

Hope this helps.

Jake

------------------
1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

[This message has been edited by JakeJr (edited February 23, 2001).]

 

Don't have any of those symptoms so it must be an exhaust leak or it's only leaking to the outside if it's a head gasket. Is an exhaust leak that close to the engine on the O2 sensor side going to cause any problems? Thanks for the help guys.

 

Sounds like an ex. leak.

Alot of times water will escape but it won't be a noise.

I would look underneath the car and see where its coming from, chances are, its not that bad.

Sometimes in the shop on a cold day, I will get 2 or 3 puddles under a car while doing a smog. They all are rust colored, and the car has no ex. noise at all. Water just creeps through the seams in the pipe joints.

------------------
ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

R.I.P. #3
My favorite quote about D.E. "He can see air"

 

Try the simple things first: tighten all the manifold bolts and the bolts where the Y-pipe hooks up to the manifolds.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

and check the intake at the back of the heads for leaks

 

Thanks for the help, fellas. I popped the hood just after I started it again today and it didn't leak anything, but maybe that's because it was 70*F instead of 38*F. I'll have to get it on ramps tomorrow early in the morning and try it again so I can get a closer look. Does anyone think an exhaust leak close to the engine will cause any driveability problems? Doesn't seem like it would, but I've heard of stranger things happening.

 

One thing if it has a blown head gasket you will notice is consistantly less coolant after every drive. You can also check for a blown head gasket by seeing if you have any wet plugs and also do a compression test, if the compression is way down by 2 cylinders, you know there's a blown gasket inbetween the bores.

------------------
1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!