Hey. I have a 95 Z28, all factory aside from cold air intake and cat back exhaust. The vehicle has about 120k miles on it, I got it at about 104k miles a year ago and have put around 16k miles on the car without any issues aside from basic maintenance.

Recently I decided to flush the cooling system. After doing so the vehicle ran with no issues for a week and I got my heater back! Yet after about a week of regular driving the car felt like it was lightly missing. I assumed plugs and wires, pulled a few wires all looked good, few plugs, all in good shape as if replaced recently.

I noticed when looking around that I was low on radiator fluid, which I topped off. Within a few trips (short, about 15 miles) I realized I was losing coolant quickly. I did a pressure test and couldn't find any leaks at all. Then after a short around the block drive the car started to shake and hesitate, almost like one does when hot or running on a wet distributor or wires and then steam started spilling out the tail pipes.

I figured it was a head gasket issue so I checked a few of the basic symptoms. I'm not a mechanic by any means, but I work at a small car lot so this basic stuff and maintenance is common place.

I found: No water in the oil. No oil in the coolant. With the radiator cap off there was no crazy bubbling or cough puking of coolant out of the radiator. The car doesn't get hot, nor has it ever gotten hot in my possession. It is starting to miss worse, at the rate water is going to the exhaust I am assuming that is clogging a bit and water is no doubt reaching the wires as well. Of course, if you rev it good it shoots a bit of water out of the pipes and then quits missing entirely for a while.

I have talked to a few mechanics and people who have just been around sports cars forever and they are claiming it to be an intake gasket going. I do know it has been leaking oil out of the front for a while and I'll assume the back too. I was planning on fixing it just to make the oil leak stop (never been bad enough to have to top off between oil changes) so if that is in fact the problem, it's go time.

A few other mechanics (and a minority of the people I have asked) claim it to be a headgasket, but don't deny that it may just be an intake.

What do you guys think? If it is an intake gasket, I may want to upgrade to perhaps an LT4 or performance intake. Any ideas on what is good?

Hopefully it's just that. A grown man (me) may start crying if its a headgasket and I never got the car hot. Thanks guys.

 

try a leakdown compression test. It shouldnt be your intake, since there are no water jackets that go through the intake

 

There's a couple test kits available for us driveway mechanics to use. One is a combustion gas detector. It consists of a bottle of fluid, an empty bottle, and a hose with a squeeze bulb. You pour a measured amount of the fluid into the empty bottle, one end of the hose goes into the bottle that now contains the fluid, and the other end of the hose has a "stopper" that is placed in the radiator neck. Start the car and begin squeezing the bulb. If any combustion gases are in the coolant, the fluid will change color.

The other is the coolant leak detector. The one that comes with a fluid you put in the radiator, and use a UV light to check for leaks.

Check NAPA and see if they have these kits.

 

Sounds like the weep hole on the water pump....

 

I would check that as well. Check for any leaking around the water pump. Chances are your misfire is from moisture on the opti cap. It's not the intake gaskets (no water passages, as already said).

Try replacing your radiator cap first. A leaking one will cause the coolant level to fall with no apparent leak, plus it's cheap.

Water out of your tailpipes on start-up is just condensation, and it's normal.

 

It sounds like these "mechanics and people" have never seen an LT1. The LT1 has a dry intake, no coolant. Check your water pump's weep hole. Also, wouldn't hurt to change the intake gaskets to stop the oil leaks.

 

A fine tuned motor creates condensation which will make a water from your pipes, but not much.

You said you had a "steam" comming from your pipes. That means water is getting into the cyl. and burning off. It may be a small leak, thus the reason its not in the oil yet.

ORRRRRR, your cyl. head cracked. your plug may show wear, but you really need to pull the heads. You may find 1 of the 8 cyl heads will be a different color (changed by the burning coolant)

4.0L Ford iron heads are notorious for this, my explorer had the same symtoms, and it was a thin crack between the valves, let just enough coolant through to drive daily, but had a monster cloud of white smoke when at idle.

Lemmie know if that helps a little...

 

Long shot - but any chance you damaged the gasket that seals the bottom plate to the body of the throttle body? That plate has channels for both coolant and idle air, and a leak there can allow water into the combustion process. Would explain loss of coolant, misfires and excessive water vapor out the exhaust. If its leaking bad enough, might even drip coolant on the Opti. In very cold weather, it isn't unusual to see water vapor coming out of the exhaust pipes, since one of the major components in exhaust gas is water.