JDVETT92

Hello everyone, I'm new to the community. Not just Corvette forum, but Corvettes all together. I've got a 1992 LT1.A couple months ago, after making a cross country trip, is when I had my first problem. I took my car to the hand car wash, cleaned it, then on my way back, my lower radiator hose that leads to the thermostat came off. It wasn't until I got home (2 mile trip) that I started to see smoke coming from right side of the engine (coolant reservoir side). I replaced the hose, the coolant, and burped the system. For awhile that seemed to do the trick, and no problems for a week or so. Then sometimes I'd hear the coolant boiling in the overflow tank up by the passenger side of the firewall. Then I started to get the low coolant light. I would try to add coolant and burp system, and inspect for leaks. I couldn't find any. After several times of doing that I took it into an auto shop and had them look at it, at first they didn't really see anything. I took it home, and did my research and found that the low coolant level sensor wasn't even plugged in. And I'm not just talking about kinda hanging outside the sensor. Someone deliberately moved the wiring harness down between the wheel well and oil dipstick. The harness itself was full of crud. But what struck me as odd is that I've had this car since January (5 months), and this is the first time the light has come on. I took it to the same auto shop again and they tested the harness and told me the wiring is bad, but the wiring hasn't even been an issue since I bought it (this was free of charge by the way because of my last visit). Well I found their conclusion odd, so I took it to a Corvette mechanic. They cleaned out the lines that come from the radiator and the lower overflow tank, and they also attached a new wiring harness. I noticed carbon buildup in the hose that T's off of the hose from the radiator and goes behind the block (what is that hose for?). Also, they cleaned off the front of the radiator (inside the housing). After everything was replaced and refilled, the light still came on. The mechanic then noticed that when he bumps the fuse panel that is between the door and dash, the light would dim but not necessarily flicker. I'd also like to make a few side notes. They are factors which may or may not play a role.

When I take off the radiator cap, and let the car warm up, there will be some bubbles that come up intermittently and the fluid level will rise to nearly boiling over. I'll give it some throttle but the fluid level just goes right back up.

Sometimes the exhaust will be a faint white smoke. There's a lot of white smoke on startup (I assume just early morning condensation), but after it has warmed up that faint white smoke will show up. Some days it is hardly noticeable, other days it gives me those head gasket worries. But it never billows like you see in cars with a serious blown head gasket. And the oil isn't milky. Yet, perhaps I'm showing enough symptoms?

Now the Low Coolant Light is the weirdest part of this, and it is the source of most of my worries. Some days I'll get in and it'll be there on startup, others, it won't show up until I get on the road. If I punch the accelerator, it might go away for a minute, but it'll come right back. Or I'll be on the road and it'll go off for a bit, but once I start putting on the brakes it'll come back on. Bumps in the road also cause it to flicker on and off. Inclines haven't really affected it. It's the only light that'll stay on. Perhaps its electrically related, but does any of the sensor's wiring run through that fuse box I mentioned? I do get water leaks between the window and A frame weatherstripping, but the other fuses works fine.

Also of more thing, perhaps normal. But remember that T in the radiator hose I sponge of? The one that heads back to the reservoir? Well a can hear what sounds like boiling, almost like a crackling boiling (if that makes sense). Was it cleaned incorrectly or clogged up again?

I apologize if all this is kind of overwhelming, but I've tried to resolve this problem with nothing resolving it. I'm kind of strapped for cash at the moment so I try to do as much DIY as I can. If Adobe could hello that would be great. And if you live in SoCal, perhaps I could get a few good pointers on someone who really knows their way around cars like this. I love this car and there's other stuff I want to do to bring it back to its golden years, but if I have a ticking time bomb I want to fix it right.

OVRPWRD

My low coolant light came on intermittently too. I found a my t-stat housing hose had a small drip. Snugged the clamp, still came on. Found another small drip at bottom to the throttle body. I by-passed the throttle body, but light still came on randomly.
I ended up starting the car with the radiator cap OFF, watched the level and waited for the t-stat to open and circulate coolant, then held the throttle at about 1500-1800rpm's ,filled radiator to the top and placed the cap on tight. Topping it off this way seemed to work, been 4 months, NO LIGHT!!

JDVETT92

OVRPWRD,
I haven't seen any leaks, and when I talk about refilling in my post I did the exact method you talked about. I haven't seen any leaks around the throttle body. Our could it be so small I don't notice? Come to think of it could I have a block somewhere? The reason I say that is when I lift up on the throttle cable, add fluid, then let go, the level comes up even higher. Any possible leaks anywhere, that perhaps aren't so common or visible? I also noticed while driving at highway speeds on a cool day, it'll go anywhere 200-213 (digital readout). Yesterday I was punching it on the highway (about 70°), and I got it going down to 190. I was glad to see it, but thought it was odd. Maybe a clogged radiator?

A Peter C4

Has the rad. been removed to clean the fins to allow proper air flow? That was the problem with my 94 coupe, when I removed it you could not see thru it after a good flush with the hose from engine side out to the front I got about a shovelful of crap out of it and now runs at 186-192 unless I'm going 15 mph or slower or stuck not moving in traffic or along time at a light. Also pulled the knocks out and did a good coolant flush now runs nice and cool with a new 180 degree stat.

JrRifleCoach

Chased this gremlin for a summer until I pulled the sensor wire and connected it to a ground.
After confirming the system was properly burped and packed the connector was returned to the sensor.
Would have no further problems for years.

Leaps

White smoke= coolant leak in head

cadmaniac

White smoke?.....If money is tight, and you're getting desperate, try some Blue Devil. Guy at work used it on his Nissan with the same issue, and it went for years with no head gasket replacement, driving it daily. I usually avoid these products like the plague, but this product is supposed to be pretty good. Might get you by for a while till you can tear it down for the new head gasket.


First thing I would do is get a camera, and see which cylinders pistons look "too clean". That will help you know which cylinder has the coolant gasket leak.

Also, Do not let it overheat!!! Worst thing you can do to an engine....maybe not the worst, but definitely not good. If you let this go too long, you could hydrolock the engine, and break a piston....That would be worse..

Good luck.