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It seems as though some (most? all?) of my coolant has disappeared on me. I hit something on the highway that did some damage to a tire, but other than that everything has been going great.

Today the engine tried to overheat on my 7 minute drive home in 29* weather and was blasting cold air out the vents when the heat/defrost was supposed to be on. Between the overflow tank and directly into the radiator I've poured in just shy of a gallon of the 50/50 premix stuff. That seemed to fix the problem.....for a few minutes. Now i'm waiting for the engine to cool down so I can pop the radiator cap again and see if more coolant is needed.

I've not seen any unusual puddles on the ground; there's usually some at the tailpipes though...but it's no bigger than usual (although likely bigger than it should be). No signs of leaky coolant hoses either, at least not the ones I can see from above with a flashlight. So the big question is......where'd all my coolant go? Anyone know the fluid capacity of the coolant system off the top of their head? I need to find the problem and fix it fast before I spend all my money on gallon jugs of coolant.

Thanks!

Your lower intake gaskets are probably leaking, allowing coolant to leak internally into the engine and burn off. Probably why you are seeing puddles at the tailpipes (not normal).

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harofreak00 wrote:Your lower intake gaskets are probably leaking, allowing coolant to leak internally into the engine and burn off. Probably why you are seeing puddles at the tailpipes (not normal).

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If I buy you a beer will you find me a different answer? :sad5: The above isn't something I'm willing to tackle at night in below-freezing temps on my only means of transportation. If you're right, and I suspect you are, it's a question now of if they are leaking more than they had been before. I'll still cross my fingers for a hose leak I missed while looking at the hoses in the dark though.

Its a gradual progression leak, but its best to fix ASAP. Fill the coolant back to full and either save up and have a shop do it, or ask a friend for his garage for a weekend. You can do it yourself in a weekend.

You said you hit something on the highway. Have you put it up on jackstands and inspected underneath?

Check for leaks by placing a cardboard under it after you turn it off.

How many miles on the engine?

It is quite normal for condensate or water to exit the tailpipe when the engine is first warming up.

2000Silverbullet wrote:You said you hit something on the highway. Have you put it up on jackstands and inspected underneath?.

I have not done it myself, although it was up on a lift at the tire place while they were fixing the tire damage. I asked them to do some looking around for other damage but they didn't report finding any.

Check for leaks by placing a cardboard under it after you turn it off.

With the car running there are no obvious leaks, but I was looking at night with a flashlight. I'll take another look on my lunch break and see if I can spot anything. I'll slide some cardboard under it tonight, but I've not noticed any spotting on the driveway.

How many miles on the engine?

I've got 151,xxx miles on the car which has the original engine and tranny

It is quite normal for condensate or water to exit the tailpipe when the engine is first warming up.

I was hoping someone would say that. Now I don't feel as bad for ignoring it for the past couple of years.

Now don't stick your nose INTO the tailpipe..bad bad bad...but get kinda close and try to get a whiff, does it smell sweet? Also, if you are sitting at idle and give it a bit of throttle does a lot of smoke come from the tailpipes (Obviously not to be confused with normal steam from being cold out so this is gonna be kinda hard to do now). You saying you poured in almost a gallon starts to have me worried, and the mileage..hate to say it. One quick thing, has your coolant system been flushed recently? Our cars are notorious for having issues with "burping" and when I had mine done it got very hot before it actually burped and then I had to throw a LOT of coolant into the system after that one time.

I'm no great sniffer of exhaust smells, but I guess it smelled sweeter than other whiffs I've gotten in the past.

smoke vs steam....couldn't tell you. I did fire it up and there was very little coming out, hit the throttle for a few seconds and big plumes of something came out, let off and it dwindled down to a comparatively small amount. Temps being what they are, I can't say if it's steam or something else.

Almost a gallon went in yesterday...bought another bottle on my lunch break and I poured in another half gallon or so. Coolant system hadn't been touched in quite a while and no real problems to speak of prior to this. With the amount of coolant I've put in and the mileage on the car, I think I just have to accept that it is a leak in one/both of the intake manifold gaskets. I'll spend the afternoon calling more places for pricing....but the big winner right now is a reputable Chevy dealer near me who says they can replace both gaskets for roughly $600 including any other gaskets/seals that need to be replaced along the way. They say they can also do a coolant system pressure test to verify that this is the problem before they start taking everything apart.

That $600 sounds like a decent deal. Parts cost about $150, with gaskets, RTV, etc. Make sure they install the Aluminum framed gaskets, and ask them to do a thorough coolant flush and re-fill with green, mixes-with-any.

You'd have to pull all six spark plugs to check them all, but if one is crusty white, that cylinder is burning coolant.

Make sure they know that they'll be replacing the upper intake, not just the gasket... You'll want Upper Intake, Upper Intake Gasket, Lower Intake Gasket (revised aluminum framed part)

Needless to say the better way to go for your upper intake is a Dorman or...APN..IIRC part because the EGR Stovepipe coming into the Upper Intake is actually gapped, which helps with one of the main causers of your upper intake failure (if that is what happened). The stovepipe stock is directly touching the plastic around it, causing it to break down at a faster rate...which then leads to the coolant ports to your throttle body breaking down and leaking into your upper intake.

On an SSEi you will not need to replace the upper (that is the supercharger).

You know...next time I'll check out what his car is before posting...sounds like a good idea.

just wanted to give you all an update and thank you again for the ideas and advice.

The car is at a nearby Chevy dealership being worked on. I was losing coolant due to a leak in the LIM gasket as well as at the coolant lines over by the tensioner pulley. As they started to tear into it they had some problems with the vacuum hoses cracking (which would explain the P0442 that I was getting) and one of the nipples on the supercharger bypass valve actuator re-broke (broke when I pulled it off a salvage car but was able to repair it....knew it wouldn't last forever). Reportedly there was a fair amount of coolant mixed in the oil, so they're flushing it to clean it all up.

Provided they don't run into any other problems, I'll get the car back on Monday and pay out $1,075.

How many miles on your odo?
How long do you suspect it has been leaking?

My LIM gasket began leaking at 25K miles. I replaced it immediately. That was only three years ago.

151,000 miles on the odo. Not sure how long it's been leaking but i've had to add a little fluid to the surge/overflow tank every now and again for the past couple of years. since the cap on the overflow tank doesn't seal well i chalked it up to evaporation...i'm guessing that wasn't what was going on. live and learn.

I hope that over those last couple of years you have been changing your oil frequently cause all that coolant in your oil will corrode/etch the rod and crank bearings.

Definitely will decrease the life of that engine.

2000Silverbullet wrote:I hope that over those last couple of years you have been changing your oil frequently cause all that coolant in your oil will corrode/etch the rod and crank bearings.

Definitely will decrease the life of that engine.

Yes it will. I bought an SSEi that I discovered the LIM was leaking on. Replaced right away, but about 8k miles later, spun a rod bearing. In getting an L32 transplant right now.

Jon

Like I said, I figured it was just evaporation out of the overflow tank and didn't think much of it. Every 3 or 4 months I'd have to top it off to get it to where it was supposed to be.

I didn't really notice any real problems until Christmas week when the car felt like it was "dragging". It was a couple of days after that that it tried to overheat on me. I was originally thinking maybe a caliper was hung up or the e-brake wasn't fully releasing, but now I'm thinking it was due to coolant getting in places it's not supposed to be.

So while it's true it likely started leaking a couple of years ago, it didn't get 'bad' until a few days before I took it to the shop.