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Okay, so I daily a 1991 coupe with a 40 thousanths overbore in the engine and things have quickly gone to hell.
221k miles, 21k since the overbore.
last oil change: 6k miles (was going to be done tomorrow)
Today I discovered I had a coolant leak from my resevoir thanks to getting stuck in traffic and my engine getting close to the redline for my temp guage. I was able to get it back down when I got through and when the engine cooled, filled up the resevoir with water (was planning to fix it tomorrow).
Later I drove to a car meet, and when cranking the car to leave the meet, I heard two clunks from the engine bay (oh ****). I get out of the car, and everything seems fine. I kill the engine, start it up again, and no clank or scary noises.
I drove the car roughly 100 feet and noticed I was in a cloud of white smoke (not extremely thick). I immediately parked the car and turned off the engine. After a little looking, I figured out the smoke was all coming from my tailpipes.
I have never had any problems with the engine itself until tonight. It has a new radiator, and new transmission. I plan to go check out the damage some time tomorrow. My question to you guys is what should I look for, and what this could possibly mean for the life of the engine, as well as my wallet? Any input is greatly appreciated as I am a college student and that is my only car.
Take out all the spark plugs and crank the engine. If you have a blown head gasket water will come out of the affected cylinder.
Thank you! I'll post tomorrow about if it the head gasket or not. I'm really hoping it's just that.. if it was a cracked head or block, I would be literally screwed
Run a compression check (autozone will rent you a tool for free). Start with the outside cylinders (1,2,7,8) I'm guessing it will be one (or more) of them. Most likely just a blown head gasket, it won't necessarily pump water.
My guess is that you have a cracked head, block or most likely a blown head gasket. Pull every plug and lay them out in order. The plug in the bad cylinder will look washed and different from the others. Look at the oil fill cap. Any condensate there yet? Dipstick level risen or oil look milky? Water WILL be mixing with the oil. Pull the heads, have them shaved true and use blue fel-pro gaskets. Add a bottle of Bars Stop Leak and Conditioner to the radiator on restart. Figure on a little over $200 for the head shave and gaskets. Labor extra. You`ll need new oil / filter and anti-freeze. If you run the engine with a risen or elevated oil level, the engine and ur wallet will suffer. Good luck. I have a 91 with 109k miles.
Last edited by RICHARD TILL; 04-22-2016 at 01:23 AM.
Depending on the gasket, getting close to the red line (260ºF) will result in extreme squeezing of the head gasket and fire-ring; beyond the point which the gasket can rebound, resulting in the gasket loosing its ability to seal. And, especially with the over bore, it gets even more critical (less lateral gasket material between the cylinders). So, head gasket would be the most likely. Cracked heads or block are more likely to happen if after extreme over-heating the motor to the point of blowing the water out, pouring in COLD water to refill the radiator is like you jumping into a pool of ice-water (thermal shock!).
For what it's worth, in the two years I worked in a garage evenings and weekends we changed out prolly 8-10 head gaskets for every cracked head or block. And, in just about every case of cracks, it was a motor that had a coolant leak (radiator or hose or something) and the owner kept it filled with a garden hose. You'd have to be very unlucky to have cracked something - chances are.
Other symptoms mentioned: IF your oil looks like chocolate milk or there is traces of such up at the dipstick handle/seal, especially coupled with coolant loss, but no visible leaks, then you can start worrying about something cracked. There is usually a sign of a crack in the head that is visible. But, sometimes they have to be disassembled and be magnafluxed to be find cracks - especially if they are in the area around the valves.
So, "don't bleed until your cut!" Chances are it is only the head gasket(s). The spark plugs will tell you which hole is getting wet- (usually) -super clean porcelain and electrode - like new= coolant; the rest are sooty-brown.
You can be happy you don't have a DOHC motor (at least in this case). At least the motor can stay in the car as you don't have to pull it to re-phase the cams!)
Anywayz.... I'm betting it is just gaskets. Not a bad job on an SBC - done it a dozen times - even a couple BBCs. Good luck!
Last edited by Paul Workman; 04-22-2016 at 06:40 AM.
If its good enough for the military, and it fixed a (5 litres of water in 10miles) cracked head problem on my wife's Suzuki Vitara, so it should walk the walk!
I'm told that many hi spec cars have this in them from new to prevent water leaks during breaking in periods and its actually on GM's inventory under their own part number.
I bet it's the head gasket and probably leaking in #7 or #8 cylinders. I had the exact same problem when I was in collage with my 86. Luckily its not a super difficult job to do. You will want to get the heads machined and crack checked though, couple of hundred bucks. That will be the most expensive and time consuming part. The rest of it shouldn't take more than a couple of days. Be sure to use proper torque specs and sequences when going back together. If you're close to Tulsa let me know.
A lot of good info here but will add. Do not turn it over with the plugs in any more can do much more damage. After finding your leak drain the coolant oil too if milky and put oil in the spark plug. Holes and turn it over by hand. The sooner the better.
Last edited by antfarmer2; 04-22-2016 at 09:57 AM.
Me too! The head gasket replacement is almost a rite of passage with these early C4s. The thin wall iron head castings are as much at fault (and they crack or warp) as the aluminum heads... overheating either one is asking for trouble.
Update: the pressure test showed that it was the second cylinder from the front on the driver side of the car. We also tested it by pulling the fuse for the fuel injectors and a few others and turned the engine over until there was a large spray of water/ coolant out of the affected cylinder. So hopefully it's only the gasket. Will get the head inspected just to be safe.
We took off the air intake manifold (might as well clean it up), and basically unhooked every single sensor so everything could be worked around. We took off the gasket cover (that sucked) and are currently attempting to remove the head. We ran out of light and called it quits today. All of the visible bolts inside are out. Tomorrow's plan is to remove any other neccesary bolts and the header so we can actually get the damned thing off.
The picture below is before we decided to attemp to remove the fuel rail (my buddy wanted to see something), and also before we removed the bolts from the gasket. I also made sure to take pics of where things go ( learned my lesson )
After buying the new gasket, oil, oil filter, and coolant. The total with my friend's 20% off discount at autozone was $66. We were going to attempt to tackle the head on the passenger side... but that is an entirely different ballgame
Thank you guys for all your advice. I'll post more pictures as the project continues. I am still open to any advice you have to offer (and no I'm not touhing the otherside unless I have to... My deadline to fix the car is in 9 days or else I have to call a tow). I'm doing this in a college parking lot in Marietta, Georgia... and the sunburn is pretty painful
Also! I'm sorry my reply is so late. I've been very tied up with school and work. Finals are next week also and it's needless to say that this could not have happened at a more inconvenient time.
Last edited by JamesThatGuyy; 04-29-2016 at 09:35 PM.
If you plan on just Fixing It, and keeping it relatively stock, get a set of cometic MLS headgaskets.
If you plan on modifying...nows the time to start.
time is of the essence, do u have a metal straight edge and feeler gauge set to determine the warpge if any?
there are ways to machine your own head but not sure if you have the time.
what are your plans for this?
Originally Posted by MavsAK
If you plan on just Fixing It, and keeping it relatively stock, get a set of cometic MLS headgaskets.
If you plan on modifying...nows the time to start.
04-22-2016, 12:00 AM
S.O.S. White Smoke Coming From Exhaust
w/ the others. Just to add...
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