Droshki

Hi everyone-

Really this could have been posted anywhere, it's not really that C3 specific...but..it is a 1976.

This car may go 2 -4 weeks without being run (because I also have a C4, and only a one car garage). Not always, but sometimes after sitting for the longer end of that spectrum, when I start the car up, there is a moderately strong semll of hot coolant, and a steady whisp of white smoke coming from the left pipe (4 inch hooker sidepipes). For about 5-10 minutes. Then it goes away and doesnt reapperar as long as I am running the car at least a couple times a week). Seems that I've got a head gasket problem? What kind of risk of serious damage am I taking by not addressing this right now?

tia

fugawi

you should get that fixed. what will happen is cilynder wash down. it will take all lubrication away from that piston, and make it seize up and,break rings and ring lands on piston..including possible bad scoring of bore...

bashcraft

I think your biggest concern is going to be overheating. If coolant can seep into the cylinder when it's not running, cylinder pressure is also entering the cooling system when it is running. This will push coolant out of the system through the overflow.

markdtn

I would not drive it until you get it fixed. If it leaks enough that you can smell and see it, it is time to fix it. How much coolant are you having to add?

Droshki

Thanks for the input guys.

Naturally I was looking for someone to tell me to just go run the hell out of it and not worry about it, ha, ha. Of course I knew better.

Well, really a negligible amount of coolant is disappearing..but still....Id really rather not have to have this motor rebuilt over some short term laziness.

OK, lets go this direction with the conversation:

1. Recommendations on head gaskets? The engine has Holley systemmax aluminum heads, and a B&M blower putting out no more than about 7 psi. CR is about 8.5

2. It would be my guess that B&M quit selling blowers some time ago and gaskets might be an issue (although I think I might have one spare set). Ive seen the product called "The right stuff" discussed here. Thoughts on using this to seal the blower base if necessary?

thanks again!

Droshki

ttt

Droshki

421 views and no one can give me a reccomendation on a head gasket brand?

63mako

Cometic MLS if the head and block finish is smooth enough. Felpro if there is a question on finish.

Z-man

You might re-post in the engine section...

Ragtop_Rob

Before you change anything let's check a few more things. When it gets hot does it knock a lot? Is the engine oil miky looking? Pull the plugs on that side and have a look, are they white or gray looking?

Droshki

Ragtop- Good questions, as Im still not entirely convinced Ive got a head gasket prob. The car does not get hot. It runs same as it always does, 170* indicated on the analog gauge (to 6K (3.73 gears) where the rev limiter kicks in). There is also no coolant in the oil. Ill pull the plugs on that side soon as I can, prolly this weekend. Remember this only occours after extended sitting times, 3-4 weeks.

63 Mako- thank you for the gasket advice. Thought there might be something special these days in the head gasket dept, esp with the boost.

Ragtop_Rob

The "only occurs after an extended rest" is another red flag to me for the head gasket. At rest the system is under no pressure, I would have to think it wouuld really leak when the 10 or 12 lbs of system pressure is built up.

Just had another thought, check the inside of your windshield, is there a slight oily film on it? If so the answer is the heater core. It would cause the smell for sure and the white steam could easily be condensation in the exhaust from sitting.

Droshki

heater core is not connected. Good shot though. I checked last night and it was about pint or so low on coolant. I do have a slow leak at the water neck though, and I dont fix it because I dont think I can get it off w/out pulling the blower.

ya think a comp test would show the leaking cylinder? Its such a bear getting the plugs in and out-headers

Ragtop_Rob

That is a good point, you could do a leak down test. Pump it up and let the compression gauge stay there a bit and see if one side leaks down much faster than the other. You would have to have the screw type of gauge to do it though - the rubber mount ones are not good for that sort of test.

Manuel Azevedo

Well it will always be the wrong time to have to fix any engine. But do try and fix it soon. If you really have coolent in the cylinder it will corrode the cylinder wall even if you do not run it. Fel Pro Blue head gaskets are by far the best out there also. The other thing to be sure of is to check for a head crack, GM heads are prown to cracking with heat on the center two exhaust seats. Also be sure and seal the head bolts threads as they do go into water. Manuel

jackson

Droski:
Next time ... begin w/ a better description of your motor ... seems you have a crate ZZ4 w/ holley Al heads & BM blower.
Some good suggestions here ... I'll add this:
Check the intake manifold to head(s) seal ... leak there not uncommon ... can easily draw coolant across from coolant port(s) & weep into intake port(s). An otherwise good seal can quickly go south after even a minor backfire thru carb/blower.

I'm not familiar w/ your blower ... if the blower itself has any coolant passages (probably not but maybe) ... check that coolant not weeping into plenum.

HG's:
Victor Reinz/NAPA 5746
GM 10105117

Droshki

Jackson: sorry I wasnt clearer. The blue car in my avatar has the zz4. Its a 1985. Cant blow them really, the CR is too high.

The one with the problem is my 1976. Its just a home built 350 with a cam and holley systemmax heads and the blower, oh and holley headers and sidepipes.


I was wondering what the odds were that the colant was coming in through the intake versus the heads themselves.

Im gonna do a leak down test this weekend on that side and see if I can tell whats going on.

I guess there is one sure way to find out.....ugh

wolfyffs

There are several things you could do but look at from a common sense point of view. Does the radiator show any air bubbles when running? Do a pressure test on the cooling system and listen for any air coming out of the exhaust on that side. If your getting air out of the exhaust then you you have a blown head gasket, a cracked head or block.

Next do a compression test both wet & dry and look for more than 10% difference between any adjacent cylinders. This could indicate a blown head gasket but could also be caused by wear depending on mileage of motor. If you hear air coming out of the dip stick this indicates worn rings & wouldn't cause the problem you describe.

You could also remove the side pipe from that side & put a small container under the header collector & let it sit form however long you usually do to see if you get coolant out of the header. I suspect you won't because the leak would have to fill the cylinder before leaking out of the head into header.

Your plugs should tell you what cylinder is at fault. If they are burning white then they are getting coolant on them. This is best checked right after start up after your usual set time of the car.

The best test are gonna be the leak down test on the cylinders & the cooling system. If after all this you still can't tell anything I would suggest a tear down on the motor. I realize it may be hard to pull the plugs and do all test but it is easier than pulling the motor for a full tear down. Hope this helps. Of course this is just my opinion. You have to make the final call.