We are new to the forum as well as Z cars (though we've had Roadsters for several years.) We recently purchased a '73 project that blows white smoke through the tailpipe. Len was able to drive the Z home from the seller's house, and after a few minutes driving the smoke cleared out.

It is our understanding that this is indicative of water in the cylinders, so we will be pulling off the head & replacing the head gasket. It's been recommended that we also have the head checked for cracks.

Our biggest concern is a crack in the engine block. Is there way to diagnose this at home?

Thanks!

Charlotte & Len

The only way to check the block at home would be to completely strip down the engine. You can buy a kit from someone like Eastwood's to check for cracks in the block.

I find it kind of odd that the smoke quit after driving it for a while, usually it will still have a bit of smoke or vapor out the exhaust if the headgasket is leaking or the head is cracked/warped.

Before you start taking it apart I would do a pressure check on the radiator, just to make sure you do have a leak that requires immediate attention. You might also do a compression test if you have the tester available. After you do the pressure check on the radiator, and it does lose a lot of pressure, pull the plugs and turn the engine over. You might be able to see which cylinder the water is gettting into and then you will have a good idea of where to check the head and/or head gasket when you do remove the head. This way you will know which cylinder is giving you the problem and if the head checks out OK and the gasket doesn't look to be blown, you will know where to look in the block for any problems.

Don't know how well your toolbox is stocked, but most any decent shop could do the pressure test and compression test for a small charge. This could save you from a lot of head scratching later when you start taking the engine apart..

We did a compression test on the engine, numbers are (from cyl 1 to 6); 160, 150, 130, 0,140, 175 Pulling the plugs, #4 was wet. The rest are black. I would like to figure out the compression/water problem before tackling the fuel mix :eek:

There is also the slight possibility that the water could be getting in through the carbs if the car still has the flat top carbs with the water still connected to the carbs. The late carbs had water going through the carbs and the intake, so that is another possibility, albeit a very slim one. I have never heard of anyone having water enter through the carbs/intake but it is another place to look.

If the smoking stopped after the engine warmed up, it could be the carbs as the thermostat would have closed on the intake and carbs (if it is still in working order that is) and that could explain the smoke stopping after the engine reached operating temp.

It would be a one in a thousand chance that this could be the problem, but a possible one just the same if the car sat outside with no antifreeze in it and it got near freezing..... course it all depends on what area the car came from....

A cracked block would be very unlikely. If the motor got HOT, the aluminium head would probably crack long before the cast iron block would crack. Still, if you have reason to believe that the motor got very hot or suspect a bottom-end problem, it is better to do all of your checking before spending major money on the engine.

2ManyZs has given you good advice on what and how to check the engine.:classic:

Compression on number 4 is 0? Eek, that isn't good. :sick:

Sounds like number 4 is more than likely the cause of most if not all the problems then. Hard to say what it might be until you get the head off, but I'd say that a pressure test on the radiator isn't going to do much good. You might have a cracked head after all or a holed piston. If it were a head gasket blown you should at least find a little compression on the cylinder. Even a cracked head should some compression, it just wouldn't hold compression but for a very short time.

I guess pulling the head would be your next step to find out how bad it is....:disappoin