My 75 Comet may have a cracked block or head, according to my mechanic. He did a test that led him to that conclusion. Anyway, he said he doesn't know which one is cracked. So is there a way (in my driveway) to know for sure? Or while driving for that matter? Ant tell tail signs?? (Inline 6)
It could be a blown head gasket. It really depends on what the car is doing, what symptoms you have that led you to take it to the mechanic. I doubt you cracked the block, or head. Only way I can think of doing that would be to fill it with water without antifreeze, and leave it out in a hard freeze. Or put a huge blower or turbo on it and spin it to 8000 rpms. My guess is your mechanic wants your car, told you a horror story, and hopes you will sell it to him cheap instead of paying to fix it.
The head gasket was blown when we bought it so we installed a new one (felpro). After installing the brand new head gasket. the car would constantly get hot fast and overheat if we pushed it just a little too much. We also blew the heater hoses and fried a T-stat. It has poor throttle response and it just doesnt sound healthy overall. We recently discovered a very slight seepage where the head gasket is (just around where the block meets the head) This is barely noticable though. No antifreeze in the oil, no oil in the antifreeze, no smoke, no puddles.
I don't remember the name of the test they did. It produced a blue colored gas or something like that. I'll look it up
This is it... To do the test, add the blue detector fluid to the (block-tester) plastic container according to the directions, and place it onto the radiator filler neck. The squeeze bulb is placed on top of the reservoir and squeezed repeatedly (Some block testers, have a tube that connects to a vacuum line instead of a squeeze bulb). Squeezing the bulb will draw air from the radiator through the test fluid. Block tester fluid is normally blue. Exhaust gases in the cooling system will change the color of the fluid to yellow, indicating a combustion leak. If the fluid remains blue, exhaust gases were not present during the test. The vehicle should be started and at operating temperature before performing the test. Vehicles with head gasket leaks may overheat, and purge hot water and steam out of the radiator. Perform this test, at your own risk, and do not do the test, unless you are experienced and are wearing clothing and equipment to protect you from burns, or injury.
If you have no coolant in the oil, chances are its a cracked head. Either way, it's time to pull the engine and take it apart to find the problem. If you want to keep a six cylinder engine in it, I'm sure there are more than a few members here that have an extra engine after doing a V8 swap.
If you added cold water to a hot engine, you could have cracked the head. Question is, did you put the head gasket on right, and not upside down? I'm not even sure there is a wrong way to install a straight six head gasket, just asking. If your timing is way off, it will make it run sluggish and also will cause it to heat up. By the test being done, I'd say gasket is blown. While I had the head off, I'd take it to a machine shop and get it checked. While it might not be cracked, if it was overheated sometime in the past, it could be a bit warped.
Trying to bear the rain here and do the compression test. I'd like to do a 302 swap bit that's an entirely different ( and expensive ) issue. I know she's running a bit rich and the idle is high too. So I'll need to check all that too. I will pull the head and get it checked if other fixes don't alleviate the problem. The gasket is on correctly btw. I'll check back soon.
Overheating it. Especially if the coolant is too low, then there's nothing but the iron to transfer the combustion heat. Happens all the time.
Do an easier check: With the engine cold fill the radiator and crank the engine. A blown head gasket or cracked head will allow the compression to bubble the water, and/or puke water out the filler. Watch the water in the radiator until the thermostat opens the water should flow steady without bubbles, after any air is expelled from the system. I have had 6 cyl engines for years and never had a block to crack, unless it was frozen hard. It will normally push the freeze plugs out first. I'm betting that the head warped when it ran hot the first time. These heads can be planed to .090". Therefore you should be able to have your's planed. These engines came with thin metal head gaskets. When putting a new gasket in the head should be planed at least .030" for the difference in gasket width.
Compression test results: 1-135 2-135 3-135 4-135 5-135 6-125 (this may be low due to its location. I'm using a press-in tester, not a screw-in kind)
