Would a blown head gasket cause my car not to start?

[zalex]

To SteveJ:

I'm sorry for not including specific details, but my car started fine, meaning I know everything worked fine, new battery, good ignition coil, computer running fine, new connectors all in place... and on.

I just know that my car stopped starting once I found the symptoms for the gasket. I'm assuming that would mean it's not starting because of the compression. I guess I should include that next time, I just didn't want to write for days. All I really wanted to know was if a blown head gasket would keep my car from running, and describing briefly the details leading up to this problem.

Edited July 18, 2009 by zalex

[FastWoman]

Alex, I think you mentioned that you put antifreeze in the radiator just prior to this happening. FAIW, antifreeze has anti-corrosion additives, so I'm guessing you won't encounter pronounced rusting/corrosion anywhere in the engine because of its exposure to the coolant. However, I'd try to get as much of the coolant out of the engine as possible. I'd drain out all the milky oil and spray everything possible with WD-40, draining that into the pan too. After you remove the head (if you're doing the work), you should take it to a good machine shop and have them look it over for the potential problems others have mentioned (particularly warping). Get a price quote on any rebuilding work they recommend. Also inspect your cylinders. You'll probably see some coolant in one or two of them. Those are the ones you want to pay particular attention to. Are there any rust perforations in the cylinder walls? Turn the motor, so that you can see all parts of the cylinder walls. After you know what you're dealing with, THEN decide how to proceed. I think that's all Steve was suggesting. It was actually good advice.

Good luck!

[kensval]

I bought a 280z a few weeks ago and it started up and ran fine. There was water visible in the radiator when I got it home, and the oil was clear. Now after replacing the water with antifreeze and water, I have found I have a blown head gasket as shown from no liquid in the radiator and a milky oil color. Now my car won't start. I can't figure out why it won't start aside from the leaky head gasket. I'm going to try and seal it with some gunk you put in the radiator that will hopefully seal the leak from the inside. Any ideas?

Generally speaking, a car with a bad head gasket will start. If the leak is so bad that enough water to cause a hydrolock enters a cylinder, then the engine might not start, and you should be glad that it doesn't. Water cannot be compressed, so if your cylinder is full of it, and the piston tries to come up in the bore anyhow, something's going to break. Might be a connecting rod, a wrist pin, or the piston itself, but something will break. However, that being the case, a hydrolock would also likely stop your engine from cranking properly.

From the sounds of it, you should find someone with more experience to assist you if you're going to attempt to change the head gasket yourself. Since your engine is an overhead cam design, if you're going to remove your cylinder head, you will have to disconnect your cam from your timing chain and gears. If the top and bottom gears somehow become misaligned during reinstallation of the head, your engine will be improperly timed and likely will not run and may even do damage to itself. (Perhaps someone else viewing this forum knows the piston-to-valve clearance of a stock L28E... I don't)

Providing you get your head off without screwing up your timing, your head will still need to be checked out at an automotive machine shop. I submit to you that this is not even an option. The leak may well have caused damage to the gasket mating surfaces that would render a new head gasket useless, and then there's the need to discover the root cause of the leak. Your engine employs a cast-iron block with an aluminum cylinder head. Because the heat expansion and retention properties of cast-iron and aluminum differ greatly from one another, stresses are created when the engine is run that tend to cause the head to want to change shape. Normally, your head bolts are more than tight enough to prevent this from happening, but they will lose tension over time, making the engine more prone to this kind of damage. So, the head will likely have a little warp to it, and will have to be resurfaced to make it straight again, or the new gasket will leak almost right away. I would also highly recommend that you use new head bolts or studs. Using the old ones is a recipe for disappointment... every time.

Because you say your oil is milky, I suspect that either your head is badly warped or it has a crack. Both, if the damage is not overly severe, can be repaired. Again, you'll have to send the head to an automotive machine shop. I would call around for one that specializes in Japanese engine work.

As for your oil, I would recommend that after all the work is done you change out your oil and filter, run your engine under no load for a short period of time at normal temperature, dump the oil hot, and change the oil and filter again. You might also look into a special oil additive flushing agent to use with the first oil change to help clean your engine out. You want to do everything you can to get rid of all the emulsified oil/water in your engine.

Since this could all run into quite a bit of money and trouble, you might also consider getting an entirely different engine if you can find one at a wrecking yard. You'd do best to find a yard that pulls and tests their engines so you'll know what you're getting. You need one from a 1975 or newer 280Z, or the head won't have the notches for the fuel injectors. An engine swap is easier to do for a novice mechanic, and you can always save your money up to have your original engine completely rebuilt at a later time.

There is one last, way cheaper option available to you. It carries about as good a chance of screwing your engine up as fixing it, but you might not consider 50/50 odds all that bad, so here it is... Look for a product called Iron-Tite. It comes in a white bottle, is a clear liquid, and is an antifreeze additive like you mentioned looking for. I have actually used this product on two engines in vehicles I wished to spend no money on and didn't care if I killed in the process. Provided you can troubleshoot your engine to get it running again as-is, you just pour it in, get your engine hot, run it that way for 10 minutes, shut it off then let it sit for a few hours or overnight before running it again. It causes a reaction with the metal in your water passages to remove some of it and keep it in suspension in your coolant. The suspended metal gets clogged up in your leak and cures when you cool your engine out. The result can be a stopped or severely reduced leak, but there are NO guarantees. It could also screw up your heater core, react badly with the aluminum, plug some of your rad passages... you get the picture. Use it at your own risk. It'll also make the engine harder to clean out if you do eventually find the dough to send it out for a complete rebuild. You've been warned.

I used it on a Buick 3800 V-6 engine with a mild head gasket leak on one cylinder bank and about 180,000 miles on the engine. The head gasket stopped leaking for over a year, and we drove the car from Saskatoon, SK, Canada to Minneapolis, MN and back in the heat of the summer with no trouble. I drove the crap out of it and it held... for a year. Again, I knew the chance I was taking when I used it, and if it hadn't worked I had other options for transportation and the car wasn't worth spending money on to fix correctly.

Anyhow, that's my long winded 2 cents worth. Good luck.

Edited July 18, 2009 by kensval
Correction of a spelling error.

[zalex]

I am taking much advice into consideration. I called a local machine shop that was referred to me by a Z owner in my town. They said they would repair a warped or cracked head for 300 (depending on the damage maybe less, working with me on the price.) That isn't too expensive for me, knowing it will probably be worth it after when I can get it driving. My mailman has offered to help with his experience after I gave him some 240 wheels I didn't need. Generosity pays off.

Honesty I am afraid of what I've gotten myself into. But I've already gotten myself into it, and I don't feel like giving up and selling.

Another question: do I drain the oil beforehand or after the work?

[kensval]

In your case, because there's already water in the oil, drain the oil now. You will absolutely have to waste an oil change to clean the system out.

$300 sounds downright reasonable. My own L28E head is at the machine shop right now, and I don't expect to get out of it for under $700.

I bought a 280ZX engine today for $150...and it runs. There are definitely bargains out there to be had. Got the engine from a member of my local Z club that needs to clean out his garage. Keep that in mind if things go from bad to worse when you get the head off... you have options.

Well, back to polishing my valve cover...