Cold/Warm start issues -- bad head gasket?

[DMCVegas]

No, overfilling wouldn't cause an issue with damage the the cylinder heads, or the cooling system itself. Water isn't compressible, but air is. So the empty space of air inside of the cooling bottle can shrink and expand as the coolant expands and retracts with the heat cycles. If by chance you were to overfill the bottle and didn't give enough space for the coolant to expand, or even no space at all, it wouldn't hurt the system. That's because the Radiator Cap acts as a fusible link to prevent damage. As the pressure built up and pressed against the cap, it would slowly vent out coolant steam until the pressure went back down. Given that it's a closed circuit system with an external expansion tank (not an external overflow reservoir), you'd probably have to burp it after that to let some air in. But the fluid level should never change. We have an '07 F150 still running it's original coolant (I plan on flushing the system later this year), and for the 7 years of which we've owned it, the coolant level hasn't once dropped below it's cold level.

But when you say ⅓ of the way, are you saying that the coolant level dropped below ⅓ of it's capacity? Or that you simply keep adding ⅓ of coolant each time? As long as you keep the coolant about ⅗ full inside to cover the bottom, and to let the bleeder return pour in unobstructed, you'll be fine.

Quick question: Does your windshield ever get really greasy on it's own?

[bluscreen]

I didn't think "overfilling" it would hurt the engine. I'm just wondering if there's a correlation to this smoking-not-starting issue and the fact that I filled the tank more than usual.

As for 1/3 capacity question-- basically I'm trying to say that the bottle seems to stay at 1/3 capacity. If I fill it with more, it'll be back down to 1/3 the next time I check it. However, I've not seen it go lower than this.

Windshield greasy? No. Are you thinking of gas vapors from the filler? I've had my filler refurbished somewhat recently (well after any issues here) and I know it's not a perfect seal but I think it's OK. I have a locking gas cap that I will replace with the standard DeLorean non-locking and better-sealing at some point soon too.

[DMCVegas]

You could wait and see if the fluid level drops more, but I'd for go for the compression test & oil analysis instead.

The reason I ask about the windshield is because of the heater core. It is possible to have a tiny leak there with the vapor escaping, but not dropping out. That too could be the cause of a leak. But the tell-tale sign of that would be a greasy windscreen on the inside. The water just evaporates, but the glycol sticks to the glass.

[bluscreen]

Results are in! When I pumped the DeLorean's coolant system up to 14 psi, it dropped 1 psi after 15 minutes, 2 more at 30 minutes, and 4 more at the 90 minute mark.

Thoughts? I think this sounds reasonable.

Even better, when I first pressurized it there was a small leak at the line that connects to the bottle. This might explain where the coolant has been going. A few turns of the worm clamp fixed the leak.

I also tried running the car with the pressure system attached (and not artificially pressurized). The car started with just a little bit of white "smoke" (smelled a bit like fuel) and after idling for about 5-10 minutes the pressure has risen to 2 psi. I don't know the norm, but I didn't want to leave it idling all day so I stopped there. I would imagine a head gasket issue could also drive the pressure up in this case too-- which thankfully didn't happen.

Upon doing some quick research on the internet about how long a car should be able to keep cooling system pressure, I did find an article about hydro-locking an engine and the warnings involved with it. If indeed you're leaking into a cylinder, it's not unheard of to compromise an engine this way.


At this point I'll need to do some serious driving to run this gas through the car. Then it looks like the task will be to see if it's still having trouble starting. If so, it must be the WUR or something like that. I should probably change the fuel filter and take a dwell meter to it as well.