I have a 2004 Discovery. It has had a lot of work done over the past 2 years. The truck makes the typical ticking sound from the engine. This past weekend the overheat light came on, so I went to a local garage where they did the computer diagnostic and determined the thermostat needed to be replaced (even though it was replaced by another shop less than 6 months ago). The mechanic showed me that the coolant was leaking on the bottom of the truck. After that thermostat was replaced and the coolant was topped up, we were able to drive about 2 hours on the highway with no issues. Once arriving at our destination, we parked and a couple hours later tried to start the truck. The exhaust was putting out quite a bit of white smoke, and the engine had very little power. I then noticed that the coolant was almost gone. After i shut down the engine and let it sit a bit, i tried starting it again, and this time it wouldn't turn over at all. Im wondering if, with this info, is it pretty clear this is a head gasket issue? Or could it be something else altogether? Realize its hard to diagnose without more info than this. Any ideas?

 

Wouldn't turn over at all? Yikes. When you try, would it make any noise? A click or something maybe?

Very well could have started as a HG issue. The first thing I would do would be to crawl under the truck with a breaker bar and a.... 1"? I think a 1" socket. Put it on the harmonica balancer and see if you can rotate the engine at all, even by hand.

Depending on how badly you overheated the engine, you could've seized her stiff. This will let you know one way or another.

Also, have you got any engine codes? That would be a huge diagnostic help. Sorta shooting blind without codes.

 

When i try to start it, i can hear the starter trying to work, but no engine sound. I dont have any engine codes unfortunately. I spoke to the mechanic that replaced the thermostat, and he said it could be that a cylinder has filled with coolant and that might be why it isn't turning over. Any truth to that?

 

 

yes the mechanic is talking about hydro-lock...if a cylinder is full of coolant it will be unable to turn over...remove all spark plugs and try and start....it will clear the liquid out of the cylinder (s).

 

You need to replace the head gaskets. Hydro locked with anti freeze, that is why it won't turn over. Don't force it, the cylinders are designed to compress air...not fluid. You can cause internal damage by forcing engine to rotate with fluid in the cylinders.

Brian.

 

Thanks for all the helpful responses, guys. Appreciate it.

Yes, it was hydro-lock the mechanic was mentioning. So it sounds like the cylinder is full of coolant. If i remove the spark plugs to try to turn it over and drain the coolant, could that cause any additional problems? Hoping i haven't already seized the engine. It's possible though, as this all happened after a 2 hour highway drive.

Any idea of rough magnitude of cost to replace head gaskets? It looks like the head gasket kits are in the range of $100-200 online. I'm guessing the labor is where the major cost is And i suppose while this is being done, i should replace the lifter that is slipping as well? If i did seize it, im guessing theres a hole other list of things that i need to have done too, correct? Or is the engine toast at that point?

Thanks,
Sb

 

You going to be doing the HG job yourself? May not be cost effective to have shop do it, if you can find one that will. More diagnosis still needed. You in the city?

 

Im in the city, but the truck is now up in the Hudson Valley. I'd like to try to do the work myself, but that might be a bit overly ambitious.

 

Well, there's a few of us in and around the city. Welcome to the boards. That truck issue really needs more investigating to get a better idea of what's going on and what all needs fixed. Could just be a head gasket, might be more.