Something seized?

SCIONxB had problems over the summer of 2010 until aug when it really suddenly got hot-n-died;had it towed to the house instead of shop and now wonder why it turns the belts,has no water in the oil though its not holding coolant either.Shouldnt it at least crank??

It wont crank if its seized up.
Where is the water going?
Does the starter engage?

Volkswagon? Back in the day we would put a socket and ratchet on the harmonic balancer bolt to check if an engine was seized

water is either a pump or head problem-really just wondering why the key does no more than turn th belt.Doesnt really sound like th starter is doing anything more than that.

scion is a toyota thang

So the pulleys turn when you turn the key and it doesn’t crank?
What do you mean by ‘crank’?

“Cranking” would be the chug of cam or plugs;all I get is a solid electric whine while the belt turns,like nothing’s firing.

Neighbour suggests its jumped time…?

I can’t figure out what you’re describing either. If you’re talking about your serpentine/accessory belt most of these are turned by the crankshaft. If your belt is going then your crankshaft is going. Thus it is “cranking.” If you want to say that it sounds abnormal that’s another thing entirely.

But you want to back up. What year is it? How many miles are on it? Give some idea of its maintenance history. It had problems over the summer. What problems? The last problem, it seems, was overheating, and when it overheated it stopped running. And between August and now - what? Its just been sitting? Or after it “got hot-n-died” it was running again for a while? Describe “its not holding coolant”. You mean you dump it in and it pours out someplace or what? Or it wasn’t holding coolant before and that’s why it overheated? I feel like I just walked in at the end of a movie.

So - can’t make heads or tails of it - but I’ll take the wild guess that you ovrheated it, blew the head (gasket/warp/crack/whatever) and now have no compression. Since you have no compression it sounds weird when you crank it. That would be my guess. Put a compression gauge on it.

OK…2nd owner(bought from dealer in 2006) 2005 scion xb,245000 miles,ran like a champ on basic oil,plugs,filter-n-belt changesuntil mid-summer 2011when squeals began making me think either belt or compressor.Drove on a number of weeks until hotlight prompts me to check radiator whereupon I note that STOPLEAK had been used to sell me th car.Coolant was only low,never more than a 1/2 gallon ever needed every couple -hundred miles.Really think it was the waterpump,given where water showed on the ground.I never let it get the hotlight on without checking levels first,but I did add some 1000 miles to the situation.And then in August of 2011 as soon as the light came on,the engine chugs-n-coughs to a halt,with a subsequent half-start after Id pulled over.From then on,its only given an electric whine that turns the serpentine when I turn the key(its beginning to kill the battery)Note that there is no sign of water in the oil.

I think ciggie is right: blown and warped head…

This is sort of a long shot, but your timing chain may have failed, or your camshaft(s) may have broken. If you have lost cam timing, that will cause the engine to crank far too easily. It could also cause a lot of damage to the cylinder head and possibly the pistons. Pulling the camshaft cover (valve cover) will quickly answer that question.

I am sticking with the (near) zero compression assumption. I figure zero compression because that will sound really weird when the car cranks. My first guess of going from running to no compression would be what mark said - timing chain/cam failure. However the coolant loss and overheating also leave the head in the mix. I’m betting this car ends up at the scrapyard or getting a used engine.

Majikbox, I think the one point you are missing is the starter only turns the crankshaft… That is its job, the crankshaft then turns the belts which drives the waterpump/ps pump/alternator etc… SO if the belt is moving the crank is turning which means your motor is not seized… What everyone else is trying to say is that if it sounds odd, its most likely due to no compression. As others have said possibly from a warped head, but can be holes in the piston, bent valves, valves stuck open, or 101 other things. There is nothing that can be done except taking the car to a mechanic and having him look at it, but in all likely hood as cigroller says you are looking at a used motor…

This vehicle has a 4.5 quart cooling system, operating 1/2 a gallon low will result in disaster/warped head, no compression.

My brain is spinning.

Like Cig, I too wondered if the camshafts were turning (if the chain had broken). There is a simple way to check this. Remove the valvecover and turn the crank. Or, look at the camshaft with a borescope while you turn the crank. The crank should turn by hand wityh the tranny in neutral.

I’m an optimist, but I’m reluctant to suggest a warped head because there would have to be mutiple cylinders with breeches in order for the engine to not fire at all.

Can you describe the problems it was having over the summer? Knowing that might just be the clue we need to provide a definitive answer.

mountainbike is right (of course!) about the head and firing. It would be a super-catastrophic head failure to got straight to no compression/firing in any cylinders. I know that timing chains are affected by maintenance of oil. Does overheating commonly affect them? I’m just asking for enlightenment, but it would explain going from overheat to zero compression and make everything fit in terms of an explanation. Of course the coolant loss & overheating could just be tangential to the whole thing - if it was a cam or timing chain failure.

I’ve nevr heard of overheating affecting a timing chain, but knowing that parts of the timing chain assemblage (the runners in the guides and tensioers) and perhaps sprockets may be polymer, I guess it would depend on how hot things got.

I’d love some more detail from the OP.

Lack of oil maintenance (not changing the oil often enough or not checking it, allowing it to run low) can cause sludging problems, which can block oil passages and starve the timing chain of oil. Severe or extended overheating, or numerous overheating episodes, could also overheat the oil, causing sludging and similar problems (although this normally occurs some time after the head has been warped or cracked to death and those repairs are made). This can lead to timing chain failure. GM Quad Fours are notorious for this.

245k miles, chain driven water pump, I think your water pump has been going out for awhile now. Somehow it has either seized and broke the timing chain or the shaft got so loose, the chain has lost its tension and no longer engaging the sprocket on the crankshaft.