coolant re-routed?

[p1n]

ok heres the deal.. got a '96 grand marquis..the heater inlet/outlet hoses are missing completely.. and as i was putting on a new water pump, i noticed that the water pipe that goes under the intake manifold thru the valley, is also missing completely.. not there at all.. but even with these missing pieces, the car still is able to run just fine, but overheats.. coolant isnt squirting from anywhere, no visible leaks at all, yet the coolant level goes down pretty quickly...
so um, what the hell.. i'm assuming the dude who sold me this car re-routed the coolant somehow.. but why in the world would somebody do this.. and how do i figure out in what way it was re-routed so i can get this thing in proper shape..

[1987cp]

On SBF cars, I've often looped a heater hose around to bypass the heater core when it goes bad. I've also heard of people just putting rubber caps on coolant fittings, especially if they live somewhere like CA or PR where you never need the heater.

[p1n]

ok, i looked at it again.. the heater inlet and outlet hoses are missing, but theres a rubber hose going into the intake manifold where the heater inlet hose would normally be connected.. its looped around or curved from the driver's side of the engine behind the block somewhere. it's really hard to get my hand down there to feel where its from.. so yea, however its rigged, theres a hose coming from the back of the block somewhere pretty far down on the driver's side and that's what is going into the intake manifold.. anybody know what that hose is and where its coming from? caus i don't have a clue.. if the heater core is being bypassed, that's fine and dandy, then i assume the core isn't functioning and replacing the heater core is alot of work i really don't feel like doing. so i'll leave that be.. my main concern is getting my car to stop overheating, and figuring the routing is crucial. what that hose is, thats looped into the intake manifold, where that's from.. and etc etc.. and how to troubleshoot to find the cause of the overheating

[mcninetyone]

On that car you have two heater core outlets coming out of the firewall side by side on the pass side. The one on the left, closer to the pass side fender goes down behind the pass side head to connect with the tube that goes to the back of the water pump. This as you know travels under the intake manifold. The other outlet/hose, the one closes to the drivers side goes to a water outlet on the left rear corner of the intake manifold, on top.

The only way to by-pass the heater core is to connect these two outlets together with a hose. A basic loop from the intake manifold outlet to the outlet just behind the pass side head. This must be the way it was done, there is no other way to by-pass that heater core. That long hose you describe might be what was used to make this connection. Because if the heater core is not hooked up it has to be by-passed or you couldn't drive the car at all.

But a car can run just fine with the heater core by-passed. So having yours by-passed doesn't have a thing to do with it overheating. Unless the hose used to make the by-pass is pinched, and even that might not cause overheating. Something else is causing that, and it could be several things, you'll have to check them one by one. Until you find the reason for the overheating, but it's not going to be a bypassed heater core. I've never heard of that being the cause!!

If you decide to replace the heater core, I've done it a few times, it's not nearly as bad or as hard as it looks!!

Why not find another car with it's heater and all hoses in place to look at? Even one in the JY, maybe that way everything you see under your hood will make more sense.

Good Luck!

[p1n]

On that car you have two heater core outlets coming out of the firewall side by side on the pass side. The one on the left, closer to the pass side fender goes down behind the pass side head to connect with the tube that goes to the back of the water pump. This as you know travels under the intake manifold. The other outlet/hose, the one closes to the drivers side goes to a water outlet on the left rear corner of the intake manifold, on top.

The only way to by-pass the heater core is to connect these two outlets together with a hose. A basic loop from the intake manifold outlet to the outlet just behind the pass side head. This must be the way it was done, there is no other way to by-pass that heater core. That long hose you describe might be what was used to make this connection. Because if the heater core is not hooked up it has to be by-passed or you couldn't drive the car at all.

the two heater core outlets from the firewall have absolutely nothing attached to them.. no looped hoses, nothing... and the water pipe under the intake manifold that connects to the water pump is completely missing.. it is not there... the hose that is currently going into the intake manifold is coming from somewhere on the drivers side, somewhere from the lower dr side of the block

[mcninetyone]

If the heater core is by-passed I would expect the heater core outlets to have nothing attached to them.

But unless there is something else I don't know about. The only way to by-pass the heater is to run a hose from the outlet at the top of the intake to the rear of the water pump if the tube is now gone. There is no other way to do this.

You really need to follow that hose around the engine until you find out where it's hooked up at. But even if it somehow is serving as a by-pass, that still wouldn't account for the overheating.

If it's a police car check to see if it is attached to the oil cooler at one place or another. That would be at the front/bottom of the drivers side.

Sory I can't be of more help!

[1987cp]

Yep, sounds to me like the heater is bypassed and it's leaking from something else.

Have you performed any of the usual minimal cooling-system service, such as making sure the thermostat functions and isn't gooped up?

[p1n]

If the heater core is by-passed I would expect the heater core outlets to have nothing attached to them.

But unless there is something else I don't know about. The only way to by-pass the heater is to run a hose from the outlet at the top of the intake to the rear of the water pump if the tube is now gone. There is no other way to do this.

You really need to follow that hose around the engine until you find out where it's hooked up at. But even if it somehow is serving as a by-pass, that still wouldn't account for the overheating.

If it's a police car check to see if it is attached to the oil cooler at one place or another. That would be at the front/bottom of the drivers side.

Sory I can't be of more help!

well, even though the pipe under the intake manifold is missing, and that isn't what is hooked to the top of the intake, somehow it is still able to run just fine besides the overheating.. i will do my best to trace where the connected tube is coming from, and it isn't a police model or tow, but i will check the oil cooler too.. thank you for the pointers..

[p1n]

Yep, sounds to me like the heater is bypassed and it's leaking from something else.

Have you performed any of the usual minimal cooling-system service, such as making sure the thermostat functions and isn't gooped up?

yes, infact it has a brand new thermostat. and when i squeeze the upper radiatior hose the thermostat clicks just fine...

if it's leaking from somewhere, are there any tests or ways to find the source of such leak? because if there is a leak, it isn't visible anywhere. and there is no coolant dripping to the ground at all..

[mcninetyone]

You need to check for anti-freeze in the oil, it turns it milky looking.

You need to check for a blown head gasket, they will overheat with this problem, are you losing coolant?

Could you have a warped head? overheating can easily warp an aluminum head.

Could it be a cracked block? probably not but you never know.

And yes, you can do a preassure test to check the entire system, most shops will have a preassure tester and should do the test cheap. Since it is extremely easy to do.

Or, you could try Autozone, they may do it for you or loan you the tester free if you leave a refundable deposit with them.

If it's not a police car it won't have an oil cooler, so that won't be the problem, but look around under there anyway.

Is it overheating real bad? To the point you can't drive the car, or just enough to be a problem?

[Mainemantom]

Does the radiator overflow tank have coolant in it ? It could have air in the system causing it to overheat. A friend had this happen on his 96 CV.

[1987cp]

+1 on no-drips possibly pointing to internal leakage.