cooling system leak

[lilmanu24]

I seem to be leaking coolant from the back side of my engine, but not totally positive. I would like to find some diagrams on the cooling system but am having a hard time finding one. I don't know of any hoses on the back of the block. Can someone please help.

[fopu]

What engine do you have? Your profile says something about a 90 Lumina but nothing about the engine. How do you know that what you see is coolant and how do you know it's coming from the back side of the engine? There are no hoses back there but if there's a leak, it may come from the head gasket... How does your oil look?

[lilmanu24]

I forgot to mention what type of car it was. 1990 Chevy Lumina 3.1

[jeffcoslacker]

You've got heater lines back there

[jeffcoslacker]

There may be a small fuel line sized heater hose that goes to the throttle plate on that, I can't remember for sure. Get a mirror and a flashlight, you might see where it's coming from.

[lilmanu24]

Originally Posted by fopu

What engine do you have? Your profile says something about a 90 Lumina but nothing about the engine. How do you know that what you see is coolant and how do you know it's coming from the back side of the engine? There are no hoses back there but if there's a leak, it may come from the head gasket... How does your oil look?

It is the 3.1 liter v6, and the fluiud is green, smells like coolant and there is steam rising when the engine is hot. My oil is clear and not milky, hence the reason I asked. I am not sure if one of the heater hoses at the fire wall are leaking and spraying coolant, I need to check. I just hope it isn't a head gasket. My wife would shoot me then. We just got done replacing the water pump and hoses because they were leaking. The leak went away for 1-2 weeks and reappeared 2 days ago.

[dwalmop]

Jeffco's right. There are a couple coolant by throttle, one as he described. The other one, however, goes to the front of the engine, so if it is that one that's leaking, it has to be leaking right at the throttle body area.

[jtls66]

Originally Posted by lilmanu24

It is the 3.1 liter v6, and the fluiud is green, smells like coolant and there is steam rising when the engine is hot. My oil is clear and not milky, hence the reason I asked. I am not sure if one of the heater hoses at the fire wall are leaking and spraying coolant, I need to check. I just hope it isn't a head gasket. My wife would shoot me then. We just got done replacing the water pump and hoses because they were leaking. The leak went away for 1-2 weeks and reappeared 2 days ago.

Check those small lined right under the throttle body but also be aware the 3.1 engine looses intake manifold gaskets all the time. They either leak water in the engine or it will drool all over the top of the trans. Head gaskets usually don't leak outside the engine.

[crazee2u]

Had the same prob for awhile...and it sounds like mine. My best advice start at the heater core inlet under the hood (2 silver hoses in the firewall) follow them down they will turn to the pass. side of the car (my leak was at that connection) it then turnes again and goes up by the water pump area. I am not sure where it goes cause I didn't need to go that far. I would let the engine cool and stop drippin ( and dry a little) and then start the car to see it start. AS A LAST RESORT most auto part stores sell a blue dye that you can add to help detect leaks. I have never used it but I have told it works but can cause more probs. Again I have never used it so i don't know