'93 Coolant leak, oil fine, pump, heater core/pipe OK near fire wall pass side HELP!

[Responder1]

Hi,
I write in hopes an expert will lend his wisdom to a poor student... my lumina is leaking coolant
the rad is intact, the pump doesnt leak, the heater core metal pipe looks new
the leak is at the back towards the firewall on the pass side
it drains the system in a matter of minutes
and yet my oil is not contaminated... so could it still be a head or intake gasket? at 286 000 KMS would you pull it and replace gaskets in a teardown or risk dropping in a 1991 3.1L and tranny with unknown history put runs and has only 190 000 KMS? what prep work would you do to the 91 if indeed i go with that? just the plugs wires, thermostat and an engine rinse oil change? will sensors and wiring and the PCM be the same 90-93?
also, I can't get my fuel filter off and the nut is rounded... can a shop cut it off and reflare the pipe to get me a new filter installed... I think I have a flow problem too
many thanks for any and all thoughts on the issue... I own this car and I would dearly love to see it on the road for a year or 20 000kms at least (graduate, get a real job and a real loan for a real car... living the dream)
Cheers!
Jeff

[richtazz]

Your coolant leak sounds like the heater box drain tube, and is most likely caused by a bad heater core. If you can smell coolant inside the car, or if your windows fog easily, it's a leaking heater core. The 93 Vin-T 3.1L engines didn't have the intake gasket issues that plague 94-newer Vin-M and 97-newer Vin-J 3100's. On the fuel filter issue, there is a fuel line repair kit for the fuel filter connection which is a fairly simple repair. If the fuel filter is plugged up, it can cause a fuel flow issue, so get that fixed first before getting into it any further. Most parts are interchangeable from 90-93, on the ECM, make sure the service numbers match, and swap the prom from your original unit into the new one. I would suggest against installing a used ECM (if that's what you were getting at), as they are a high failure part due to being mounted under the hood.

[Responder1]

Thanks for your input... I got a copy of the relevant haynes manual and checked out the heater core... the problem is I didn't get any coolant in the cabin that I noticed and I don't remember a sweet smell when the major failure occured. I could see the water spurting under the engine (pass side) when I added water and let her idle... or am I not understanding where I should be checking? Also, do you think I could have popped a frost plug?
Also Also...is this an engine in repair if its part of the heater or even a frost plug?
Thanks for patience with a newbie,
Jeff

[richtazz]

Is the spurting coolant coming from down low or up high on the engine?

[Responder1]

I think its from down low...
without rotating the engine forward I tried to look at the valve cover towards the firewall... it seemed wet or spongy compared to the front valve cover...not sure if thats a signifigant finding or if it had to do with splashback or something
but from the fast flow coming out of the car... like a constant stream under pressure really did seem like it was coming from towards the bottom
I have yet to get her home to the driveway... she's stuck out behind the machine shed at my uncles farm 40Kms away (arg)
what's the prognosis doc?
jeff