'03 EB V8's water broke. Trouble diagnosing

[Lost Sailor]

I have a 2003 4.6 EB with 45k miles. About a month ago I noticed the "heat" wasn't really heating the cabin anymore. I drive short distances normally, but usually, the heater comes on and cranks after a few minutes. The blower will now come on, but no heat to speak of. I'm not sure this is related to the more serious problem, but I wanted to mention it first. I don't think it's related. I've also noticed my MPG slowly dropping over the last month: from 17.9 to 15.3 today. Not good.

So a few days ago, out of the blue, the temp gauge redlines and it goes into safety mode. Then goes off, and I'm at my destination. I remembered a post here about someone's doing that while getting on the highway and couldn't remember the reason, but sort of forget about it, hoping it's a quirk.

Then today, I'm on the highway for a few miles, coming home, and once again temp gauge goes straight up, EX goes into safety mode, service engine soon light is on. I make it home (just a mile away) and park it in the garage. Steam from under the hood and that familiar smell. Open the hood, and there's water everywhere on the driver's side-above and below. Also dripping heavily from underneath, of course. I climbed all over and under the engine compartment and couldn't pinpoint anything. I can't see any busted hoses, any indication of where it's coming from. Let it cool, check the coolant level-not bone dry, but darn close. Fill it up, cut it on with the AC running and let it idle for 30 minutes hoping it will act up again and I can see where the damage is...nothing; running great, but 'service engine soon' light remains on. I drive to the store, stop by the bank, let it run, hoping I'd get some adverse response for diagnosis--runs fine. There is also white crap all over the engine cover, which I'm imagining is dried coolant. But I can't get it to overheat again. I have no doubt it will with some extended driving, though.

I noticed on my trip to the store the cabin heat is back.

I'm hoping it's a hose with a leak, that I can replace myself with some new clamps. It seems with so much liquid coming out today, I'd be able to see something after letting it run, and it's not a slow leak. But I can't see what's going on or what may be causing this-not a drop now, and the engine was up to normal temp (according to the analog gauge).

Anyone had any problems like this? Anyone have any ideas? The last thing I have the time and $ for is a trip to the dealer, especially if it's something I can fix myself. But think I may be spending my Friday there, if they can even get me in....uuuggghhh.

Thanks for any help!

 

[rrgone]

Sounds like the thermostat is shot and sticking open then closed.

 

[sledneck9]

i agree the stat is probably bad or you had a air pocket in your coolant system and it worked its way out.

 

[Lost Sailor]

I guess I'm going to have to make an appt. at the dealer...at least they can pull the codes and cut off the service engine light and check the pressure.
I'm just afraid they're going to start replacing things unnecessarily.

I still can't get it to act up again, although I checked the coolant level today after driving it for a while and it was a little low-not much. My biggest concern is the gas mileage dropping so much so quickly (18 down to 15). Maybe it's the O2 sensor and it's running rich? Who knows....

 

[rrgone]

Those are 2 good ideas, but you don't have to go to the dealer if you think you'll get ripped. Some auto parts stores (Autozone) can pull codes and try to reset them for free. If it's a continuous fault it will just come back. You can try a radiator shop for pressure testing the cooling system instead of the dealer too. Have them put in a new t-stat while you're there. Let us know how you make out.

 

[Lost Sailor]

Well, just an update: went to Autozone to have the codes pulled 2 days ago. Service Engine Soon light, which has been on since the initial overheating went off as I was heading over there, of course. Got there, he tried to pull codes, said what he was getting was up the 1200 range, and all his manual would read was 400 and below, or some nonsense like that. No help at all, which was about what I expected from them.

Took it to a radiator shop today. Put a pressure tester on it and it read fine. But inside the reservoir there was a buildup of gook on one side of the container and a ring around the inside of it of goop, which looks like bacon grease. I asked the guy what it was, but couldn't understand him, even after asking 3 times, so I didn't want to keep asking.

He said Ex's are notorious for getting a pinhole leak in a seal in front of the head, but that wasn't my problem. He also didn't know why or from where all the spraying/leaking had come from on the driver's side. Neither of us could see any leaking anywhere, as usual.

He said it may be the pump, may be the t-stat. But he suggested putting some dye in it and checking it out the next day to see if and where there's a leak. I don't have time this week to go back, so I plan on doing it next week if possible. Not that I want to put this off. The coolant level (it's just h2o in there now) is dropping, but very slowly. The dash gauge has been reading just below center, on the cool side.

My biggest worry is the MPG dropping, and continuing to drop. I reset the dash computer this morning when I filled it up, but it was down in the 14's beforehand. Just a few months ago I was in the 17/18's, and it's been dropping quickly ever since I had the overheating issue. And it might be my imagination, but it sounds like it's louder when I accelerate from a stop like it's having to put more effort into getting going. My worst nightmare is that water is leaking into the engine. And I have to make an 800 mile trip this weekend.

 

[rrgone]

Thanks for the update Lost Sailor. Good luck chasing this gremlin - keep us posted what you find out.