Mr. Cynical and the case of the No-Start 99 GTP (197k)

[Mr. Cynical]

It's been cold in Chicago.

After a recent cold snap, looks like I had my coolant mixture just a little off. Just enough to slush things up. I think I've busted the o-ring on my thermostat. (the last time I changed it, a few months ago when the elbow connectors went to the junkyard in the sky, it didn't come with a replacement, so I had to reuse the old one.)

Antifreeze was immediately corrected. I realized what was happening in time, and let it thaw before going anywhere, and promptly brought the mix back up to good. NOW, I'm getting intermittent spitting. I'm theorizing that as the temp is coming up, the housing starts to leak until the thermostat opens. I'll get some steam for just a little bit, and it dries right up as it warms to operating temp. I've got a replacement in the back seat, and am just waiting till I can get the right extension to be able to undo the bolts and replace. Hopefully THAT is all it needs in that department.

Today, I started getting the no-start that sometimes happens in cold weather. It'll turn over, but won't stay running unless I have a foot on the gas keeping it at idle speed. Foot comes off, car goes dead. After the two-footed drive to work today, it was idling really, really low, around 500, and wanted to keel, so I just shut down. Out at lunch to try to replace the thermostat, and it's no-start. I'm in for a two-footer on the way home again, I've already disconnected the MAF to check that, no change.

So, today's question: I'm ready to pull the IAT, but I can't really tell how to get it out to clean. Does it just pop out?

I'd rather not break it; this is still our only car, and we have to go out of state this weekend.

I'll never get away with this if not for you meddling kids!

[Mr. Cynical]

So I made it home.

I went out at lunch to try and parking-lot mechanic the thermostat, but didn't have the right extension to get the thermostat housing off. So there's that still in the mix. I threw a low coolant almost immediately, so I stopped in a parking lot, filled up, and continued on. As usual, got some steam a couple miles in, and it stopped again.

When parking, I took my foot off the gas, and she dropped to about 500 rpm and just shut down. It was already dark, and the wind chill already dropped under 0f, so inside I went.

About an hour later, we had to go to the store for some important items. Got in the car, and it fired right up. No problems. No steam, no low idle, nothing.

I've convinced myself that I need to change the lower intake manifold, and I'm scared to death to go that deep. I think I can see coolant in other areas, but I'm not quite sure yet. (I'm pretty sure)

Now, it's -10f. How long can I nurse this in before surgery is necesary? If I had the means, I'd probably just get a different car, but I can't do that.

I love my car, and I hate that it's hurting like this. I know that's nothing more than anthropomorphisation, but hell, it's seen me through a hell of a lot of years, and a hell of a lot of miles. She's rusty and old, but I don't want to put her to pasture, you know?

[olopezm]

If idle is going that low, I would think there's something wrong with the IAC valve; you can remove it and give it a good clean with carb or intake cleaner, make sure to also clean the passage at the throttle body. Sometime taping on the valve helps, but that's more a diagnosis aid, not an actual fix.

If you see coolant puddling around the head or lower intake, I wouldn't wait much to fix it, if they go completely bad, the engine can get severely damaged, which would mean even more money to fix it. I decided to park my car for some time until I was able to get the right parts.

A hissing noise after turning off the engine is what lead me to suspect the gaskets were bad.

Oscar.

[Mr. Cynical]

So we're back from out of state. Topped off and cruised nice and easy to work, eyeballing the gauges the whole time. Didn't overheat, but got some really nice steam from under the hood. Can't afford to fix it till Thursday.

However, on the way back home (after topping off again - best I can do right now), it was over 50f outside. I turned off the heater.

NOT A PUFF OF STEAM.

Someone tell me that this is just likely a hose, and mean it. I can't do the LIM myself, but a hose, I can do.

[DrRadar]

Turning off the heater doesn't change coolant flow...only the air flow over the heater core. My guess is the "steam" was only water vapor at the warmer ambient temperature.