coolant incident???

[mitsubluetalon]

Hey guys, i have a little incident here. i was coming home from work and when i was just about home i was coming to a stop sign, so i downshifted and braked. and as soon as it was in neutral rolling to a stop, my car started sputtering and stalling, hitting 500rpms and jumping up to 1100 and it even stalled completely out once. now my coolant light was on, so i checked it and it was a little low. I know it didn't leak out however, it was probably just that i was recently working on the coolant area and didn't fill the reservoir all the way up. *this incident was just before winter and have been pondering this since*. So i got in my garage with it still stalling and popped the hood and added some coolant to the reservoir, and like magic my car started running completely normally.

1. why did this happen?

2. i'm glad it wasn't something really serious but what does the coolant LEVEL have anything to do with the idle? *my engine temperature at the time was normal and no codes from the ECU came up. the coolant reservoir wasn't empty, just really low*

3. i see that there are coolant lines on the throttle body for the idle speed controller for making the engine rev higher on startups in cold weather, but is there any other purpose for them?

4. if they are just for that, why would my car run so eradically because of it?

5. is this maybe caused by something else malfunctioning? sensor? idle speed controller?

 

[boostedgst2984]

wow thats strange. My car when it tries to overheat the ecu automactiaclly ups the rpm to like 1500 2000. And those coolent hoses to the tb are only for warming up the air in a really cold temps. I dont even have mine hooked up cuz i wont need them ever.

 

[luv2rallye]

Holy water? !

 

[mitsubluetalon]

HEHE yeah i guess.............has anybody else ever had this kind of experience or know about what happened?

 

[GTM]

...
added some coolant to the reservoir, and like magic my car started running completely normally.

1. why did this happen?

2. i'm glad it wasn't something really serious but what does the coolant LEVEL have anything to do with the idle? *my engine temperature at the time was normal and no codes from the ECU came up. the coolant reservoir wasn't empty, just really low*
...
5. is this maybe caused by something else malfunctioning? sensor? idle speed controller?

It's possible it was in "limp home mode" because the coolant was low. The temp sender and the temp sensor require complete immersion to read correctly. They won't work off steam or radiant heat until it's too late. You should check the the level through the radiator cap and not the overflow to make sure you have a filled system. Certainly you should monitor the system until you are certain that you have no other problem.

Cheers,
GTM

 

[mitsubluetalon]

Hey thanks GTM........yeah this happened just before winter, probably just preparing the car for winter by changing coolant-water mixture and the thermostat. No problems since except for the fried ECU............geh! what a nightmare. I just bought a couple more, one of which has been performance modified, and the other a direct model number replacement. so yeah thanks again. Oh, could you explain "limp home mode" to me and what other failure would cause the ECU to go into that mode? just intrigued as to how my car works. thank you very much.

Friend to the North

Jason.

 

[GTM]

Hey thanks GTM........yeah this happened just before winter, probably just preparing the car for winter
...
No problems since except for the fried ECU............geh! what a nightmare.
...
I just bought a couple more, one of which has been performance modified, and the other a direct model number replacement. so yeah thanks again.

Oh, could you explain "limp home mode" to me and what other failure would cause the ECU to go into that mode? just intrigued as to how my car works. thank you very much.
Friend to the North
Jason.

Your welcome. Don't feel bad that coolant fill nonsense has done in many a person.
..............

Nothing like being a pack rat with ECUs when one lets you down.
..............

Limp home mode as I understand it is supposed to first fire 2 cylrs for a while and then switch to the other 2. It doesn't fire spark plugs or injectors on the limp cylrs so only cool air is taken in so supposedly pistons don't melt etc. Needless to say you won't have any power and I'm thinking 40 mph max. I've not heard any distance figure for this. My Northstar which runs 12 qt oil claims 50 miles without water so if you let it cool off you could leap frog stopping at every McDees for coffee and a leak. I've seen 252F a couple times but never switched to limp mode.

Some of the new engines can change the cams so the exhaust valves are held open on the compression stroke until it's their time to switch from cooling to propulsion mode... aint science wonderful.

Cheers,
GTM

 

[drk mrk iv]

wow thats strange. My car when it tries to overheat the ecu automactiaclly ups the rpm to like 1500 2000. And those coolent hoses to the tb are only for warming up the air in a really cold temps. I dont even have mine hooked up cuz i wont need them ever.

How would you plug up these lines? I have a leaky one right now and would rather just not have it plugged in.