Fried_Chicken

this is going to be pretty long, but i feel you need to know whats been going on the last few days to fully assess the situation, so please bear with me.

8/25
i have a 96 gsx, and i took it to a friend's house to have an 02 housing put on. the car sits too low to fit a jack underneath it, so i drove the car in between the driveway and the street to create a space for the jack to fit. i turn the car off and the turbo timer kicks in. well after the tt runs for it's alotted time, the car is still running. and all the while the coolant/temp needle is steadily rising. we unplug the battery. no go. at this point the coolant needle hits the top of the gauge and coolant starts to spew from the overflow tank. we unplug the spark plug wires and shut the car off. after letting the car cool down, we bolt the 02 housing back in, add coolant and i get the car home asap.

the problem isn't the fact that the car stayed running, thats been taken care of. read on. during the drive home, the car didn't overheat. i even let it idle and it didn't overheat. the fan came on like it was supposed to.

8/26
in an attempt to change the 02 housing out again, i drive over to my friend's house(car is fine, no overheating) and he changes out the 02 housing. i hop in the car ready to leave, turn the keys and the car starts and then dies almost instantly. we thought the problem was electrical, since the gaskets were put on correctly, and everything was bolted up like it should've been. fast forward to today.

8/27
we start the car up, it idles really crappy at maybe 100-400 rpm. it dies most of the time, but we catch it idling a few times and try to give it gas. a stream of white smoke comes out of the exhaust, not alot but enough to make me think that a blown head gasket is a serious possibility. the car is outfitted with a 4 layer cometic hg, so it'd take a lot to blow it. we burped the coolant lines after adding some. no go. we replaced the spark plugs. no go. unplugged the maf sensor and even changed the 02 sensor. no go. there was no coolant leaking from the seals or anything of that nature, and we checked the dipstick to make sure there wasn't any coolant in the oil.

honestly, i'm leaning toward a blown head gasket. but the car NEVER overheated that rapidly before, while idling no less. sure it would slowly rise a bit if you stayed in WOT/boost, but i assume that's normal for boosted applications. any ideas? anything would be appreciated at this point. thanks in advance guys.

you can reach me at 757-619-0970 if you wanna talk in person. my name is ri.

Fabrik8

I'm thinking that the O2 sensor housing has nothing to do with the problem here.

Was the turbo timer somehow wired such that the fan doesn't come on when the engine is being kept on (by the turbo timer)?


You can blow a head gasket from either a lot of pressure, or too much temperature. You have a good head gasket, which will keep it from blowing with too much boost or cylinder pressure most likely, but that doesn't keep temperature from being an issue. If the head or block gets too hot, the expansion forces can be so huge that it really doesn't matter what type of head gasket you have. It can still warp and leak, and now there may be a path through the gasket or some type of misalignment. Whatever it is, if there is water getting into the cylinder then it may not do it all the time. It might only do it at a certain water temp, or engine temp, or both. I'm not saying this is the issue, I'm just trying to get you thinking about how this stuff works.

Not all head gasket failures result in water in the oil, that really depends on how a head gasket failed and where on the gasket, and how much of a leak there is. It may just be weeping water into the cylinder when the coolant system is under pressure, for example.

I'd be surprised if you blew a head gasket overheating just once, but I've seen it happen before.

Fried_Chicken

^ thanks for the swift response. what would you suggest doing next? the funny thing about the fan is that when ever i start the car and it dies, the fan starts spinning briefly. and i believe that the fan only comes on when the ecu senses that the engine is too hot. i'm trying to avoid taking it to a shop, but i'm seriously stumped on this one

Daft Punk

check your connections on your turbo timer. i would recommend solder the connections this time if you find a bad one.

Fried_Chicken

when we couldn't get the car to shut off we cut the turbo timer wiring where it hooks up to the e-brake. and the car was still running lol. but that problem was resolved, it was the ignition wiring. i just don't understand why it overheated, and why i can drive it one day and the very next day it won't start or hold idle

Fabrik8

In many/most cars the fan is controlled by a mechanical temp switch, I don't know enough about DSMs to know if that's true or not here. Why your fan is coming on after engine stall I don't know, unless something is interfering with the fan turning on and off as normal.

Fried_Chicken

to be more accurate, when the car dies the last thing you hear is the fan shutting off. i'm just amazed because i drove it fine yesterday. not even 8 hours later, it won't run. i guess i'll have to start looking at shops

Fabrik8

Well, if the fan is already spinning, it'll take time to spool down once power is removed. That seems normal. That might mean that you have a thermostat problem and the fan needs to run more than usual to try to keep the engine at proper operating temp though. the fan should be turning on and off at idle because the heat generated isn't that much.

Fried_Chicken

a faulty thermostat could keep the car from running? or were you speaking in reference to the fan?

Fabrik8

Yes, the fan. It would need to work more to cool the engine if the radiator isn't getting proper coolant flow through it.