91 Jetta Coupe Stalling

[lipunx]

Starts up fine but after it reaches operating temp it stalls out. All I've done thus far was change the fuel filter but that didn't fix it. If driven it starts to buck and eventually stalls but starts up again. I'm trying to get it to at least work so I can drive it 30 miles to my mechanic. I don't know if it's related but the reason I'm taking it there is for a head gasket. Could that cause stalling?

Thanks

[zukgod1]

When it does is it like someone turned off the key or is it like it's running out of gas?

Also, you said it starts fine but after it gets up to temp it dies correct?
So does that mean if you jump in a nd start it up and leave at that moment you get a ways before it dies?
How long till it will restart after it dies? Right away or do you have let it sit and "cool off" for a while?

[Mr_Diesel]

Just a thought... unplug the coolant temp sensor when it dies to see if it starts and runs better.... CTS is blue and located on the front water outlet flange.

[lipunx]

Ok I unplugged it, at first it wouldn't start at all with it unplugged so I unplugged it while it was running. Now it's running fine haha. So I guess I should pick up a new sensor? The other thing that this car does is consume coolant. I'm wondering if it's all somehow tied together but I doubt it. There is also a ton of pressure in the hoses even when the car has been off overnight and the only way to relieve it is to unscrew the expansion tank cap. I'm pretty sure it needs a new head gasket but could it be clogged or something?

Thanks again

[Mr_Diesel]

That sounded like the CTS to me! If the CTS was bad, it could trick the ECU into thinking the engine is cold... Which means it would revert to a pre set rich mixture designed to aid the engine in it's warm up cycle.... except when hot the rich mixture can stall the engine out or make it run like rubbish. I think you can get the CTS from Autozone for about 10 bucks.

If it's burning coolant you will find steam coming out of the tail pipe... It will almost look like white smoke and it won't necessarilly do it all the time... When I had head gasket issues it "built up" somehow and released extreme puffs of white smoke/steam only once in a while. Weird. If it's leaking into the crankcase oil, you would have oil that appears white or cream colored. An easy "back-yard-mechanic" way of testing the gasket is let the engine sit overnight and cool off. Go out in the morning, release the pressure from the coolant tank. Start the engine... immediately rev it up to 3,000rpm.... hold it there for 5 or 10 seconds. Shut the engine off then go open the coolant tank lid again. If any pressure comes out, then compression is leaking into the coolant system. Remember, this isn't the only way a headgasket can fail.

You are sure you can't smell the scent of collant while the engine is hot? Smell the engine :D and check all teh coolant flanges for any sign of coolant leakage. There should be crusty buildup the color of your coolant near the flanges if leaking.

[lipunx]

I ordered a new cts so that takes care of that. Hmm it sounds like compression is leaking into the system unfortunately. I also bought a dye tester kit that sits on top of the tank and if the dye turns from blue to yellow it means there is exhaust gases getting into the coolant system and it did haha. I'll also try that test you suggested tomorrow.

[Mr_Diesel]

Damn, man... I guess you have the 1.8L 8V engine, yeah? I don't think I have ever heard those head gaskets failing. Anyways, head gaskets aren't too hard to do on those. Hardest part is removing the manifolds. It's kind of tedious to remove the bolts in the middle if you don't have the right tools. Anyways... good luck and keep us posted.

[zukgod1]

Damn, man... I guess you have the 1.8L 8V engine, yeah? I don't think I have ever heard those head gaskets failing. Anyways, head gaskets aren't too hard to do on those. Hardest part is removing the manifolds. It's kind of tedious to remove the bolts in the middle if you don't have the right tools. Anyways... good luck and keep us posted.

Cant ya just undo the down pipe and remove the head with the manifolds installed?

[kirochan]

I took mine off at the head when I pulled my head off. No problem with the nuts either. And it was easy to put on too. Just loosen the downpipe though. If you pull off your Cclamps for any reason I can give you a tip to get them back on with a screwdriver and jack. (they were new Cclamps)

But you can leave it all attached. Which ever way you do make sure you have a new gasket or doughnut.

If you pull your head you probrally will need a special tool for the head bolts. You can pick up a set at autozone. And replace your headbolts. I got a 1.8 8v so that I did a head on so if you have any problems or questions please ask.

[lipunx]

I know this is a few months later but I just ordered a head gasket kit from gap and a bently. So I should be able to pull the head off with the downpipe attached? If so that would make it a hell of a lot easier (and I wont ***** out and take it to my mechanic). Poor coupe has been sitting in my driveway for since September now. Btw it's the head gasket for sure because I had the car off for about a month and opened the coolant expansion tank cap and pressure escaped and smelled like poor exhaust almost knocked me out haha.