Possible Coolant System Problem - Effecting Idle - Help?

[HashiriyaS14]

Ok, so I just bought a nice 1995 S14 Automatic. 133k on the clock, bit of chain rattle, leaky oil pan gasket, but generally a nice solid car.

It just had the distributor replaced by the previous owner about a week ago. It started , ran, and idled fine after that.

Just before I took delivery, the previous owner said that while he had been driving, the car began to overheat. Apparently, the lip that keeps the radiator hose on the radiator had somehow failed, and the radiator hose had slipped off while driving.

He firmly hose-clamped it back on, with a couple of clamps, and then it was good to go. When I took delivery, soon after driving away, it began to overheat again. I pulled over and checked the hose, and it was still attached. The coolant resevoir was completely dry though, and so I pulled into a gas station and refilled the coolant with off-the-shelf summer stuff, just whatever they had. Mind you, this only entailed about 1/8 mile of driving from car pickup to the gas station.

The car continued to overheat a tiny bit for the next 1/4 mile or so, and then it appeared fine. It drove to my garage, about 10 miles away, without incident.

I went to start it the other day, just to check up on it, and it would start, but not idle. It wouldn't sputter or anything, just immediately die if I didn't keep it revving. Then yesterday, I kept it revved (about 3k rpm) for maybe 5-10 seconds, and then it settled down, with a bit of sputtering, back to idle.

My question is, what is going on with this car? Vacuum leak, coolant temp sensor, air bubbles, que? I don't really know what I'm doing, so I didn't want to keep starting and revving it if I was going to do some sort of damage. What should I check to narrow down the cause?

Thanks in advance

[nametakennow]

Sounds just like what happened when my coolant temp sensor went...

Then again I had faulty injector wiring at the same time...

But yeah, sounds like temp sensor to me.

[HashiriyaS14]

How hard is the sensor to replace?

I don't need a detailed description of where it is/how to change it, I'm sure I could search for that, I'm just wondering if this is going to have to be a shop visit or if it's just a couple hours of wrenching.

[HashiriyaS14]

I'm also wondering about the possibility of air bubbles in the coolant system.

The hose just came off, then the guy put it back on, and I put in coolant. There was never a flush or anything like that. Should I not be revving the engine until I do a proper coolant system flush?

I don't want to break anything.

[tiger]

Well.. with the KA's you have to be sure not to have any bubbles in the cooling system.. ...with the car running..heater switched to HOT..I turn the fan on ... just get yourself a good jack and put it under the front end on a jack point... jack it up some and add coolant... then take the screw off and let bubbles and stuff come out, jack up more and repeat.. give it a couple bumps.. squeeze the hoses a little and all the air bubbles should rise up to that small hole and come out. I guess you'd have to get the car running smoothly before you'd be able to do that... does your exhaust smell strongly of unburnt fuel? When I first got my car there was so much wrong with it you wouldn't believe... It had idling problems and the coolant temp sensor and wiring was bad... it was a very easy fix.

[HashiriyaS14]

When you say "the screw", do you mean the radiator cap? I think I'm going to try this this weekend.

The car idles fine/runs smoothly when it's warmed up. Once I've been driving around for awhile, I can turn it off, and then turn it on again and it'll start right up with no funky idle, it's only after it's been sitting.

[tiger]

nope.. I meant to say the bolt right above the coolant temp sensor.. it has a little gold label in front of it that say "do not open when hot"

[HashiriyaS14]

I didn't notice it so much until today (car started in a garage instead of out in open air), but the exhaust does smell strongly of unburnt fuel.

I will be able to do the coolant system "burp" just fine, as the car runs perfectly smoothly once it's warmed up.

I guess I need to track down a replacement coolant temp sensor.

EDIT: Tried to get sensor off, couldn't do it. It was *really* gunked up on the bottom, just caked in stuff. Looks like there's a strong probability it'll just need a cleaning. I also wasn't trying very hard, because I have a suit on, but I'll try harder later.

[tiger]

yea they are very cheap at the auto parts store, just replace it.. get a wrench on it and turn it.. when you install the new one.. just wrap some teflon tape around it to prevent leaking.

[HashiriyaS14]

Ok, I'm at work right now, getting ready to go get a replacement sensor, when it occured to me that I'd probably have to drain the entire coolant system to replace the sensor.

Is that accurate? If so, I definitely can't do that today, not here.

[Silvia2NR]

you don't have to drain anything. just make sure the engine is cold..you don't want any pressure in the lines. You will need a deeep socket. a little coolant will spill..no biggie.

[HashiriyaS14]

Ok, coolant temp sensor replaced.

Problem persists. Exhaust still smells of unburnt fuel.

When it's been sitting for awhile, car will generally start fine the first time, and then worse each successive time. The second time it may sputter a bit, and then the third time it generally will sputter and die, fourth time it may not start at all.....

Any other theories as to what might be causing this?

It recently had the distributor replaced and it had the cooling system problem I mentioned up above. Either, or something else, could have something to do with this.

Once it has been on for a couple minutes, it idles FINE. The idle does NOT sputter around except when starting. The battery has plenty of charge.

[JNM240]

Did you replace the electrical connector to the coolant temp sensor? Or even clean it up a little? I bet if the sensor itself was coated in gunk, then pigtail electrical connector is a nice bright shade of green. Pick up another (off a junkyard donor or something similar) and solder it in place.

[HashiriyaS14]

Did you replace the electrical connector to the coolant temp sensor? Or even clean it up a little? I bet if the sensor itself was coated in gunk, then pigtail electrical connector is a nice bright shade of green. Pick up another (off a junkyard donor or something similar) and solder it in place.

I sprayed some electrical contact cleaner on the connector before re-attaching it. It actually looked fairly clean inside (totally gunked-up on the outside).

I've never soldered anything in my life, so I'm not up for cutting or soldering anything. Is everyone really pretty sure that this sensor is what's causing my problem? Any other ideas?