A few days ago, after about 15 minutes of driving, my car stalled, the temp gauge shot up and I glided over to the shoulder. I pop the hood and see coolant everywhere. A hose from the block to the firewall burst. I presume that is the heater hose. I tried to start the car up again in order to move it a half block to a safer spot. It would turn over, but immediately turn off. At that point I assumed there was something seriously wrong with the engine (head gasket, warped/cracked block). While waiting for a tow truck, I notice that the radiator was not hot.

Today, I cut the hose and reattached it in order to do a leak check with a block tester. I also put in some coolant/water. I didn't notice a change in color with the leak check (yes, I followed the directions on the box). The car was able to idle for about 15 minutes before dying again. Just like how it died previously, it would only come back to life for a second or two. This time the radiator was hot. I thought I saw a very small puff of smoke come out of the muffler, but it could have been steam. There are no signs of oil in the coolant system and no signs of coolant on the dip stick. I only saw steam come out of the radiator. Any ideas of what I should troubleshoot next? Should I try another leak test?

 

It sounds to me like your thermostat stuck closed and the heater hose was the weak link
that blew. I had a pinhole leak that shot onto the alternator and killed it.
Coolant plays havoc with electrical stuff, I would start by cleaning any connectors that
got sprayed, it's easy and cheap. Also check fault codes, this might give a clue.

 

Thanks! I'll check that out in the morning. The hose burst right next to the distributor where there is a huge variety of wiring harnesses :-/ . I didn't notice the check engine light going on, but that could be a lack of awareness on my part.

 

If the distributor got blasted, I would pull the distributor cap and check inside.
normally if the cap has moisture it usually mis-fires and runs rough, but better safe
than sorry. Do you know how to check your ECU fault codes?

 

Thanks! I know the MacGyver method for fault codes. It seems like my symptoms might correlate to problems with the ECT/ECT sending unit, which are next to the distributor and were blasted. I'm off to clean everything off - I'll try to pay special attention to those.

 

It appears that the problem is solved. I have yet to take it on a test drive, but it idled fine for about 45 minutes. The temp gauge went up from the bottom up to about 40% (normal operating temp) and stayed there. Radiator fan kicked on as normal. The idle started to be a bit rough after 15 minutes, but that cleared up after 25-30 minutes.

What I did:
Checked for fault codes - no error codes flashed.

Took off distributor cap - found condensation and a small amount of sludge on the inside edge of the cap. Cleaned it off. Also found a small chunk of black plastic housing inside the cap, but I couldn't find where it broke off from (?). From the looks of things, I'll probably need a new distributor in the not too distant future.

Put cap back on, took off distributor. Cleaned off small amount of sludge close to o ring.

Cleaned off massive amount of sludge and coolant around ECT sensor, EC sending unit, and various other electric components in the region. Took connectors off and cleaned them out with contact cleaner after carefully scraping out sludge.

Put everything back together. Then I turned it on and ran a block test again. Test liquid stayed blue.