capezig

Settle in, this is gonna take a minute...
So my daughter calls and says the D4 is flashing. Jump the connector, code 1. Checked the lock-up solenoid and one side sparks a couple times and then both sides start clicking again when getting 12v off the battery and both sides measure about 15 ohms...good enough. Reset the codes and carry on. Quick test drive and find the rpm's are surging 1000-2000 or so in Park and Neutral, steady but too high in gear standing on the brake. Decide to take it back to my house because this does not seem like a parking lot job. Make it about a mile before the engine temperature starts to spike. All stop and the nice guy from AAA tows it home instead.

Upon further review in the home garage: only about a quart of coolant drains out of the engine/radiator, melted plastic/rubber in the neck of the radiator, melted rubber seal on the valve disc of the thermostat, lovely burnt smell in the radiator neck and behind thermostat, a little more oil than is acceptable on and under the intake manifold down the back side of the engine, a coolant drip from somewhere on the driver's side rear of the engine that drips on the left half shaft (drive shaft) (edit: terrible sinking thought...is there a tell tale hole or such for the water pump that would come out in this area?), CEL stays on solid when connector jumped and off when running (no codes), no codes on D4 or ABS. No coolant in the lube oil. There was a decent level in the recovery tank, but that was obviously not getting sucked back into the system...

So...I'm thinking to replace the thermostat (that seems to maybe be the initial failure) and radiator cap (that the guts melted in), fill her up with coolant ( what came out was awful watery) and burp her, and then see what else leaks. I've seen some stuff about cooling system faults causing the temperature sensor to cause whacky things with the idle due to mixed/bad signals so perhaps there is that connection that might make sense. The lock-up solenoid maybe stuck due to high heat as well, causing the initial warning that got me into this.

My daughter reports that she never noticed any warning lights or high temps until the D4 started flashing.

Overall this does not seem like its looking real good for the home team (and this engine), but I would love to hear some thoughts from guys that know.

capezig

The next phase was completed tonight. New thermostat installed, radiator neck cleaned up of all melted debris and checked the hose to the expansion tank for being clear. Next I started refilling the cooling system, right up to the point where it started running back out of the water pump tell tale hole. So, next I learn how to change the water pump on this engine with my trusty Haynes book..

I still would love to hear some thoughts from guys that know, what is going to be the next failure I find after changing the water pump out and trying again to re-fill the cooling system ?

And now the questions re: how this went down multiply...what went away first ? Water pump, thermostat, radiator cap...or another culprit as yet to be located

holmesnmanny

The very first thing you need to do is to compression test the motor. It's likely the head has warped. Whenever a car starts to overheat it's really important to immediately pull over and turn off the engine but turn the temperature **** to full red and turn the heater blower on full blast to help cool the engine. Fixing an overheated engine is minimal cost compared to that of an engine that fully overheated to full red and warped the head.

capezig

holmesmanny, thanks for the compression test idea/thoughts...I will do that soonest. I was still back on trying to find all the cooling system problems, figuring to keep filling it up and seeing where it runs out of next. I was guessing that after the water pump the next site of failure to inspect would have been the head/head gasket, but I had spaced on a compression test.

capezig

holmesmanny, compression test results don't seem horrible...#4 (distributor end) 160-175, #3 175, #2 175, #1 175-185. Two or three passes on each cylinder. That trend probably means something to someone else, but I'm thinking in my simple thoughts that at least all 4 have compression...so no blown head gasket hopefully, and no warped head hopefully? New water pump, timing belt kit and drive belts arrived today but it will probably be a week before I get a chance to turn a wrench again on the car. So there she sits adjusted to #1 at TDC and waiting to have the front end of the engine ripped off down to the water pump.

amerc

Heat issues are related to cooling system (most probably) ... I would check first the
1- The coolant level (leak beneath the engine, close to the water pump)
2- Hoses in the coolant system (for leaks)
2- Thermostat ...
3- Engine fan (should start only when the engine gets hot and turn off when the temperature gets normal)
4- Engine oil

** Check your transmission since the D4 was flashing.
As a general tip / advice check your engine oil and coolant liquids regularly before each drive and notice any change. Also while driving keep checking the temperature gauge.
All of these can be checked while the engine is idle and running. It is not safe to drive when the engine overheats so much .. could damage the engine.

capezig

amerc, I appreciate the reply. I think I have already covered most of your points, some in the initial post. My daughter was driving the car and did not catch the overheat condition until the D4 flashed. That was a stuck lock up solenoid which was gently persuaded to work again. The coolant was cooked out except for about a quart. When I can get the system to hold coolant I will check the hoses, but they are only a couple years old. The thermostat was melted, and has been changed. The radiator cap was melted and we have a new one on hand. The engine fans are fairly new, but good idea to check when I can get the car to hold coolant again. The engine oil was ok and not milky, so combined with the compression test results above I am hopeful that the head and head gasket are ok. Once I get the water pump changed out, which was definitely chooched since it would not hold water even not running, we'll see what the next thing is. As always, any and all replies and ideas are welcome.

capezig

Wrap up...I think...with the water pump changed, the cooling system again is holding water and seems to be operating correctly with its new thermostat, radiator cap and fresh coolant. No other leaks are evident at this time. Of course, while all the way into the water pump, we also changed the timing belt and balance belt w/ new adjuster pulleys, as well as new drive belts. Everything went back together with no parts left over (a bonus) and it even runs! About 217,000 miles and still on the road...what's next?