FPBBrandon
01-13-2014, 08:22 PM
Fair warning- long post, in stream of consciousness form, with a problem I'm not sure how to attack.
I drove my D from Denver to Colorado Springs for Christmas, and while there, I noticed a small puddle of coolant collecting under the car. I took a look under the hood to note a small weep from the fitting that the drivers side coolant hose attaches to. I tightened the two bolts on the fitting just a bit, and the weep was gone. By the size of the puddle, I judged the car needed a bit of coolant, so I drove to the local store, bought some 50/50 and filled the overflow tank. I idled the car with its tail above its hood and the lid to the overflow tank to let air clear through the system. While idling the car, the floodgates opened, and I had large visible coolant leaks under the passenger side behind the rear wheel and at the coolant hose joint at the front of the car, pushing a good volume of coolant out of the system. The volume of fluid in the overflow tank does not change when the car is leaking. There was large intermittent bubbles coming up from the bottom of the overflow tank, probably relieving the air pockets made as the coolant leaked. When I capped the overflow tank, the coolant leaks stopped. The car has been sitting parked in my garage since I returned it just after Christmas, and having left the overflow tank's lid on, there are no puddles or spots on my floor.
The car's heater has not been very good ever since I bought it, and the car has always seemed to run cool. Perhaps a little too cool, based on some of the reading I've been doing. It will always read between the 100 and the next mark up, but always well below the 220 degree mark. When I filled the overflow with coolant and ran it open, the temperature gauge climbed to 220 and levelled off there, and the heater blew hot air. When I capped the Overflow, the coolant stopped leaking, but the temperature gauge dropped back to its normal position of just above 100, and the heater went back to tepid slightly-warmer-than-room-temp air.
Without knowing where the temp sensor is in the system, I guess my concern is that hot coolant is never making it to the heater core unless the overflow tank's cap is off and the car is leaking. I'm not sure if this would be a faulty Thermostat that doesn't open and allow coolant to flow, air trapped in the heater core, or something else. The car was coolant pressure tested before its sale to me about 1000 miles ago, but the car's heater has never really worked, and I'm concerned that coolant is not circulating.
I've also had a flare up of the car deciding to idle at 1500RPM, curable with a throttle blip much like my colleague at the thread referenced here;
http://dmctalk.org/showthread.php?8778-Strange-idling-after-coolant-replacement
Just like in his case, the car will hang at 1500 RPM, and a blip of the throttle brings the idle back down to 750-800. My car hunts idle RPMs when its cold, but I've read this is somewhat normal behavior. What I do find odd however, is as I was exploring the issue at the throttle spool, if I push the hammer back into the microswitch and trip the microswitch, the car stalls out and dies. Very peculiar. The behavior started for me after I had the center console out, and I was checking for free play of the throttle cable worrying I had pinched it on the re-installation, per the advice here;
http://dmctalk.org/showthread.php?8633-Vacuum-Leak&p=126363#post126363
Now all of these symptoms showing up at once have me worried about my headgaskets. The coolant leak by itself could be me overfilling it, the heater could be trapped air, etc, but the combination of all of the circumstances above has me very nervous. I plan to find a compression tester and try to check the cylinders to see what I'm reading. As to the rest, I'm not quite sure where to start. Any advice would be well appreciated. I pulled the dipstick and the oil is clear and not milky, nor do I see oil in the coolant in the overflow tank. The overflow tank does continue to bubble intermittently (once per minute approximately) if I leave the cap off.
On the plus side, over Christmas I reupholstered the headliners, and fixed the dome light, and both of those projects turned out stellar. It seems to go with the old adage of "two steps forward, and then your engine explodes". I replaced it for driving the rest of Christmas with the '87 Audi Coupe, which picked up a star in its unobtanium windshield. Its not a good month for my cars!
I drove my D from Denver to Colorado Springs for Christmas, and while there, I noticed a small puddle of coolant collecting under the car. I took a look under the hood to note a small weep from the fitting that the drivers side coolant hose attaches to. I tightened the two bolts on the fitting just a bit, and the weep was gone. By the size of the puddle, I judged the car needed a bit of coolant, so I drove to the local store, bought some 50/50 and filled the overflow tank. I idled the car with its tail above its hood and the lid to the overflow tank to let air clear through the system. While idling the car, the floodgates opened, and I had large visible coolant leaks under the passenger side behind the rear wheel and at the coolant hose joint at the front of the car, pushing a good volume of coolant out of the system. The volume of fluid in the overflow tank does not change when the car is leaking. There was large intermittent bubbles coming up from the bottom of the overflow tank, probably relieving the air pockets made as the coolant leaked. When I capped the overflow tank, the coolant leaks stopped. The car has been sitting parked in my garage since I returned it just after Christmas, and having left the overflow tank's lid on, there are no puddles or spots on my floor.
The car's heater has not been very good ever since I bought it, and the car has always seemed to run cool. Perhaps a little too cool, based on some of the reading I've been doing. It will always read between the 100 and the next mark up, but always well below the 220 degree mark. When I filled the overflow with coolant and ran it open, the temperature gauge climbed to 220 and levelled off there, and the heater blew hot air. When I capped the Overflow, the coolant stopped leaking, but the temperature gauge dropped back to its normal position of just above 100, and the heater went back to tepid slightly-warmer-than-room-temp air.
Without knowing where the temp sensor is in the system, I guess my concern is that hot coolant is never making it to the heater core unless the overflow tank's cap is off and the car is leaking. I'm not sure if this would be a faulty Thermostat that doesn't open and allow coolant to flow, air trapped in the heater core, or something else. The car was coolant pressure tested before its sale to me about 1000 miles ago, but the car's heater has never really worked, and I'm concerned that coolant is not circulating.
I've also had a flare up of the car deciding to idle at 1500RPM, curable with a throttle blip much like my colleague at the thread referenced here;
http://dmctalk.org/showthread.php?8778-Strange-idling-after-coolant-replacement
Just like in his case, the car will hang at 1500 RPM, and a blip of the throttle brings the idle back down to 750-800. My car hunts idle RPMs when its cold, but I've read this is somewhat normal behavior. What I do find odd however, is as I was exploring the issue at the throttle spool, if I push the hammer back into the microswitch and trip the microswitch, the car stalls out and dies. Very peculiar. The behavior started for me after I had the center console out, and I was checking for free play of the throttle cable worrying I had pinched it on the re-installation, per the advice here;
http://dmctalk.org/showthread.php?8633-Vacuum-Leak&p=126363#post126363
Now all of these symptoms showing up at once have me worried about my headgaskets. The coolant leak by itself could be me overfilling it, the heater could be trapped air, etc, but the combination of all of the circumstances above has me very nervous. I plan to find a compression tester and try to check the cylinders to see what I'm reading. As to the rest, I'm not quite sure where to start. Any advice would be well appreciated. I pulled the dipstick and the oil is clear and not milky, nor do I see oil in the coolant in the overflow tank. The overflow tank does continue to bubble intermittently (once per minute approximately) if I leave the cap off.
On the plus side, over Christmas I reupholstered the headliners, and fixed the dome light, and both of those projects turned out stellar. It seems to go with the old adage of "two steps forward, and then your engine explodes". I replaced it for driving the rest of Christmas with the '87 Audi Coupe, which picked up a star in its unobtanium windshield. Its not a good month for my cars!