QuestionQUESTION: Hi Roland,
I have a 1999 Chrysler Sebring convertible JXI with a 2.5L V6 engine that has about 190,000 miles on it. I have been wrestling with this car all summer because it’s been having over heating problems (as well as multiple others) but heating is my main concern at the moment.
My step dad contacted you earlier this summer (early June) on my behalf because I was burning coolant and producing white smoke out of my exhaust. Per your advice, we retorqued the cylinder heads and that solved the smoking problem (as far as we could tell). A few weekends later, I added some stop-leak which ended up just clogging my radiator and my engine overheated to the point of a break down three blocks from my house at 1 in the morning. We ended up flushing the radiator and adding new coolant and for about three weeks I didn’t have any problems.
On Friday the 2nd of July I began to notice some temperature problems. Driving in the city while at a stoplight the temperature gauge would come up to about 65% (and the oil pressure light would come on as long as my foot was on the brake, though it would flicker sometimes and be definitively lit other times) but as I started moving again the temperature would drop below 50% and the oil pressure light would go off.
Now, it’s like the coolant is doing absolutely nothing: engine temperature will rise, then hold steady, then rise some more so on and so forth until the needle reaches the red. I can hear the radiator fan coming on at 50% heat, but that doesn’t seem to abate anything. Also, it sounds like the coolant in my reservoir is boiling once my car gets about 75% heated, which I understand is an issue with the system pressure.
A possibly related symptom is the fact that my car will idle at ~1500rpm when it should be at about 900rpm. It doesn’t have this idling problem all the time, but I can’t determine the variable that makes it so. It may also be worth noting that I had a tune up in January 2010 and I had my distributor cap replaced over the Fourth of July weekend.
If you have any suggestions or ideas I would greatly appreciate them (and I could certainly use them). Thanks Roland.
ANSWER: Hi James,
Do you hear any bubbling sounds in the system fairly shortly after starting the engine? If the radiator seems good and you are hearing coolant release into the recovery syatem when the needle is only mid-scale then it could mean that the system is being pressurized due to an internal head gasket leak. Also watch for any loss of coolant to the ground or again white smoke from the tail pipe when first starting it from cold, just to be sure you don't have an internal leak. I am pleased that you were able to control that by re-torquing the head bolts. If none of those symptoms are present, then a replacement of the filler cap might be in order.
The thermostat might be another item to consider for replacement, but I would also want to be sure that the radiator is flowing well before doing that. Compare by touch the temp of the left and right side manifolds of the radiator. Make sure that the left side is nearly as warm as the right side. which if not would indicate that despite the unit having been flushed it still is somewhat impaired in its flow-through from right to left and back to the right side.
The oil light is not an issue if this occurs at idle and goes off as soon as the idle is raised. It may be mitigated if we can get the engine better cooled. Is your mixture 50/50 in the coolant system, and if not actually boikng over are you having to add coolant frequently?
On the high idle, you might want to see if the engine computer has noticed a fault and put a fault code number in the memory for readout via the plug that is under the dash next to the steering column. Autozone parts stores will ofter do a free code readout. Get any 4-digit fault code numbers and let me know what they are.
Roland
PS: Please 'rate' my answer. Thanks
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QUESTION: Hi Roland,
In the last few days of summer, before I had to go back to school, I spent some time under my time under my hood and replaced the thermostat as well as the cap for the coolant system. For about a month, I wasn't having any problems with my car. Well, in the last week or so, my temperature gauge had been acting erratically: the needle would be stuck at cold after driving for a few minutes, then snap up randomly to a given temperature. Other times, the needle would pop up to about 65% heat, then drop rapidly to 25% and back again. The car has been doing better on the freeway, but the needle fluctuates during city driving. So before my night class this evening, I dumped the rest of my 50/50 water antifreeze mix I was stashing in to my cars radiator cap. I was driving my car to the campus so I could go to class, when I noticed some smoke in my rear-view. In a matter of seconds, I could see smoke coming up from under my hood. Also, the check engine light started to flash. I was close enough to my destination to ditch the car, so I nabbed the first parking spot I saw and proceeded to pop the hood. I was unable to see where smoke was coming from EXACTLY; to me, it looked like smoke was coming from every connection coming away from the engine, as well as from somewhere under the exhaust manifold. What are your thoughts?
(also, I took my car to autozone one day to see if there were any engine codes. I got one related to the IAC (which was NOT related to my "high" idle problem because a. my problem was actually a idle speed that was too low and b. I still get a high idle sometimes), but the only other message the OBD device gave me was that there was some sort of manufacturer lock. possibly the OBD will display BLATANTLY obvious problems that cause the check engine light to come on, but irregularities such as faulty engine timing are not displayed)
AnswerHi James,
I don't understand how it could be going well, except for the somewhat unusual temp gauge needle behavior, and then when you add antifreeze it really begins to act up. But let me say that those unusual swings in the gauge could be the result of air trapped in the cooling system which if located in the thermostat housing can lead to sudden changes in actual temperature as 'seen' by the coolant temp sensor as air leaves and coolant enters. But more of concern to me would be the sign of smoke from the rear if it came out the tailpipe. So start the engine briefly and see if you find smoke coming from the pipe in large amounts and also if you can let a bit of that condense on your hand see if it smells like antifreeze. All those signs would indicate to me that you have a head gasket leak that is allowing coolant into the combustion chambers (and would leave air in its place in the cooling system (which I conjectured about above). If that is the case, then I would suggest removing the spark plugs from the front bank (those are easier) to check if the plugs look wet, and after the engine cools down with the plugs out of the sockets try cranking the engine while a helper watches to see if coolant is pumped out the spark plug holes. If so, then that side of the engine has a blown gasket. If not, then more likely it is the rear cylinder bank that has the blown gasket.
Roland
