Need Help Diagnosing a car?
(2011-10-20 14:20:13) 1. Says: -Rough idle(slight shaking) once the car has heated up.-On the freeway the speed hesistates occasionally then bursts in speed
-the engine overheats but the raidiator is new and there is no coolant leak
-The car has died on me twice
-loss of gas mileage.
I was leaning toward fuel injector but I am not too sure. It doesn't make any actualy noise like a grinding or screeching and the actual driving is still okay so that is why I do not think it is the tranny. Although I got to take it in on thurs or else it may affect my engine/tranny :(
Any help plz,Thanks in advance!
92 camary.
No transmision light on, the check engine light is on but at old cars like that it is pretty much always on.2. Says: Ok, before you take on any of these other answers and try them out, I've got a solution here that I think is exactly what your looking for and is extremely easy and cheap to fix.
By the sounds of it your thermostat is getting sticky on you.
Why i say that is because the rough idle is your fans kicking onto high power because the engine is getting hot because the thermostat is stuck and it is trying to cool it down. You will feel those burst of speed because the thermostat will all of a sudden open and let the coolant into the engine and everything will go back to normal for a while until it gets stuck shortly after again. The new radiator is great, but its not being used because in order for coolant to get to the engine it has to go through that thermostat which controls the amount of coolant that is let through by pressure. After the coolant runs through the engine and your heater core it then goes to get cooled off through the radiator. The loss of gas mileage is just another symptom that fits in with the thermostat.
Replacing a thermostat should take 5-10 minutes and about $10 out of pocket.
Just replaced mine last week, literally my car was doing everything you listed here lol
But change it out ASAP, a simple $10 piece will save the car from thousands of dollars worth of damage to the engine!3. Says: Suggest OBD1 scan first to check codes and get sensor readings before you waste money on stuff you don't need. There are various sensors that can cause you condition. Could also need new fuel filter should be replaced every 36,000 miles. If engine overheats could also be part of problem. Get pressure checked and thermostat and rad. fans checked also. Also possible leaking head gasket if no visible leaks. Any time engine light on you have a problem maybe minor or major problem, that's why you start there.4. Says: You have a blown head gasket or cracked head, the engine is basically shot. There are probably multiple problems going on. And check engine lights are not "always on" on old cars, I have some.
....5. Says: all the symptoms point out to oxygen sensor failure. if it is failed, the malfunctions start after vehicle warm up and the warning lamp comes on. so better replace and check6. Says: The chck engine light is on because the computer has set a code relating to the problem. Now, this is the old OBD I diagnostic system so you will need a scan tool with the right adapters for your car in order to retrieve the code. This way, you have a basis on whatto do to go about repairs.
As gokul nair already said, a failed oxygen sensor also stuck out in my head. This being bad will also be accompanied by black, sooty exhaust expulsions and a "rotten egg-like" odor. This means the engine is running very rich and the computer is trying to compensate by leaning out the mixture too much, which could explain why the engine is also running hot. So basically, check for trouble codes and if it boils down to the oxygen sensor, replace it. Good luck. Tag: Need Help Diagnosing a car?