Dodge Repair/Symptoms of a blown head gasket
I had to start a new question since allexperts.com only allows three. I did not see any codes, but only "done".
No fault codes leaves us with no alternative except to check for exhaust gas presence in the cooling system which a radiator shop will have a device to check out. With such a leak there is the possibility of the symptom you most recently described as being due to that. The white smoke from the exhaust pipe when you first start the engine from a cold shutdown will also have the odor of anti-freeze if you are using a mixture of water/antifreeze in the cooling system so that would be another way to decide about the leak or not. If it is there, it could be that one or more of the cylinder head bolts are loose and you might then correct the leak by loosening all the bolts 1/2 turn, then tighten to 50 foot-pounds, again tighten to 50 foot-pounds, then tighten 1/4 of a turn. The tightening pattern is from the middle to the ends, going back and forth.
Question History: Is it possible for a car (like a 2001 2.0L Dodge Neon) to not overheat, and not have coolant in the oil, and for there to still be a head gasket problem? I have noticed the water in my coolant reservoir making a boiling sound, especially when idling or when the car is turned off. There had been a rusty radiator in there, and I have recently started using radiator cleaner + water to clean out the system. The old radiator had a small hole, and when I emptied the old coolant, it had some solids in it. The radiator and cap, hoses, and the thermostat, have been changed out.
A few years ago the water pump went out, and the car started to overheat. I'm guessing this could have weakended the gasket, but I haven't noticed this problem until recently.
ANSWER: Hi Ian,
It is possible for the leak to be between a combustion chamber and the cooling system and thus not loose any coolant to oil or vice versa. Do you see excessive white smoke come from the tail pipe when you start up the engine from cold? Are you loosing coolant with no sign of a leak? Those would all be indicative of such a leak.
Sorry for the delay in responding but I just found your question in the "pool" to which it had been referred by Kevin.
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QUESTION: Thanks for the reply. I've seen some white smoke, but not a lot. I don't think there is any smoke when it has warmed up. The only time I'm losing coolant is when it boils into the overflow tank, but does not return from the tank to the radiator. The radiator cap is a new $6 Stant cap, by the way. I have noticed bubbling/fizzing in the housing when the radiator cap is off, and I let the car run. I thought it might be the radiator cleaner instead of a bad head gasket.
A new problem I had today was that I was revving while idling, then shut the car off, and then turned it back on and it revved up high, then started revving up and down. I put it in drive and it stopped, but when it is in park it starts doing this again.
The early pressurization of the cooling system, and the immediate white smoke at start up coming from the tailpipe are signs of a head gasket leak of coolant into the compression chamber of one of the cylinders after shut down, and conversely the leak of exhaust gas into the cooling system at start up, and the failure of the return of coolant back into the radiator after shut down. A radiator shop can test for the presence of exhaust gas in the cooling system if you would want to be sure before you remove the cylinder head to replace the head gasket.
The one thing to try if the leak is small would be to loosen the head bolts one step and then re-torque them following the pattern for removal and installation in so doing. The leak could be due to a loose bolt allowing the leak rather than the gasket itself.
QUESTION: The cooling system was the biggest problem I was having until yesterday. Yesterday, the car was revving up and down while idling, but stopped when I put it into drive. Today, it seems to have gotten worse because when it is put into drive or reverse it is accelerating the car and the brakes are not stopping it. I had to throw it into park to get it to stop. It's an older car, so I don't know if it is related to the cooling system or if something else has gone wrong with it.
Try using the ignition switch to get a diagnostic fault code:
Turn the key: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window of the speedometer to see the mileage reading replaced by a four digit number preceded by a P. Let me know what you find.