I recently had an issue with my radiator that caused a leak. I had a mechanic replace the radiator. I also had the valve gasket replaced as it had turned from rubber to plastic and broken off. Since these repairs, I no longer have heat at highway speed and I have developed a stutter between 1400 and 2200 rpm at speeds greater than 30mph. I also replaced the upper radiator hose last week. Before I added back the coolant that I lost, I took the car out and had full heat and the car seemed to be smooth with no shutter.
What I would describe as a shutter is once I am on the gas, it will vibrate hard in the front of the car. Shifting is fine and smooth. I am at a complete loss.
My car has 111000 miles.
My car has an automatic transmission.
The stutter, or vibration, could be due to an engine management (tuning) issue or is possibly caused by worn motor mounts that are allowing engine vibration to transfer to the body when the engine is under load. To evaluate the motor mounts, request an engine vibration diagnostic. If you do end up replacing motor mounts, genuine OEM mounts are recommended in order to maximize the chances of resolving the problem. If the motor mounts are not judged faulty, vibration and rough running can be caused by faults in the air induction system as well as the ignition and fuel systems. To obtain an evaluation of the running condition of the engine, please request a rough running diagnostic.
With regard to the intermittent cabin heat, that is typically due to an obstruction in the coolant flow to the heater core and that obstruction can be due to a problem with the heater control valve, a hose that is collapsing at times, or air pockets in the system possibly due to coolant boiling within the engine or exhaust gases leaking in to the coolant. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a cabin heater diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
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