Help to diagnose low MPG and high oil consumption.

ANSWER : The fuel pump will not stay on if you loose oil pressure. This is why it is shutting off. The loss of oil pressure may be from bad crankshaft bearings or camshaft bearings. The engine oil pan should be removed and the oil pump needs to be checked to ensure that you put in the pick up tube seal to the pump and connected the pump to the block. Then remove at least one main bearing cap and inspect the bearings for excessive wear and crankshaft damage. If you need some help with this, consider YourMechanic, as a certified technician can help diagnose the issue with your oil pressure firsthand and help you fix it accordingly.

ANSWER : A few different things may contribute to oil consumption and poor fuel economy. Typically, high oil consumption is related to worn piston rings or worn out valve guide seals. In your case, it is unlikely this is related to worn piston rings as indicated by the proper compression you have already tested for.

A clogged or failing catalytic converter can cause the vehicle to have poor fuel economy. As you know, the catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When this is clogged, this causes these gases to be backed up into the exhaust system not allowing the engine to breathe properly. When this happens, the engine is forced to work much harder to expel these gases. This often results in the engine bogging down, hesitating, shaking and causing very poor fuel economy. A clogged or dirty EGR valve may also cause poor fuel mileage. The EGR valve is a small component designed to allow the flow of exhaust gases into the intake manifold in controlled amounts. Whenever you start the engine, the valve comes alive and waits in a closed position, blocking the flow of exhaust gases. Once the engine reaches operating temperature and speed increases, the valve, either through vacuum or electronic control will gradually open, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. When the EGR valve is clogged or dirty, as they are prone to, it may not function properly causing the engine to idle rough, stall at idle speeds, cause the car to get poor fuel mileage, or emit a strong smell of fuel due to excess hydrocarbons which also results in failing emissions tests. I would recommend checking the above to determine what may be causing your poor fuel mileage.

ANSWER : Hello – oil consumption is, for some reason, higher on this specific engine than on other 4 cylinder engines, turbocharged or not. Typical oil consumption is approximately 1 quart per 1500 miles. If you have blue exhaust smoke on an on-going basis, the turbocharger seals may have failed and will require a rebuild of the turbocharger. The low oil level warning is for your protection to avoid engine damage. Make sure that the oil level is correct after an oil change service – check it before leaving the facility. It has happened that not enough oil was put in the engine. If these checks are not satisfactory, I would recommend an engine inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

ANSWER : Hi there, thanks for writing in. The valve stem seals are the most common cause of this on your engine. When they fail, it requires that the cylinder heads be removed and rebuilt to fix it. The piston rings can also cause this but they are not as common. Unfortunately there is not anything, not even heavier oil that will fix this. You will need to have the heads rebuilt.

ANSWER : It is possible that they put in the wrong viscosity oil. In rare instances, a defective filter will also cause low pressure. If there is too much oil, it will aerate and cause low pressure. Be sure the oil level is really not above "max". The P2187 code will appear if the oil fill cap is not tight but it will also appear due to a myriad of causes because that code only "generally" identifies a lean running condition. Consequently, numerous parts would have to be tested including the O2 sensor, gas cap seal, manifold air leaks, any vacuum leak anywhere including PCV and EVAP systems, exhaust leaks, and fuel system faults such as failing fuel pump, clogged filter and more. Since the car has relatively low mileage, you would not expect a failed oil pump, although the pressure sensor (or switch) could be bad. However, the occurrence of the oil pressure warning light is quite coincidental to the oil change, thus I would suggest bringing the car back and asking them to redo with a new filter and double check the viscosity of the new oil that they use. If the problem persists after that, you will have to test actual operating oil pressure (at idle for instance) as well as the oil pressure switch. Finally, if the oil pressure warning light comes on continuously, unless the warning circuit itself is malfunctioning, that means the oil pressure is too low to operate the engine without damaging it. Anytime the light comes on for more than literally an instant, you should shut down the car and thus an issue like this obviously has to be repaired.

If you’d like, a YourMechanic certified mechanic can come to your home or place of business to inspect the vehicle and perform an oil pressure light is on inspection to diagnose the vehicle and suggest potential repairs.

ANSWER : Hello. If you put too thick of an oil in the car, then you may have damaged the engine bearings but this should not have caused oil to get in to the spark plugs unless the oil got into the intake of the engine or one of the pistons rings broke. If you ran it without oil and then tried to put oil in thinking it would be okay after that, then you were not that lucky and broke or damaged all of the rings on the pistons. If you would like to have this looked over, a certified professional from YourMechanic can come to your car’s location to inspect the stalling issue and go over all of the relevant systems for a better diagnosis.

ANSWER : Bob: Thanks for your inquiry. Oil level and oil pressure are measured using separate sensing systems. If the level sensing feature stopped working at the time the pan gasket was replaced, either the level sensor was damaged, not reconnected, or the wire harness and terminal were damaged. There is a possibility that the wire harness was just never re-connected to the level sensor so check that first. If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a warning light diagnostic – oil level and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hi There,
It sounds like you may need to replace the oil cap o-ring. If you haven’t done this before there are two O-rings to replace; a small green one on the base of the filter cap stem and the large black one that seals the filter cap (which seems to be the one you are having issues with). The large O-ring sits in a small square-shaped groove that is at the base of the oil filter cap. It is very easy to not properly seat the large O-ring because the threads for the oil cap are quite large and will accept the O-ring if you are not careful. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle.