Cylinders misfire after using motor flush and oil change – possible sludge issue?

ANSWER : Hi There,
If there are misfires, there should be a check engine light on, which should have stored specific fault codes. Many times these fault codes will indicate whether the misfire is related to a specific cylinder or if it is a general misfire code. Misfires can happen for many different reasons such as faulty spark plug wires or even an injector not pulsing correctly. I would suggest having a professional from YourMechanic come to your location to diagnose and inspect your vehicle to determine what may be causing this to happen.

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 : 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 : Excessive oil consumption is usually related to piston ring wear or valve guide seals not properly sealing causing engine oil to pass by and be ignited and burnt in the combustion chamber along with the fuel and air mixture. Generally, synthetic oil will not cure a situation like this as this is something that will require a fairly extensive repair job. With that said, there are many different opinions and theories on engine oil. Synthetic vs conventional oil is one of the most debated myths surrounding the topic of oil changes. This will not hurt your engine when switching from synthetic to conventional or vice versa. In fact, Synthetic blend oils are actually a mix of conventional oils and synthetic oils. It is recommended that you use the same oil to top off when needed, giving you the best protection from the oil you have chosen to use in your vehicle. Many people often wonder about the benefits of using synthetic oils. Many synthetic oils are made up of a base oil of approximately 80%, with other additives making up the remaining 20%. The main difference between the molecules in synthetically engineered oils and conventional oils are the uniformity of the molecules. The molecules found in most conventional oils differ in shape, size and impurity. The type of oil that should be used for a specific application depends largely on the driver’s driving habits, the environment in which the car is driven, the mileage on the car’s engine and the limits that the engine may be pushed to. I would recommend having an expert from Your Mechanic come to your home to diagnose your engine oil burning problem as this may be a sign of a bigger problem.

ANSWER : This light will usually come on when one of two things are happening. Either the motor is in fact low on oil or the oil pressure sending unit is not working properly and may be producing a faulty reading. I would recommend first, to check the actual oil level in the motor by using the dipstick. Be sure the oil level reaches the "full" mark. If this registers as "full" then you likely have a faulty oil pressure sending unit. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle to determine what may be causing your low oil pressure light to come on.

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 : Oil change intervals on your vehicle are determined by the vehicle’s engine oil change monitoring system. A message on your instrument panel will alert you when it is necessary to change the oil. The change interval is based on a computer algorithm and is "duty cycle based". Consequently, the oil change interval is not fixed and will vary depending on personal driving style and drivings conditions. For example, lots of short trips will necessitate a more frequent oil change than if your driving mileage is accumulated under continuous highway driving. An engine computer keeps track of all the required data, processes the data, and then the car’s messaging system lets you know when to change the oil. With some minor caveats, as stated below, synthetic oil can be used at any time and you can switch back and forth between conventional oil and synthetics at any time. Although existing leaks may potentially leak at a somewhat greater rate when using synthetic oils versus purely mineral based (aka, "conventional" oil), the added leakage, if any, is meaningless in most seal locations and in most circumstances. The potential for a leak is due to the smaller size of the molecules in synthetic versus conventional oils. However, synthetic oil cannot possibly cause or otherwise mechanically enlarge a leak. In any event, any "distinction" in leak rate is meaningless simply because if you put synthetic oil in a car and you can see a leak from a seal, that seal was most decidedly leaking anyway with regular oil and so would have to be repaired regardless of the oil "type" you are using.

In your specific case, with a relatively newer car and low miles on the engine, this possibility of a leak probably does not exist at least for a while, although you are getting close to the time frame when just due to rubber aging (over time, not mileage related), leaks will start developing anyway. The bottom line is you can and should use synthetic oil in your circumstances due to its huge advantages in physical properties and potential to lengthen the service life of your engine and even seemingly unrelated parts such as oxygen sensors and the catalytic converter (synthetics don’t have the sulfur and other elemental contaminants that mineral oil has). Full synthetics will be less subject to degradation and evaporation during the oil service interval, too. I would recommend you use "100% synthetic oil". If it were my car I would use the most expensive, highest rated synthetic oil I could find. Changing your oil removes dirt and contaminants and newer cars with all sort of oil actuated mechanisms, such as variable valve timing, need very clean oil. YourMechanic offers oil and filter changes during mobile visits right to your location and you should certainly avail yourself of that service as the cost is lower and the service is much more personalized than at a shop or dealer. If you have additional concerns, don’t hesitate to re-contact YourMechanic.

ANSWER : Hi there. I am really not sold on these engine flush products, as they tend to clog up bearings and damage seals if left in the engine over too long of a time. The best way to ensure they are completely flushed is to change your oil and filter twice in a 3,000 mile period. It might be an extra expense, but it ensures that residual materials from this "stuff" is removed.