Q: car running very rough, making oil 1990 Nissan/Datsun 300ZX
The car was running great. The next morning when it was started it was smoking very badly and barely ran. I checked the oil, it is over full and smells like gas.
My car has 70000 miles.
My car has a manual transmission.
Recommended Services
| Car idle is rough Inspection | $94.99 - $114.99 | Get a Quote |
Hello - I suspect your cold start system has gone "full on" or you have leaking injectors. Without question your fuel system is pumping way too much fuel into the intake, leaking past the piston rings, and entering the crankcase. I would recommend a engine fuel system 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.
The statements expressed above are only for informational purposes and should be independently verified. Please see our
terms of service
for more details
Get an instant quote for your car
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing
What others are asking
Car remote malfunctioning.
Hi there! Keyless entry systems are wonderful when they work properly, and very frustrating when they malfunction. If your Keypad were still functioning, we would look to your keyfob as a likely suspect. However, seeing as how the Keypad is...
How do I control the fuel efficiency backlight?
You can choose to have your fuel efficiency reading be backlit. To control whether or not it is backlit, follow these steps: 1. Turn the ignition to On, while making sure the vehicle is completely stopped. 2. Press the Menu...
Whistling sound when accelerating from a stop
Hello. There could be a vacuum leak in the intake or intake gasket. The breather tube from the air filter box to the intake could have a leak in it as well, which may cause the noise you are hearing....
Engine turns over but won't start. Could it be a sensor and how do I check?
Hi there. There is a possibility that no power is being supplied from the ignition switch (https://www.yourmechanic.com/services/ignition-switch-replacement) to the power distribution center fuse. The ASD relay fuse may have blown (https://www.yourmechanic.com/services/fuse-replacement) on the ground "control" side of ASD relay. Circuit...
Changed head gasket car won't start.
Hi there: In most cases when a cylinder head gasket has been pushed due to overheating, it can cause additional damage to valve train hardware; most of the time problems with valve guides. However, if you've double checked all hardware;...
My 2010 Ford Ranger is not shifting right
Hi there. When this occurs on this transmission it is almost always due to an internal issue with the transmission. The most common issue I have seen is a failure in the front sprag assembly. When this assembly fails the...
Loud noise coming from underneath the car muffler leak manifold
If you suspect that you have an exhaust/exhaust manifold leak and/or an engine related noise, the recommended service to diagnose and repair that problem is an engine noise diagnostic (https://www.yourmechanic.com/services/noise-from-engine-or-exhaust-inspection). If you request that service, the responding certified mechanic will...
overfilled transmission fluid
You will need to have the excess fluid sucked out of the transmission so it is not overfull through the fill tube. Most mechanics have a suction tool that can pull out the excess fluid for you. The transmission may...
I have a 2007 chevy impala ltz with 3 codes coming on P0121 / P1516 / P2135 ,accelerater pedal an throttle body have been replaced
Trouble Code P0121 (https://www.yourmechanic.com/article/p0121-obd-ii-trouble-code-tps-a-circuit-range-performance-problem-by-jay-safford) can set if there are faults in the wiring or terminal connections to the throttle/accelerator position sensor. Circuity integrity should be checked and the output of the sensor should be viewed on a scan tool to...
Related articles
Symptoms of a Bad or Failing Fuel Pump Relay
If the engine is stalling or not starting, or the fuel pump is not making any noise when the key is on, you may need to replace the fuel pump relay.
Symptoms of a Bad or Failing Fuel Rail Sensor
Common signs include the Check Engine Light coming on, the car not feeling right when running, and issues with starting the car.
Top 10 Best-Selling Cars of 2016
Ford F-series pickup trucks, Toyota Camry, and Honda Civic are some of the best-selling cars of 2016 and all deliver on reliability and efficiency.
Browse other content
Maintenance
Services