Skip the auto shop - Our mechanics make house calls

Q: Idles up, burns 1 quart oil every 20sec with no oil leak.

asked by on

Hi there, my father in laws Bonneville blew the plastic portion of his oil sending unit clear off the 1 1\16" thread nut and we replaced it. After that I discovered the car he's ownered for 2 years had not seen an oil change in 8 years total so we did that. Then we got a low oil pressure read on the dash and saw smoke coming from the the engine right valve cover. When we killed the motor and opened the oil fill cap on that valve cover, we heard a relief of back pressure come from thru out the whole motor. I replaced the PCV valve today and checked the oil again and it was close to the max oil level. I started the vehicle and after idling down the normal operating RPMs the car, on its own started to increase rpm from 1,100-1,600rpm and a whining internal noise became gradually louder as the RPMs rose. I killed the motor and checked the oil and it was now at the minimum film line, about 1 1\2qrts down. I don't know if the rings finally gave or what but there are no leaks or dripping.

My car has 213000 miles.
My car has an automatic transmission.

A: You might not have burned that much oil in ...

You might not have burned that much oil in 30 seconds of running the motor but the oil is not draining back from the upper parts of the motor. The sludge that has built up in the motor has clogged the return drains in the heads and oil gets trapped up in the valve covers. You should look in one of the valve covers to see if the engine is sludge blocking drains in the heads. If it is then you may have to clean out both valve covers and heads of sludge and then run cleaner through engine several times to remove some of the sludge build up. If this does not help then rebuilding of the motor is only option.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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

Get a quote

What others are asking

Q: My dash lights don't come on in the morning until I'm just about to my jobsite at around 6:45 or so.

Hello there, this is an unusual fault. When the vehicle has strange intermittent faults like this the most common failure points are a wiring harness fault or a shorted wire. If you need assistance with this check, consider getting some...

Q: Car won't start due to rain

A no-start condition can be caused by many things, and is sometimes one of the most difficult problems to diagnose. It may be possible that the rain may have something to do with this. No-start conditions can be caused by...

Q: Flooded car

Hello. You likely have issues caused by the flood. Get your vehicle inspected by a qualified professional, or if you have insurance on your vehicle, consult with your insurance company and have an adjuster determine the extent of the flood...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.