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Oil Sludge In Rocker Box and Pipes

Oil sludge found in Air Cleaner, replaced PCV and filter and cleaned and had to replace filter in 6 months due to yellow oil sludge

Yellow sludge found in system, cleaned hoses replaced filter and PCV and six months later had to repeat process
Posted by xxxx on
Oil sludge can be caused by a few different things including a clogged pcv valve, which you say you have changed. I don't think you have head gasket/head problems as you say you've been using the vehicle for 6 months.

However, do check your oil dipstick and see if the same sludge (also known as 'mayonnaise') is on it. Mayonnaise on a dipstick is a symptom of a defective head gasket that is allowing coolant into the oil system.

If your vehicle looses/uses coolant this may be a sign of a faulty head gasket/head.

Very short- repeated - journeys can allow sludge to form , simply because on short journeys the engine does not reach its normal operating temperature. The engine is 'cool'.

It can also be caused by a faulty thermostat. If the thermostat is jammed in the open position it can take a long time for the engine to reach normal operating temperature. Other than changing the thermostat (maybe for one that opens at a higher temperature - a ' winter' thermostat) there's no practical way of checking it. Replacement is the easiest and cheapest option. It's not a difficult job.

It's not unknown for a thermostat to have been removed by a previous owner (for various reasons..). If you're going to check if there's a thermostat there - replace it anyway.

If you're not losing/using coolant and there's no mayonnaise on the dipstick it may well be due to repeated short journeys where the engine doesn't reach normal operating temperature - or the thermostat.

The reason that sludge - or 'mayonnaise' forms is because of water content/moisture. For every gallon of fuel your vehicle uses in the combustion process, it produces 1 gallon of water. The water vapour will condense in the coolest place - and in the engine this is the rocker box and pipes. If the engine is at normal operating temperature the sludge should not form in modern engines (it happened commonly on engines in the 70s and 80s..).

Another cause of sludge - though it is black sludge - as opposed to a creamy colour, is an egr valve that needs cleaning.

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Oil sludge found in Air Cleaner, replaced PCV and filter and cleaned and had to replace filter in 6 months due to yellow oil sludge


Oil sludge can be caused by a few different things. I don't think you have head gasket/head problems as you say you've been using the vehicle for 6 months.

However, do check your oil dipstick and see if the same sludge (also known as 'mayonnaise') is on it. Mayonnaise on a dipstick is a symptom of a defective head gasket that is allowing coolant into the oil system.

If your vehicle looses/uses coolant this may be a sign of a faulty head gasket/head.

Very short- repeated - journeys can allow sludge to form, simply because on short journeys the engine does not reach its normal operating temperature. The engine is 'cool'.

It can also be caused by a faulty thermostat. If the thermostat is jammed in the open position it can take a long time for the engine to reach normal operating temperature. Other than changing the thermostat (maybe for one that opens at a higher temperature - a 'winter' thermostat) there's no practical way of checking it. Replacement is the easiest and cheapest option. It's not a difficult job.

It's not unknown for a thermostat to have been removed by a previous owner (for various reasons..). If you're going to check if there's a thermostat there - replace it anyway.

If you're not losing/using coolant and there's no mayonnaise on the dipstick it may well be due to repeated short journeys where the engine doesn't reach normal operating temperature - or the thermostat.

Feb 05, 2016 | Cars & Trucks

2 Answers

How often should I change the Transmission fluid, normal driving ? Thank you Gary


It's listed in your owner's manual. Schedule A is normal driving conditions.
SCHEDULE "A"
7,500 miles (12 000km) or at 6 months
- Change engine oil.
- Replace engine oil filter.

15,000 miles (24 000km) or at 12 months
- Change engine oil.
- Replace engine oil filter.

22,500 miles (36 000km) or at 18 months
- Change engine oil.
- Replace engine oil filter.
- Inspect front wheel bearings.
- Inspect brake linings.

30,000 miles (48 000km) or at 24 months
- Change engine oil.
- Replace engine oil filter.
- Replace engine air cleaner filter.
- Replace spark plugs.
- Drain and refill automatic transmission fluid and filter (4.7L).

37,500 miles (60 000km) or at 30 months
- Change engine oil.
- Replace engine oil filter.
- Drain and refill automatic transmission fluid and filter (5.2L/5.9L).
- Drain and refill transfer case fluid.

45,000 miles (72 000km) or at 36 months
- Change engine oil.
- Replace engine oil filter.
- Inspect front wheel bearings.
- Inspect brake linings.
- Flush and replace engine coolant at 36 months, regardless of mileage.

52,500 miles (84 000km) or at 42 months
- Change engine oil.
- Replace engine oil filter.
- Flush and replace engine coolant if not done at 46 months.

60,000 miles (96 000km) or at 48 months
- Change engine oil.
- Replace engine oil filter.
- Replace engine air cleaner filter.
- Replace ignition cables (5.2L/5.9L).
- Inspect PCV valve, replace as necessary.
- Replace spark plugs.
- Inspect auto tension drive belt and replace as necessary (5.2L/5.9L).
- Drain and refill automatic transmission fluid (4.7L).

67,500 miles (108 000km) or at 54 months
- Change engine oil.
- Replace engine oil filter.
- Inspect front wheel bearings.
- Inspect brake linings.

75,000 miles (120 000km) or at 60 months
- Change engine oil.
- Replace engine oil filter.
- Drain and refill automatic transmission fluid and filter (5.2L/5.9L).
- Drain and refill transfer case.
- Flush and replace engine coolant if it has been 30,000miles (48 000km) or 24 months since last change.
- Inspect auto tension drive belt and replace if required.

82,500 miles (132 000km) or at 66 months
- Change engine oil.
- Replace engine oil filter.
- Flush and replace engine coolant if it has been 30,000miles (48 000km) or 24 months since last change.

90,000 miles (144 000km) or at 72 months
- Change engine oil.
- Replace engine oil filter.
- Replace engine air cleaner filter.
- Replace spark plugs.
- Inspect front wheel bearings.
- Inspect brake linings.
- Inspect auto tension drive belt and replace as necessary.
- Drain and refill automatic transmission fluid (4.7L).

97,500 miles (156 000km) or at 78 months
- Change engine oil.
- Replace engine oil filter.

105,000 miles (168 000km) or at 84 months
- Change engine oil.
- Replace engine oil filter.
- Flush and replace engine coolant if it has been 30,000 miles (48 000km) or 24 months since last change.
- Inspect auto tension drive belt and replace if required.

112,500 miles (181 000km) or at 90 months
- Change engine oil.
- Replace engine oil filter.
- Drain and refill automatic transmission fluid and filter (5.2L/5.9L).
- Inspect front wheel bearings.
- Inspect brake linings.
- Flush and replace engine coolant if it has been 30,000 miles (48 000km) or 24 months since last change.

120,000 miles (192 000km) or at 96 months
- Change engine oil.
- Replace engine oil filter.
- Replace engine air cleaner filter.
- Replace ignition cables (5.2L/5.9L).
- Inspect PCV valve, replace as necessary.
- Replace spark plugs.
- Inspect auto tension drive belt and replace as necessary.
- Drain and refill automatic transmission fluid (4.7L).

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Sep 05, 2010 | 2001 Dodge Durango

2 Answers

i have a small amount of oil and water (mayonnaise) in my air filter and car feels sluggish and doesn't start properly


oil is mixing with coolant then only it can happen , replace oil cooler cause oil cooler it is mixing, ,and clean all hose radiator for sludge free.

Jan 21, 2010 | 2001 Ford Focus

1 Answer

i have oil around my air cleaner housing what can i do ?


I'm assuming you mean inside of your air cleaner you either need to clean air cleaner housing replace air filter and PCV valve and or PCV breather filter hose, PCV system or your engine has excessive blowby and is worn internally.

Oct 17, 2009 | 1983 Peugeot 504

2 Answers

Camry 1991- really sluggish and jerky


It's just going to take some time and simple cleaning. If there is an Auto Zone around your area, you can buy all the things needed to get the car running 100% again in no time at all for under $40.00. Here is a few things that I do when i get a new car with a few years under it's wheels. Buy a bottle of injector cleaner for the fuel injectors, like STP, a bottle of Marvel Mystery Oil to add to the engine oil, and two can's of Throttle body cleaner for the throttle body and follow the instructions on the can. Make sure it's throttle body cleaner. The Carburetor cleaner is to corrosive for the throttle body gasket. Once you have reached 3,000 miles, service the engine and have them replace the oil (5W-30) and filter and add another Marvel Mystery Oil. This will clean out all the carbon and sludge in the engine to free up the oil passage ways, replace the Air filter, and PVC valve every 30,000 miles or once a year. Cleaning out the throttle body and adding the fuel injector cleaner will also help the fuel system and have them replace the fuel filter every 30,000 miles or once a year to ensure there is no fuel restrictions in the fuel system. Once this has been done you will notice the engine runs like new and you may have to use the Marvel Mystery Oil and fuel injector cleaner every 6 months to keep the internal engine free from sludge and carbon. Good luck and keep me posted, be glad to help you keep the car running 100% for a long time. 

Sep 05, 2009 | 1991 Toyota Camry

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