Ewww sludge!!

[ottofalcon]

Today i was replacing the valve cover gaskets on my 97qx and when I removed the covers to my surprise there is sludge in my engine but its soft not that hard. I bought this qx4 from its first owner and to my understanding the maintenance was always done at the dealership. I've had it since feb 2010 and since then I've always used Mobile EP 5w-30 and changed it every 4500-5000 miles. I really like my qx and I dont want the engine to give out on me, what should I do? My mechanic told me to use change the oil at least every two weeks to see if the sludge goes away. What else can I do?

[Towncivilian]

Don't run any engine oil additives. Let the engine oil do all the cleaning, you don't want to attempt cleaning stuff up too quickly. Perhaps switch to M1 High Mileage 5W-30 which will have more detergents, and shorten the oil change interval to 3,000 miles. If you can't afford using M1 HM for such short intervals, use a quality conventional oil such as Pennzoil Yellow Bottle which also contains a lot of detergents. Change your PCV valve with an OEM part, too. See here for its location.

Do you have any pictures of the valvetrain?

[D13_R50]

You might want to try out Seafoam. Seems to work well in my Jeep.

Oil changes every two weeks just seems pointless in my opinion.

[ottofalcon]

Ok, i'm goiing to go with the mobile 1 hm and let's see how that works out. I was told to be careful with sea foam because it might remove to much sludge and might clog up oil lines and such.

[yngw13]

Ok, i'm goiing to go with the mobile 1 hm and let's see how that works out. I was told to be careful with sea foam because it might remove to much sludge and might clog up oil lines and such.

yea heard the same about seafoam...it can do wonders but if youve never done it to an OLD car then you run the risk of getting these big chunks of corrosion come off all at the same time IN your engine

[yeldogt]

How many miles on the engine? Where and how much "stuff" are we talking about? Did you check the other side?

I would not use any additive.

[Towncivilian]

Also, do you take primarily short trips (less than 5 miles)? Constant short trips that do not allow the oil to reach operating temperature to boil off moisture can lead to problems very quickly.

[ottofalcon]

Well it has 140,345 right now, just did and oil change and yes both sides have sludge and it isnt that much. And I do take short trips I live 5 mins away from work and school is about 10 mins away, but every morning I turn it on about 5 min before I leave. Also the sludge is soft it isnt baked on, i guess with a couple oil changes it should clean out.

[ottofalcon]

@ Towncivilian: No I dont have any pictures of the valve train.

[Towncivilian]

Try to drive for at least 20 minutes on the highway every week or other week to boil off moisture from the oil. Also avoid "warming it up" before taking off for extended periods of time - this contributes to fuel dilution of the oil and barely warms things up.

[ottofalcon]

Ok i'll try this and keep you guys posted, thank you!