Oil changing - gunked up engine

[Slumpert]

So I used my inspection camera on the oil fill port and pretty much the cylinder top is a gunked mess. I could not even see anything shiny in there. I got my new valve cover gaskets in today, but I won't have another day off till next week so I won't really be able to see just how bad they are till then..

I paid to have PepBoys do a oil change when we first got it 6 weeks ago and we have maybe put 600miles on it so far.

So based on what I read here and there, I bought a 5 gal jug of Mobile 1 Advanced with a Bosch premium filter on sale for $34 total and picked up a quart of Marvel Mystery oil.

The 600 mile old oil that came out was already quite black... So I put in 3.5 quarts of the Mobile 1 and 1/2 pint of the Marvel Mystery Oil.

How many miles should I run that and should I just do a filter change sooner than later?

Under normal use that oil would be good for 6,000+ miles but with as much gunk as I have I am thinking I will need too at least change the filter after 1,000 or so and top it back off.. Once the filter gets clogged up its just a paperweight in regards to cleaning.

[Towncivilian]

Skip the MMO and any oil additives and just let the oil alone do the cleaning. M1 High Mileage will clean better than EP, and your Bosch D+ filter has a very high capacity. I would run M1 HM 5W-30 and the D+ filter for 5k miles for several oil changes.

[Buzzman]

From the limited info you have given us, it appears to me that the previous owner didn't take very good care of it when it comes to oil changes.
Is there any way you can get a service history on your truck?
If the oil is that dirty after 600K, and the engine is all gunked up, you can bet your booties that the PO didn't change his oil.
I would also question the Pep Boys: were you there to witness the oil and filter change?
I've been ripped off more than once over the years by crooked dealerships and private garages who supposedly changed my oil and filter, but actually didn't do a damn thing.
One of them was a Ford dealership which I caught red-handed. That was fun.
One other question: how many miles on the truck?

[Slumpert]

The pathfinder has 190,000 miles on it. Pretty sure mileage is correct based on the very limited reporting on carfax when I bought it. I bought it from a craigslist ad and they were "selling" it for a friend... Not my ideal purchase situtation but I had been looking for a vehicle for my daughter for almost a year and everything under $3,000 usually was very messed up and this on seemed in really good shape. They were going to see if they can find the paperwork as thier friend was moving.. Yea surprise surprise no paperwork. At least the title transfered correctly lol...

The body is in great condition, the interior is near perfect except for the leather on the front seat starting to rip up, no underbody rust at all except surface rust under the running boards and on some sort of spacer in the control arms.

When I took off my lower shield to work on the timing belt/waterpump I saw the oil filter for the first time and it was a white Proline.. After watching a few videos I saw that those proline are used by pepboys for the house filter change.. $2.00 filter.

There is seepage all around the valve covers and they leak enough that oil drips on the exaust creating small amounts of smoke so I already got the replacement seals just need to put them in.. I totally think this could this being a fire hazard esp when full summer heat of Houston kicks in soon.

I bought the magnetic drain plug that I read about here, but when I went too install it, it would not go in more than a full turn without getting jammed so I think it is possibly the wrong one.. The current bolt goes in pretty easily and had a nice degraded rubber washer on it that was even seeping.. New Nissan washer fixed that.

[Towncivilian]

Which magnetic drain plug did you buy? You have tried tightening the valve cover screws to see if it slows or stops the leakage, correct?

[skiski329]

cleaning it out is going to be a double edged sword. nevertheless i recommend to clean up the engine, but i can only image that the oil gunk has created false seals in your engine (i'm not saying for sure, but it's a possibility why the previous owner didn't change the oil as much). As you clean out that gunk that is creating false walls, you may find new leaks. Just a heads up to keep an eye out for leaks as you get the gunk out.

[Slumpert]

I did tighten the valve cover screws I could reach... Did not seem to make much of a difference as I am sure there is quite a bit of gunk between the seal and the surface and well nothing going to slow that down at this point.

I just replaced the front seal as well as the camshaft seals so that will just leave the rear main seal which surely will be leaking if it already isn't. (Lots of oil around the starter area and not sure that would come down from the valve covers.

So would it be totally crazy to drain the oil, remove the filter, take the valve covers off and pressure wash the rockers... Check the sparplugs holes after for water and just re-filter refill and then idle for minute and then change oil + filter again?

[Towncivilian]

I would not use a pressure washer. Manual cleaning only of the top end (under valve covers) and also remove the oil pan and clean out what's there to prevent the oil pickup screen from becoming clogged and leaving your engine starved for oil. Change your PCV valve too with a new OEM part afterwards if you haven't yet.

[Slumpert]

OMG... I just read the steps to remove the oil pan..... Needing a engine hoist to get-er-done sounds like a real pain. How long does it actually take to tear out everything under there and do it?

[Towncivilian]

Perhaps we're jumping to conclusions here. If you're not having excessive oil consumption and a compression test yields results within specification, I would replace the valve cover gaskets and clean what you can and then let oil do the work of cleaning things out - no additives, no rushing. I feel that if everything is running fine given the deposits, don't mess with it too much or too quickly.

I think you should use Mobil 1 High Mileage 5W-30 and Purolator PureONE filters to slowly but gently clean things out. Mobil has even stated in their FAQ that if your engine has an unknown history and may be dirty, some shorter oil change intervals with their HM oil will help clean things out a little quicker.

[ianh]

Listen to Towncivilian, good advice.

I had a Buick 455 and the PO thought non detergent Engine Oil was the best !!! He even told me this during the sale !!
Needless to say there was sludge like I have never seen in the valve covers and coke in the V !!
So hand clean up, and re assemble. didn't take off the sump.

DO NOT DO the next thing i did, i got lucky.
I added 1 qt of OIl additive and ran for the recommended 20 mins stationary, drained and OIl change.
Now I realize that others have had blocked Oil pickup screens doing this....

So nice and slow, let the Oil slowly dissolve the sludge, and yes i would change oil more frequently, maybe next change at 1000 miles.

[Slumpert]

This weekend I replaced the gaskets on my valve covers. The old ones were "cooked" into a state like hard plastic and the drivers side actually had a full crack in it presumably from my attempts to tighten the screws to stop the leakage.

I was not surprised at the amount of nasty nasty gunk in there, I did clean out the valve covers really well but I mostly just left the top of the cylinder alone.



Closer shot



Granted the truck is parked on a slight incline on my driveway, but is it normal for the oil to be pooled up like that or do I have a clogged drain in the heads? Both sides were pooled up exactly the same.

[Slumpert]

Here is picture of the drivers side with the oil seeping all over the heat shield..

Visable smoke was comming off the engine once it started to warm up.

[ianh]

The Oil is probably pooling because the drain hole is not at the lowest point. Seen that with other V engines, but have not taken the VQ down yet.

[Towncivilian]

That looks pretty sludgy. I hope you did all the manual cleaning you could with the valve covers off? You may want to pull the oil pan and see how things are on the bottom end and do as much manual cleaning as you can, if you're so inclined of course...

[ianh]

If you are going to pull the pan would it then be advisable to use an additive before you pull it?
you can then clean the pick-up screen.

[Towncivilian]

I tend to avoid any engine oil additives. The engine oil formulators spent millions of dollars in research & development, testing, etc of their oils, why play chemist and put some bottle of gorilla snot in your engine oil because it claims to clean better? Most of the time such additives are based on harsh solvents, and should they loosen large chunks of sludge or other deposits, the oil pickup screen can become clogged and there goes your engine...

[ianh]

I tend to avoid any engine oil additives. The engine oil formulators spent millions of dollars in research & development, testing, etc of their oils, why play chemist and put some bottle of gorilla snot in your engine oil because it claims to clean better? Most of the time such additives are based on harsh solvents, and should they loosen large chunks of sludge or other deposits, the oil pickup screen can become clogged and there goes your engine...

Yes I agree, and would only suggest this if he is going to pull the pan and clean the screen anyway.
I did this on an engine, added 1 qt of cleaner run for 20 mins at idle, then oil change. I didn't pull the pan, I was lucky !!!