New Sludge Question

You gotta Love these old VG30E/i powered beasts, raw truck DNA to the core.

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Joe Piro
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Location: Columbia SC

New Sludge Question

Postby Joe Piro » Fri Apr 15, 2022 12:27 pm

Summary - The question is: Is it OK to run an older engine that has a lot of sludge, without cleaning out the sludge.
Please share experience and opinions.

I have been working on my 1995 Pathfinder engine and ya'll have been very helpful (repeat... Very Helpful... thank you) under the topic Camshaft Seal Grooves.
Now my new question is this: I bought my Pathfinder at auction 100,000 miles ago for $1000. I knew there was a lot of sludge in the engine when I bought it, but for what I paid, I expected reasonable service and got it ! It has always run well. I have learned to love it and am replacing hoses, injectors, water pump, belts, etc. and hope to get another 100,000 miles before an engine re-build.

When I was growing up engine oils were not as good and I expected some sludge in stop-and-go vehicles. I always ignored it if everything else was OK.
I want to just ignore the sludge now (see photo- yeah... lots of sludge). What are the chances that the engine will continue to lubricate properly and this workhorse VG30E will serve heroically.
I have already read most of the sludge solutions on this forum (ATF, Seafoam, etc) so I don't need recommendations.But please share your experience and opinions about whether I can expect continued service: Am I right??? The situation is just cosmetic or do I need to clean the engine.
If I need to clean it, now is the time as the valve covers are off, I can drop the pan and clean it, and I have a 12 volt electric Pre-Luber pump that I can connect to pressurize, circulate and filter ATF while I brush all surfaces.
... looking forward to your opinions.
Attachments
Sludge Passenger Side.png
Sludge Driver Side.png
Sludge Valve Cover.png


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VStar650CL
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Re: New Sludge Question

Postby VStar650CL » Fri Apr 15, 2022 3:20 pm

That's pretty extreme, but there's a good chance cleaning it out chemically will end up making every seal on the engine spring a leak. It's pretty obvious the drain passages in the heads are your big issue, the sludge is building on itself because the oil pumped into the top end isn't draining back to the pan fast enough, so it puddles there and bakes. I'd drop the pan so the debris has somewhere to go and snake out all the oil drain passages, then blow through them to make sure any "solidified sludge" is cleared away and won't create blockages. Since the covers are off anyway, those should get a chemical cleaning to make sure the baffles aren't clogged. You want to make very sure the PCV system has unobstructed airflow, when that clogs up you'll get even more sludge in a hurry.

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smj999smj
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Re: New Sludge Question

Postby smj999smj » Fri Apr 15, 2022 9:58 pm

I've been down this road before, twice with Plymouth Dusters with Slant-6 engines and once with a customer's Pathfinder VG33E engine. My advice is to NOT use any chemical cleaners on it or try to "clean it up" unless you plan to remove the cylinder heads and send them out to be hot tanked and completely cleaned and remove the oil pan to completely clean it out and make sure the oil pickup screen is not restricted. You also want to thoroughly clean the valve covers and make sure the PCV path is clear and not clogged. If you try to clean it up without doing that and just using chemical cleaners or additives, the sludge will likely break apart and start dropping into the pan will it will get sucked onto the screen of the oil pickup tube, restricting oil flow to the engine. If you are lucky, the oil light will start flashing and you will shut the engine off before more damage occurs. If you are not lucky, the engine may fail in a way that is not repairable. The former is what happened to the Pathfinder and one of the Dusters, which has a 225 CID Slant-6 (it happened to be my father's car on which I adjusted the valves and the top of the engine was sludged). The latter happened to my 74 Duster with a 170 CID Slant-6 when I was driving home from the Englishtown Speedway swap meet; the oil light flashed for a couple of seconds before one of the piston rods blew a hole in the side of the block!
If you don't want to do all that, then just leave it be and continue regular oil and filter changes every 3000-4000 miles and hope that it will last a long time.

Joe Piro
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Location: Columbia SC

Re: New Sludge Question

Postby Joe Piro » Tue Apr 19, 2022 5:54 pm

My question today is: Do I have to disconnect the steering rod from the Pittman arm in order to lower the oil pan?
And a second question is: Besides the cam shaft seals and the front main seal (which I am replacing already) how many other seals are there? If I had a leak in the rear main seal, I would not consider that too difficult to repair. It might be a couple of days work, but not difficult.
smj999smj wrote:
Fri Apr 15, 2022 9:58 pm
remove the oil pan to completely clean it out and make sure the oil pickup screen is not restricted.
I have been out of touch while I worked on my taxes so did not respond sooner to your thorough replies.
By the way, I accidentally clicked the exclamation point when I meant to click the quotation mark. I hope that didn't "report" this post.
(just wanted to explain in case it created a problem)

So my plan is to drop the oil pan and throughly clean it and the valve covers, which I can do 100% without any chemical or solvent treatments. Then I just want to be sure I have plenty of lubrication to the valve train, so I am going to connect my external 12 volt Pre-Luber oil pump, sucking out of the oil pan drain hole and into the oil pressure sender port, and observe the open valve train. If everything is good, then I'll put it all back together and feel pretty good about it.

If I don't see plenty of oil delivered to the valve train, then it would really be stupid to ignore that so I'll decide then. I expect and hope to see plenty of oil up there.
Looking forward to answers about steering arms and "how many seals."
Thanks a million !

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VStar650CL
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Re: New Sludge Question

Postby VStar650CL » Tue Apr 19, 2022 6:30 pm

I'd dunk the covers in chemicals anyway, you want to make sure the space above the baffles is clear. That will be difficult-to-impossible without some gum cutter.

Joe Piro
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Location: Columbia SC

Re: New Sludge Question

Postby Joe Piro » Tue Apr 19, 2022 7:48 pm

VStar650CL wrote:
Tue Apr 19, 2022 6:30 pm
I'd dunk the covers in chemicals anyway, you want to make sure the space above the baffles is clear. That will be difficult-to-impossible without some gum cutter.
I can do that. Also I have a bore scope so I can look in there to be sure it's clean.

Joe Piro
Posts: 23
Joined: Sun Jun 16, 2013 11:04 am
Location: Columbia SC

Re: New Sludge Question

Postby Joe Piro » Thu Apr 21, 2022 9:43 am

And so.. Do I have to disconnect any of the steering arms in order to lower the oil pan?
Thanks,
Richard

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smj999smj
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Re: New Sludge Question

Postby smj999smj » Thu Apr 21, 2022 5:44 pm

I believe I used to unbolt the idler arm from the frame and just lowered the linkage down for clearance. If you have a 4x4, you'll probably have to lower the front axle down or remove it. Now, that said, it's been an awfully long time since I pulled an oil pan on a WD21 Pathfinder! I would refer you to the factory service manual for the procedure. Nico Club's site has free, online FSM's; hopefully they go back that far.

Joe Piro
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Joined: Sun Jun 16, 2013 11:04 am
Location: Columbia SC

Re: New Sludge Question

Postby Joe Piro » Sun Jun 12, 2022 12:04 pm

I've been working on other projects so just getting back to this.I have another question... Will valve covers from a 2001 VG33DE engine fit my VG30E engine?
Thanks in advance for your help and experience.

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smj999smj
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Re: New Sludge Question

Postby smj999smj » Wed Jun 15, 2022 6:53 pm

According to the Nissan parts catalog, the part numbers are different for the valve covers for the 95 Pathfinder VG30E and a 2001 Frontier VG33E (I had to use Frontier because a 2001 Pathfinder has the VQ35DE engine). All are shown as discontinued by Nissan. You could try Car-part.com to look for a set of used covers, if you need them.

Joe Piro
Posts: 23
Joined: Sun Jun 16, 2013 11:04 am
Location: Columbia SC

Re: New Sludge Question

Postby Joe Piro » Thu Jun 16, 2022 2:15 pm

Thanks for the information. I believe the part numbers are different because the oil filler is different (passenger side) and a couple of welded on brackets are different (Driver side).
However I was able to determine that the footprint is the same. I don't know if the valve cover gaskets have the same number, but they appear to be interchangeable. There are two at Pull-a-Part, and I am going to cut out the tops of the covers so that I can install them and use them like dams to keep the cleaning solution from running down the sides of the engine when I circulate cleaning solution with an external pump.
I can't explain why I am so determined to clean up the top end, but I am (maybe because its so caked in) and by doing so with an external oil pump and external oversized oil filter and the valve covers off to allow physical brush cleaning should reduce the risk of clogging up the oil passages considerably. If it works I'll post on it later.
I do understand the risk, as I just destroyed the thrust bearing in my D21 KA24E engine, and "some people say" that plastic particles from busted chain tensioners clogged up the oil passages. I was skeptical because oil from the sump passes through a filter first, except on a cold start, maybe a winter start, where the bypass opens. I am still skeptical since I didn't find any debris in the oil pump pickup, but we'll never know for sure.
Thanks for checking those part numbers. We'll see if the gasket footprint matches.
Thanks again.

Joe Piro
Posts: 23
Joined: Sun Jun 16, 2013 11:04 am
Location: Columbia SC

Re: New Sludge Question

Postby Joe Piro » Thu Jun 16, 2022 2:44 pm

So BTW, I checked the part numbers for the valve cover gaskets. I checked at RockAuto since it was quick and easy.
The Victor Reinz and also the FelPro numbers for the gaskets are the same even if the Nissan numbers for the valve covers are different.
So the 2001 VG33 valve covers will work. Also the 2001 Pathfinder I found at Pull-a-Part has the VG33 engine (it has the timing belt instead of a chain). Here is a photo of the label from the door, so apparently it must be an early calendar year build that slipped through before they changed the engine.
Here goes !!!
Pathfinder 2001 Door Label.png


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