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If you were in my situation, which product would you use to de-sludge this engine?

  • Auto-RX

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  • Diesel

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  • Kerosene

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  • Pennzoil Ultra Platinum 5W-30 Synthetic Motor Oil

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  • Other — Please Describe in the Comments

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Best Way To Desludge My New-To-Me 2002 Dodge Dakota?

7K views 5 replies 4 participants last post by  OSHA Violations 
#1 ·
About a month ago, I picked up a 2002 Dakota SLT Club Cab 4x4 with the 4.7L V8 SOHC and 104,000 miles. Since purchase, I've done a lot of reading online in the course of researching DIY repairs for some of the mechanical imperfections I inherited from the previous owner. In the course of so doing, I've stumbled across many threads related to the dreaded "oil sludging" problem in the Dodge 4.7L V8's, often attributed to the smaller-than-normal oil drain passages in the block.

I don't have any maintenance records from the previous owner(s) of my truck, but judging from the way various things have been cobbled together under the hood, it hasn't been maintained by the book. That said, the previous owner (who owned it for only 8 months) did recently perform an oil change with Mobil-1 5W-30 synthetic and some Lucas Oil Treatment, which has a few hundred miles on it at this point and is still fairly clean.

Partly because I'm a perfectionist and partly because I plan to use this truck somewhat heavily for business purposes, I wanted to find out what condition the engine internals were in and whether I have any sludge build-up or cause for concern regarding the oil pickup tube becoming clogged and starving the engine of oil. I read that one of the best and easiest ways to do this is to either remove the oil fill tube from the passenger side head or pull off a valve cover entirely. I therefore took a look down the oil fill tube and could see a light, dried coating of sludge on its sides:
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After removing the oil fill tube from the cylinder head, I found quite a bit of soft goop at the entrance to the head, and began to fear the worst:
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However, upon pulling the passenger side valve cover, things didn't look quite as bad as I had thought — the only true "goop" was located at the entrance to the head from the oil fill tube. The cam and rockers have a light coating of varnish with concentrations of light sludge in nooks and crannies, but there's not much that you could pick up with, say, a Stanley screwdriver. Below are some photos, click to enlarge:
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Engine Auto part Vehicle Automotive engine part Car

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While the exposed topside of my passenger side cylinder head looks far better than many of the sludged 4.7L V8 engine photos that I've seen, it also looks quite a bit dirtier than some others I've seen which are more or less spotless. I'd be interested to hear from other 4.7L V8 owners how this looks for an engine with 104,000 miles on it compared to what you've seen.

Sludge Removal Process
This brings me to the second part of my question — I'd like to clean out my engine of any and all existing sludge as best as I can now so I have peace of mind. I usually run Pennzoil Ultra Platinum 5W-30 Synthetic oil and Fram Xtra Guard synthetic filters in all of my vehicles, and strictly manage change intervals by vehicle duty cycle. I feel good about my ability to prevent new sludge from forming if I can just start with a clean slate.

I feel that now would be the perfect time to flush my engine, as the oil pan is rotting through and leaking anyway. I have plans to replace both it and the oil pump pickup tube, with the assumption that it may be somewhat blocked. If my planned flushing were to disturb any hardened particles that would manage to stop up the oil pickup entirely, it shouldn't be a problem since I need to drop the pan anyway. If at all possible, I would like to clean out the engine as best I can before installing the new pickup tube and pan.

I've done quite a bit of reading on the topic of cleaning agents, and have found a host of different products / solvents recommended:
  1. Automotive Transmission Fluid — I've read many recommendations to add a quart or so of ATF prior to an oil change, then let the vehicle idle for an hour or so (in Neutral to keep the 45RFE's ATF fluid moving / cooling) prior to draining the oil. However, I've also read that ATF can soften rubber seals and cause leaks and that Marvel Mystery Oil will work just as effectively while serving as a better lubricant, making it a somewhat safer option. If I do go this route, what type of ATF is recommended?

  2. Auto-RX — Read lots of glowing reviews on this over on the Bob Is The Oil Guy forums, with many claiming its cleaning performance is second to none. However, I've also read posts claiming that Auto-Rx has employed paid forum posters to shill for their product, that they've changed the formulation and patent four times in twelve years, and that the owner of the company is a real piece of work. On top of that it appears to be a slow-cleaning formulation — the instructions state that it works slowly over several oil changes. This makes this a questionable fit for my application as I'd like to clean out my engine now, but the truck currently isn't road worthy.

  3. Diesel — I've seen #2 diesel recommended plenty of times to be used as a one-quart oil substitute an hour or so before an oil change, much like ATF. Some claim that diesel is what most "engine flush" products are based on, anyway. The upside here is the low cost on a per-oz. basis compared to other products, but this seems like it would be one of the more aggressive solvents with low lubricity that could possibly do some damage if you weren't extremely careful.

  4. Kerosene — This is probably the second-most recommended product I've seen for cleaning out severe sludge immediately, second only to ATF. That said, the pros and cons seem to very closely mirror those of diesel. Low relative cost and immediate results, but low lubricity and the very real potential for engine damage if not used judiciously.

  5. Marvel Mystery Oil — One of the most popular "snake-oil" additives for all types of things, MMO doesn't get rave reviews when it comes to sludge removal as it is a very mild cleaner. I get the feeling that it's more on the "protective lubricant" end of the spectrum as opposed to a cleaning solvent. That said, it's cheap at $3.88/quart and is recommended as being less harsh than ATF / Diesel / Kerosene and therefore lower risk. Likely won't provide immediate results, but will work slowly over time.

  6. Pennzoil Ultra Platinum 5W-30 Synthetic Motor Oil — Pennzoil's Ultra Platinum is one of the most highly regarded synthetics, even more so than Mobil-1. Some say that it is so high in detergents that it is basically equivalent to an engine flush. It has significantly more detergents in it — Boron, in particular — than does Pennzoil's Platinum synthetic, making it better at combating deposits.

  7. Sea Foam Motor Treatment — Sea Foam is one of the most popular cleaners, with many stating they've obtained good results. However, others state that it's so thin that the cleaning agents likely dissolve quickly with engine heat. Another con is that the instructions indicate that it should be run at least 100 miles prior to an oil change for most effective results. It doesn't sound as if it works as immediately as ATF / Diesel / Kerosene.
Final Thoughts
Since I'm not positioned to actually drive my truck for hundreds / thousands of miles during the course of an engine cleaning, I'm leaning away from Auto-RX, Marvel Mystery Oil, and Sea Foam. The more immediate results of ATF / Diesel / Kerosene are more appealing, and since I can afford to stop the cleaning if need be to drop the pan and clean the pickup screen, that con of the more aggressive cleaners becomes less of an issue. I likely won't rely on Pennzoil Ultra Platinum alone for the initial cleaning, but will be running it as my motor oil of choice after the fact.

Based on the above photos, how severe is the current sludge condition of the crankcase and valve train, and what product and process would you recommend for removing it? I am planning on tackling a fuel system and throttle body / combustion chamber cleaning separately, so this question is primarily intended to focus on the crankcase and valve train.

I've created a poll at the bottom of the thread and would appreciate if you'd take the time to vote and comment with your reasoning. Also, I would be very interested in hearing recommendations on what ratio of cleaner-to-oil, how long to let the engine run during the cleaning, and when to swap oil filters during the flush. Thanks in advance!
 
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#2 ·
For compasrison here's my '02 as of last summer with 125K on the clock. Yours shows some less than desirable attention to oil changes/oil type used but it isn't terrible. Google for "dodge 4.7 sludge" if you want to see real bad. That being said I'd be hesitant to go knocking all that varnish off...do some research. I'd probably run some Seafoam along with a quality synthetic oil and anything but a Fram filter. I use Wix exclusively on all the cars, trucks, and bikes.
109816


109817
 
#5 ·
Dude .....look at the first picture .....the oil drain back holes in the cylinder head have oil puddles over the drain back holes in your motor .....your drain back holes are plugged solid .....those holes should be wide open and clear WITH NO PUDDLES .....EVER.....If there are puddles they are all plugged.....dude you gotta clear those tubes or your engine is in danger of failure. This is exactly what mine did too. This is a well known problem. Here is an exerpt from an article. You need to clean those out as soon as possible or it will destroy your engine. Put dura lube in it immediately until you can fix it.
110107
 
#3 ·
Thanks a ton for those photos! Helps me get a better understanding of where my valve train stands by way of comparison. I'd done quite a bit of searching online to try to find some comparisons, and found everything from ****-and-span valve trains like yours to true sludge monsters. I'm thinking on a scale of 1-10 with spotless being a 1 and 10 being sludged full, mine probably falls around a 4.

I did pull both valve covers and verified via a bore scope that the oil return passages in the heads and block are completely clear. Most of the sludge that exists is either hardened varnish or a thin layer of soft goo. I think the current Mobil-1 synthetic is helping to loosen some previous sludge that had built up from the truck's past.

I am in the midst of performing a piston soak with 32 oz. of Marvel Mystery Oil (4 oz. per cylinder) in the hopes of potentially freeing up what I believe may be some partially sticking piston rings. Once that quart of MMO drains to the crankcase, I plan to run the engine as per normal for some additional miles in the hopes that it will facilitate cleaning.

After, I plan to try an oil and filter change along with a quart of ATF, then run the engine at idle for 30-60 minutes while watching oil pressure and see what I can drain out. Ideally, I'd like to get the worst of the sludge loosened and down to the pan prior to the pan and pickup tube replacement.
 
#4 ·
Hi
Okay ....here is the skinny....."no cleaner is going to solve your sludge problem" .....the reason for this is the sludge that is the problem is concentrated in the drain back holes in the block. There are 7 of these cast in tubes 4 on the drivers side and 3 on the passenger side. These tubes are smaller than they should be and plug frequently too eaaily. Oil gets pumped up into the heads and then cannot drain fast enough back to the oil pan causing oil starvation. When this happens You will start noticing the oil pressure drops to zero at idle after driving a short distance and coming to a stop at a red light or stop sign etc...and you will have to tap the gas pedal to get it to come back repeatedly so long as you are stopped. As soon as you resume driving down the road the pressure will remain stable.
You will need to remove both valve covers and the oil pan and physically clean all 7 tubes out with brake cleaner until they are fully clear. You will know the tubes are blocked deep in the block because there will be puddles over the draim back holes in the cylinder heads when you take the covers off. If you have any puddles on any of the 7 drain back holes then they are plugged solid. Unfortunately you will need to clear them with a sping type pickup tool with a small rag wad soaked in brake cleaner to clear them out. Also have a wet vacuum with a length of 1/2 " neoprene tubing adapted to it so you can suck out material until you clear the blockage and break through the sludge. Unfortunately these tubes when blocked must be physically unblocked the old fashioned way .....physically. once you have them unblocked then make sure you use dura lube anti sluge in every oil change. Also until you can clear the tubes i recommend you put a liter of dura lube in your oil (drain out 1 liter then add the dura lube) as it will protect your engine when the pressure loss events occur. But beyond that ....you will physically need to clear the tubes if you are experiencing the pressure dipping at idle after driving then stopping. Its a shitty labourious job but its the only way to be sure and keep it clear. And 3 of the tubes on the drivers side are in tight spots on the bottom side of the engine. When you drop the pan make sure you cover it with 6mil poly plastic to keep the crud from fouling the oil pan ....its going to be a messy affair to clear out the goop. Just make sure you get it all. Home depot sells the perfect grabber tool for like $3 it is completely springed there is no ridgid metal tube on the end so its perfect its the HDX house brand its usually in the plumbing section. Anyway best of luck.
 
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