Engine Flush

[Akula69]

I wanted to visit this toipic again as it has been several years since anyone has talked about flushing the oil passages in the Jeep engines.

 

While there was one post that talked about it, the jury was evenly hung with 2 for and two against. The folks against talked about the gunk and accumulated build-up fouling the oil pump pickup screen, and generally perdicting doom and gloom. The ones for had said it breathed new life into the engine and they got better performance all the way around.

 

I am considering using one of the products on the market (I have certainly not chosen - so if someone wants to tell of thier experience that would be great) like Seafoam or the AMSOIL engine flush. All the 'flushes' instruct you to warm the engine and then add the cleaner...then run for 10 minutes and immediately drain. (Similar to warming the engine to suspend the debris and then draining the oil). I have also had folks advise to drain about 1/2 a quart of the existing oil and add a similar quantity of kerosene, then run the engine for 10 minutes and drain.

 

Some searching on Google indicates that it is more effective on lower mileage engines for fear of the seals failing. or allowing new leaks due to crud-covered seal failure points being 'cleaned'.

 

If any of you folks have done this please chime in, as I am looking for opinions here.

 

Thanks!

[jimoshel]

Take an old Ouija board. Place all the options around the outer ring. Spin the needle. About as good a method as any. I have at one time or another, used all the options you mentioned, plus a couple others. Cannot recommend one over another. Main thing is to get the engine clean, All the old crap, crud, oil, whatever you used for a flushing agent, everything out before filling with fresh oil.

[jpdocdave]

I can personally attest to the results of oil flushes, they do work. I've removed valve covers, seen gunk to no end, ran a flush through, and saw the results, clean. They do work, I have also seen them unstick horribly stuck lifters, I am a fan of what they do.

 

Now, it is entirely possible that the gunk that is freed, can end up in the pump screen. The bottle will say, on a higher mileage engine, after using this product, remove the oil pan, and clean the pan and pump screen.

[jimmy21669]

I can personally attest to the results of oil flushes, they do work. I've removed valve covers, seen gunk to no end, ran a flush through, and saw the results, clean. They do work, I have also seen them unstick horribly stuck lifters, I am a fan of what they do.

 

Now, it is entirely possible that the gunk that is freed, can end up in the pump screen. The bottle will say, on a higher mileage engine, after using this product, remove the oil pan, and clean the pan and pump screen.

 

 

DING DING DING...tell him what he's won Bob!!

 

They DO work. They can cause problems. On a high mileage engine they are not just add and walk away. They are add, then clean thoroughly once it has freed the gunk. It can and will add life and performance to an otherwise good engine.

[A-man930]

Gotta consider too that most flushes on the market are solvent-based. Kerosene, sea foam, gunk, etc... all have the same effect as carb cleaner from a spray can; very agressive and won't offer any lubricating prioperties. Another old-time trick you might consider instead is adding a quart of ATF to the crankcase in place of some oil (or slightly overfill it). Its oil, with tons of detergents... not so agressive as to dislodge chunks of stuff but still effective at removing sludge buildup and freeing sticky lifters and rings and such.

[Akula69]

OK - we bit the bullet and decided to go with the Seafoam. The decision was made for us based upon the fact that it has gotten cooler here, and we recently replaced the stock single core radiator with the 3 core CSF model...both things conspiring to make the initial oil pressure at start-up be about 80+ PSI abd stay there for what seemed to be a long time.

 

Before the new radiator and in warmer weather it would sit at 70 PSI at start and after the warm-up it would idle at 25-30 PSI, and under RPMs it would sit at about 60 PSI while using dino 10-40W oil.

 

Sunday, we started her and after warm-up we added 1/3 can of the Seafoam to the vaccum line at the brake booster and then shut down for 10 minutes. At second start-up it smoked like a demon but quickly sunsided, and ran much smoother! We then added the rest of the can to the crankcase and drove it for 10-15 miles. Came back and changed the oil HOT (daymn that smarted through the gloves!) and new Bosch filter - oil was pitch black in color. Re-filled with dino 5-30W and parked.

 

Next morning at cold start it was 70 PSI and after warm-up it was 25-30 PSI at idle. :yes:

 

If necessary I will repeat the procedure, but if the pressure starts to build again I may step down to the dino 0-30W or go with a 5-20W. If it improves too much I will mix the 5-30W and the 10-30W to maintain the hot idle at or above 20-25PSI to avoid engine failure.

 

Oh, so far there are no leaks and thats a good thing. :D I will pull the pan this next weekend and check for screen debris.

[jpdocdave]

Glad you're happy, but I would advise against 0w20 or 5w20. Also remember that most oil gauges aren't all that accurate in the dash. Before you go any further, I'd back up your dash gauge with a mechanical test gauge to verify what your oil pressure really is.