theaaron90

Recently I had gotten an oil change done at the local Jeep dealer and when the oil change was finished the gentleman working the service desk stated my engine is sludged up. I was online searching for possible cleaners and had mixed results. Some say it works some say it gets worse. I know a flush has never been done on my motor and it has 188,000 miles on it. I was hoping to get some insight on what to do to alleviate my engines sludge build up. Any help would be greatly appreciated.

glass3222

I would not trust most dealer on anything, they typically are looking to get you to do un-needed maintenance to make more money.

Go get another opinion, do you know any mechanics. Also, what did they say was "sludged up"?

theaaron90

He had stated the whole motor is sludged up and doubts I get my oil changed every 3 thousand miles. He also stated it's "on its last legs" because it's near some sort of "200,000 lifespan" and to start looking for a new car. I do get a regular oil change done on time. if not my jeep beeps at my telling me to service the engine everytime I start it up/

glass3222

I would not trust him, sounds like he wanted to sell you a new car. Did he drop the pan to see the crank and remove the valve cover to look at the cam/valves? A well maintained, not abused 4.0 will last more than 200k. Mine is running great with 210k.

One thing you can look at....take off the oil filler cap, and take a flashlight and look in at the valves, you may be able to see if some of the valves are clean or sludged up. You will not get the whole picture of the condition of the motor, but may give you some insight

bigbadon

This late in life I would leave it alone. Breaking the sludge loose might send it somewhere it don't belong. You might try running a diesel oil like Rotella...it is high in detergents and will SLOWLY clean up some of the crud. Check your CCV, make sure your thermostat is keeping engine warm and change oil every 3k.

theaaron90

I don't think they took anything apart considering how short of a time I was waiting. I also had the valve cover replaced last summer and the shop I did it at did not mention any sort of build up.This is the first time hearing about a build up and I've owned the vehicle for four years and had the oil changes done at Gregory Jeep until they lost their ticket about 2 years ago. So go with the diesel cleaner just to help clean it or would seafoam do the job? Another user stated not to do the flush because it would send something through the system that shouldn't be there.

Bustedback

The service tech is trying to upsale you. Pull the oil fill cap off and look inside the valve cover, if you're changing the oil every 3000 miles (too soon in my opinion) there should not be any sludge build up.

dave1123

What he might have seen was a small amount of white milky-like deposit on your oil cap. This is condensation that burns away when the motor heats up. If not run long enough the burn it off, it turns black and builds up. If all of your trips are short and the motor doesn't fully warm up, it will sludge up. I think SAE states trips of less than 15 miles will cause sludge buildup. So, drive it! Moist cold climates accentuate the problem.

If this is a 4.0, I know of one that is still going after 385K miles. Anyone got a better one?

Hamster

My 90 4.0 has 235k and sounds like a diesel in a drive through but, she's still going strong and still has excellent throttle response.

97zjnoob

Ive got a 5.2 in my zj with 218k miles and she runs like a top. Just losing mpgs. Ive not used it yet in my jeep but have on several other vehicles with no ill effect, autozone has a 5 min engine flush you can buy. Its in a grey bottle by the oil additives. Just follow the directions and youll notice that your oil will be jet black when you change it. Ive not tried the diesel oil for oil changes but seafoam works well for me too. Ive also heard of guys running kerosene in their engines while it idles before an oil change. I personally wouldnt do that only because i cant afford it to break haha

dave1123

I believe I'm the one that posted the kerosene treatment. My grandpa used to do that in the 40s. I did it once on a 62 Chrysler 383 that I got cheap. It worked well and I literaly beat the snot out of it for 4 years after. You've got to put at least i qt. of oil in with it or it will knock, 2 to be safe. The motor has to be warm before you do it and DO NOT GO BEYOND 5 MIN. AT IDLE ONLY.

97zjnoob

I didnt mean any disrespect by my comment. I just get overly worried about stuff failing. Ive had some bad vehicle luck these past couple years lol tires falling off while i drive and the like haha

dave1123

I didn't take any disrespect. I was meerly retelling an experience. I wouldn't recommend it on something you cared about. The Chrysler was cheap because it was sludged so bad. I cleaned it and then had some fun with it. It was a big white convertible and I loved harassing Cadilacs and Lincolns. The 383 was the small engine for the Chrysler but it was no dog either. Top of the line motor was a 413 with 2 4bbls.

The only emissions equipment was a PCV valve.

97zjnoob

That sounds like my 79 tbird i had. It only had the 302 but i could get over 120 pretty fast lol

PatriotGT

My uncle use to flush his using mineral spirits. 3qts + 1 oil and one left in the filter.
I tried it once in a 64 Chevelle (he hadn't told me about adding the oil while flushing).
Ran it for a couple minutes, drained, added oil and new filter. Went to start the engine and crap the engine just would turn over. I had washed all the oil from the bearings. Overfilled the crankcase and had to have a jumper to help spint it over.
Once it fired, I've never felt so relieved (it was my dd). Never did have any trouble
with it afterward ------ right up til I traded it.