How should I clean out my Jeep 2.5?

Status
Not open for further replies.
Joined
Apr 9, 2008
Messages
16,443
Location
Central NY
I just picked up a real pile of a Jeep. 133K miles on it. It has the venerable 2.5L AMC engine in it.

I know it's been overheated a few times. It has recently had a new water pump, fan clutch put in it, but still overheats.

Because of it's overheating, it has some black crusties in the oil. I know the previous owner only put a few hundred miles on it total, after doing an oil change, and the oil is already black and has some crusty in it. Similar problem happened to a friend's 4.0L that was severely overheated; it had crusty stuff in it and it plugged the oil pickup tube.


This is not going to be a reliable highway cruiser. It's so rusty. Just going to use it as a woods toy that occasionally sees the road. Beat it for a year or so and then sell what's good and scrap the rest. So I'm not pulling the oil pan and cleaning it out.

Should I ...
(1) Supertech 15w-40 - it seems HDEO is often recommended.
(2) Supertech 10w-30 for a short OCI
(3) Douse it in MMO and do an oil change and see what happens
(4) Kerosene / Diesel in sump!?

This is more of an experiment to see what happens. It won't see much highway, but will be lugged around on rocks and stuff or bounce off the rev limiter in mud (yuck).

Low dollar so the filter will, of course, be supertech.
 
I would fix whatever is causing the overheat first. Only then would I change the oil and filter. please post results TIA
 
Originally Posted By: andyd
I would fix whatever is causing the overheat first. Only then would I change the oil and filter. please post results TIA


The coolant is full of rust. My guess is no one ever changed the coolant. It already has a flush and fill kit. I'm replacing the radiator and thermostat before driving it any more.

Seems to be somewhat of a thermostat issue. When it starts the temperature cycles between 240 and 180, then after about 20 minutes of driving it settles between 210 and 220 ... which is more or less ideal.
 
+1 fix the overheating.

I'd run a HDEO and a good filter, or maybe a really good cleaning PCMO like PYB 10w30.

Don't use any kind of heavy duty cleaners unless you plan on pulling the valve cover and oil pan to clean them first, that will only clog up the pickup screen and oil passages.
 
How about Delo 10w30 HDEO. Its $16 at WM and should do a nice job and it a tad bit lighter.
 
Originally Posted By: Eddie
Sounds like a needed overhaul to me or it's going to be one problem after another for life. Ed


A year from now, this jeep will be sitting in the junkyard.

Originally Posted By: sw99
How about Delo 10w30 HDEO. Its $16 at WM and should do a nice job and it a tad bit lighter.


That's an option too. HDEOs are good.
 
Before I did much, I'd test the head gasket. Maybe do a citric acid flush on the cooling system and see what that shakes out.

But then for the oil, here is what I would do:

1) Drain 2 qts of oil out, add 2 qts Diesel/kerosene then flush. 2 x 20 mins flushes.
2) Dump that out, then add the old 2 qts back in, + 1 qt MMO and enough other oil to top up.
3) Run that a 100 miles or so to clean more, flush out kerosene, etc.
4) Dump that out and run good oil w/a pint of MMO in it.

This vehicle is an excellent candidate for that.

As to "good" oil, M1 10w-30 HM is just under $13/5qts at WM after rebate. Can't beat that deal with a stick. (MMO is 3.88qt there) It's going to be better than any HDEO in this situation; I've tried Delo and Delvac for problem engines and this oil works better.
 
Originally Posted By: Oro_O

But then for the oil, here is what I would do:

1) Drain 2 qts of oil out, add 2 qts Diesel/kerosene then flush. 2 x 20 mins flushes.
2) Dump that out, then add the old 2 qts back in, + 1 qt MMO and enough other oil to top up.
3) Run that a 100 miles or so to clean more, flush out kerosene, etc.
4) Dump that out and run good oil w/a pint of MMO in it.

This vehicle is an excellent candidate for that.

As to "good" oil, M1 10w-30 HM is just under $13/5qts at WM after rebate. Can't beat that deal with a stick. (MMO is 3.88qt there) It's going to be better than any HDEO in this situation; I've tried Delo and Delvac for problem engines and this oil works better.



Well good thing that engine isn't yours, because that is just stupid.

Fix the fan/radiator/thermostat overheating problem, change the oil with the cheapest 30 or 40 weight you can find (SuperTech 15W40 is good), done.
 
Originally Posted By: bubbatime


Well good thing that engine isn't yours, because that is just stupid.


Actually did it to my SUV engine last week. Vast improvement.

It's actually an MB factory proceedure, btw.

I'll take a little stupid over a 'whole lotta ignorant any day. One isn't your fault, the other sure is.
 
Or, just run 5W-40 HDEO and a full can of BG109 at each change. Oversized filter if you can make one work. Change at at 2,500 miles. Since it won't see the road much, that might be a year ...
 
Oro's flush doesnt seem stupid at all unless you know your engine is extremely sludged...in which case I wouldnt risk it.

I like amsoil flush for a lighter strength flush and the liqui moly if I need something stronger.
 
If it's just gonna be a beater to use in off-roading for a year, I wouldn't hesitate to do a quick kerosene flush - 80% oil, 20% kerosene, idle for 5 to 10 minutes. After the flush, just run whatever's cheapest. If both ST 10w-30 and ST 15w-40 cost the same, I'd run the 15w-40.
 
Originally Posted By: Oro_O
Before I did much, I'd test the head gasket. Maybe do a citric acid flush on the cooling system and see what that shakes out.

But then for the oil, here is what I would do:

1) Drain 2 qts of oil out, add 2 qts Diesel/kerosene then flush. 2 x 20 mins flushes.
2) Dump that out, then add the old 2 qts back in, + 1 qt MMO and enough other oil to top up.
3) Run that a 100 miles or so to clean more, flush out kerosene, etc.
4) Dump that out and run good oil w/a pint of MMO in it.

This vehicle is an excellent candidate for that.

As to "good" oil, M1 10w-30 HM is just under $13/5qts at WM after rebate. Can't beat that deal with a stick. (MMO is 3.88qt there) It's going to be better than any HDEO in this situation; I've tried Delo and Delvac for problem engines and this oil works better.



What is MMO ?

Thanks , :)
 
What kind of Jeep is this? I've always been under the impression that the 2.5 was pretty tough.

As for the overheating issues, you are on the right track replacing the radiator and thermostat. I am assuming it's a 195* like the 4.0.
 
I'd go with the kerosene/oil flush 2x for 20 minutes per run. Take it up to 2500 rpm or so and let it get that oil hot, change filter for each flush cause you're gonna be needing a rock catcher lol. Since you are already fixing the radiator and thermostat take the opportunity to run a cooling system flush during the oil flush. Drain, marvel at what came out, fill up with a 15w40 HDEO and go flog it in the woods. If you run the oil hit enough for long enough it will dissolve all that buildup. Just pray that nothing comes loose in chunks big enough to plug something.
 
Originally Posted By: WyrTwister
What is MMO ?

Thanks , :)

MMO is Marvel Mystery Oil. It's a slow cleaning additive, which unlike a "flush" such as straight kerosene or Seafoam, can be used for a full OCI. You can substitute MMO for 20% sump capacity. It is also a fuel system cleaner and UCL.

Click to reveal..
 
Originally Posted By: Triton_330
Originally Posted By: WyrTwister
What is MMO ?

Thanks , :)

MMO is Marvel Mystery Oil. It's a slow cleaning additive, which unlike a "flush" such as straight kerosene or Seafoam, can be used for a full OCI. You can substitute MMO for 20% sump capacity. It is also a fuel system cleaner and UCL.

Click to reveal..


Just to add to Triton's comment, I personally like stepping it up a grade when 20% is used. I can't remember MMO's instructions, but I believe they advice doing something like this as well.

Example: If the car takes 10w30, use a 10w40 (or 15w40) if you plan on watering it down with MMO.
 
Status
Not open for further replies.
Back
Top