3.7 oil crud probelm

[Conundrum2006]

Hi,

I hope you all will pardon me asking this question here.
We have a 2006 Commander 4x4 3.7 with almost 150K we recently bought. I know it's not the same as the KJs but I'm thinking KJ owners have more experience dealing with the 3.7 motor.

We've had it a few months and drove it just about 800 miles before getting our first oil change with it. Long story short we were talked in to a engine flush and since then (after about 20 miles) the oil filters (Mopar and Bosch filters) have been clogging and the pressure warning lights keep coming on.

I did an oil change myself today, cut open one of the filters and could see the small black particulates of crud clogging it. With a fresh filter it will idle fine once the rpm are up like driving on the road the filters clog. (I couldn't get two miles in our neighborhood)

Before I knew it was the oil filters clogging causing the problem I assumed it was the pump screen and was going to drop the pan to replace the oil pump tube/screen and the pan (some rust on the out side.).

Besides being ton of work I'm a little worried the engine has more trouble than I bargained for and just dropping pan to replace it with a clean pan and picktube/screen is a futile effort. Also I've never seen something so bad it clogs the oil filter.

Is it time to give up on the motor?
Is there something else we could try to save it?
If we do replace the motor what would interchange? it's a 2006 I was thinking any Mopar same year (like a KJ 3.7) would work as long and the casting numbers match. (Re-builders list about everything in those years as the same, used separate them by application)

Thanks in advance for you help.
Truly appreciate any insight and experience with 3.7. My impression of the 3.7 is not bad despite our stupidity flushing the motor. It had plenty of power and felt good on he road.

 

[tombo_ontario]

it sounds like the flush may have loosened a bunch of crud in the engine and now its just working its way through to the filter...hence why its clogging. If that is in fact the case, I'd be worried about buildup happening in oil passages within the engine which could I guess lead to oil starvation in some areas..

You may also just want to check the oil pressure sensor above the oil filter (i think it would still be there on 2006 3.7L). I think they tend to go out and give you a false oil pressure warning. Could either be broken or maybe it's all gummed up too..its a fairly inexpensive and simple fix just to rule it out as an issue.

 

[LibertyTC]

Welcome to the forums!
That does not sound good. Is the coolant in the reservoir tank remaining stable, any leaks of any kind?
Do you know what kind, or brand of oil flush was used?
At this point, I would want to know engine compression readings on all cylinders, record the psi readings and post back the numbers.
I would also want to see under the valve covers & hope there is not too much crud built up in there.
If it looks good, well then a screen clean ,may do it.
And Edit in: I wonder with the drain plug removed, and add/ use a bunch of clean oil through may help to push stuff through & drain.

 

[Conundrum2006]

it sounds like the flush may have loosened a bunch of crud in the engine and now its just working its way through to the filter...hence why its clogging. If that is in fact the case, I'd be worried about buildup happening in oil passages within the engine which could I guess lead to oil starvation in some areas..

You may also just want to check the oil pressure sensor above the oil filter (i think it would still be there on 2006 3.7L). I think they tend to go out and give you a false oil pressure warning. Could either be broken or maybe it's all gummed up too..its a fairly inexpensive and simple fix just to rule it out as an issue.

The pressure gauge is indeed above the oil filter. It seems to be working fine, I'll get a warning then the clatter as the oil flow trickles down.
Worried about the oil passages clogging too.

Welcome to the forums!
That does not sound good. Is the coolant in the reservoir tank remaining stable, any leaks of any kind?
Do you know what kind, or brand of oil flush was used?
At this point, I would want to know engine compression readings on all cylinders, record the psi readings and post back the numbers.
I would also want to see under the valve covers & hope there is not too much crud built up in there.
If it looks good, well then a screen clean ,may do it.
And Edit in: I wonder with the drain plug removed, and add/ use a bunch of clean oil through may help to push stuff through & drain.

The reservoir tank (I believe) has held steady. (have not seen it lose anything noticeably in our short time owning)

Not sure what brand flush was used. I want to say BG but that may not be correct.


I did do a compression test a few weeks ago, have to look for the sheet the numbers were wrote down on, as I remember the divers side bank had great pressure, want to say 150 psi to 160. The passenger side bank, first forward cylinder had great psi as well, the last two seemed low 110 psi- 120 (head gasket was what I was thinking), redid the middle cylinder (passenger side) when the engine was warm because it was easy to reach and got number in range of the first cylinder and drivers side bank. I was assuming I didn't get a good seat with the compression tester, there was a bunch of crud around the sparkplug holes, blew them out with compressor but there were nut shells from a rodent of some sort.
The main difference was the first test was plugs out of all the cylinders and the warm test wast just one plug pulled to test it.

Spark plugs look normal too.

Have not pulled the valve covers yet.

Did pour some oil through the engine with the drain removed. about two quarts in total. Wasn't sure how much it would remove if draining it didn't get the job done. Willing to pour more through if it'd help.

Also cranked the motor with out running it with the filter removed and cup catching the oil, the amount of little black crud was amazing. once I cut opened the filter it was clear it was doing it's job, oil that went though the filter was clean looking, the stuff the motor pumped out was littered with detritus.

Oddly there were some pieces of plastic, think very small pebble, in the oil drain pan, from draining the engine. Looked black I was assuming it could be a from the timing chain guides or whatever they are called. had a ford 5.4 V8 that had the chain guides beak and crumble.

I'll try to find the exact compression numbers but I'm fairly certain of the number range


thank you both for your help!

 

[Conundrum2006]

This may be a stupid question is there a larger capacity oil filter for the 3.7 motors?

I use a larger ford filter on our 91 Cherokee 4.0 (278k original motor), I was thinking maybe there is a bigger filter I could use for the 3.7.

 

[LibertyTC]

Jeep Tall oil filter is Napa 1516 you can cross reference it to any other here: Link:Oil filter cross reference
Compression 3.7 between 170psi-225psi with no more then 25% difference.

 

[Conundrum2006]

Jeep Tall oil filter is Napa 1516 you can cross reference it to any other here: Link:Oil filter cross reference
Compression 3.7 between 170psi-225psi with no more then 25% difference.

Thanks! Hum, the napa 1516 is the same as the Bosch(3422) and Mopar (MO-452) filters I used.

Wow as high as 225 psi! That's a big change form the old jeep motors.
I might do a fresh test just because I'm look for something specific now. I'm wondering if the test where I got low numbers was a fluke (ill seated connection) or a BHG. If it's a BHG maybe the cylinders leaking in to each other might artificially raise the PSI. For example the middle cylinder that tested well at warm test when it's neighboring cylinders had the sparkplugs in place keeping the pressure up in those cylinders. Maybe it doesn't work that way.

Thanks, I've got a few more things to check out. getting the valve cover off and seeing what the top end looks like, perhaps redoing the compression test. I'm starting to be more convinced we should yank the motor out rather than putting the time and money in pulling the pan and cleaning screen.

 

[M38 Bob]

Were it mine; I'd drain pan, install a cheap filter. Add one gallon kerosene + one quart of oil. Start. Run at idle for two minutes, change to another cheap filter. Run an additional 2-5 minutes, then drain. fill with cheap oil and another economy filter, drive around block, then drain and refill with preferred oil and filter.

Kerosene flushes have been working for years if done properly.

Bob

 

[belvedere]

The 1515 will fit.

 

[Hockeygoon]

Have you pulled a valve cover to see what you are dealing with? Much easier than pulling the oil pan. Sludging isn't uncommon by any stretch in the 3.7 and 4.7 engine. If it is sludged up I wouldn't bother trying to repair. The direct swaps are 2005 and 2006 (I believe). Problem is every other 3.7 junk yard engine that's 10 years old probably isn't going to be much better than what you have.

 

[dude1116]

x2 pulling the valve covers. Gotta see if it's clean or not under there.

 

[LibertyTC]

Yup ^^ Compression & leak down test !!
A dropped valve seat can replicate the OP condition.

 

[Conundrum2006]

The 1515 will fit.

? really, that is much bigger if it's the one I'm thinking of it's equivalent to a motorcraft fl1a I use on the Cherokee. I've got a few of those around in the garage. I'll see if it fits.

:favorites13:

 

[Conundrum2006]

Have you pulled a valve cover to see what you are dealing with? Much easier than pulling the oil pan. Sludging isn't uncommon by any stretch in the 3.7 and 4.7 engine. If it is sludged up I wouldn't bother trying to repair. The direct swaps are 2005 and 2006 (I believe). Problem is every other 3.7 junk yard engine that's 10 years old probably isn't going to be much better than what you have.

I've been looking around there are a few low mileage motors to be had, but without the history or pulling the covers it's a gamble. back in the late 90's I worked the sales counter at several junkyards, I know how the business works. What a junk yard will do is try to get the car running, a few revs if it does not present any problems (codes, smoke, noises) it's assumed to be good to go. Honestly it usually is. We might pull a compression test if it was easy to do, usually not just because of the labor intensive work load the crew has.

With the sensitive modern motors I'm leery of taking a chance unless it makes sense. I found a AER rebuild, costly, but if they are the same people I think they are they rebuild for ford and we've had good results with a rebuilt 5.4 from them two years ago (shop said it was the sweetest crate motor they've seen, waterpump, plugs and covers on ready to go). Somebody here (sorry forgot their name) got a 3.7 AER rebuild for a earlier KJ around 2013 but I didn't see a follow up on how it went.

 

[Conundrum2006]

x2 pulling the valve covers. Gotta see if it's clean or not under there.

Thanks for all the advice you guys are incredible!

I'm going to assume the valve cover gasket will probably break on removal. I'm going to try to get it off and redo the compression test, maybe pick up a leak down tester too, but if it looks like junk under the cover it might not be worth doing the rest of it.

 

[dude1116]

Thanks for all the advice you guys are incredible!

I'm going to assume the valve cover gasket will probably break on removal. I'm going to try to get it off and redo the compression test, maybe pick up a leak down tester too, but if it looks like junk under the cover it might not be worth doing the rest of it.

Might not break but definitely worth replacing while in there.

Not sure how long you've had the Jeep...but if it has been well taken care of, it should look something like this...

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[troutbum]

Great post, I'm learning a lot. What causes the engine to sludge up. I just bought a 2012 Liberty with 38 k on her. Dealer changed oil at 37,900 , I,m going to change it at 40k and use syntech oil and a good filter. I'm sure dealer used regular oil.

 

[dude1116]

The beauty in the picture above is my engine. Clean as a whistle. I used dino oil every 3k religiously. I've since switched to synthetic since, though. Make sure you change the oil and change it often.

 

[LibertyTC]

Great post, I'm learning a lot. What causes the engine to sludge up. I just bought a 2012 Liberty with 38 k on her. Dealer changed oil at 37,900 , I,m going to change it at 40k and use syntech oil and a good filter. I'm sure dealer used regular oil.

In a short statement, poor maintenance and infrequent oil & filter changes or internal head problems.
Your 2012 KK is more modern/different, but with the KJ...(2002-2007)
The KJ's like to run!
Check your Pcv/ the oil filler neck mounted ones on Kj's get some gunk sometimes! Short trips can cause build ups too!
See post 4 ...need a spoon? :icon_lol:Most of the time this stuff melts down but see the plugged pcv valve! Link:http://www.jeepkj.com/forum/f196/possible-head-gasket-leak-please-help-58803/
I run full Synthetic 5W-30 Jeep likes it! :gr_grin:

 

[Conundrum2006]

Might not break but definitely worth replacing while in there.

Not sure how long you've had the Jeep...but if it has been well taken care of, it should look something like this...

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That motor looks great! We have not had ours even a thousand miles yet.
Pulled the passenger side cover just enough to see inside.
Surprisingly the seal was in good shape so it was reused.
Here is what it look like. honesty it is not near as bad as I thought it would be.

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This is the crud being pumped into the oil filter.

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