When I bought my '97 Wrangler TJ,2.5 4 banger, it had 92,000 miles. Oil was black, but no sludge. I changed the oil and filter and checked the oil after about 200 miles and it was black. I changed the oil and filter after 2,500 miles, check it at about 150 miles and again the oil was black, still no sludge. I have changed it the 3rd time and the oil turned black after a couple hundred miles. The engine shows good oil pressure, it does not use any oil and there are no leaks. The new plugs I installed when I bought the TJ show no fouling with about 7,000 miles on them. What could be causing my problem and should I risk adding a cleaning agent?
Oil dirty after a couple hundred miles
- Thread starter Dixiejack
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- Sep 28, 2002
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DJ,
You're spending a decent amount of money on short OCIs here. I'd give the whole list of products that are widely accepted as being "the real deal" by most of the membership here a try. In your case ..with your concerns ..(that is, the stuff that's bothering you) ..you've got nothing to lose.
I'd recommmend Auto-Rx first off ..since I've used it and seen its benefits. I'd also lean toward using the FP/LC products since the concensus here appears to have them in the same level of effectivness.
You also don't know if your "dirty" is from accumulations of a mildly neglected oil related maintenance schedule ...or fuel system degradation due to lack of periodic maintenance. Your injectors may have a wide variance of spray patterns and flow. The DC PCM isn't that sophisticated to poll and control each individual injector ..opting for the simple and cheap "batch fire" mode of pulse width control. That is, even if you're in close loop operation most of the time (at cruise) ..the computer only sees the 'average' tail pipe condition. You may be running one cylinder on the rich side ..and the other 3 a little lean. In open loop the thing is even more numb ..it just pukes out a pulse width from a preset fuel curve based on the MAP sensor reading. It then, increases this pulse width over time ..if it records too many lean or rich conditions while in open loop.
btw- ..use a xw-40 with that jeep engine. The things shead iron like it was a bad case of dandruf. xw-30 weights have been proven more times than not to fail in controling this.
There you are ..more than you needed to know.
You're spending a decent amount of money on short OCIs here. I'd give the whole list of products that are widely accepted as being "the real deal" by most of the membership here a try. In your case ..with your concerns ..(that is, the stuff that's bothering you) ..you've got nothing to lose.
I'd recommmend Auto-Rx first off ..since I've used it and seen its benefits. I'd also lean toward using the FP/LC products since the concensus here appears to have them in the same level of effectivness.
You also don't know if your "dirty" is from accumulations of a mildly neglected oil related maintenance schedule ...or fuel system degradation due to lack of periodic maintenance. Your injectors may have a wide variance of spray patterns and flow. The DC PCM isn't that sophisticated to poll and control each individual injector ..opting for the simple and cheap "batch fire" mode of pulse width control. That is, even if you're in close loop operation most of the time (at cruise) ..the computer only sees the 'average' tail pipe condition. You may be running one cylinder on the rich side ..and the other 3 a little lean. In open loop the thing is even more numb ..it just pukes out a pulse width from a preset fuel curve based on the MAP sensor reading. It then, increases this pulse width over time ..if it records too many lean or rich conditions while in open loop.
btw- ..use a xw-40 with that jeep engine. The things shead iron like it was a bad case of dandruf. xw-30 weights have been proven more times than not to fail in controling this.
There you are ..more than you needed to know.
I did forget to mention that I had the injectors cleaned and adjusted. And most of my driving is commuting. I am running Castrol 10w30. Next change I will go with 10w40. What is the concensus on the best brand of non synthetic oil? Maybe I should change brands.
I had used Castrol 10w30 in my '94 Ranger and it had 150,000 miles on it and it was not using any oil when I sold it. Talked to the guy I sold it to about a month ago. He said he had put about 50,000 miles on it with no engine work so far.
I had used Castrol 10w30 in my '94 Ranger and it had 150,000 miles on it and it was not using any oil when I sold it. Talked to the guy I sold it to about a month ago. He said he had put about 50,000 miles on it with no engine work so far.
Not sure if you mean straight dino or are willing to go with a blend, but you might try Maxlife 10w40. It has very nice tech stats and high flash point along with about 15% PAO (per MSDS), though not promoted as a "blend." Worked nicely in my straight 6 F150.
Alternately the synthetic blend Valvoline Durablend 10w40 looks great and meets the ACEA A3 spec. I will be trying this one in my pickup as soon as the AutoRx cleaning process is done.
I used Delo 15/40 for 2000 miles on my truck it really cleans. Perhaps after that you could try the ARX for a longer slower cleaning.Just follow the directions if your not sure send Frank a e-mail he will help you out further.Good luck
I have the same problem with a 2002 TJ. After about 200 miles the oil turns black (Mobil1 10W30). Then I switched to Amsoil 0W30 and added a bypass filter and now the oil turn black at about 3K miles (I am assuming the type of oil didn't play a big role). After that I added LC and I now have about 5K miles and it still is dark brown...
I just checked with the dealer and the FSM; no EGR valve. Maybe it’s something else like the PCV valve (actually the Crankcase Ventilation (CCV) system in the TJ) that is not working properly. It is leaking air/oil from one of the valves located on the top of the valve cover... I sealed it with some gasket maker last weekend so we will see....
Bad EGR Valve....
Gene
Gene
Run an ARX bottle with one of your short changes.
Purhaps you have dirty ring packs, oil seal as well as compression rings. Can't hurt. Better sealing of the cylinder walls from clean rings, may turn this motor around.
Purhaps you have dirty ring packs, oil seal as well as compression rings. Can't hurt. Better sealing of the cylinder walls from clean rings, may turn this motor around.
Could be normal. I see alot of people confused because the oil turned black. Run a Used Oil Analysis. The UOA would give you an idea if there is anything in the oil worth worrying about.
If the Jeep runs well, I would just continue with a safe and sane OCI with whatever oil you are using. If the weather pattern is acceptable, a diesel engine oil(HDEO), like a 15w40, could also be used and is cost effective. A 5-10 minute flush should also be considered at your next oil change interval.
And, a larger oil filter might be a good choice for more filtration, more oil capacity....
I'd also check/replace all normal tuneup items. The air/fuel filters, plugs cap rotor wires, 02 sensor, timing, thermostat, CCV, compression, are places to start.
If the Jeep runs well, I would just continue with a safe and sane OCI with whatever oil you are using. If the weather pattern is acceptable, a diesel engine oil(HDEO), like a 15w40, could also be used and is cost effective. A 5-10 minute flush should also be considered at your next oil change interval.
And, a larger oil filter might be a good choice for more filtration, more oil capacity....
I'd also check/replace all normal tuneup items. The air/fuel filters, plugs cap rotor wires, 02 sensor, timing, thermostat, CCV, compression, are places to start.
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Both my TJ's retain oil "clarity" for over 6k. My wife's has a big sump (10.5 quarts/ 90k+) ..so you kinda expect it (looks "normal" @ 12k) ..but my 4 banger (4quart/41k) doesn't even turn opaque @ 6000 ..where I typically change it. It just gets "tinted".
Spray some cleaner into your metered orifice tube to assure that it's clear.
Yes, NO EGR. DC uses cam overlap and timing to control NOX emissions (42 some odd degrees on the 4.0) by leaving spent combustion material in the cylinder.
Auto-Rx is a good thing to use. Make sure you go xw-40 with this engine.
Life is good
Spray some cleaner into your metered orifice tube to assure that it's clear.
Yes, NO EGR. DC uses cam overlap and timing to control NOX emissions (42 some odd degrees on the 4.0) by leaving spent combustion material in the cylinder.
Auto-Rx is a good thing to use. Make sure you go xw-40 with this engine.
Life is good
I third and fourth the use of Auto RX. I am in the end of a cleaning phase on my 99 4 banger, I have teamed that up with about 3 stright tanks of fuel power and my idle is so smooth and quiet.
If you would like to "clean" up your little 4 bangers internals, I highly reccomend auto rx. I was kind of skeptical too, but look at the great results that so many people have with the stuff on this site! I would also purchase a gallon of fuel power and start adding that to every tank (1-oz per 5 gallons) I saw improvement with fuel power after my second tank! (might I add, I am running 31 BFG MT's with 4.10 gears and am currently getting 19mpg with my 99 4banger TJ)
If you would like to "clean" up your little 4 bangers internals, I highly reccomend auto rx. I was kind of skeptical too, but look at the great results that so many people have with the stuff on this site! I would also purchase a gallon of fuel power and start adding that to every tank (1-oz per 5 gallons) I saw improvement with fuel power after my second tank! (might I add, I am running 31 BFG MT's with 4.10 gears and am currently getting 19mpg with my 99 4banger TJ)
My wife's car tends to darken the oil rather quickly. This last oil change it was dark when I put it, but after adding 2oz of LC at 2000 miles, the oil is actually clearer now at 3000 then it was after I put it in.
With FP I saw fuel economy improvements immediately with my higher mileage cars and even my gas guzzling modified 3800 SC, is getting better after several tanks.
-T
With FP I saw fuel economy improvements immediately with my higher mileage cars and even my gas guzzling modified 3800 SC, is getting better after several tanks.
-T
- Its not the plugs (I change them every 10K)
- I hope its not an 02 sensor (its a 2002 model so the sensors are pretty new and no error codes come up)
- It's not an oil filter issue either; changed regularly
- C0/NOx.. are all normal according to the state emission inspection report
- It might have been a CCV issue. I think its a venting issue. One of the hoses that came out from the valve cover was loosing air so the engine might not have vented properly.
I did a cylinder compression test and here are the results:
cylinder 1: 152 PSI
cylinder 2: 165
cylinder 3: 180
cylinder 4: 175
cylinder 5: 150
cylinder 6: 147
According to the FSM:
CYLINDER COMPRESSION PRESSURE
Pressure Range 120 to 150 psi
Max. Variation Between
Cylinders 30 psi
I'm assuming these are good results. BUT I can't understand why such a big variance (33 PSI). What does that mean?
- How can an engine have such a big variance between cylinders?
- Why is cylinder 3, 30 PSI higher than the max range?
cylinder 1: 152 PSI
cylinder 2: 165
cylinder 3: 180
cylinder 4: 175
cylinder 5: 150
cylinder 6: 147
According to the FSM:
CYLINDER COMPRESSION PRESSURE
Pressure Range 120 to 150 psi
Max. Variation Between
Cylinders 30 psi
I'm assuming these are good results. BUT I can't understand why such a big variance (33 PSI). What does that mean?
- How can an engine have such a big variance between cylinders?
- Why is cylinder 3, 30 PSI higher than the max range?
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