2000 Trooper, The Oil Saga Continues

[LEM]

Well, my Trooper (135k miles) uses about 1 qt of Pennzoil Higher Mileage Vehicle oil every 300-400 miles. The tailpipe is coated with black soot on its interior. I decided to have a BG Motor Flush performed, cost me about $75.00; this is supposed to break up and remove any sludge or varnish in the engine, I'm hopiing it will clean up the oil return ports in the pistons (supposedly a major root cause for the oil consumption).

I was talking to the ASE certified mechanic (independent garage, not a dealership) about the oil issue and he told me that every Trooper he's ever worked on has the same problem. He's talked to Jasper about it and they say it's a problem with the oil wiper rings, not the compression rings, being a bit undersized. According to him, Jasper bores out the cylinders and lines them with cast iron cylinder liners on their rebuilds to remedy this clearnace problem between the cylinder wall and the oil wiper ring on the base of the piston. Doesn't sound like the Motor Flush will help with this :0(.

COncerning the sooty tailpipe, he said that this is caused by the engine running rich; too much fuel getting into one or more cylinders and not being burned. He thought it could be a leaking injector or bad pressure regulator. Has anyone had any experience with this?

I'll post this question on another thread to make it easier to gather feedback.

Thanks.

[amigo-2k]

I've had sooty tail pipe from day one of own my truck since new.

There is a post on planetisuzoo about some guys with Troopers have some luck with Rottella oil that has help to lower their oil useage a bunch.

[amigo-2k]

http://forum.planetisuzoo.com/viewto...hlight=rotella

[rodeo02]

LEM you are still at it! Every vehicle I've ever owned had soot in the tailpipe. If you swipe the tailpipe on my 2005 trailblazer or 2001 windstar with your finger, it will come out BLACK. That doens't mean anything. Puffing black smoke, running rough, horrible MPG's, CEL, etc... means you are running rich. As far as the oil rings go, I do believe that is the likely cause for the 1998+ 3.2/3.5 oil usage. They can either be burnt and stuck, which can sometimes be remedied by a cleaning, or they can just be too small which would require a teardown and rebuild. I forget all you've done, but have you tried a 15w-40 motor oil or even a 20w-50?

Joel

[LEM]

Yes, I refuse to quit; either I'll fix the problem or trade the vehicle...Anyway, I changed the plugs last night and they were all coated with a light white coating, looked a bit like light ash. So I decided to look into what that might indicate. Seems that it shows the engine is running too rich! Here's a quote I found on another site which may help explain the CEL for miscellaneous misfire:

"As shown below, a buildup of combustion deposits stems primarily from the burning of oil and/or fuel addatives during normal combustion.
These are normally nonconductive. However, when heavier deposits are allowed to accumulate over long mileage periods, they can "mask" the spark, resulting in a plug misfire condition."

If this is the case, what causes the engine to run rich? One cause is not enough airflow which can be caused by a dirty air filter. Has anyone a recommendation for a high flow air filter?

What are some other causes for an engine running too rich?

Thanks!

[amigo-2k]

maybe your maf needs a good cleaning to let in more air.

[rodeo02]

Originally Posted by LEM

..What are some other causes for an engine running too rich?

Thanks!

Yep, the MAF makes huge fuel trim changes. A dirty MAF could cause a rich running condition. O2 sensors make smaller fuel trim changes, 2 new upstream O2 sensors *could* help. Air intake temp sensor could also keep you slightly rich. MAF, O2's and IAT sensors all would throw a code if they were 100% out to lunch. LEM, with all the combustion chamber cleanings you've done, I doubt you have a carbon/buildup problem.

Joel

[LEM]

Well, I drained the Pennzoil 10W-30 and replaced it with Rotella 15W-40 Heavy Duty over the weekend. I will monitor the oil usage and report back later...wish me success ;0)

[rlhoward59]

my daughter has a 2001 Isuzu Trooper with 87k and is having the oil burn issue. it appears outside of the correct (expensive) rebuild, piston and ring design and fitting the sea foam, marvel mystery oil or any other form of cleaning the engine as well as it's ability to vent and breath should be done and then maintained. without doing this, I think the heavier oil will undoubtedly have a more difficult time draining back into the bottom of the motor where it should be and the problem will continue or even worsen. it seems the motors were somewhat poorly designed in their ability to allow oil wiped off the cylinder walls to drain back into the bottom end easily, instead it is trapped and then burns, along with the combusted gas it exits your exhaust...... good for the atmosphere and the arabs selling us the oil.
with what I have learned regarding this issue, I am going to coach my daughter through the cleaning of the motor, she lives in Boston while I am near Chicago. then hopefully the use of correct oil with high detergency and keeping the PVC and other aspects of engine maintenance should remedy this, I hope!

[LEM]

I regularly check my PVC valve and have performed several cylinder soaks on my 200 Trooper. I've tried Seafoam severla times as well. I've also taken steps to ensure my EGR valve and tube are clear; I've cleaned them twice myself. None of this helped the oil usage.

As noted in an ealier post, I switched to Rotella heavy duty oil. I went from using 1 quart of 10W-30 Pennzoil every 350 miles to 1 quart of Rotella every 750 miles. This is still pathetic, but compared to what I was getting, it's a drastic improvement.

I can't wait for my wife to get a better job so we can trade this lemon in on a Toyota!

[amigo-2k]

I agree you shouldn't have to worry about 1 qt every 1k or even 3k, but you are probably spending over 100 bucks in gas to travel 750 miles, and now it is 101 for 1 quart of oil. An extra 20 bucks a year for oil doesn't seem to be that much.

Be happy you know to check your oil on your trooper!