Jeep Enthusiast Forums banner

What is Happening to my Engine Oil in my 95 ZJ LAREDO 5.2 V8

2K views 15 replies 7 participants last post by  PolkaPower 
#1 ·
Okay so i have had my 1995 ZJ Laredo since September 2009 It has the 5.2 V8 318ci Magnum,NP249,Auto the Vehicle currently has 190XXX miles. I for the last 3 years have always changed the oil using a Fram Filter and always Mobil1 10W-30 or 5W-30 seems to be the Best oil i have ever used even when i was driving my Z28 (Pre 2009) anyways.

Well it must have been the last 2-3 years i have documented it anyways it seems that my Engine Oil disappears and there has never been a single drop on my Driveway i swear i am AMAZED. So i do not know what is happening is it getting burned up or is my Engine or the "HOUDINI" of Engine Oil LOL i can't figure it out at all. I have heard something called an "EGR VALVE" I think though i know it is a 19 year old vehicle (Engine and Tranny Never Rebuilt).
It was Elderly Owned prior to me. I know it's normal for a Car with this many miles and years to burn/consume a little oil but this is crazy it seems i have to add some 1 week or every 2 weeks. I work out of my home so i try not to drive so much anymore except for the Essentials you know.

Anyone know what is happening to my oil???

PS: I love this ZJ and Magnum aka LA Engine (that is no longer produced) It has been really reliable not the best on Gas obviously but it gets me where i need to be. Even to the Outdoor Shooting Range i go to that is on top of a mountain.
 
See less See more
#2 ·
Every magnum 5.2 and 5.9 in a Dodge or Jeep has a faulty plenum gasket from the factory. They stupidly put a steel plate on an aluminum block. The metals heat and cool at different temperatures which squeezes the gasket out and causes a plenum leak. That means oil is getting into the intake and burning off, gumming up sensors, causing poor mileage, and less power.

I'm betting your plenum is bad. Take the air hat off the throttle body and look down in there with a flashlight. If it's brown then it's oil. It should look like clean metal. Even if there is a sheen on it it's leaking.

This will fix it. http://www.hughesengines.com/Index/products.php?partid=27091
 
#8 ·
don't forget the 3.9 has this problem too, it shares the same bore and stroke as the 5.2:D
 
#3 ·
#5 ·
Yep, it was a mistake in the transition to MPI from the older carb and TBI engines. The other intakes available for the magnum motors are closer to the carb style intakes and don't have that problem.
 
#9 ·
Yes, the 3.9 is basically the Magnum V8 with two cylinders lopped off. Just like the truck V10 is the V8 +2 cylinders. The V10's use a different intake though.
 
#10 ·
Of course those ****ers at chrysler will not do the right thing

I wish they would perform the replacement of that plenum gasket free of charge i mean it is the right thing morally. But it is all about the $$$Bottom Line$$$ also my 1995 ZJ also has the recall for the rear gas tank potential rupture. They won't make that right either and i am always driving around with a potential Bomb in the back LOL. I mean they could spend a little $$$ to fix that to but no they would rather pay my family $$$ in a lawsuit for my death LOL

Man these ZJ's are one of the Best Vehicles ever made except for the Rear Gas Tank issue,Plenum Gasket and the permanent 4WD aka Quadra Trac that was a bad idea especially for the V8. Should have only made Selectable 4WD these Gas Guzzlers i know it was made for the year 1995 when gas was a $1.08 anyways it is love hate thing with me and my ZJ i love it more though.
 
#11 ·
Oh no, you got a bomb in the back of your vehicle. A bomb! That can only be activated be a rear end collision, and only in certain cases, and usually just causes a fire, not an explosion, but a BOMB!

And they put an AWD system into a Jeep that has parts that wear out. After only 150k miles! Or faster if you ignore the ****ing owners manual and run mismatched tires. How could they!

But gaskets that fail, thats just the last straw, and they won't even replace a gasket on a 20 year old vehicle for free! We have to buy $20 worth of parts and fix it, or have somebody else fix it.
 
#15 ·
I'm guessing that the plenum gaskets lasted well beyond 5 years from when the Jeeps were new. At what age, or what amount of mileage, is it generally necessary to replace the plenum gasket? I'm guessing that they go 100K miles or so before it's necessary. This is way outside of any manufacturer's warranty, and certainly not reasonable to expect compensation on such a repair. No car is perfect, nor has a lifetime guarantee, no matter what you pay for it. Rolls Royce might have a really good one though.

My model of '99 Bimmer has an ABS controller that started failing when the cars were about 5 years old. When it first started happening, and the Bimmer owners were talking about it among themselves, it was figured out that they virtually all failed. Many tried to get BMW to pay for part of the repair, as it was a "safety item", but it fell on deaf ears. The fact that the engineers placed a computer, with small solder traces, etc., close to the exhaust manifold, can be seen as a design flaw, but BMW never relented. If one had to replace it at the 5 year mark, say in 2004, that repair at the dealer would have run close to $1200 or so. That's when companies started repairing the failed circuitry, and charging 1/2 of what a new unit cost. Many cars, including our Jeeps, have this same problem, delicate electronics placed in the inhospitable environment of the engine compartment.

And, BMW V8's also have problems with their plenum gaskets, and the owners get no help from the factory that made them.

As you said, Jeeps are great vehicles, but there are certain items that are very well designed for their purpose, but not for lasting indefinitely. I don't know how old the OP is, but I can say that cars that were built in the sixties and seventies ended up in junkyards much earlier than our Jeeps today. I remember when a car with 150,000 miles or so was a spent rattle-trap for the most part. Our Jeeps go 2-3 times that, maybe more, if properly maintained, and serviced with quality in mind. Again, they're not perfect, but I have few complaints at 183K miles. I am the original owner of the ZJ, which is a big plus in the mystery removal area.

The plastic gas tank behind the axle, and the fuel-pump serviceability on '97 and '98's, well, I don't know what they were thinking there. The ZJ's aren't perfect, but they are pretty impressive overall, IMHO. :cheers2:
 
#16 ·
I'm guessing that the plenum gaskets lasted well beyond 5 years from when the Jeeps were new. At what age, or what amount of mileage, is it generally necessary to replace the plenum gasket? I'm guessing that they go 100K miles or so before it's necessary. This is way outside of any manufacturer's warranty, and certainly not reasonable to expect compensation on such a repair. No car is perfect, nor has a lifetime guarantee, no matter what you pay for it. Rolls Royce might have a really good one though.

My model of '99 Bimmer has an ABS controller that started failing when the cars were about 5 years old. When it first started happening, and the Bimmer owners were talking about it among themselves, it was figured out that they virtually all failed. Many tried to get BMW to pay for part of the repair, as it was a "safety item", but it fell on deaf ears. The fact that the engineers placed a computer, with small solder traces, etc., close to the exhaust manifold, can be seen as a design flaw, but BMW never relented. If one had to replace it at the 5 year mark, say in 2004, that repair at the dealer would have run close to $1200 or so. That's when companies started repairing the failed circuitry, and charging 1/2 of what a new unit cost. Many cars, including our Jeeps, have this same problem, delicate electronics placed in the inhospitable environment of the engine compartment.

And, BMW V8's also have problems with their plenum gaskets, and the owners get no help from the factory that made them.

As you said, Jeeps are great vehicles, but there are certain items that are very well designed for their purpose, but not for lasting indefinitely. I don't know how old the OP is, but I can say that cars that were built in the sixties and seventies ended up in junkyards much earlier than our Jeeps today. I remember when a car with 150,000 miles or so was a spent rattle-trap for the most part. Our Jeeps go 2-3 times that, maybe more, if properly maintained, and serviced with quality in mind. Again, they're not perfect, but I have few complaints at 183K miles. I am the original owner of the ZJ, which is a big plus in the mystery removal area.

The plastic gas tank behind the axle, and the fuel-pump serviceability on '97 and '98's, well, I don't know what they were thinking there. The ZJ's aren't perfect, but they are pretty impressive overall, IMHO. :cheers2:
Germans used to overbuild everything in their cars. It wasn't until they had to compete with the Japanese that quality went down. What a shame too.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top