'98 Sport 5.9L major oil usage?

I have used 2-3 quarts of oil in the past week, about 400 miles driven. The shop claims it's not leaking They claim they done a test on intake manifold and that it's not leaking. My question is what do guys think the problem is. The shop said its probably the piston rings losing that much oil and that means engine rebuild or replacement, which do they neither. What do guys think. Truck has 164K miles on it. No check engine light on, truck seems to run good. I did have to replace both oxygen sensors and catalytic converter when first purchased the truck in December. Truck does not seem to smoke any. PCV valve and hose been replaced as well.

Comp test and plenum, **** what the shop says about the manifold all "tests" are proven to be inaccurate

OK. I plan to take it to a 2nd shop as soon as I get my van back from the shop, for I'm not left carless.

Plenum.

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Those guys don't know what they're talking about. Most shops spray soap water or parts clean around the intake to check for leaks, which is fine, but all it means is the seals between the intake and block/heads isn't leaking. What they seem to be unaware of is the intake/intake gasket that leaks EVERY DAMN TIME and cannot be tested by any conventional spray test.

Your rings are probably fine, a compression test will tell you that for sure. But i'd find a different shop to do that test, just tell them you think one of the cylinders has a head gasket leak and you'd like to know. Or just goto autozone and rent the tool yourself. All you have to do is remove the spark plugs and screw the tool into the spark plug hole and you're ready to test.

The problem is your plenum gasket, the fix can range from about $30-160 depending on which fix you buy. (I like my shiney new aluminium pan that no one will ever see). All you have to do to fix it is remove the intake and replace the gasket on the bottom, a shop will probably charge 3 hours if they don't break a bolt. But they will, so tell them walking into it, to hit those bolts good with something then heat up the front 4 bolts and quench first as those are the ones that like to break every time.

dudeman2009 said:

Those guys don't know what they're talking about. Most shops spray soap water or parts clean around the intake to check for leaks, which is fine, but all it means is the seals between the intake and block/heads isn't leaking. What they seem to be unaware of is the intake/intake gasket that leaks EVERY DAMN TIME and cannot be tested by any conventional spray test.

Your rings are probably fine, a compression test will tell you that for sure. But i'd find a different shop to do that test, just tell them you think one of the cylinders has a head gasket leak and you'd like to know. Or just goto autozone and rent the tool yourself. All you have to do is remove the spark plugs and screw the tool into the spark plug hole and you're ready to test.

The problem is your plenum gasket, the fix can range from about $30-160 depending on which fix you buy. (I like my shiney new aluminium pan that no one will ever see). All you have to do to fix it is remove the intake and replace the gasket on the bottom, a shop will probably charge 3 hours if they don't break a bolt. But they will, so tell them walking into it, to hit those bolts good with something then heat up the front 4 bolts and quench first as those are the ones that like to break every time.

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Well spoke to the 2nd shop on the phone, they said they wouldn't be able to tell me whats wrong without tearing the motor apart and that it probably needs a replacement motor. Asked them about the intake manifold and he acted like I was stupid saying he dont even see how that would cause oil burning. The next step is the dodge dealer. They want $125 to find the problem and will deduct it from any work done. Guess I'm likely to go that route.

Real typical problem on the kegger intakes.

bikerlbf406 said:

Well spoke to the 2nd shop on the phone, they said they wouldn't be able to tell me whats wrong without tearing the motor apart and that it probably needs a replacement motor. Asked them about the intake manifold and he acted like I was stupid saying he dont even see how that would cause oil burning. The next step is the dodge dealer. They want $125 to find the problem and will deduct it from any work done. Guess I'm likely to go that route.

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No offense, but most dealers aren't into it to fix problems on old vehicles like these. They want to look at it and nitpick every little problem then add them all into a huge problem that would be better to just buy another vehicle.

Not all dealers are like that, but the unfortunate truth is some exist. They won't lie, they will just bend the rules.

You can take it to the dealer, if you get a decent tech, they will find the real problem and fix it. But its still gonna be a lot more than if you did it yourself. If you're worried about doing it yourself, take a breather. There is only 2 steps where you can screw things up, removing the bolts, and cleaning the old gasket material off the heads. As long and you take things slow, and follow the advice of us guys on here, you'll be fine. All you need is a basic socket set and some screwdrivers. You'll be able to fix it for less than what the dealer charges to diagnose it.

But, to each their own. Don't let anyone tell you the engine is bad without some real good proof, like a hole in the side of the block. If you're unsure, just tell them that you want to do some research of your own to confirm and come talk to us. I'm not sure about IL, but in Michigan, by law, they cant hold your vehicle ransom, they cant force you into getting services, you must sign off on the paperwork before they can charge for anything (some states authorize a base diagnostic fee). I'm an auto tech now, before my current job I was a diesel tech, we have no problem with customers who want to verify what we are saying is true. Its not hurting us, we are just going to go park your car in a parking spot and move on to something else.

Bring it to the dealer and see what they have to say, request a tech that has a few gray hairs. Very common problem they should be aware of if they have a tech who has been with Dodge for a while

Blown plenum.
Almost 100% guaranteed.

A quick test I used to do on these engines was this.
Pull the pcv from the valve cover, leave it attached to the hose, now pull the fresh air tube from the other cover that goes to the air cleaner. Start the truck up.
Put your thumb over the empty hole in the valve cover that the pcv came out of, put your other thumb over the fresh air tube you removed from the air cleaner.
There should be a slight pressure buildup as the engine runs, from normal blowby past the rings.
If there is any vacuum at all in the crankcase, your plenum gasket is leaking.

If it wasn't for the fact, I'm physically disabled and am not capable of performing much to any work on a vehicle now days, I'd consider doing it myself. However I'm not capable of doing the work physically, and don't have no friends or family who I trust to work on my vehicle, so a shop is pretty much my only option when it come time to repairs and since there's only 2 shops I trust in this town, and neither of them is willing to take a real look at it (one says manifold gasket is good, the other act like I am talking out of my mind when asking about the intake maniifold gasket, the dealer is about the only option I have left on my plate besides sell the truck, which I'd hate to do over something that could be a couple hour job.

The shop that acts like your out of your mind may just not be familiar with the intakes on these trucks, doesn't necessarily mean they are idiots.
The dealer should be familiar, unless all there techs are young.
Or show someone my post about how to test it.
Your crankcase should never have vacuum with the PCV out of the picture.

I don't think the shop I called today are idiots at all, but I don't believe they ever dealt with the intakes on these truck, or with them blown at all, hence why he don't see how that would cause oil burning. I'm hoping the dealer will be able to straighten this out.

I asked a local Dodge dealer about the plenum issue/repair and he said it was rare and did not remember doing one for at least 10 years. Whatever......

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Need a backyard mechanic to do it. 95% of shops/dealers will do spray or vacuum tests or tell you you're full of **** it doesn't exist, it's super rare blah blah blah etc.

Or soak the manifold bolts in pb blaster for a day or two while driving it and take a weekend day to do it yourself

If I knew of a backyard mechanic that I trust, I would go that route, unfortunately I don't. Do to physical health issues, I'm not capable of doing the job myself.

If you lived close to me, i'd say bring it over, we'll have it done in an afternoon.

To ensure the shop knows of the issue and doesn't just blow you off, print out this TSB and bring it with you.

TSB 09-05-00

Tell them that you don't want the diagnosis done, that you just want the service as described in the repair procedure section of the TSB. Once again, i'm not sure how IL law works on this, but in Michigan if a customer demands that you skip the diagnosis, you are required to put that on the work order and have it signed, then you may proceed with the repair.

As a tech, I love it when a customer comes in with a clear and defined objective, it means no diagnosis time for me, just straight up wrenching.

OK. With the help of a friend, done some testing on my truck. First test was unplugging the pcv valve from the valve cover, then pulling the vacuum line from the driver valve cover to the air cleaner off at the air cleaner. Putting a thumb over the whole in the valve cover where the PCV Valve is and the other over the vacuum line end. You could feel the air blowing out of the vacuum line and the air sucking at the pcv valve location. 2nd test we did was with everything plugged in was run the truck with the oil filler cap off and you could feel the suction there as well. It is my understanding that both of these tests is conclusive for the intake manifold gasket failed. Am I correct on this?

Easier to just pull cyl 8 spark plug and do a visual. In my opinion, more accurate as well. But yes likely blown