Hi all,

Just did an oil consumption test on the my 97 ram 2500 120k miles (5.9L V8 gas). I have apparently consumed about 1.25 QT of 10W-30 in only 600 miles of usual driving. Yikes. I don't like that.

- I do not appear to have any leaks even remotely nearing this magnitude (but I am double checking with some flourescent oil dye to be sure)

- I have not seen smoke exiting the tailpipe in cold or warm starts (I'd imagine if a lot of oil was passing the piston rings and getting combusted I would see the truck throwing significant blue-ish smoke esp on cold start before the rings have temp expanded to the cylinder walls, maybe that is not true)

- I pulled the air cleaner and looked down the throttle body with the throttle open. I attached pics of what I saw. It looks like some gunk on the surface facing up, I guess it may be gunked up engine oil.



From what I've read it seems it could be due to a bad PCV valve or intake plenum gasket. Still weird as I would think I would see smoke if these were the issues, but nonetheless. Any advice before I start throwing parts at it?

Thanks,

Nick

 

Reading is your friend............................................ ..................

https://dodgeforum.com/forum/2nd-gen...um-thread.html

Almost 100% sure this is a plenum gasket problem

 

lol dude ya thats really bad its time to get a new plenum gasket in there, im sure its using a lot of coolant as well. get one of these and put it in http://www.hughesengines.com/Index/p...p?partid=27091 . also ya i would replace your pcv valve. Make sure your cat isnt clogged either and replace the 02 sensors if their old as well.

 

Just yanking your chain. Thanks didn't find that exact thread so I will read it.

Thanks for the advice.

 

Always trying to help.

The thread has a lot of good info in it. When I was diagnosing my plenum issue I hadn't found this site yet. So I was pulling my hair out.

And as zildjian3707 gave some good info too. You want to replace your upstream O2 sensor for sure and should really look at replacing your cat too.

 

Before I pull the thing and throw the parts at it, can I pull out the crankcase breather hose from the air cleaner, hook up a vac gauge to it, and verify that I am in fact getting vac in the crankcase? That would sort of confirm that the issue is either with the plenum gasket or the PCV valve or both, right.

Also, it is really possible that this issue would explain 1.25 QT in 600mi consumption? That order of magnitude makes sense?

Nick

 

IMO you don't need any further testing. Described symptoms plus that pic is enough to say it's time to order a Hughes Plenum kit...

 

X2 They all start to leak and need to be replaced at some point. So put in the Hughes kit and forget about it.

 

Did you read the thread I linked for you? In short as the other two posters have already said YES it can be explained. Read the thread!!

 

Alright, so in the cart I've got:

- Hughes plenum kit including intake gasket, intake bolts, bypass hose

- SS 195* thermostat

- water pump inlet tube

- NGK 23151 (pre-cat) and 23099 (post-cat) o2 sensors (figured i'd replace both)

- throttle body base gasket

- oil pan gasket to be safe

Cat is brand new so I'm going to pray I don't need to re buy it.

Now I'm starting to wonder what else to monkey with while I'm this deep in. I know that my timing cover gasket is leaking, so should I pull the timing cover and do the gasket?

What about the chain itself (I'm guessing since it's a chain it doesn't need regular service like a belt would.) This also doesn't appear as a regular service item in the manual.

Would it be worth it to do water pump while I'm in here? 120k on the stock unit, I looked in the service manual and it doesn't appear to be scheduled maintenance but I figured you all would know the trends. And that seems like a while of mileage on the pump.

Sorry for all the noob questions and thanks a lot for all your guys input.