H3 2009 H3 3.7L excessive oil usage, PCV?

[SGT-Wright]

How is the best way to clean the internal PCV? I am having issues with oil consumption and I am willing to try about anything to fix it. When I accelerate really hard I get a puff of brown smoke but that's the only time I ever see any smoke. I found the oil 2 qts low at oil change. Used Mobile 1 or Valvoline full synthetic for it's whole life. At 138000 miles on it now. What else should I look at for the oil issue and what other issues are expected at this mileage that should be addressed??? Thanks in advance for the help!

 

[Mr_Rich]

My '09 3T has 118K miles and is starting to use more oil. It used to be that I could go 5K between my oil changes not having to add any oil during that interval. Now I add at least a half quart in 2-2.5K miles. I might suggest adding a couple of ounces of Seafoam before your next oil change. I hope it's not my imagination that it helps. My other vehicles are DBC and I can squirt carb cleaner down the throttle body bore while modulating the throttle.

 

[alrock]

If I recall correctly, the PCV system is built into the top cover of the engine, so it's not really serviceable. What I've found on my truck is that oil consumption only happens under high RPMs, like long hill climbs. I can lose a quart in 1000 miles, but I can also go 5000 miles and maybe use 1/2 quart. 175,000 miles on my engine.

For curiosity's sake, you may want to take off the intake resonator and see how much oil is in there. The breather hose from the top of the engine may dump oil into there, which slowly gets into the throttle body and then of course gets burned up in the engine.

 

[gamma195]

Having just gone through this a month ago, here is my take. I was experiencing excessive oil loss at high RPMs under load (i.e. long drives on the freeway). I was also getting oil in the intake. The problem with this motor design is that there is no PCV valve. The I5 uses a Valve Cover with a series of small plates with small holes that act as a baffle. High mileage motors (like over 150,000) will have these baffles caked up. When this happens crankcase pressure increases pushing oil out the intake, into the combustion chamber, and out engine seals. I was getting increased oil consumption of 1 Qt per 500 miles, leaking front crank seal, and oil in the intake. I tried everything to clean mine, Carb clean, engine flush, even pipe cleaners. You just cant fix it that way.

The only sure fix is to replace the valve cover. It's not fully possible to clean it unless you hot tank it. A new Valve cover is about $100. You have to take the intake off to get at the valve cover bolts, which is a bit of a PITA. On the upside, you can also replace the intake seals and make sure your intake is secure, mine had a couple of bolts loose. You have to access it via the driver wheel well. This fixed all the issues mentioned above.

1) Jack up the front end
2) Remove the tire
3) remove inner fender liner
4) Disconnect the battery
5) Remove the serpentine belt
6) Remove the Alternator
7) Remove the Oil dipstick tube
8) disconnect the wire looms from the intake
9) Remove the air cleaner all the way down to the TB
10) remove the intake
11) remove the valve cover

Install is the reverse. Also recommend replacing the sparkplugs if you have been eating oil as they are probably partially fouled. Running synthetic or Rotella will help prevent build-up on the baffles in the future.

 

[rascole]

I use .5 qt every 2500 mile oil change.

 

[SGT-Wright]

Ok, if I were to order valve cover and all new gaskets for cover and intake, where is the best place to order everything from in one order? I prefer OEM even if it costs a little more. Thanks everyone for the help!

 

[gamma195]

Ok, if I were to order valve cover and all new gaskets for cover and intake, where is the best place to order everything from in one order? I prefer OEM even if it costs a little more. Thanks everyone for the help!

Get the Valve cover from GM. I got mine from GMPARTSDIRECT. Any GM dealer parts online store is fine. Get the cheapest. The Factory valve cover comes with Valve cover gaskets and grommets installed. No need to buy those separate. FRAM is fine for the intake gaskets. Got mine at Autozone as they were cheaper. It comes with the intake and TB gaskets.

Dont forget to clean/scrape the intake and valve cover mating surfaces. Carb cleaner and razor blade work. BTW, if your alternator is weak or noisy, now is a great time to change it since you have to pull it out anyways.

 

[EndeavoredH3]

I changed up my oil to a 0w-30 mobile one for the winters here in flagstaff. Changed the oil ~1500 miles ago and the dipstick shows the oil is low. I usually run 5w-30 Castrol full syn high mileage. This sucks because it starts so much better with the 0w-30. Why can’t we have nice things.

First time I’ve ever seen my motor burn this much oil, no leaks that I can find even in the intake. Thinking about installing an oil catch can to monitor how much is going through the pcv system

 

[gamma195]

I changed up my oil to a 0w-30 mobile one for the winters here in flagstaff. Changed the oil ~1500 miles ago and the dipstick shows the oil is low. I usually run 5w-30 Castrol full syn high mileage. This sucks because it starts so much better with the 0w-30. Why can’t we have nice things.

First time I’ve ever seen my motor burn this much oil, no leaks that I can find even in the intake. Thinking about installing an oil catch can to monitor how much is going through the pcv system

Generally, you shouldn't see too much consumption increase using a lower cold weight oil (like going from a 5w-30 to a 0W-30) except for on start/warm-up perhaps. How many miles are on your engine?