I am baffled and need your help...

2005 Dodge Caravan, 3.3 L engine, 130k km, Well maintained.

I need to put a Litre of oil every 1.5 to 2 weeks.

I have no idea where the oil is disappearing.

New PVC, No leaks on block, No leaks on driveway, Oil is clean on dip stick, Coolant is clean, No smoke from exhaust.

Did a compression check. All Cylinders in the green. Lowest is 185, highest is 200.

Spark Plugs and wires were replaced approximately 4 months ago. During compression check yesterday, noticed cracked plugs, therefore replaced again. This could be from over-tightening.

New Catalytic converter.

Anyone know where this oil is going? Any ideas?

Thank you

 

I would suspect something in the top side like worn valve guides, stems or seals.

 

yeah... you are probably down for a Engine Rebuild.
before you go big, Try some Oil Treatment like Lucas or BG oil stablizer with 5w-30 oil, it might help, and it might not.
The Minivan in that year has some problem with the Piston Rings. But if you are going that far, might as well install some valve seals.
Ur Cat Converter is probably destroyed by all the oil it is burning.

 

Thanks for your input and advice. I suspected valve system, focusing on seals, but wouldnt that show in the compression check? The pressure seemed ok and wasn't losing pressure. I had to press the release button. I think i am going to replace the seals. Hard to get at the side under the wipers but will do before i ruin the new cat.

Thanks again

 

Show on a compression check? If I'm picturing this right, no. A compression check checks pressure built up during the compression stroke inside the cylinder in the engine block. Valve channels are bored into the cylinder head. The head is attached above the block. Nothing above the lower surface of the cylinder head is pressurized on the compression stroke because the valves have sealed into the valve seats in the head. Much lower pressures may hit the valve guides when the valves are open but a compression check isn't looking at that. It is looking for pressures built up when the valves are closed as they are on the compression stroke. Since your pressures are good the valve seats and valves are sealing great. Seats are where the valve rims make contact with the head to seal the cylinder. Also the rings and cylinder walls in the engine block are good. That leaves the valve guides and seals in the head. Clear as mud? Someone who does this for a living could explain this much better. Check with a pro before diving into this.

One caviot to all of this. Oil leaking past valve guide seals usually produces smoke at the first start of the day.

You say the cat is new. Excess oil will trash a cat. One indication the engine is burning it.

Coolant level is good? If not it may help to do a leak down test on the cooling system.

To help you access the rear bank it would probably help to remove the wiper tray and the intake manifold/plenum.

 

yeah remove the wipers gives plenty of space

link on how
https://dodgeforum.com/forum/2531517-post37.html