My car has been burning oil like crazy. Everytime I change my oil I'm down to a quart our less. I have changed the plugs, the oil and filter.I have high flow cars with hks high power exhaust. Bored upper plenum with cai. My cart runs like crap.I have 127000 miles. What should I do. It feels like it s being held back when I accelerate and when I push the clutch in it decelerates very quickly. When I get on it, it seems to lag. It's an 04 coupe brembo. Please help.thanks

 

Im not that good on this issue, but i was told that with airflow like that, you might need to get fuel injectors

 

If that is true then you are lucky the engine runs at all! Why wait until the oil change to add oil? I'd get rid of that car before you have to replace the engine. Have a mechanic check the compression and tell him how low you let the oil get so that he can tell you the same thing.

 

This may be aside from the oil burning issue, but when you push the clutch pedal in you take the engine out of the equation.

Are you talking the ENGINE RPM decelerates quickly? Or the car itself?

Any funny sounds?

 

Mine is burning more than 1 quart every 2 days. I estimate I lost 20whp gradually over the last few months. It also has horrible blowby at WOT in between shifts showing the ring lands are bad since oil gets past them and in the combustion chamber and because of that the compression is low and fails the test. This can be avoided simply by not installing high flow cats or test pipes. After reading Tony@Motordyne conclusion I agree that relieving exhaust gas pressure is what leads to the piston ring lands to fail. Mine started shortly after the test pipe install but god damn that **** was fast with stellar compression.

It's an easy fix actually by installing piston rings correctly. I don't know who at Nissan ****ed that up but I would definitely find out and fire them if I had the power.

 

^ so what your saying is that you think after having test pipes installed is what can lead to OC?

 

or high flow cats. Mine started after test pipes went in. Tony@Motordyne knows what he was talking about. Also since my car has a free flowing exhaust and a dual 3" with no back pressure at all it burns the most. 1 quart every 2 days is insane. It's almost up to gasoline level consumption. The OC problem also makes the oil wear out faster and it makes it acidic, really bad for crank and connecting rod bearings.

I only wish I could find out who at Nissan is at fault for it. Probably some silver spoon fed rookie fresh out of a 55k USD/yr mechanical engineering school in Japan.

 

Wait.. So what do you mean responsible for what? The OC?
Hmm how many miles do you have on your car btw andrei?
Soo it's not exactly a proven fact that changing out your stock cats is the cause of OC right? Because that's extremely scarry haha

 

I've replaced a few long blocks (excessive oil consumption) on completely stock vehicles

also seen many stock vehicles that burn oil. to say that a bolt on modification can cause an engine to burn oil is quite a stretch..

 

I never said there haven't been any stock cars that didn't burn oil. There's been plenty. I have 110k now on my car.

But basically on deceleration with the car in gear and a free flowing exhaust like mine there is no exhaust gas pressure in the combustion chambers to keep oil from going past the rings lands into the chambers - the more free flowing the exhaust is the more oil gets past the ring lands and that's why mine burns 1 quart every 2 days. The reason this problem is more significant on the Revup is because of the variable exhaust valve timing which pretty much eliminates ANY exhaust gasses on deceleration making oil go into the chambers in higher volume. The Revup cylinder heads flow better than the DE.

The proper fix is to install piston rings correctly. If the replacement shortblock from Nissan has piston rings that are 1 faulty OR 2 installed improperly it will burn oil again. Normally on the VQ30s I had the piston rings lasted past 210k miles.

I've seen a **** load of Toyota shortblocks with high mileage that didn't burn oil. However Toyota ****ed up bad on the 4cyl Camry in or around 2007 and some burn plenty of oil with improper rings.

Here is a pic. About 4 Toyota blocks in there.

 

These are pics of cracked ring lands. Usually compression test results would read 90 psi or lower on something like this and it should read 180+ if it was good. Big power loss and response to throttle. Oil goes by the cracked rings into the combustion chambers. When running a compression test the piston moves up and the ring lands leak compressed air down into the crank case.

 

Mine did something simular as you described, but I actually cracked two pistons. Nothing major, but it was small enough to start producing blow by, oil consumption and loss of power. Resulting in a loss of compression.

 

Pistons cracked when the ring lands did and I've seen that on a Toyota motor before. Mine could possibly have cracked pistons as well since it's really severe blowby and oil consumption. Either way at least it still runs on borrowed time.

If I could find that silver spoon fed rookie at Nissan who is responsible I would kill him as a service to us all. Painfully and slowly.