Help with oil consumption...

[Nikolai]

Hey guys, my car has been using alot of oil now. I put in a quart it seems like every 500 miles or so. I do the WOT thing, and I do drive aggresively alot of the time. What is there to look for concerning a leak? I know that they are supposed to eat oil but I think mine does it in excess of what everyone else is reporting. I'm going to change the oil tommorow, I know the guy before me put the cheap gas and oil in it, and I have been putting premium in it, and am going to put Mobile 1 synthetic as well.

Also, just curious, but would there be any benefit of switching MAF's with say a Corvette or F-body?

[BodybyFisher]

I don't believe that Mobil 1 will help and it might make the problem worse. I would look for any leaks, snug up the pan and use a high mileage 10W30. If that does not help your rings might be badly caked with carbon and frozen.

The proper WOT procedure is

1) fully warmed up engine on highway that you can vary your speed on

2) tranny in 2nd gear

3) at 40 mph, WOT to 70

4) take foot off gas and allow the tranny gear to slow the car down to 40

5) repeat 10 times

The deceleration to 40 is as important as the WOT portion as it exercises the rings. Do this twice weekly for a month always check your oil before doing it. After a month see if that improves the oil usage.

[BodybyFisher]

I would say that the WOT procedure I noted above while it was recommended by a guru, is more aggressive and may not be practical at all times, it is the procedure that I use however. See below for a variation of the WOT procedure at about 5,800 RPM on my LD8 I am beginning to get nervous but I am a chicken :

If you have not already check out these articles:

http://www.cadillacforums.com/cadillac-tech.html#noil

Pay particular attention to these paragraphs:

The exercise that I think works best for many things is to select manual 2nd gear on an isolated stretch of expressway. This takes the transmission shifting out of the question if you are worried about hurting it. Start at 55 MPH or so and go to WOT in 2nd gear and hold it until the RPM reaches near the normal shift point - i.e. 6500 for an L37 and 6000 for an LD8. Hold the throttle wide open until the engine reaches, say, 6200 for an STS and then just let completely off the throttle. Leave the transmission in 2nd so that the engine brakes the car and creates some pretty heavy over-run conditions at high vacuum levels. Let it slow until it is about 55 or so and then go to WOT again and repeat. This exercise really loads the rings, allows variable RPM operation at WOT for several seconds continuously, creates heavy over-run which tends to unload the rings and make them move and thus exercise them in the ring grooves and it will blow-out carbon and the exhaust - all without creating a spectical of yourself and attracting the attention of cops. You can do it on most any freeway and stay within the 70-75 MPH range allowable. Once a week like this will keep the engine cleaned out and healthy and is DEFINITELY recommended for the Northstar in particular.

An last, but not least, air the engine out frequently. It likes to be used and red-line upshifts at WOT help promote clean combustion chambers, exercise the piston rings to keep them free of carbon buildup and keep them mobile and to ensure the engine is broken in and maximum sealing is obtained. The Northstar does not like to be babied around. It likes to be run hard frequently with a WOT blast in merging or whatever.... Even engines reported to use 1 quart per 1500 miles tend to improve to 2500 miles per quart or better when subjected to a regular schedule of use and "abuse"...

Carbon buildup in the rings and ring sealing are also variables that come into play with break in, operating schedule, type of oil used, etc.

[mikeal1892]

hey mike,

why dont you like mobil one ? thats all i use fully synthic . isnt that what was recommended from cadillac ? i have 99k miles and it barely leaks and does not use any oil.

i would try adding lucas to the crank case on that. sometimes i have added it mine.

michael s

[mikeal1892]

what about maybe using a motor wash. i do mine everyother oil change or on the 3rd.

[BodybyFisher]

In a word, synthetic is not necessary. It tends to be thinner than the state viscosity and tends to find a way to leak.. I know that others will disagree with my heavily but that is my opinion. The guru also stated that synthetic was not necessary and kind of described it as overkill.

[mikeal1892]

hmm, i didnt look at it that way i use 10w 30 in mine the 5w is just to thin and will break down easier from what i have read. everyone see's everything a little differently. i have 99,127 when i just got home 100k here we's come ! i was looking at the devilles though...hehe

michael s:D

[Spurlee]

It tends to be thinner than the state viscosity and tends to find a way to leak.

I agree - I'm also an avid motorcyclist and it's pretty common on forums to hear people experiencing slight leaks when switching from dino-juice to synthetic on engines that weren't originally designed for synthetic oil. It can also cause transmission problems (many motorcycles lube the transmission with the engine oil) like missed shifts and false neutrals.

[confusion]

I'll agree with Bodybyfisher here. He told me about synthetic oil not being necessary, so, I checked out his info. He's right. Regardless of whether or not synthetics cause leaks and are too thin, regular oil will meet our performance needs. Buying synthetic oil is just extra money, for performance secs we'll never reach. Trust his advice. He's the man!

[BodybyFisher]

I can't take the credit guys, my opinion comes from the Guru, I am just the messenger, Thanks Guru!

[KHE]

hmm, i didnt look at it that way i use 10w 30 in mine the 5w is just to thin and will break down easier from what i have read. everyone see's everything a little differently. i have 99,127 when i just got home 100k here we's come ! i was looking at the devilles though...hehe

michael s:D

The Northstar engine was designed and validated on conventional oil. There is no need to use synthetic oil unless you like spending triple the money on an oil change.

The newer RWD Northstars use synthetic oil because the oil cooler in the radiator has been eliminated - not because it is any better than conventional oil.

Most of what you have read has probably been marketing hype from the synethetic oil manufacturers. This is not an insult - many people fall trap to the synethetic marketing machine.

[BodybyFisher]

what about maybe using a motor wash. i do mine everyother oil change or on the 3rd.

Explain how the motor wash is used. If you are squirting stuff through the TB intake, look at this photo, it was caused by a Cadillac TECH using too much and having it pool in the manifold, as soon as he test drove the car and pulled away from the curb, the solvent was sucked into the cylinder and the engine hydrolocked blowing the rod through the side of the engine. I vowed when I saw this photo never to squirt anything through the intake

[mikeal1892]

mike is always right. hehe i didnt know how it held some of the fluids. its just a motor wash you pour in the cank case and let the car run for 5-10 mins then change the oil. is what your talking about cleaning the throatle plate ?

michael

[Ranger]

mike is always right. hehe i didnt know how it held some of the fluids. its just a motor wash you pour in the cank case and let the car run for 5-10 mins then change the oil. is what your talking about cleaning the throatle plate ?

michael

No, what BBF is talking about is the GM carbon cleaner that is sucked in to clean the carbon out of the cylinders through the vacuum brake booster hose. As you can see, it can be disaterous if not done correctly.

[mikeal1892]

the guy that did that must have used alot of it. he way over did it. i recently cleaned mine and it kinda suprised me . its the second time ive done it but this time the black smoke from the car which the first time it only ran rough for a few and then it was ok .

michael

[BodybyFisher]

That motor flush in the crankcase won't cause any problems, I wanted to make sure you weren't spraying anything into the thottle body (TB) without knowing the potential problem it could cause. Given that a GM tech did that with his experience, I was scared off from ever doing that procedure..

[mikeal1892]

oh ok! but what if yer it gets all sticky ?

[BodybyFisher]

Are you saying what if your throttle body gets sticky? Mine is right now, its annoying as hell. I keep getting the SERVICE IDLE SYSTEM message after I drive long distances and my in drive RPM is about 850 up to 1100 in Neutral. I have thought about that and figure that long distance high speed driving must pull the CARBON GUNK off the back of the throttle plate toward the edge and hang the plate open when you come to a stop. This weekend I plan to pull my throttle body off and clean it extensively focusing on the rear. I need to buy a quart of GM upper engine cleaner to soak it and will use a dremel tool with brass and brush and use the polish wheel on it, I just brought one of those Flex Shafts for my Dremel tool. I am hoping to be able to polish (carefully without removing material) the plate and throat.. If I see any scratching by the brass brush I will stop quickly however. Will take photos if it comes out as I hope it does. Here is that flex-handle. The dremel tool is a tool that I wonder what I ever did before I had it,

http://www.mytoolstore.com/dremel/flexaccs.html

[BodybyFisher]

By the way, its not necessary to go nuts like I described above, I tend to go nuts once in a while and overdo it. I used to enjoy rebuilding carburators in the old dayz and got quite good at it, so I think that cleaning the TB really good and replacing gaskets would produce good results..

If you buy some GM upper engine cleaner (comes in a quart, its a liquid not a spray, I will post the part number). Dip a tooth brush, detail brush (non metallic) in it and hold the TB open and scrub the rear of it and the throat. Focus on the place where the plate meets the throat there is usually a line of carbon. Throttle smoothness will be improved and sticking high idle should be gone. If you do what I described above you will need to purchase a new TB gasket or O-ring is it has one. My memory recalls that someone opened something around the TB (can't recall details) and the O-ring would not go back in as it was too big, so if you take your TB off, make sure you have all gaskets and orings on hand. I will do a search to recall the thread and post the link if I am successful in finding it. Maybe someone else will recall what I am thinking about.

[mikeal1892]

heh, i think that guy really over did it though.

[BodybyFisher]

Here is a photo showing carbon buildup that takes place. If these engines are designed to use oil because of the aggressive cross hatching, this type of carbon build up is not surprising. I also think its interesting to note how THIN the wall is between the water jacket and the cylinder I think I will change my coolant...

Does anyone know if any oils have a characteristic that would minimize carbon buildup. Maybe these engines would benefit from an oil with the right characteristics. That was something that was noted in the link I provided above, that the type of oil mattered... More research to do... What do the oil experts think?

heh, i think that guy really over did it though.

I agree Imagine..... Sir, there will be no CHARGE for the THROTTLE BODY SERIVCE..... its on the HOUSE....Its MR. GOODWRENCH'S way to show our appreciation for your patronage Just our way of saying THANKS! We will see you in 3,000 miles for your oil change What hole?

[Ranger]

My memory recalls that someone opened something around the TB (can't recall details) and the O-ring would not go back in as it was too big, so if you take your TB off, make sure you have all gaskets and orings on hand. I will do a search to recall the thread and post the link if I am successful in finding it. Maybe someone else will recall what I am thinking about.

I recall that thread. The "O" ring swelled and was bigger than original once removed so it could not be replaced.

[BodybyFisher]

My memory recalls that someone opened something around the TB (can't recall details) and the O-ring would not go back in as it was too big, so if you take your TB off, make sure you have all gaskets and orings on hand. I will do a search to recall the thread and post the link if I am successful in finding it. Maybe someone else will recall what I am thinking about.

I recall that thread. The "O" ring swelled and was bigger than original once removed so it could not be replaced.

Exactly Ranger, what O-ring was that? Between the TB and the manifold or between the plastic MAF collar and the TB?

[mikeal1892]

hehe, its always something.

michael

[winterset]

After pouring, or spraying what you believe may be too much into your TB, I remember someone suggesting to disconnect the power to the coil pack. cranking the engine for a bit will distribute the fluid, and possibly prevent that hydrolock explosion.