Adding Oil

97 grand prix gt 114k. My car burns oil right around 3 months there is about 50% of the oil left. My question is, is it okay to add a different brand oil in between the next oil change.


If penzoil 10w-30 is currently in my car now, could I add mobil 5w-30?

How many miles did you go over the 3 month period?

Regardless that is too high oil consumption for any L36 or L67 SII 3800 engine especially with your mileage which isn't that high considering. Do you see any externals oil leaks? Any blue smoke out the exhaust?

Is the Mobil oil you plan on using synthetic or the regular dino? If synthetic and based on your mileage make sure all your engine seals are good including the valve cover and oil pan gaskets. Also, if your valve guide seals are prematurely worn causing the high oil consumption switching to synthetic may not be a good idea.

How many miles did you go over the 3 month period?

Regardless that is too high oil consumption for any L36 or L67 SII 3800 engine especially with your mileage which isn't that high considering. Do you see any externals oil leaks? Any blue smoke out the exhaust?

Is the Mobil oil you plan on using synthetic or the regular dino? If synthetic and based on your mileage make sure all your engine seals are good including the valve cover and oil pan gaskets. Also, if your valve guide seals are prematurely worn causing the high oil consumption switching to synthetic may not be a good idea.


Actually I don't even know what oil it is I take it to a garage and they put the correct oil in it.

According to the DIC after 3 months and around 3k miles is when the DIC tells me the oil is at 50% and I also get a check oil light.

Is my car gonna start burning oil at a faster rate and what could happen in the future?

I also see external leaks in the driveway from my car and its prob oil, what do the leaks mean?

I'd be willing to bet your car is leaking oil.

Have you have your valve cover gaskets replaced yet?

LIM End Cap seals, and oil pan gaskets are other places that leak commonly on the 3800 motor.

I'd be willing to bet your car is leaking oil.

Have you have your valve cover gaskets replaced yet?

LIM End Cap seals, and oil pan gaskets are other places that leak commonly on the 3800 motor.



I've been told in the past that I have an slight oil pan leak. Never had valve covers replace, what will happen if I don't get them replace, and are they definetly bad?

Mine were bad at 70k when I bought it. You risk having an engine fire and burning your car to ashes if your valve covers are leaking and you don't replace them.

Mine were leaking about a quart out every 3000 miles or every oil change. There were no drips on the driveway because the oil that leaked out was being burnt off on the exhaust manifolds.

Mine were bad at 70k when I bought it. You risk having an engine fire and burning your car to ashes if your valve covers are leaking and you don't replace them.

Mine were leaking about a quart out every 3000 miles or every oil change. There were no drips on the driveway because the oil that leaked out was being burnt off on the exhaust manifolds.

So if the oil is leaking on the driveway it's okay. Any way to tell if the valve covers are leaking? I've had this car for over 4.5 years now, wouldn't something have happened by now if the oil that leaked out was being burnt off on the exhaust manifolds?

If oil is leaking on the driveway, If it were mine I'd fix it.

And no, if your valve covers are leaking, they can cause a fire at any time. If your valve cover gaskets are original, I'd start with replacing them. Its an easy DIY job if you have a few hours and gaskets only run about 50 bucks for fel-pro replacements that includes new bolt grommits.

Here is what can happen if your valve covers are leaking and your don't replace them... (this is best case scenario where the owner caught the fire before it engulfed the entire car).

http://www.automotiveforums.com/vbulletin/showthread.php?t=974654

An apartment building near where I work was actually burned to the ground because a GP owner who hadn't replaced their valve cover gaskets parked inside of the apartment complex garage and their car stared on fire. Luckily no one was killed.

So if they is a recall why would I spend $50 when they would fix it for free?

Because the recall on the 3800SC motors they only replace the front valve cover gasket and instal an updated spark plug channel.

And I believe on the 3800NA motors they don't even bother replacing any valve covers, they just install an updated spark plug channel that wont catch fire.

Not to mention the stock GM gaskets are absolute Junk IMO. You are way better off installing the Fel-Pro brand.

Because the recall on the 3800SC motors they only replace the front valve cover gasket and instal an updated spark plug channel.

And I believe on the 3800NA motors they don't even bother replacing any valve covers, they just install an updated spark plug channel that wont catch fire.

Not to mention the stock GM gaskets are absolute Junk IMO. You are way better off installing the Fel-Pro brand.


If I don't install the gaskets is it definetley going to take life off my car, does my car def have this problem????

Basically I'm asking maybe my car doesn't have this problem and never will, is that possible?

Why would you take that risk?

I could say yes you are correct that your car probably wont engulf itself in flames. Then tomorrow it could and you would come back on AF and say "that SOB Advisor Tim told me it wouldn't burn apart".

If you have an oil leak, and have not replaced the valve cover gaskets yet, That would be the first place I would start. I have gotten the job down to about a half hour to 45 minutes per each valve cover. It is really not a hard job, and we could help you through it.

Why would you take that risk?

I could say yes you are correct that your car probably wont engulf itself in flames. Then tomorrow it could and you would come back on AF and say "that SOB Advisor Tim told me it wouldn't burn apart".

If you have an oil leak, and have not replaced the valve cover gaskets yet, That would be the first place I would start. I have gotten the job down to about a half hour to 45 minutes per each valve cover. It is really not a hard job, and we could help you through it.


How can you be sure my car even has this problem?

Say my car doesn't engulf in flames, would the problem with the valve cover gaskets effect my car in any other way?

Also is valve cover issue the same thing as the problems with intake manifolds like this model seems to have? Is this the same thing?

How can you be sure my car even has this problem?

helicopter23, you're going to have to find out where the leak is coming from. We can't be sure of much on our end. The best way to tell if your valve cover gaskets are leaking is by looking (and feeling) under the valve covers. The front is pretty easy. Is it oily under it? When you start the car cold and let it run, do you see smoke coming off of your exhaust manifolds? Can you smell burning oil? Did you look under the engine and see where it is wet? Take action and get it done.

helicopter23, you're going to have to find out where the leak is coming from. We can't be sure of much on our end. The best way to tell if your valve cover gaskets are leaking is by looking (and feeling) under the valve covers. The front is pretty easy. Is it oily under it? When you start the car cold and let it run, do you see smoke coming off of your exhaust manifolds? Can you smell burning oil? Did you look under the engine and see where it is wet? Take action and get it done.


No blue smoke or smell, this has been going on for a couple years now. I was told in the past that I have a oil pan leak(drip). Plus I have never had a problem with this vechicle.

My question is, is it okay to add a different brand oil in between the next oil change.

If penzoil 10w-30 is currently in my car now, could I add mobil 5w-30?

yes, you will be absolutely fine. if you add the fully synthetic, it may leak a little faster, however nothing bad will happen from mixing oils