My car is leaking oil

[TheV6Bird]

My 3.4 has 103K on it. On a cold start, it will poof out a little bit of smoke. Smells like oil is burning.

I currently run Mobil 1 5W-30 motor oil.

Along with the smoke at startup, I have an oil leak coming from the passenger side valve cover. I don't have the cash/tools/knowledge to replace the gasket. It's been leaking for a while now :(

Is there a good oil additive I could use to slow this down? Or should I change my oil type? Is it ok to go from Mobil 1 (synthetic) to a dino oil? How about going from 5W-30 to 10W-30?

Thanks in advance! [img]smile.gif[/img]

[mcjoslyn]

You really don't have much choice. Live with it or drop the cash to get it fixed. Don't mess with the oil. Putting additives in oil is a very bad idea. Compounds that are engineered to work separately don't always work well together. You could change back to a non-synthetic to save money, but it won't stop the leak. Changing the weight won't make any difference either.

[3.4 slow to go]

Smoke on startup is most likely leaking valve stem seals. FOr the valve covers, may as well suck it up & change them both, so that if you change one, the other wont go 2 mos later

[camaro_speedemon]

<blockquote>quote:</font><hr>Originally posted by mcjoslyn:
You could change back to a non-synthetic to save money, but it won't stop the leak. Changing the weight won't make any difference either.<hr></blockquote>

NOOO!!!! Once you go synthetic, you can NEVER go back to conventional oil! From what I understand, going from synthetic back to conventional oil will create oil leaks. It has something to do with the way synthetic wears the motor.

Heavier weight oil will slow the leak, but not stop it. With 103K miles you should probably be using 10W-30 anyways.

[mcjoslyn]

Not true. Synthetics don't "wear" the engine any more than petroleum-based oils. When synthetics were first introduced, there were problems with seal shrinkage, but that was back in the 80's. Today's synthetics are manufactured differently. There are some other potential complications with seals, but it is too involved to go into here and it relates to switching from petroleum to synthetic, not the other way around.

The biggest problem in switching oils is that you never get all of the old oil out of an engine so that you are cross-contaminating each time you change. This is especially true of synthetics as they will actually leave a thin film of oil over engine components for days after the engine was last run. That is actually one of the best reasons for using a synthetic, since the oil film lasts so long, cold start-ups are less damaging.

It's true that a heavier weight oil will tend to flow through a hole more slowly, but you are only talking about a cold start weight (5W vs 10W) and that won't make much difference to your leaks.

Do a Google search on "switch to synthetic oil" if you like, there are a lot of good articles out there.

[93v6firebird]

if youve got 103k miles its time to take some of that b!tch apart. Replace the valve cover gaskets, take the heads in..get them reworked and put it back together. Replace all your gaskets from the heads up.
That is if you want your car to last... if youre not planning on keeping it anymore than a year just suck it up and trash it soon.

[TheV6Bird]

<blockquote>quote:</font><hr>Originally posted by 93v6firebird:
if youve got 103k miles its time to take some of that b!tch apart. Replace the valve cover gaskets, take the heads in..get them reworked and put it back together. Replace all your gaskets from the heads up.
That is if you want your car to last... if youre not planning on keeping it anymore than a year just suck it up and trash it soon.<hr></blockquote>I'm not going to do a big rebuild...pulling an engine, taking the whole thing apart, putting it back together; I don't have the time or the tools for that.

I think what I will do is switch to Mobil 1 10W-30, and then just replace the valve cover gasket.

I've never replaced a valve cover gasket (or any other gasket)...this will be the biggest job I've ever done with my engine. I want to do this myself, because its cheaper, and I just want do it to know "I can do this" [img]smile.gif[/img]

Is it hard? What is involved? I would assume the bolts in the rear are a PITA to take off.

[CamaroKing]

I'd just live with it, my 3.4 has 106k and still runs strong. Just have it checked for oil leaks, but be careful who you go to. I was told I had just about every fluid leaking including and intake manifold oil leak and guess what?- all the fluids are being used up at a completely normal rate. They wanted $800 to fix the manifold leak, and either it doesn't exist, or its so minor it doesn't matter. I have no smoke on startup. In the cold you may want to make sure its not just from the weather, it may still have an odor, but may only steam in the cold. Does it happen in warm weather? Theres plenty of guys here runnin 3.4's with high mileage and the motor is strong if its taken care of. I wouldn't dump tons of cash in it for a leak at that point in the cars life, living with it is probably best, especially if its minor. You don't want to spend half what the car's worth on an engine rebuild. Make sure you diagnose the problems first of all, your decision completely depends on the result. Good luck.

[mcjoslyn]

Valve cover gaskets are easy to change (I would do them both while you are at it). Just take out the hold down bolts, clean the surfaces, put in the new gasket, and bolt it back down. Be very careful to not over-tighten the bolts, that will cause leaks by warping the cover. Good luck!

[Blizzard96]

You can go back and forth between synthetic and conventional with no ill effects. I wonder who started that myth...maybe the oil companies?

"If you go back to conventional, your engine will explode so you better stick with our synthetic and continue to pay up!"