Dirty engine - Wrong type of oil?

Try tightening the valve cover nuts and see if that helps. They're the huge 30 mm nuts where the spark plug wires go.

I did that on my wife's '99, 91k mile Camry, and a mystery oil seep seemed to go away. (Valve cover nuts were slightly loose.)

Autozone sells individual socket wrench sizes, I don't remember where I bought my 30 mm socket wrench. I remember I was able to buy just the one (about $6), and not have to buy a set. It's a 1/2" socket, so you might need a 1/2" to 3/8" socket adapter... or not, if you have a

1/2" torque wrench.

Otherwise it's probably time to change some of the engine seals...

Michael

Front the front bank (radiator side) or the rear bank (firewall side)? Or from under the plastic cover on top of the engine?

Mobil-1 5W-30 or even the 10W-30 should be fine. I've suggest people use the thickest approved grade for the temperature range they operate in. For most that's 10W-30. BTW, Mobil-1 are great synthetic oils.

Look at the valve cover gaskets. These are likely the culprit. The covers have stoppers, so you cannot just tighten the 10mm bolts. Most likely you'll need new gaskets, applied dry. Fel-Pro has a kit with spark plug tube seals, check

for prices. You need small dabs of RTV (such as Permatex Ultra Grey or even just the regular Blue) at the seams of the semicircular plugs on the heads so oil doesn't leak from there.

Also check your PCV valve. If it's not working the engine crankcase can build up pressure (well, at least not enough vacuum for the PCV system to properly operate). change the grommet as well. Be care the now brittle grommet can disintegrate and fall into the head. Both are probably ~$8-10 at the dealer.

I don't know how mechanically inclined you are, but with the covers off, might as well check the valve clearances. Check the free repair guide on

Read specs at M1 5-30 is better at low temps and better. Wash the motor.

Thanks, great tips! It's from the front, mostly where the engine is sealed and underneath it. Looks like some gunk or muck but not very thick. I haven't seen how another engine looks like at 150k miles, but probably I'll take the other person' suggestions and just wash it.

How about Mobil 1, 0W-40? Should it apply to this engine situation or is it a good idea to use on a 150k engine? John

Mobil-1 5W-30 or even the 10W-30 should be fine. I've suggest people use the thickest approved grade for the temperature range they operate in. For most that's 10W-30. BTW, Mobil-1 are great synthetic oils.

Look at the valve cover gaskets. These are likely the culprit. The covers have stoppers, so you cannot just tighten the 10mm bolts. Most likely you'll need new gaskets, applied dry. Fel-Pro has a kit with spark plug tube seals, check

for prices. You need small dabs of RTV (such as Permatex Ultra Grey or even just the regular Blue) at the seams of the semicircular plugs on the heads so oil doesn't leak from there.

Also check your PCV valve. If it's not working the engine crankcase can build up pressure (well, at least not enough vacuum for the PCV system to properly operate). change the grommet as well. Be care the now brittle grommet can disintegrate and fall into the head. Both are probably ~$8-10 at the dealer.

I don't know how mechanically inclined you are, but with the covers off, might as well check the valve clearances. Check the free repair guide on

I would go back to Mobil 1 5W-30. While it is sometimes a good idea to increase viscosity on an engine with 150K miles, that would not hold true if you have been using Mobil 1 since engine wear is negligible with a full synthetic oil.

I is possible that the extra viscosity caused some leaks in already fragile seals. Also, make sure you don't overfill the crankcase.

You have 150K miles, so some rubber parts are going to harden. Most are NOT high grade Viton rubber. The likely ones are rear main seal and valve exhaust stem seals. Even the intake ones are cheaper rubber, that's why Toyotas are more likely to puff blue smoke on cold startups.

The Mobil-1 0W-40 is an excellent oil that meets the demanding BMW LL-01, VW 502/505, and MB 209 specifications. However, the 0W would be of concern because it's too thin at lower temperatures for Toyota engines. In fact, if the prices are the same, you can pick up BMW

5W-30 too. It has stronger film strength than Mobil-1 5W-30 from what I hear. But using it won't turn your Camry into a BMW. ;) ;) ;)

I think Mobil-1 10W-30 should be fine (and Toyota approved viscosity grade). If needed, try the High Mileage version of Mobil-1. But I think yours is a simple case of "old rubber gaskets need replacing." And much less about 5W/10W difference.

Mobil-1 High Mileage:

On old camry's this was caused by distributor. Don't know how current design is but in the old days as distributor o-ring wore out it spun oil in a fog over engine. Check underneath top of hood. It would be covered with oil too from the distributor.