2006 Grand Cherokee Laredo - White Gunk on Oil Fill Cap

[Screameans]

Today I noticed some thick, white goo on the bottom of the oil fill cap and near the top of the fill tube. The oil on the dip stick was clear of any of this and looked normal aside from being dark; but it's due for an oil change.

Reason for concern?

[fredjacksonsan]

Are you driving a lot of short trips? If so, then the oil never gets hot enough to burn off the white gunk.

Back in the 90s, Quaker State and Pennzoil had the reputation of wax buildup, but supposedly that has been fixed.

How long has it been since your last oil change?

[Screameans]

Originally Posted by fredjacksonsan

Are you driving a lot of short trips? If so, then the oil never gets hot enough to burn off the white gunk.

Back in the 90s, Quaker State and Pennzoil had the reputation of wax buildup, but supposedly that has been fixed.

How long has it been since your last oil change?

Thanks for your reply!

It's been waaay too long since the last oil change. Thought the wife was keeping up on them but I am wrong. The last one we did was at a Chrysler dealer and I believe they use Valvoline products but I could be wrong. I know she's topped it off with Penzoil and I with Quaker state.

Our typical trips are about 30 miles (commute to work) and maybe a few miles here and there to local destinations under 10 miles. We're planning on a 400+ mile road trip this weekend and an oil change is definitely taking place before then.

[fredjacksonsan]

I'd make a plan to change the oil every 4000 miles or so, for the next 3-4 changes, to help clean out whatever may have built up.

How many miles do you have? What engine?

[Screameans]

Yeah I definitely need to get back on top of this. It's a 6 cyl, 3.7 liter that just turned 100k this past weekend.

Thinking of using a max life or high mileage synthetic blend.

[fredjacksonsan]

If you don't have any leaks, you don't need one of the "high mileage" oils. Synthetic sounds like a good idea; I've become a proponent of using it, after doing the research. Plus, my wife's 04 Wrangler with the 2.4L four banger has had a steady diet of synthetic since break in, and recently we had a new head gasket put in....inside the engine was spotless.

You might get a little seepage when switching to synthetic, but it should go away after a couple thousand miles. I've had 2 vehicles that I switched over to synthetic, one at 140k the other at 86k; both had a slightly wet spot near some of the seals, which went away after awhile. I didn't even really notice a drop in oil level.

I had the 3.7 in my 04 Dodge truck; it's a good motor and liked Amsoil 5w30....got me a mpg or two more than regular oil if I took it easy.

Gotta change it!!

[Screameans]

So a decent quality synthetic is the way to go.

I noticed some oil on the left side near the front of the engine compartment on some AC or or vacuum hoses but I can't tell where it's coming from. I've never seen a drip (except where the Valvoline Instant oil change dudes didn't drop the skid plate entirely when draining) under the vehicle so I'm hoping I'm good. I've been interested in the full synthetic but have been hesitant because of the cost. At this point though it's a matter of engine life so it's well worth it.

So based on your experience you would say the gunk I described is a byproduct of the oil and not due to coolant entering the oil?

[fredjacksonsan]

IMHO it's not coolant, but if you're concerned have a used oil analysis done to check for it. I use Blackstone Labs; for around $30 they'll analyze your oil and let you know how your engine is doing.

A small oil leak could be in a hose, power steering, or just some that the jiff lube place spilled. If the vehicle were mine I would wipe it off and check it every day or two to see where it's coming from.


Cost of synthetic:

I get about 1.2 mpg better in my Grand Cherokee using synthetic oil. Doesn't seem like much, but over 5000 miles it saves more than double the increase in price of oil. some vehicles don't get an increase in mpg, and if yours doesn't you'll have to decide if the extra cost is worth it.

[Screameans]

We're heading out tomorrow evening so I'm going to clean it up and change the oil before going. I looked over the records and we usually put Valvoline Dura Blend 5W-30 in it. Figured I'd throw that in there since I guessed in a previous post.

I'll make the jump to full synthetic and see how it acts. I'm not expecting any gains in fuel usage, but rather maintaining this thing for the long haul. It's the wife's and she's really into it, so as long as it stays running reliably I'll be happy.

Thanks again for your replies!