Originally Posted by Valley Viking
Bought a used Taco 4x4 DCLB that had 116,000+ on it. My first oil chnge on it was at 120,000 put Mobil 1 in thinking I was going the extra mile. I have checked the oil level a few times and the level seems to hold solid as a rock and the oil looks fine. The other day I was looking around under the hood and unscrewed the oil filler cap to look inside. Holy crap I about had a friggin heart attack when I saw this cream colored peanut butter had filled the underside of the cap and was coating the inside of the filler neck to a couple of inches down from the top. Thought for sure my head gasket must be gone. Dug out the goop and checked my dipstick, it was fine. checked my radiator level, it was fine. Warmed it up and watched the exhaust for excessive steam, it was fine. Truck runs fine. Jumped on Taco World and saw this thread and others like and figured I didn't need to jump off the roof. But I will keep an eye on it. The goop that was in the filler neck wasn't just foam it looked like baby crap.
Yeah, it looks pretty daming.
Usually, a good long 30 to 40 min drive once a week will eliminate it, and/or change the oil more often.