Howdy. New here First time posting. I have a '92 Pickup (2wd), 22re motor, with about 220,000 miles on it. The other day a buddy randomly asked if he could look under the hood and noticed "milkshake" in the oil cap. We also noticed the coolant was low. He topped up the coolant the next morning I checked it again and it had gone down slightly and the dipstick was showing a little above full. Oil looked normal. There also seems to be some dark bubbly marks inside the overflow reservoir that I don't recall seeing before. To my knowledge though, it's never overheated. Trying to figure out if it's a compromised headgasket, timing chain wearing a hole in the water jacket, or just condensation (humid Tennessee and the weather recently got colder).

I haven't driven the truck since other than to move it from one part of the driveway to the other, and when I fired it up to do that, it made a pretty loud knocking sound that subsided pretty quickly. A few days later we did a compression test and when I warmed it up for that, there was no knocking sound, and probing with a stethoscope it sounded "pretty clean." I did drive it around the neighborhood then and the temp climbed to its usual spot 1/3 way up and stayed there. Here's the compression test numbers:

1. 2. 3. 4.
Dry 195. 180. 183. 182
Wet 210. 200. 212. 200

And here's a pic of the plugs in case you can glean any info from looking at them:






Any ideas what my next diagnostic step should be?

Thanks in advance!

Alex

 

There’s a cheap kit you can buy from the parts stores that can detect exhaust gasses in your coolant.