Low oil pressure gauge at Idle make engine coolant hot

Podor · April 15, 2017

So, it sounds like it gets hot enough to turn the warning on and the oil pressure goes low enough to turn the warning light on. That eliminates the stepper motors.

I had similar issues on my '05, which were caused by the Castech cracked heads. I don't drive mine during the week, so I don't sit in traffic for it to get too hot. There were a few things that tipped me off. The first thing I noticed was the oil pressure was about 10 psi at idle. I also assumed it was a stepper motor so I didn't pay much attention. I noticed the fans were at high almost immediately after driving, with or without the AC. It never overheated, but no traffic. The final clue was that I would have to add coolant about every 300 miles or so with absolutely no external leaks. I even pressure tested it for several hours and it didn't drop a bit.

The oil pressure was caused by the coolant leaking into the oil. Over time, the water evaporated leaving the glycol which diluted the oil wearing the bearings, but didn't cause the oil to be milky. I never saw any evidence on the dipstick. It was getting hot because there were air pockets caused by the cracks.

The first thing to check is if the head casting number is 706. On the passenger side head, the casting number will be on the front lower corner, right under the valve cover. If the casting number is 862, it isn't a castech head. If it is 706, you still may not have a bad head. The real way to verify is to remove the valve cover and look for a battery shaped casting mark under the rocker mounts. You'll also find lots of milky residue on the valve cover. See the article below.

http://www.agcoauto.com/content/news/p2_articleid

Grizzlyghost · May 3, 2017

So, it sounds like it gets hot enough to turn the warning on and the oil pressure goes low enough to turn the warning light on. That eliminates the stepper motors.

I had similar issues on my '05, which were caused by the Castech cracked heads. I don't drive mine during the week, so I don't sit in traffic for it to get too hot. There were a few things that tipped me off. The first thing I noticed was the oil pressure was about 10 psi at idle. I also assumed it was a stepper motor so I didn't pay much attention. I noticed the fans were at high almost immediately after driving, with or without the AC. It never overheated, but no traffic. The final clue was that I would have to add coolant about every 300 miles or so with absolutely no external leaks. I even pressure tested it for several hours and it didn't drop a bit.

The oil pressure was caused by the coolant leaking into the oil. Over time, the water evaporated leaving the glycol which diluted the oil wearing the bearings, but didn't cause the oil to be milky. I never saw any evidence on the dipstick. It was getting hot because there were air pockets caused by the cracks.

The first thing to check is if the head casting number is 706. On the passenger side head, the casting number will be on the front lower corner, right under the valve cover. If the casting number is 862, it isn't a castech head. If it is 706, you still may not have a bad head. The real way to verify is to remove the valve cover and look for a battery shaped casting mark under the rocker mounts. You'll also find lots of milky residue on the valve cover. See the article below

http://www.agcoauto.com/content/news/p2_articleid

kind of hard to find the casting head number but as i see in my truck, im not losing any coolant, over time engine oil will burn off and i refill as needed, i couldn't click the article link doesnt work, and yeah my oil isnt milky nor is anything smoking out the pipe... i dont know where the valve cover maybe a picture description would be better. but thank again...

Grizzlyghost · May 3, 2017

im still driving the truck and if i start it up it start fine then after 5-10min it would start to go down the oil pressure guage... if i be driving in the neighborhood with lot of stop and go slow driving, it will get hot on me with low oil pressure showing at 10 psi then when i rev my engine while at netural, it goes back up to normal... still i couldnt find anything making it hot... what could it be...