TexanInFL
Junior Member
- Joined
- Jul 11, 2016
- Posts
- 2
- Reaction score
- 0
- Ram Year
- 2003
- Engine
- Hemi 5.7
I just bought a 2003 Quad Cab 1500 5.7L Hemi with a blown head gasket. I spoke with the mechanic before I bought it and he assured me the owner had caught it in time before any damage occurred. $1300 later, I had 2 new head gaskets, the heads got the full spa treatment at the machine shop, I had 16 new spark plugs, all new fluids from bumper-to-bumper (yes, including blinker fluid), and a flush of 15 qts of cheap oil through the engine to make sure it was clean.
That's when I got the call that the timing chain cover was rusted through. Damn. $347 to Rock Auto later, I had a new timing chain cover. Then, after he put it all back together, the water pump leaked. Really? Another $100 to the auto parts gods. FINALLY, I got my truck! (All this happened before I ever got to take her home!)
I drove the truck the 45 min to the house and, about 2 mi away, the oil pressure gauge started playing games. It would go from normal to zero, then back in about a second. Then again. And again. This continued until it just sat at zero. No other indications of low oil pressure, that Hemi was humming along happily.
After shutting it down and letting her sit for a few minutes (10-15 min), I started it back up and the oil pressure was back to normal. I talked to a few buddies and they suggested the oil pressure sensor was bad, so I replaced it. When I did, the oil was hot and no oil leaked out of the pressure sensor port. Strange.
With the new sensor, I had the same problem: when the engine got hot, the pressure went to zero. I finally changed the stock sensor out for a mechanical oil pressure gauge to see if maybe there was an electrical gremlin screwing with me. Same. Damn. Thing. Only difference was this time, with the oil cold, it came POURING out of the port! Also, I saw that, on first start, the pressure was around 40 psi.
Found out the mechanic used 20W50 because, "a 5.7 Hemi has a high-volume oil pump and although it says 10:30 we live in Florida 2050 is better for it." Also found out he used a Tec Select T3600 oil filter. (See pic for difference between that and what Dodge calls for.)
I spoke with the previous owner and he told me he used 5W30 synthetic for years with ZERO oil pressure problems. After draining the oil and replacing it with Mobil1 5W30 15,000 mi Extended Protection (what I use in my 2003 Toyota 4Runner V8 and my 2005 Chevy Malibu V6), I also used an it hose to blow out the capillary on the back of the mechanical oil pressure gauge to make sure there wasn't any junk in the port.
I fired the truck up and all seemed well. The pressure was even at 50 psi! Once she got hot, though, it was around (but not AT) zero. Probably 3-5 psi when I would shut it off. 5-10 min later and it would be back around 25-30 on start-up. Old fart at the parts store assured me that, even when he ran 20W50 in his cars and trucks, during the heat of the summer, he would be around 10 psi when the engine got warm and not to worry about it because, well, if I was TRULY at zero, I would have one or two other indications.
Has anybody else run into this, or do you have any idea what might be going on?!
That's when I got the call that the timing chain cover was rusted through. Damn. $347 to Rock Auto later, I had a new timing chain cover. Then, after he put it all back together, the water pump leaked. Really? Another $100 to the auto parts gods. FINALLY, I got my truck! (All this happened before I ever got to take her home!)
I drove the truck the 45 min to the house and, about 2 mi away, the oil pressure gauge started playing games. It would go from normal to zero, then back in about a second. Then again. And again. This continued until it just sat at zero. No other indications of low oil pressure, that Hemi was humming along happily.
After shutting it down and letting her sit for a few minutes (10-15 min), I started it back up and the oil pressure was back to normal. I talked to a few buddies and they suggested the oil pressure sensor was bad, so I replaced it. When I did, the oil was hot and no oil leaked out of the pressure sensor port. Strange.
With the new sensor, I had the same problem: when the engine got hot, the pressure went to zero. I finally changed the stock sensor out for a mechanical oil pressure gauge to see if maybe there was an electrical gremlin screwing with me. Same. Damn. Thing. Only difference was this time, with the oil cold, it came POURING out of the port! Also, I saw that, on first start, the pressure was around 40 psi.
Found out the mechanic used 20W50 because, "a 5.7 Hemi has a high-volume oil pump and although it says 10:30 we live in Florida 2050 is better for it." Also found out he used a Tec Select T3600 oil filter. (See pic for difference between that and what Dodge calls for.)
I spoke with the previous owner and he told me he used 5W30 synthetic for years with ZERO oil pressure problems. After draining the oil and replacing it with Mobil1 5W30 15,000 mi Extended Protection (what I use in my 2003 Toyota 4Runner V8 and my 2005 Chevy Malibu V6), I also used an it hose to blow out the capillary on the back of the mechanical oil pressure gauge to make sure there wasn't any junk in the port.
I fired the truck up and all seemed well. The pressure was even at 50 psi! Once she got hot, though, it was around (but not AT) zero. Probably 3-5 psi when I would shut it off. 5-10 min later and it would be back around 25-30 on start-up. Old fart at the parts store assured me that, even when he ran 20W50 in his cars and trucks, during the heat of the summer, he would be around 10 psi when the engine got warm and not to worry about it because, well, if I was TRULY at zero, I would have one or two other indications.
Has anybody else run into this, or do you have any idea what might be going on?!
