High cruise temp, severly fluctuating oil psi when warm

[blueroo]

Hey all,
The weather is starting to get warmer here so I can understand the temp coming up a bit engine wise, but I was driving back here from HIA today (roughly 30 miles) and while on 283 I was cruising along at about 70mph, and my temp gauge was showing between 195 and 200 degrees. When I got off my exit, I was doing about 50 on that road, and temp was stuck around 195. Coming through Manheim at around 30mph my temp was reading about 180-185. Normally at that spot I'm running about 160.
Additionally, when the engine has warmed up quite a bit, the oil pressure drops hard when the clutch is in or the car is in neutral. Normal cruising psi is 42, when the engine warms up like this and I'm in neutral or have the clutch in, the oil pressure drops quickly to 20psi.
Is this normal or is there something I should be looking at?

 

[powerband]

Any chance you are using a Fram oil filter? I have experienced oil pressure drop significantly with the a Fram oil filter. Honestly, I didn't believe the rumors about the Frams but my son got an oil filter for me recently and he purchased a Fram which I installed on the "Road Rod" Comet. This car I drive hard and often wind up to 5K RPM and few hundred miles after the oil /filt change, I was worried the bearings were going when the oil pressure dropped from the usual @ 40 lbs at speed to less than 30 and idle pressure went from 25-30 to under 20lbs.
As a last effort to find problem I switched filters and without changing oil the pressure returned to normal.

Last year I had a similar experience with a Plow truck and was unsure wether the oil was contaminated/diluted or the Fram filter was the problem because I changed both and the oil pressure returned to normal. this is why I changed only the filter this time.

I am afraid I will ignite a flame war and the Amsoil crowd will join in but I am not advocating any specific brand and I know only a few mfg's make virtually all the brands but I am sure about the specific circumstance with my car only a few weeks ago.

Powerband 8)

 

[blueroo]

Nope, I'm using the Motorcraft FL1A with Royal Purple 5W30 synthetic

 

[Jamie Miles]

My all stock 250 has about 50 psi going down the road and about 20-25 psi at idle. Engine has 209,000 miles on it.

 

[Anonymous]

Lots of variables here that you have not covered. First thing i would say is the temps you describe are very acceptable. I was relieved when my build returned a hi running summer temp of around 200-210. Modern engines run hotter than that. A hot engine drop in oil pressure is normal. What vis. oil are you running? What is your idle set at? During the Summer months a heavier oil is good as well as a slightly higher idle. When really hot first hit, my normally 600-700 idle dropped to around 500 and oil pressure droped some with it. So i stepped the idle up to around 800 for summer use which increases air flow through radiator in traffic and at low speeds also. This increases oil pressure also, plus in summer here (Ga. 95*F is typical) I used to run 20W50 or 30W oil. Although recently i made the decision to switch to diesel duty 15w50 for the cam and lifter's sake. Oil pressure when hot and slow is around 30#. 50-60 when first cranked and at hiway speeds. All in all i'd say you really have nothing to worry about. Just keep good oil changed regularly.

 

[wallaka]

5W30 is a little thin for my taste, esp. in the summer. I'd go with a 10W30 or 15W50. That's probably what your problem is.

 

[mugsy]

Blueroo,

Typically when an engine runs hotter at highway speed than in stop and go driving it is a sign that the radiator is plugged and not transfering heat properly. The rule of thumb is that an engine doesn't need a fan above 30 mph; the engine runs coolest/cooler on the highway. I had a similar problem with another old car, the thing would get real hot doing 75 mph, but would cool off driving around town. I finally pulled the radiator and had it tested, it was almost blocked.

The oil pressure fluctuations sounds normal to me.

tanx,
Mugsy

 

[XFlow_Fairlane]

are your hoses in good shape? a bad lower hose will collasp at highway speeds and hinder flow. def kick up the weight a little.

btw I run no fan on my 62 even with the turbo BUT I have a large rad (rated for a 400 hp motor) and don't have heavy traffic to worry about. as long as I am doing 25-30 mph it keeps cool

 

[LaGrasta]

sounds normal, but maybe switching to a bit thicker oil in the summer would be a good thing.

As far as your cooling system. Yeah, make sure it work correctly. that goes without saying. A good flush will ensure that (both radiator and block).