View Full Version : Engine Oil pressure on a HOT day after stop and go driving for a while... what's ur reading?

MDC - Mike C.
05-28-2011, 05:00 PM
Im normally a cooler weather (in FL, that's a relative statement...by 'cooler' i mean in the 50's through the low 70's) driver when it comes to my D. Normally I do not drive it in the FL summers because it's so brutal, and i still have my new AC sitting in my living room.

On my last trip to Orlando, with 92 degree weather and the car running between the 220 mark and that 1st line above rest, fans running, I looked at my oil pressure. *Mind you, this is the hottest weather I have driven the car and the longest distance.*

My oil pressure at speed would vary from between the 3/4 mark and half, popping up to say 'hi' to the line directly below the 80psi marker. I know when the car is running that hot and the temperatures outside are that hot, oil temps are running hotter, hotter oil thins out, etc... At that same temp, my idle pressure drops just a hair below the 1/4 marker and climbs steadily (sometimes just below the 80psi for a second before falling into the 'hot' range listed above).

I know these cars are finicky, but im just curious as to what pressure other people experience with city driving in 95 degree heat, and what temps your car experiences.



For people in hotter climates, does this reading seem normal?

05-28-2011, 09:01 PM
I'm running MOBIL 1 20w50 right now and my oil pressure cold is 70 to 80 PSI. After the engine has warmed up (about 5 min) the pressure is 70 PSI above idle and at idle 40 PSI (half mark). I've not seen it change from those reading even after a very long hot day drive.

I plan to do an oil change soon to MOBIL 1 10w40. I did run 10w30 when I first got my car and saw and heard no difference going to 20w50.

If I were you, I would try a synthetic oil since that is an easy thing to try.

MDC - Mike C.
05-28-2011, 10:37 PM
My cold pressure running 20w50 is beautiful, always up in the 70-80psi range, and at idle, never less than half to a quarter on the gauge.

In my normal cool driving time, it will usually be right around the 70psi.

The only time I get the lower readings is during the EXTREME hot temperature days which makes the car run hotter. I can drive all day in February and the car will never go more than a hair above the first mark on the gauge (the 1/4 mark).

When I drove home today (about a 15min drive) in slightly overcast weather (still wicked hot), my pressure was excellent again until my temp gauge crept up to around the fan activation temp.

Im doing an oil change next weekend and will see if it does anything different.

I know people recommend sticking with 20w-50, but being it's so wicked hot, im thinking of running a 10w-40. Im just a lil weary because like I said, im not a normal summer driver with the heat this bad. In the cooler months, when the car gets a little warm, you can see the temp gauge drop once i get rolling decently. In the summer, that doesn't happen at all.

05-28-2011, 11:25 PM
Mike, it gets brutal in south Arkansas in summer, too.
There are two things I trust on a Delorean ... the low fuel light and the oil pressure idiot light. If that oil light comes on you have NO oil pressure. I don't rely on the gauge at all because it's usually all over the place.
I'm also a member of a Jaguar forum and the consensus over there is gauges are not to be trusted.

... and if the low fuel light comes on you've got about 50 miles left ... start looking ...

05-29-2011, 12:42 AM
I recommend Mobil Delvac Super 15w40. It's actually a diesel oil but is a very good oil for the DeLorean. My oil readings go from about half (35?) to around the top line while I am accellerating. When the car is hot at idle, no matter the outdoor temp it's around 9 o'clock. It goes up with RPM's.

FWIW, 10w40 is generally a less stable oil (sheer-resistant) compared to a 15w40.


Chris 16409
05-29-2011, 08:17 PM
The site outage deleted my post:

Anyway David T. brought up a point about the oil sender. And I wanted to ask if anybody knows if the ones that Hervey and Marty Maier sell are the same part?

MDC - Mike C.
05-29-2011, 09:48 PM

Thanks for bringing that up. I saw Dave's reply also before the outage, and I think im just gonna order a new sending unit just to be safe. Im doing the oil change tomorrow and am going to give Andy's diesel engine oil suggestion a shot. Im gonna order the sender and replace it when it comes in.

05-30-2011, 12:09 AM
Cool, you will like the Delvac. You can even get it in big jugs at Walmart.

Six or seven years ago I was the shop manager at an oil change place and I did a lot of research on oils, talked to a lot of people, read a lot of stuff about oil because that was my job. There is also a forum at bobistheoilguy.com that I still read often - that place is full of expert advice. I was convinced that the DelVac would be the best choice for the DeLorean, and it has met all my expectations in all climates and on long trips. Oil pressure is very stable and I feel good knowing I have a very high quality oil in my car!

I'm on my last Purflux filter.... I will be sad to have to switch to the Bosch filter next time.


Chris 16409
05-30-2011, 12:38 AM
Im gonna order the sender and replace it when it comes in

Mike where are you getting your sender from. Do you know if Marty has a better sender compared to Hervey's.

MDC - Mike C.
05-30-2011, 07:51 AM
IIRC, the volvo unit was a direct stock replacement which im pretty sure is what Hervey is selling; however I think i am going to order Mary Maier's calibrated unit since my whole issue is nutty fluctuation readings in EXTREMELY hot weather.

On my way to go get the oil to do the change now.