ExitWound

I've been having oil pressure problems lately. Here's the scenario:

• Low pressure at idle when warm, normal pressure during rev/cold engine.
• Power steering crank pulley was shot. got a new one. Torqued to 155ftlbs, same thing. the torquing of the crank bolt doesnt' seem to be the problem.
• Took out and cleaned the OPRV (3piece old style). As far as I see, it's not sticking. In fact, the plunger falls right out of the block smooth and silent if the spring isn't holding it in.
• Changed the oil from 10W40 to 20W50 to thicken it up. Put in ~6quarts. Started car, had little oil pressure. Slowly it built to 4.5 bars. Took the car around the block, no problems.
• Today, the car won't start. Starter cranks and cranks and cranks, but there's very little sputtering and no start. I charge the battery up, and the same thing. No matter how much over "cold of winter morning" the engine is, it won't even give me a sign that it's trying to fire.

The only thing different is the weather. went from 55F to 34F here in PA but the starter is operating fine, cranking away.

• Checked for any oil leaks and found none.
• Bypassed the idle control valve - no effect.
• Bypassed the DME Relay - no effect.
• Air filter is clean (looked for squirrel nests).
• Cleaned the terminals on the battery.
• Only thing I've done is removed the air intake to get to the fans to get to the crank bolt. But it all worked after I put it together. Car still won't star tonight.

During cranking, I have 3bars of pressuring showing, a proper torque bounce up to 500rpm, and all dash lights and dome light work properly.

How does one check for spark without a buddy to help? How do you crank the car at the same time as working under the hood?

vro944om

the problem is the oil, you bought 20 when it started to get cold, of course its gonna be too thick ;P. im using 20w 50 here in texas and its fine, just use some thinner oil...

BUT... of course this may not be your problem, it does look like you checked everything though.

EDIT: minor brain fart.... is it thinner oil for hotter weather? and thicker for cold? hmm... very embarrassing if im wrong

ExitWound

Car started and ran though after I changed the oil yesterday. Weather was low 40's at the time. Cold engine as I did it too.

You'd want thicker oil in hotter areas because it will thin out the higher the temperature. However, I put in the thicker oil to alleviate some oil pressure issues I may be having, including a (possibly) worn oil pump. Many users on the 944 boards use 20W50 and I assumed it wouldn't be *too* thick for the cold weather. Does too thick of an oil actually prevent the engine from turning properly?

vro944om

quite possible, it just depends how cold its getting, it could be doing this to your car.. if the car starts after leaving it in a garage or something then it is the oil. as a quick test get a heater and heat up your engine over night in a garage, if it starts, you need new oil. Ghetto Test

ExitWound

I was going to ask... I saw yesterday on TV that temperatures in Barrow, Alaska can be -40 overnight. The documentary said, "If you don't plug your car in, chances are, it'll be completely frozen the next morning." How are they plugging them in to keep them warm? Is there a device that can be used to keep your engine warm during the winter that's added to a normal engine or are these cars manufactured for Alaska?

My other question is, if this is the case, and if the car started fine on 10W30 (when used), and 10W40 the past 6-9 months, shouldn't 10W50 work just as well? in the cold, the viscosity should be of a 10W oil, but only thin out as much as a 50W would as it's warm. This would give me a thicker warm running temp (hopefully alleviating my 1bar of pressure at warm idle) and still start in the cold. I've never had anything less than 10W30 in the car.

vro944om

i havent heard about that.. maybe its just a heater? the worst stories ive heard coming out of alaska is people cooking their oil inside to warm it up ..now thats cold!

knfeparty

Block heaters are what you're hearing about. I don't see how oil could keep it from starting. Why don't you check your ignition rotor; mine blew up for no reason, maybe yours did too. It also never hurts to ensure that the AFM, speed & ref sensors are all plugged in.

PorscheDoc

Lol, the oil isn't keeping your car from starting, it is an unrelated coincidence. Start looking for spark, fuel, and air.

DarylJ

Please....stop...typing.

ExitWound

I didn't think it was the oil. I've read a few tales online about too thick of oil preventing a start on a cold morning, but since the engine was turning, i figured it was unrelated. I wanted to hear if I was on the right track. Now to look for spark and check the ref/speed sensors.

harrisonrick

thinner-10W30 for wintery weather, 20W50-thicker for the hot stuff.

mtccl

6 quarts of oil?????

That's at least 1 quart too many unless you have some other mods like external cooler, etc.

PorscheDoc

Lol, uh the cars take 6.3 quarts of oil, turbo, NA, S2, it doesn't matter what oil cooler you have, unless you specifically pop the lines to the external oil cooler during an oil change (at which you would probably add 7 quarts for the oil change).

There is so much bad information in this post it isn't funny.

Jay W

Interesting thread. Anyway in my case my starter is almost dead and as colder and colder mornings came in the starter turned slower and slower. So I switched to 10W40 oil for winter and at least the starter can turn the engine fast enough to get it started. Therefore if your starter/battery is bad enough that it cannot crank the engine around with the thick oil in cold weather, then you may need to change it. Otherwise the oil is unlikely to be the problem. Last thought is that thicker oil could help seal the piston rings slightly better giving slightly better compression in a worn engine, but that is a real long shot.

Legoland951

Oil is unrelated to your no start condition. I can put 90wt gear oil in my engine and it will start no problem. I had an experience with the 87 mitusbishi mightymax where my water (note not antifreeze) froze in the radiator and block just from sitting overnight. I couldn't run the car for more than a second (water pump full of frozen water keeping impeller from turning) and the starter could barely start the car. Super low temperature can keep your car from starting but oil cannot. Start looking for other problems.

BTW antifreeze is called antifreeze for a reason (I found out the hard way).