pcarfan944

I just went and picked the 944 up. I talked with the 944 specialist and after listening to him, it sounds like he really knows his stuff. On the drive home I decided to step on it and see if it still smokes. I don't know what he did to my engine (said he just tightened up some loose connections at the radiator) but it has new life breathed back into it. At 4000 rpm it took off like i've never felt before and pulled strong all the way up to the 6000. I did this about four or five times. The first time I noticed a little darker colored smoke out back (just a puff, not enough for me to get a good color description) and after that I saw nothing. Maybe the white smoke was a whole bunch of carbon that got cleared out, because it feels stronger than ever. Pretty good news. I'll keep watching for signs of a head gasket or anything out of the ordinary though.

________
Pat
86 944

pcarfan944

I was just looking over the work order and it stated that they pressurized the cooling system and saw no problems. What would that test for?

pikey7

jeez. good news! simple things are always the best! Pressurizing the system is just to make sure it's full of water, and there's no major leaks.

951and944S

The cooling system gets pressurized each time it reaches operating temperature, but what they did was attach a tool just like your coolant reservoir cap that has a hose and pump attached.
The pump has a colored and numbered (psi) gauge face so they can pressurize the system to at least what the cap is rated for.
The coolant system, under pressure would send coolant past the orings on the internal cooler (in the case of an N/A engine-the turbo's cooler is external) and it would show up in the oil pan resulting in the recommendation by the shop to have the cooler resealed asap.
If they caught this problem in the shop you'd never see the milkshake in the oil or coolant because it only "mixes" through the rotating action of the crankshaft in the crankcase then it's pumped around the internal oil circuitry of the entire engine.
Also, the engine must have been run with faulty orings for clean pressurized oil to overcome the pressure of coolant for oil to actually get into the coolant circuit.

So.....if engine is running at 4 bar(58psi) oil pressure it will overcome coolant pressure of 18 psi (estmated popoff of reservoir cap) and the result is oil in the coolant.
If the engine is static (o psi oil pressure) and coolant pressure still exist after a drive then the coolant will dump into the oil pan and mix upon next startup.
You can see that's it's easily possible to have "mixing" both ways at the same time......

Terry S.

TheMAXX

The white smoke means they elected a new Pope.





I am sorry I couldn’t resist I have been trying to since I first saw this thread but I had to give in.

JimV8

White smoke at revs may be overfilled oil. I had this once before I found out the correct level on the dipstick and belched out a smoke screen of white smoke while accelerating onto a freeway. The one and only time its done it. I'm sure the other drivers appreciated that.

pcarfan944

LOL

Another idea I thought of was that perhaps some water got into my gas tank and since tank was low (1/4) when it happened maybe, if it's even possible, a little water got squirted in with the gas. Who knows. I did some spirited driving again today and saw nothing.

Dilberto

Check the oil filter itself too. Sometimes the high pressure can blow the sealing ring apart, coating oil all over the hot exhaust. Never tighten the filter with anything harder than the skin of your hand either.

Zach