It’s time to talk Oil Pressure Relief Valves! Did you know that there are 4 different types? In this video, Tim Comeau discusses all 4 different types of OPRV that Porsche made for 944s, and explains the differences between each of them.
great videos ,… wish i had you when i was 19 😂 i found everything the hard way as i’m sure you did …. love hearing all these great things you talk about 🥰
Thanks for the compliment, bud. I’m not some general RU-vidr who is trying to break into the 944 scene. I’m not some new guy who’s trying to create 944 valuation videos. I work on only 944 types all day, every day. Gotta love 944’s!! Please encourage others to subscribe to my channel.
I really like that concept about increasing your oil pressure. It would be cool to be able to do with the one piece easily. Sometimes when it is hot, I see the oil pressure at idle go down to like 2 bar. That trick wouldn't fix it in this case (thicker oil probably), but that's a cool thing to know about.
2 bar at idle and hot isn't that scary in these cars as long as it comes up to 4 or 5 bar when revving it. Yes, run the thickest oil that your temp zone will allow. In San Diego, we run 20/50. Decreasing oil pressure in these cars is usually remedied by changing the connecting rod bearings. They have date stamps on their outside.
@@timcomeau420 in my 944 86 NA when the engine is properly warmed up, at idle, the oil pressure gauge is showing around 2 bar, but the needle is jumping all the time up to around 4 bar. when the engine is cold the oil pressure gauge is showing 5 bar without any fluctuation. could you please write any tips for the issue.
@@vertex944gt3 2 bar at hot idle isn't that scary, but not optimum either. As long as the needle goes up to above 4 bar when revving. Most likely, your rod bearings are getting thin. Re the jumping needle: Are any other gauges acting funny? If so, go for a common ground. Your engine block must be grounded properly for the oil pressure gauge to work right. If the others are ok, check the wiring to the sender. No opens or shorts. You can check the wiring by opening the 14-pin connector near the brake booster. Blue / black wire and plain blue wire ( sometime blue / white stripe.) If ok, replace the oil pressure sending unit. You need room to swing a 24mm wrench. On the sender, blue / black wire goes to Wk terminal.
I REALLY LIKE ALL THE VIDEOS GREAT STUFF. ive been watching them all. i am prepping a car for chumpcar and lemons, what do you suggest for prep and weight savings etc? could you maybe show one of the race prepped 944's and share the build with us?
That would be a really long video. I did show the cage build of a red 924S Spec car. Consider building a 944 Spec car and coming racing in NASA and PCA.
I found a Technical Bulletin by Porsche addressing the two early style spring+piston style valves you show in your video. The earlier shorter spring is 78.4mm and was upgraded in mid 1984 to a 95.5mm spring. Thanks for showing this updated version which matches up with the socket head plug with the round button in the center. It sounds like you don't find the one-piece retrofit valve to be much of an improvement over the spring/piston valve, but is that true for both the short- and long-spring versions of the valve?
Excellent info to know about. I haven't seen that tech service bulletin, so I really appreciate you informing me about it. Do you have the number for it? I'll study and memorize that too. :) The 1-piece is probably an improvement, but you can stack a washer with the spring to increase your oil pressure with the spring-type OPRV's.
Not sure if this video is too old for you to see this comment but worth a shot... I woke up to my 951 in a pool of coolant in my garage, had no leaks prior the day before. My car was do for a nice cooling overhaul but noticed as soon as I took off the Coolant Expansion Tank that there was this grey slimey build up inside as well as in the radiator hose itself. Immediately thought Head Gasket but after doing some reading, I'm wondering if it's my Oil Cooler, the only thing I could justify the pool of coolant in my garage after cooldown is maybe through the Overflow tube because of all the buildup. So after watching your video I think I might give oil cooler a shot and pray for the best !
It's extremely rare to get oil / water mixing as a result of a head gasket in a 944 type. Go for your oil cooler seals. Be aware there's an update to the aluminum sleeve that inserts in the block. Used to be asymmetrical, now it's symmetrical. Replace BOTH green o rings. You'll need to clean the whole cooling system including hoses, block and radiator flush. Sometimes easier to just replace the hoses. Fill with water, not coolant, and we add some SHOUT laundry detergent. Put the engine thru a heat cycle ( without the thermostat) and flush a couple times.
Great video. Always wanted to know how these worked. Is there any reason you have to update from the early spring and piston to the one piece? What was wrong with the early ones? Thanks again for great content.
@@BBox135 Any style will malfunction when stuck. That's why alignment of the oil cooler housing is critical. I've seen them get stuck open and closed. The video you posted refers to the tech bulletin and is great for learning about the various valves. Keep your pressure up!
There's only 2 versions of the oil cooler housing. The 5R and 6R, which differ only in the circular seat area for the oil cooler itself. See my video on oil temp sensor mod. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-a4Ql74CfcTg.html With the 6R, there's an additional alignment procedure for the cooler within the housing, using shims. Always pressure test the oil cooler separately by submerging it in water. I like that you're asking so many questions. Quest for 944 knowledge! :)
I don't mind using the 3-piece as long as it's making good pressure. Also, I prefer this style for the race cars because you can increase oil pressure by using the washers I mentioned .
@@BBox135 Certainly. The answer splits into two courses. Mount a 951 cooler console and then a stock 951 oil cooler or larger oil cooler up front. The other course is to keep the stock NA oil cooler and install a sandwich plate between the filter and its housing, then run hoses off that to a cooler.
hey there,i noticed on my 1984 2.5 litres 120kW the oil gauge was not working,and oil light apeared on the dash..i removed the oprv and cranked the car but no oil was coming out,normal or could be the oil pump bad?
That's not good. On an early car like yours, the only oil warning light is for pressure. Very unlikely the oil pump. More likely the oil suction tube inside the oil pan has broken from excessive vibrations, usually due to collapsed engine mounts or poor quality engine mounts.
I have an 86 Turbo with the three piece oprv. Recently I replaced all the gasket and o rings in the oil cooler housing. Now my oil pressure at start up is 5 bar and when warm 4 bar. It won't come down below that. I replaced the sender still same high pressure. When I put the cooler back on I used the alignment tool. Could my 3 piece be binding and should I convert it to the one piece oprv? Thanks for your video.
No don’t replace it, silly! Your Oil pressure is outstanding and very healthy for the engine. Nice work taking care of your engine. Gotta respect that.
@@ComeauRacingEnterprises Thanks for the reply. One last question. I just took the car out today and drove it around for about a half hour. When I finished the drive, sitting at idle, pressure is at 3.5 bar. When driving around and the car is warm, at 30 mph and two thousand rpm in fourth gear its pegged out at 5 bar. At 50 mph at 2500 rpm in fourth gear it is once again pegged out at 5 bar. Is this an issue since the pressure isn't coming down when driving? Thanks again.
Cracking video, I ve a 1989 2.7 with the modern 3 piece pressure valve with the 24mm hex on the end. the O ring on it was shot, there is also a 1" length 4mm rod inside the spring, is this normal?
The three-piece pressure relieve valve is for early cars. Your car should have a late 0PRV. That’s a one piece unit. Not sure what the 1 inch length rod was doing inside the spring.
The third one from the left was what I meant by modern 3 piece, all be it the main piston seemed stuck half out the block, only the cap and spring would come out, and like I said there was a small bar inside the spring. drive.google.com/file/d/1-O4ywxdo9W6WLJViGgXV2LhjehZhoFUW/view?usp=drivesdk
Don't pay attention to the model year, pay attention to what's installed on your car. It might have been changed. 5R to the later 6R. The 6R has a different shape inside the housing and has it's own separate alignment for the cooler. Then you have the alignment for the housing to the block.
@@timcomeau420 Thru some unfortunate events the cars original OPRVs threads got messed up so if i try to screw it into the housing it will ruin the housing. I have one out of a 87, my cars a 86 so that OPRV will not work. In theory can I swap out the 22mm head onto my original OPRV? Thanks!
@@BennysBenz One- piece have a 24mm head, not 22mm. Your 1986 should have a 3-piece OPRV. The system parts must stay together. I'd get another head that is an exact match for yours.
Ok so I'm building a 968 block with 2.7 head turbo . Can I use my 87 turbo oil cooler housing along with the oprv that came with it. Or do I use the one piece oprv that was on the 968 block?
@@VENTOPWR Whether it's a 3-piece or 1-piece, I would check its operation and see if it fits ok before using it or throwing it away. If it went thru a plating process, the internal O ring is prob ruined.
