Yummybud924

My car lost oil pressure (zero) over 12 months ago at idle in my garage and ran without oil pressure for 5-10 minutes I'm guessing. the top end was super load when I came in and I shut it off.

I fixed the problem which was the clinder that the spring oprv valve runs in had come loose from the block.

anyways one gear later and my engine is not knocking still but oil pressure seems a bit low sometimes. 15w50 mobil one and it is 5 bar at cold idle then it drops to 2 bar at hot idle and at 3000 rpm its about 4 bar and just stays there. sometimes it jumps to like 4.2 bar or around that then comes down to 4 bar again.

anyways I was thinking of getting my rod bearing replaced as preventative maintenance but that is expensive at a shop so I want to be sure they should be replaced.

the car has about 270,000kms on it. I'm using mobil one 15w50 right now also and mann filter. I replace my oil often every 3-4 months.

I was thinking of getting an engine oil analysis done. but I have no clue how to read it and how it will tell me I need new rod bearings or not.

http://www.blackstone-labs.com/free-test-kits.php

I foudn this site here and they have the "standard oil analysis" which I don't know if it is right for my application.

will this accurately telll me if I need new rod bearings?

I talked to a mechanic that works on porsches (911s) and is a PCA member and he told me that if my OPRV failed some oil would still get to the rod bearigns but not to the head so my head was more likely messed up.

is this true? my oprv wasn't really stuck open, but the clydinder that the piston rides in had come loose from the block and it wasn't working. so I guess all the oil was draining back.

Yummybud924

i'm guessing getting my rod bearings replaced will be a 10 hour job or around that at a shop but still cheaper than waiting for them to fail and getting a new engine or car.

but I don't want to do it if it is not necessary.

KuHL 951

Personally I wouldn't bother replacing rod bearings with a 944 with that many miles; especially if you can't do the work yourself. For the cost of rod bearings, oil pan reseal, etc at a shop you would be better off just driving it the way it is and hope for the best. Oil pressure isn't perfect but certainly within spec. You can replace the car with a lower miles NA when this one dies. Unless you are totally in love with this one and it can't be replaced. These are terrible cars to maintain if you don't perform your own repairs. Good luck with whatever decision you make.

whalebird

Might want to throw a oil pressure sending unit at it. If the oprv fails, oil is lost to the entire motor including the rod bearings. The OPRV is the first thing downstream of the oil pump. How did you remedy the OPRV sleeve coming loose in the block?

Yummybud924

not sure if this be clear but I removed the oil cooler and reglued a new oprv cylinder into the block with locktite 648. which is what is used to hold that metal cylinder on the block.

the piston of the oprv rides in that cyldinder and when it came loose from the block (I guess the locktite failed) the oprv didn't work anymore.

Yummybud924

hmm I know its expensive to replace rod bearings but way cheaper than buying a new 944 and doing all the maintenance on it.

my car had a new clutch kit installed last year and I have replaced a ton of parts myself, like fuel lines, brakes, all coolant hoses, rad was replaced and lots of other things.

also where I live you can't really buy a 944 for less than 3500-4000 in good condition.

Grandpa#3

Hi Yummy, If you have done the other maintenance, you can change out Rod Bearings yourself. Check out the link below and do a SEARCH at top of page for Rod Bearing Change. It should bring up past posts of how to do the job.

http://www.clarks-garage.com/shop-ma...ure-index3.htm

https://rennlist.com/forums/attachme...eplacement.pdf

Cheers,
Larry

Yummybud924

thanks for the link, I know I could do it myself but its my only car and if I do it myself I'll take too long and i'll have no car for a week or so. lol, I work on it for an hour take breaks etc.

plus I have dropped the oil pan before to replace the gasket and replaced the motor mounts............. and it was a pain......... well getting the engine to sit on the motor mounst properly was a major pain and I never want to do it again myeslf lol.

I will ask a shop how many hours they will charge me to get it done....... I don't want to spend more than 1500 bucks. (cdn) to get it done..........