CoreySmith

I don’t have any indication that my car has ever had rod bearings changed. I have about 150,000 miles on it now. I have read up on the job, and it seems like something I should not really tackle myself.

Long story short, I spoke to 2 local Porsche mechanics who have worked on my car. The first is experienced and works on lots of 944’s. But he cuts corners sometimes, has given bad advice and missed some obvious and important things that needed attention. I haven’t used him since finding mechanic #2. The second mechanic is Bosch certified and has 944 experience. He works at a general upscale “imports” repair shop. He is very good, caught the important things #1 missed, worked with me to rebuild rather than replace and has done excellent work. He is honest, reasonable, seems to identify how to tackle problems, takes time to talk and explain and I trust him.

I asked both if rod bearing replacement is preventative maintenance I should look into at this stage. #1 said, you should have done it 70,000 miles ago. You will be very sorry if you don’t do this NOW. #2 said, don’t touch that until there is a reason or if it becomes a “while you are in there”. He says that as long as the oil is clean, pressure is good and there is no knocking, stay away. Obviously I think more of #2, but I don’t want to disregard the experience level of #1 and am concerned I am talking my way into the easier/cheaper answer.

This is an expensive job. Parts are cheap but labor of 10-12 hours. But I don’t want to be an idiot. What does the rennlist collective say about this?

culture

i tend to follow my heart, my head, and my wallet. not necessarily in that order. but, i'd go with #2. if you don't track the car then it should give you plenty of warning, i.e. knocking before you blow something up. then you can get the most of out the "while you are in there". if you track the car, it puts a bit more stress on it and you could push it to failure a little quicker than normal.

no knocks…no worries unless you already had to open up the block for other reasons. my 2 pesos.

wilhit10

I would say no, unless you need an oil pan as well. Pressure is good, so you are not showing major bearing wear. Remember that there are plenty of good crankshafts in a very doubtful rod bearing hurts crank scenerio.

CoreySmith

culture, thanks, you bring up a good point.

I do not track the car. I have no indication it has been tracked. But, the first owner had to replace the clutch after 57,000 miles, so it has been driven hard.

Van

Have an oil analysis done at your next oil change. As long as bearing material is minimal or nonexistent in the oil, they're fine. I've taken apart high-mileage engine that have had proper oil changes, and the bearings look great.

Jfrahm

If you are doing the oil pan gasket the rod bearings are not a bad thing to get while you are in there but generally I would not worry about it. Make sure they replace the rod nuts if it's done.

The clutch could be down to improper technique, using the clutch as an expensive brake pedal is not that uncommon.

CoreySmith

Jfrahm:

Oil pan gasket: Nope. No other reason to be in there. Car is in awesome condition. I am way into a major rebuild and am now down to preventative and cosmetic things.

Clutch: I see those people who sit at a stop light just rolling back and forth, no brake light comes on at all. I just want to scream at them. My dad would have killed me if I had ever ridden a clutch like some of the people I see.

CoreySmith

If Van says it, it is true. Van, who do you recommend for analysis? What metal am I looking for?

Thanks!

EDIT: Never mind. I used this new thing called Google. It is pretty neat. Blackstone looks like a decent place and I know what to look for.

Again, Thanks guys so much for the expert information. I want to protect my emotional and financial investment. But I also don't want to do unnecessary work.

HICKS

I saw bearing material in the oil filter pleats after cutting it open the prior oil change. Not large pieces, just enough to get me thinking. Like you, I was curious on when they should be done. The car had around 165k miles, and was an 86. I had good oil pressure except when hot outside, AC on, and at idle it would bounce from 0 to like 2.

When the bearing let go I was going about 80mph, I felt a surge, then heard knocking. Oil pressure was at 4 and no warning lights. When I found a safe place to pull over I pushed in the clutch and instantly went to no oil pressure and warning light. Towed, and drained the oil when I got it home, crankcase was full of metal.

So that's my story.

mytrplseven

Clutch replacment at 57k miles is not unusual if the PO was driving the car a bit harder than "Ma Frickett". I wouldn't consider that "hard", just fun driving. Do you know if the clutch was replaced with another rubber one or upgraded to a conventional spring loaded disc like the Sachs product?

It appears that you rely on mechanics to handle the major wrenching on your car, so #2 sounds like your man.
I agree with the others who profess that if you're not tracking your car and you're doing the scheduled maintenance on the fluid and filter changes, I'd leave the rod bearings out of your mind unless you have to pull the oil pan or you start to hear a rod knock noise. Oil analysis isn't a bad idea if you're really concerned about bearing condition. My car had 120k miles on it when I pulled the pan and, though I'm not assured that the PO was as manic about periodic maintenance as most 944 owners have become about their "babies", my bearings looked like they were brand new. I replaced them and the rod bolts anyway (WYIT) while I had the oil pan off.

CoreySmith

I have only had the car since 2011. I have been an absolute maniac about changing every fluid and wearable part out (i.e. I am on my third round of Swepco 201 in the transaxle, just trying to make sure I flush anything lesser out). I have rebuilt or paid to rebuild almost every system in this car. Literally from front bumper pad to rear license plate lights and everything in between - ~$9,000 in 2.5 years invested. I also have an absolute a stack of receipts from both PO's. I am sure each was very conscientious. The guy I bought it from was an aeronautical engineer and had meticulous notes on his work on this car. He used this as his DD and also restored Chevies from the 20's and 30's. He wasn't much for maintaining cosmetics or luxuries in the car (stereo, A/C, cruise, odometer, seats, shifter, steering wheel, clock, instrument lights and much more all were in poor or broken condition). But he had the bones in good shape. The only thing that scares me is that he had just rebuilt the oil cooler before I bought it. That is why I am a little worried about the bearings.

In answer, the replacement clutch is a spring-center Sachs. The only time I have ever seen anything in the oil - and I mean anything - is the change after I had the timing belt, all rollers, front seals, cam and crank bearings etc. done. There were some shavings that time. I am pretty sure it was all those new parts making themselves at home. In all the oil changes since then, I have seen absolutely nothing. Not a speck of flash or flake.

Van

I say lots of stuff; but it's not all true.

I use Blackstone.

MB968

I agree with mechanic #2. If oil pressure is good at idle when the oil is hot after a long run on the highway, that is a good indicator of things being OK. My 968 engine runs about 2.75 bar at idle under the hottest engine conditions.

If you get into the bottom end for any reason, plastigauge the rod bearings. I'm not a big fan of changing out bearings unless they are out of spec. Old bearings already have gone through the initial wear in period and are now nicely seated to mating journals. When I was in my engine about 18 mos. ago mine gapped at about .0018". Even though they are cheap to change when you are in there, I left the old bearings in the engine. The rod bearing is basically a hydrostatic bearing which can last indefinitely with normal non-competitive use as long as proper oil maintenance is followed.

mytrplseven

Corey, your story is a mirror of mine although the "bones" were somewhat neglected, too. I bought my car from the original owner in Santa Fe because of the unusual factory color (Nile Green Metallic). Since then, though, I have done pretty much all you have done, including putting a Sachs clutch in it. Have you updated the shifter with the one made by "Only944.com"? Seriously, you have GOT to get one of these. It makes the car feel like factory new. Call it a labor of love or therapy, in my case it is both. I'm going to the other side of the state to pick up a good deal on a replacement rear hatch (mine's delaminated and I've been waiting for a good deal to cross my path). I've saved thousands by watching ebay and buying things in advance, knowing what I would eventually replace. Pristine dash standing in the corner to be replaced soon (tossing out that ugly and warped plastic cap).

Keep the faith and enjoy the adventure.

Kevin Baker

Not unless you are in therefor something else already.