Podguy

I would try some Pennzoil and their heaviest weight. Save your money on fancy oils until you sort out the problem. It is common to see a lifter click when cold and the engine has not been run in a while. For it to be noisy when the engine is hot suggests both a worn lifter and too low oil pressure. I doubt the oil pump is worn but it is a place to look. I would inspect the front seal on the oil pump. I have seen these crystallize and fail. Lifters can get dirty. If you just shifted to mobile one it can break loose a lot of garbage. Some of the garbage could get stuck in the lifter - but I would discount that because it should click all the time.

jwillman

I am running Mobile 15W/50. I changed it 2 years ago when I first got the car, was a non-runner. I have only put ~500 miles on it and oil is still translucent.

Pod wiring is good as I just did a hardwire conversion. I get 5 bar on cold start and it seems to respond to conditions so based on the lifter noise I would tend to believe the pressure reading.

The test in the WSM uses an external pressure gauge but only lists a high end check ensuring 5 bar at 4000 RPM with an at temperature engine. I will confirm that at the pod gauge today.

What oil weight would you recommend?

I do have a ever so slight oil leak that may be coming from that area so perhaps this is as good a time as any to dig into it. Would a leaking seal cause my pressure to be low even though I loose very little oil?

Bill Ball

Your pressures reported on 6/4 in message 7 were fine. These new pressures are not so fine. Was the engine running a lot hotter today? I have always run M1 15/50 and my pressures are more like your ones from 6/4 even with the motor running very hot from having an inoperative fan.

I've never have had any valve clatterat any time despite the high miles on my motor. Have you tried any additives to quiet the valvetrain yet?

txhokie4life

Any ideas on the rod bearings?

If they are starting to wear, you can see a drop in oil pressure.

Try a some 60W racing oil for a bit, you can just drain a little of your current oil
and top off.

I've got some Mobil 15W/50 in my 951 and I'm seeing some lower oil pressures (just
got the car), 4-4.5 when starting, 1.5bar at idle during track sessions, and 4 when
pulling full boost.

My rod bearings were "weathered", but this is post rod bearings.

I'll eventually move to Amsoil 60W dominator for it -- but I have some other issues
that might have me messing with oil lines -- and don't want to flush $200 worth of oil
in the interim.

You might consider putting an aftermarket oil pressure gauge -- you can get
them reasonably enough and find an oil drain plug with an adapter
at lyndsey racing.

mike


Mike

jwillman

A little background on my car. I bought the car in May 2010 from a PO who had taken the car, a spare M 28/16 4.5L engine and boxes of various parts as payment for a business debt.

Since buying the car I have needed just about every spare part the twice removed PO had acquired. This gives me pause as to why the PO had this engine. I know nothing about the history of the engine in my car or the spare engine.

I say this because I have always wondered if the PO knew something about the engine installed in the car that drove him to acquire the spare engine.

Just food for thought.

Podguy

Most 928 owners have a batch of spare parts inclueing an extra engine or so. I have an extra for each of my cars.

jwillman

The spare engine has already donated a part or two.

Guess I will go on the premise that my current engine is fine and work through the easy to do stuff first.

Plan is to pull the oil pump off my spare engine, inspect, replace seals etc and then use it to replace my existing pump to see if i have any change with all other conditions remaining the same. WSM does not have allot of information on inspecting internal parts of oil pump or did I miss something?

I did add a 1/2 can of Rislone a week ago to in preparation for an oil change. Any chance that has contributed to my lower oil pressures?

Podguy

sure

jwillman

Is that a Sure to the rislone havining thinned the oil and dropping the hot pressure?

Podguy

That was my best guess. One of the ways to clean out an engine is to put in a detergent. Detergents can thin the oil to accomplish their purpose.

jwillman

I completed my front end seal refresh. All the camshaft and oil pump O rings were rock hard. Shaft seals did not look that bad but were replaced anyway.

Oil pump had been installed by PO without the mount bolt o rings or special capture washers. Oil pump looked good on the inside.

I reassembled all, replaced timing belt and changed oil using Mobile 15W50 and added Swebco 502 per recommendations here.

I saw no signs of metal in the old oil although it was quite black. I had changed the oil a mere ~400 miles / 16 months ago when I first got the car and it had stayed relatively clean till I added a 1/2 bottle of Rislone when I started having the lifter noise that started this thread. Oil got dark very quickly after that and I ran the car maybe 50 miles with the rislone in.

It was after adding rislone that I noticed the lower oil pressure at hot idle.

Post seal refresh I am now at 2 bar at hot idle and no leaks. I am also not hearing lifter noise at extended idle as before. OAT was low 90's so I will continue to monitor on hotter days should we see anymore this year.

Thanks for all the help.

IcemanG17

A couple thoughts....... You live in Texas where it gets HOT HOT HOT....early 928's had the thinner (smaller) oil pump which Porsche later changed to INCREASE oil pressure at idle....

I would change the oil and try a "better" synthetic.....I love Amsoil, but I only run race cars & that isn't ideal for street cars..... Honestly I would follow Doc Browns advice....buy whatever oil he says with Swepco for your next oil change, which should be ASAP....

IcemanG17

maybe I should have read your post BEFORE I wrote above :>(

jpitman2

Looks like the Rislone cleaned out a lot of dirt...but thinned out the oil as well. Note that lifter noise is best fixed, as long as pressure is adequate, by going to a THINNER oil, if the problem is getting into the lifter through small passages.
jp 83 Euro S AT 54k, Delvac 5W40, min idle 2.5b