Oil Starvation

[tommy986]

It looks like your baffle already had the flaps to stop the oil flow. Are they all this way?

[insite]

tommy - they're all baffled, but the OEM baffles are rubber & deform / disintegrate over time.

[ChrisZang]

Originally Posted by jaykay

Chris did you ever get oil temp indication set up in your car?

Yep
Oil temp sensor

[Col986]

Originally Posted by insite

another note on oil starvation:

there is a piston/spring assembly inside the oil pump that varies oil pressure with temperature. when the car is cold, it's designed to increase the pressure to around 100psi. once the car warms up, it backs off to 'normal'.

my car was running about 16-17psi (hot) at idle, which seems low to me. on a hunch, i ordered a new piston & spring. interestingly, the new piston has a chamfered edge whereas the original piston had a sharp edge. this leads me to believe that porsche suspected some binding of the piston assembly in some instances......

at any rate, with the new piston / spring installed, the car is now at 23psi hot. i never logged the oil pressure under load, so i have no idea what (if any) effect it has on pressure at RPM, but i certainly feel a little better. loss of oil pressure at temp is a big concern in the M96. anything that reduces the risk to that end is a win in my book. cost is less than $20 and you can do it in 5 minutes when you change your oil.

FYI, part numbers are:

Piston: 997.107.125.01 ($ 5.00)
Spring: 996.107.127.53 ($10.00)
Gasket: 996.107.123.50 ($ 2.00)

I know this is a very old thread, however I looked back through all the old posts to see what upgrades I should do on my 2004 986 S (550 anniv) whilst doing the IMS upgrade.

I ordered the above mentioned parts, only to find they were identical to what was already installed. Not sure when the the upgraded parts became standard.

[BoxsterSteve]

Originally Posted by Col986

I know this is a very old thread, however I looked back through all the old posts to see what upgrades I should do on my 2004 986 S (550 anniv) whilst doing the IMS upgrade.

I ordered the above mentioned parts, only to find they were identical to what was already installed. Not sure when the the upgraded parts became standard.

I bought these parts too... less than $23 after taxes, a cheap DIY. Can't hurt after 15 years, I figure.
If I recall, these upgraded bits came onstream in 2003 or 2004, so I'm all in putting them in my 2000.

[Fyeganeh]

Originally Posted by insite

another note on oil starvation:

there is a piston/spring assembly inside the oil pump that varies oil pressure with temperature. when the car is cold, it's designed to increase the pressure to around 100psi. once the car warms up, it backs off to 'normal'.

my car was running about 16-17psi (hot) at idle, which seems low to me. on a hunch, i ordered a new piston & spring. interestingly, the new piston has a chamfered edge whereas the original piston had a sharp edge. this leads me to believe that porsche suspected some binding of the piston assembly in some instances......

at any rate, with the new piston / spring installed, the car is now at 23psi hot. i never logged the oil pressure under load, so i have no idea what (if any) effect it has on pressure at RPM, but i certainly feel a little better. loss of oil pressure at temp is a big concern in the M96. anything that reduces the risk to that end is a win in my book. cost is less than $20 and you can do it in 5 minutes when you change your oil.

FYI, part numbers are:

Piston: 997.107.125.01 ($ 5.00)
Spring: 996.107.127.53 ($10.00)
Gasket: 996.107.123.50 ($ 2.00)

So I know this is an old thread, but I was wondering about people's opinion on doing this "upgrade" or refresh on an oil pump piston, spring and gasket. Has anyone tried this? Did it help? If you haven't done it, what is the consensus on doing it? Could it hurt?

Any thoughts would be appreciated.
Fred

[steved0x]

Originally Posted by Fyeganeh

So I know this is an old thread, but I was wondering about people's opinion on doing this "upgrade" or refresh on an oil pump piston, spring and gasket. Has anyone tried this? Did it help? If you haven't done it, what is the consensus on doing it? Could it hurt?

Any thoughts would be appreciated.
Fred

I did it on my 2000S, but since I don't have any oil pressure monitoring I couldn't say whether it helped or not.

[Jake Raby]

All these items treat symptoms, they do nothing for the underlying conditions that are the root of the true problem.

[Fyeganeh]

Originally Posted by Jake Raby

All these items treat symptoms, they do nothing for the underlying conditions that are the root of the true problem.

I assume you mean the root problem is many oils losing viscosity at high temps whereas Driven DT40 and the xp9 racing oil not doing so. I believe you don't think it has as much to do with lateral g-forces. (I have switched to DT40).

But my question is in a 15 year old car does the piston actually wear out/break and need replacing so as to prevent damage? Is it designed to last 15-20-30+ years?

Thanks,
Fred

[Qmulus]

Originally Posted by Fyeganeh

I assume you mean the root problem is many oils losing viscosity at high temps whereas Driven DT40 and the xp9 racing oil not doing so. I believe you don't think it has as much to do with lateral g-forces. (I have switched to DT40).

But my question is in a 15 year old car does the piston actually wear out/break and need replacing so as to prevent damage? Is it designed to last 15-20-30+ years?

Thanks,
Fred

The piston doesn't wear out, but the original is more prone to jamming in the bore, leading loss of pressure than the updated replacement. The question is whether the piston jams in the bore, resulting in bearing damage, etc., or if debris going through the oil pump and through the oil pressure regulator (relief piston), causes it to stick.

[Jake Raby]

The failure of the pressure relief system is very rare. The only time I have seen this lead to issues is when the pressure relief valve spring snaps in half (Mode of Failure #17).

The biggest issue is heat being absorbed by the clutch, passing through the flywheel, then heating up the rear main bearing. This leads to shear and wear, then wear debris of the rear main contaminating the rod journals of cylinders 3/6, leading to bearing failure.

[Qmulus]

Interesting. I have seen three blown 2.5l engines recently that had bearing failure, and ALL also had pressure relief pistons (early style) stuck in their bores in a position where the bypass port was open. The springs were OK. In that position the engine would not have had oil pressure. Did the pistons stick, resulting in low oil pressure, causing the bearings to be starved and the resulting damage, or did the bearing start to disintegrate for a different reason, as Jake describes, leading to the debris from the failing bearings going through the pressure relief bore (the oil is not yet being filtered) jamming the piston? Either way, I see no reason not to put in the updated oil pressure relief piston and spring. One thing that I have learned is that the Germans rarely say why they update a part (perhaps doing so would be the admission of a problem?), so it is a good idea to use the latest parts when possible.

FWIW, these all had LN deep sump kits and one had an Accusump. They also had lightweight flywheels.

I also saw an engine with a failing dual row IMS bearing (and no other apparent issues), which I thought was supposed to be unheard of, so maybe I am just seeing unicorns...

[The Radium King]

funny you mention LW FWs - jakes comment made me think that the issue with the lw fw is not vibration or unbalance, but rather lack of a heat sink such that cluch/transmission heat goes straight to the bottom end.

[Qmulus]

Personally I think it is a bit of a stretch to think it is heat. These cars had transmission cooling and temp data, and were not much hotter than engine oil. One had a recent clutch and the disk looked new with the part number stamp still present. Until I see data (MoTec has IR sensors that would be good for this), I am not convinced that transmission or clutch heat is an issue. ALL the bearings on these cars were damaged, not just rears, although those may have been the worst.

I am more inclined to believe that the flywheel/clutch assemblies were out of balance, putting more stress on the rear main bearing. IF that was the problem. Or the oil relief valve stuck (but why..) leading to lack of oil pressure, then the failure of main and rod bearings.

It does surprise me that people that are building these engines aren't using coated bearings or friction and heat coatings on pistons, combustion chambers, valves, etc. Heat and friction are the enemy of any engine, and these modern coatings make a significant difference. That stuff may not be legal for spec cars, but if _I_ were building an M96 I would definitely be sending some parts to Calico for it.

[Jake Raby]

There's no single factor that leads to these failures. Its an equation.

[Qmulus]

Originally Posted by Jake Raby

There's no single factor that leads to these failures. Its an equation.

Yes, a very simple one:

Lack of lubrication = $

[steved0x]

Quick question so I will bump this thread up - if somebody had an oil temp gauge installed, at what temp should they back off and/or come off the track? is there a safe(r) temp <= XYZ temp?

I just installed an oil temp and oil pressure gauge (pressure sensor replacing stock pressure switch and temp gauge in the matching port on the other side) - now that they are there, what do I do with them?

I have some ideas: like check the oil pressure after turn X on the straight, RPM is usually XYZ so see if the pressure is the same each lap at that point. Or check the temp at a certain spot and make sure it is at or below a certain value.

What is a dangerous temp?

Thanks

Steve

[cmacduff]

Steve-I think most would tell you that anything above 250 degrees is getting hot. I have oil and trans coolers on my car and it never gets above 215 even on the hottest of days.

As for the oil pressure that's a tough one. My car never gets below 35 PSI even in the most aggressive of corners( have baffle mods and oil return mods) but not only do you need to analyze oil pressure but you need to make note of when you are on and off throttle. Your pressure will drop in a corner if you are just entering and have been on the brakes. I have a Motec data system in my car so I can analyze my pressures and see the corresponding throttle percentage and usually when it's low I'm off the throttle.

I think that oil pressure info is good with the gauge you installed but may not completely tell you what is going on. What it will be good for is if you are in a long banked turn and can see it you can see where your pressure is at. Topless and Tstone are probably better resources than I but that is what I know......

[BYprodriver]

Originally Posted by steved0x

Quick question so I will bump this thread up - if somebody had an oil temp gauge installed, at what temp should they back off and/or come off the track? is there a safe(r) temp <= XYZ temp?

I just installed an oil temp and oil pressure gauge (pressure sensor replacing stock pressure switch and temp gauge in the matching port on the other side) - now that they are there, what do I do with them?

I have some ideas: like check the oil pressure after turn X on the straight, RPM is usually XYZ so see if the pressure is the same each lap at that point. Or check the temp at a certain spot and make sure it is at or below a certain value.

What is a dangerous temp?

Thanks

Steve

As to max oil temp, a major factor is condition of the oil.

[steved0x]

I am running DT40 (based on a conversation with Lake Speed Jr about the level and amount of my driving) and change it every 6 months which works out to about 2,500-3,000 miles. Uoa has been good with plenty of additive still left.

I don't have a data system but my phone app captures some, I am.going to mount it to get a view of the gauges and see how they behave when I'm driving.

I have an accusump but decided not to install it right away since I'm not doing Daytona this year like I thought.

Thanks for the guidance, so far the oil stays around 200, water temp at 180, I did an autocross Sunday and they went up some during my runs but came right back down.

Steve