Alan

When fully warmed up you shoud indeed be pegged at 5 bar above say 3K' ish RPM this is quite normal.

But I don't think it should be that high down to as low as 2K RPM (hot). It varies depending on oil choice & temp of course

At idle you should typically see ~2 bar or even less if the ambient temp is very high.

BTW many GTS owners would rejoice if they had your results - not try to change them... its a lttle unusual at your mileage - but may be a good thing if there are no anomalies.. have you recently changed anything else (e.g. rod bearings?).

What has been the ambient temp when you did these measurements - that can affect actual oil temp when "warmed up" quite a bit... Also test the oil thermostat diverter for the cooler - if the oil cooler always flows you won'' get the oil to "normal" temp at cold ambients.

Alan

worf928

Nevermind what I wrote above about the OP sender. I doubt there's anything wrong with the measurement end of this problem.

Engine breaking is going to exacerbate any intake oil ingestion. I would place my bet on intake ingestion before vavle seals. Furthermore, since these characteristics began immediately after installation of the ProVent along with other bits to plumb it, Occam's razor suggests that something is not right with the install (along the lines of increasing crank case pressure rather than reducing it.)

James Bailey

The blow off is at about 8 bar where the relief bypass opens. Excessive presssure might rupture the oil cooler or the oil filter.
As noted GTS higher oil consumption is not unusual. The short skirted pistons and lack off oil ring drain holes plus high RPM filling of the heads with oil......all add to oiling issues including blow by and smoking on deceleration.

Randy V

Nothing new to add (but I think Fred's saved post that he shared may have been directed to me many years ago) but this may help you in responding to multiple posters:

https://rennlist.com/forums/rennlist...-function.html

uraniummetallurgist

Hi Alan:
Thanks for the feedback. I guess the oil consumption increase over time has me a bit concerned more than the quantity. As far as ambient temperature we have yet to approach anything approaching considered spring-like in AZ1 Temps remain in the +/- 34 - 45F range here although my static (parked) measurements were in the garage at a balmy +/- 60.

I will do the "manual temp check" and feel the oil cooler to see if it the diverter is always on.

All the best,


Joe

uraniummetallurgist

Thanks for the post and comments. I will check the install again but the ProVent is running dry although there could be something amiss with the associated plumbing.

All the best,


Joe

James Bailey

The external air to oil coolers 1990 > no longer have a thermostat diverter....they feed full flow to the cooler all the time. The heat exchanger style in the radiator tank NEEDED that diverter to keep pressures down to reduce the possibilty of the cooler leaking and it not being noticed. When you blow the external cooler you KNOW something is wrong

uraniummetallurgist

Hi James:
Thanks for the post and comments on the GTS idiosyncratic piston design. i am scheduled for a visit to the shop in early April for a look inside to see if there is anything obvious.

All the best,



Joe

uraniummetallurgist

Thanks James!

uraniummetallurgist

Hi Randy! I should have read your link first!

Alan

Jim - you sure about that...?

Just that I'm pretty sure mine was replaced (...and wasn't MIA at the time).

Plus - doesn't it still see ~the same pressure anyway - just no flow...

Or maybe I'm just dreaming of something else...

Alan

James Bailey

The later blocks they eliminated the extra oil bypass which at about .5 bar opens up for oil flow when the thermostat was closed. Not sure how it would work right without that bypass......

FredR

It would be a pretty dumb design if it had a pressure indicator that pegged at lower than the operating pressure. The visual pressure indicator on the dash tells you that the relief valve is lifting OK. If it pegged at 5 barg and operated above that you would simply not know what was going on.
The only explanation I could offer for this would be if there was a flow dynamic between the pump and the sensor location creating a pressure drop relative to flow but I doubt it.

Fred

Bill Ball

I don't think these pressures are out of line. Once warmed up my idle pressure varies from 1.5 to 2+ bar depending on exactly how hot the motor gets and has always hit 5 bar by about 2200 RPM. Oil consumption has always been negligible unless I cruise at 160+ MPH for extended periods. Approaching 253K miles with the motor internals untouched.