Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
Few more oil questions

Hi people!

Weel,my compression check was done,and luckily all cylinders are ok,all seems perfect. Bad news it that i have to change turbo water pump and some wiper stuff (they dont stop at the bottom),but thatīs other topic (f***ing s**t,itīs all $850 both things!).

Yes SoCal,please forgive me but i just cannot do it myself

Well my question is,that piston ring are not the cause of oil consumption,because compression is ok,so....in the factory they told me that i shuld try to change my oil,they say itīs too low density.Iīm using a 5W40 synthetic,and they told me i should try a mineral 20W50 (of course,changing it more often)
Is that ok?they say that will reduce (i expect only a little) oil consumption.There is no problem with mineral oils in that cars?

Well thatīs all,oil consumption still not sure,but getting closer...thank you for your help!
__________________
---------------------------------------------
85ī5 951
Old 10-03-2003, 10:58 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Aug 2001
Location: Brighton UK since 11/2012
Posts: 3,170
Good compression readings don't mean that your rings are ok.
You need to have a leak down test done. It's probable that the valve stem seals are worn. These can be replaced with the head on the car.
__________________
From November 2012; Precision Porsche Specialist
Sussex UK, +44 (0)1825-721-205
2001-2012 Gerber Motorsport Inc. 206-352-6911
07.15.06 1996 Ducati 900SP. Suprisingly enough, it's red
08.16.09 1999 Kawasaki ZRX1100. Green.
Old 10-03-2003, 11:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
ae1969's Avatar
 
Join Date: Jul 2001
Location: Edmonton, Alberta, Canada
Posts: 4,530
Send a message via ICQ to ae1969
Quote:
Originally posted by Britwrench
............ It's probable that the valve stem seals are worn. These can be replaced with the head on the car.
I agree with this as I stated it in your first post with this problem....

You can get some serious oil consumption when they are excessively worn. The rubber gets so hard and brittle they crack. I replaced my crack ones with some oem ones............and me being the rookie that I am did not seat 4 of them properly..........once again massive oil consumption. Blue smoke out the back of the car. Killed a lot of mosquitos this way. I re-installed some new valve seals the right way.......no more oil consumption. I am talking half a liter a week. It can be quite severe.

but you still have the turbo to rule out.
__________________
Alex - PCA Polar Region - Boxster Muncher
86' 944 Turbo - Megasquirt - 326 rwhp/340lbft @ 18 psi SOLD
www.edmontonhomelife.com
www.edmontonrealestate.ws
Old 10-03-2003, 01:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
What is a leak down test and how is it done? Itīs simple and fast?

Do you think i will see a great improvement changing my oil as they told me?

If they are the valve seals,i think itīs not high priority,isnīt it? There is no real risk if i wait a few months to repair them...i say this because i actually have no money to do this big repairs...
__________________
---------------------------------------------
85ī5 951
Old 10-04-2003, 07:17 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Aug 2001
Location: Brighton UK since 11/2012
Posts: 3,170
For a leakdown test you need a leakdown tester; pull the spark plugs (engine at normal operating temperature) and crank th engine to #1 TDC (firing). The leakdown tester should then be connected (read the maker's instructions and make sure you have the correct inlet air pressure) and the guage indications read. Anymore than 12% leakage means something is worn; remove the oil filler cap and listen for air movement, this would be caused by worn rings. Air loss through the exhaust pipe is exh valves, through the inlet manifold is inlet valves and in the coolant expansion tank is head gasket. Do the same for the other three cylinders.

Please note that this is still not a definitive test, the general running condition of the engine is just as important. If the oil consumption is around the accepted use for a 944, up to 1000 miles per quart, then I wouldn't worry too much. If there are oil spots on the rear bumper after hard use then obviously you need to deal with it. Oil is cheap, engine repairs are not.
__________________
From November 2012; Precision Porsche Specialist
Sussex UK, +44 (0)1825-721-205
2001-2012 Gerber Motorsport Inc. 206-352-6911
07.15.06 1996 Ducati 900SP. Suprisingly enough, it's red
08.16.09 1999 Kawasaki ZRX1100. Green.
Old 10-04-2003, 08:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Sep 2002
Location: N. California
Posts: 341
No, no. no ! Use 15/50 Mobil 1 synthetic.

What kind of logic is that? The synthetic oil you're using is too thin so change to thick dino oil. Why? Whats wrong with a thicker synthetic?
__________________
1991 944 S2 (no more, sold it, gone to a good home)

2003 Infiniti G35 Coupe, 280hp, Black
Old 10-05-2003, 08:23 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Dec 2002
Location: Richmond, VA
Posts: 484
Changing to a "dino" oil isn't necessairly a bad thing from a lubrication stand point, unless of course you condider seals.

Oil seals react differently to synthetic oils than they do to "dino" oils, particularly in how the seals "set". By changing from a synthetic to a dino oil, or vice versa, you may be making the situation worse, and may even cause other seals (like the oil cooler seals) to start leaking.

As a first step you need to determine the source(s) of the oil consumption. Start off by replacing the spark plugs. Oil burning is a lot easier to diagnose with clean plugs.

Next, give the engine a good cleaning. Finding external leaks will be much easier. Finally, remove the throttle body and look for signs of oil.

The point here is, there are two O-rings that seal the Oil filler/Mist Seperator to the engine block. Over time these O-Rings get brittle and start to leak. Since the top of the Mist Seperator is routed to the intake boot, leaking O-Rings will allow an excessive amount of air flow through the Mist Seperator and on into the intake. This excessive air flow draws oil mist with it instead of allowing the mist to condense in the seperator, resulting in an increase in oil consumption.

For external leak sources, check the front main seal, oil pan gasket, oil cooler seal, rear cam housing seal, and rear main seal.

Before I forget, find another mechanic.
__________________
Cliff Hipsher
'87 944 India Red
'86 951 Kalahari Metallic
Old 10-05-2003, 09:58 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
Yes Mark,i also think your logic is ok,a thicker oil would do the job well.I only tell you what they told me at the factory....i also think itīs a very drastic solution.Iīm worrying of the seals and gasket,like you said they will suffer with such change.

I think the mobil1 you say is a good option,i will try it.When i changed my timing belt and front seals few time ago,they put me mobil 1,but i hink it was 5w40 like the BP iīm using now.The fact s,i noticed less oil consumption...when i started to refill with the BP,oil consumption started to increase again.And,do you know??a liter of mobil1 at the factory cost me about 22$....yes,about 120$ the oil change.Of course,iīm changing the oil myself,but the factory do it ourselves when i changed that things.

The BP synth cost me about 23$ 4 liter,i expect mobil 1 costs the same.

Other thing,where are the mist separator you mean?And what is it? (itīs a problem with english,not with me).I dont see the route of the mist separator to the throttle body,maybe because iīm not sure if iīm looking the right thing.
__________________
---------------------------------------------
85ī5 951
Old 10-05-2003, 11:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
MrPants's Avatar
 
Join Date: Mar 2003
Location: dfw, texas
Posts: 1,137
Quote:
Originally posted by Porsche944
The point here is, there are two O-rings that seal the Oil filler/Mist Seperator to the engine block. Over time these O-Rings get brittle and start to leak. Since the top of the Mist Seperator is routed to the intake boot, leaking O-Rings will allow an excessive amount of air flow through the Mist Seperator and on into the intake. This excessive air flow draws oil mist with it instead of allowing the mist to condense in the seperator, resulting in an increase in oil consumption.
im not familiar with this. what is the mist seperator? what does it do?
__________________
84 944 Non Alcoholic
Old 10-05-2003, 11:47 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
well iīm not alone in my ignorance..

One little thing...one quart per 1000 miles would be a miracle;at the factory (and the worshop manual also states the same) they say that about one quart per about 420 miles is acceptable.Assuming a quart is 1.05 liter,maybe iīm wrong.But for sure,1.5 liter per 1000 km (1.58 quarts per 621 miles) is accepted as normal.
__________________
---------------------------------------------
85ī5 951
Old 10-06-2003, 12:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered User
 
Join Date: Dec 2002
Location: Richmond, VA
Posts: 484
The Mist Seperator is incorporated into the oil filler "neck". The Oil Filler/Mist Seperator is connected to the engine block at a high and a low point via O-ringed seals.

If you look at the oil filler from the side you will see it is in the shape of a 'V'. There is a hose connected to one side of the 'V' under the intake manifold. This hose runs over to the intake boot.

While the engine is running, oil vapors collect in the Mist Seperator where they are allowed to condnese and flow into the oil pan. Any vapors that do not condnese along with blow-by gasses from the cylinders are drawn out the top of the Mist Seperator and into the intake plumbing.

Here is another tip: Check the O-Ring in the Oil Filler Cap, and the seal for the dip-stick tube. Leaks here will cause increased oil consumption as well as being souces for vacuum leaks.
__________________
Cliff Hipsher
'87 944 India Red
'86 951 Kalahari Metallic
Old 10-06-2003, 04:57 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
Oil filler....you mean the pipe where you refill the oil,isnīt it? Iīve never suspected thereīs anything mora complicated than a pipe there.

Now i donīt have the car,is at the factory,when they finish it i will take a look,and the dipstick too,but seems that it closes well.

One thing is sure,there are practically no leaks,i changed front seals and now there is only a pair of drops in days,and i expect they dissapear when i switch to a ticker oil.
__________________
---------------------------------------------
85ī5 951
Old 10-06-2003, 10:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Registered User
 
Join Date: Dec 2002
Location: Richmond, VA
Posts: 484
This area is typically overlooked because it is difficult to see the O-Rings unless you remove the intake manifold.

As far as oil leaks go, the lower seal will leak more oil than the upper because the lower seal is on the out let side of the mist seperator.

Seeing the actual leak is difficult because there is a small "shelf" right below the port where the out let tube enters the lower block. This "shelf" will trap the leak (remember the block sits at an angle). Add some road grime and you get a nice build up of "crud" that does not flow.

On the other hand, leaking O-Rings will manifest themselves as a vacuum leak. What happens is the air that gets drawn past the leaking O-Rings is entering the intake plumbing DOWN STREAM of the Air Flow Sensor. Since this air is not being measured by the Air Flow Meter, the fuel/air mixture will be lean.

This is not as much of a problem with Oxygen Sensor equipped U.S. specification cars as it is with European Specification cars without an Oxygen Sensor, but it is a problem none the less.
__________________
Cliff Hipsher
'87 944 India Red
'86 951 Kalahari Metallic
Old 10-07-2003, 04:35 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
That crud you mean would be visible in the shelf you say,may be if i remove the shelf i can see it.

Euro cars donīt have O2 sensor?Itīs worse the problem in my euro car?
__________________
---------------------------------------------
85ī5 951
Old 10-07-2003, 10:23 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Dec 2002
Location: Richmond, VA
Posts: 484
The "shelf" I was referring to is part of the block casting and cannot be removed.

Yes, a vacuum leak is "worse" for a Eupopean specification engine. Because there is no exhaust parameter feed back to the DME you need to be a little more attentive to how the engine is running.

However, because you do not have O2 sensor "masking," diagnosing fuel/air mixture problems is actually easier.
__________________
Cliff Hipsher
'87 944 India Red
'86 951 Kalahari Metallic
Old 10-08-2003, 04:32 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
Thank you Cliff...the engine runs good (i think)...if itīs not ok,i suppose they will told me at the factory when they finished it....the last time they noticed few things,but nothing with the engine.
__________________
---------------------------------------------
85ī5 951
Old 10-08-2003, 10:21 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Sep 2002
Location: N. California
Posts: 341
What factory do you mean? Surely not the Porsche factory? Or do you mean the porsche dealer?

1.5L per 1000km still sounds high to me - I'm used to the same every 5000km. But engines vary, and I guess if the engine is otherwise running OK and the only way to reduce consumption is an expensive rebuild then you'll just live with it. Does yours smoke, or leak? Yes try the 15/50 it might help.

Mark
__________________
1991 944 S2 (no more, sold it, gone to a good home)

2003 Infiniti G35 Coupe, 280hp, Black
Old 10-08-2003, 10:31 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered User
 
Manute's Avatar
 
Join Date: Aug 2003
Location: Madrid,Spain
Posts: 728
Yes Mark,i mean the officcial Porsche worshop in my city,and they have a lot of experience.But if you donīt believe them,just see the owners and the worshop manual....i have mineīs and 87 oneīs....on my owners manual,oil consumption is 1 liter per 1000 km,but in worshop manual,oil consumption is 1.5 liter per 1000 km..it says this literally. A year later,87, ownerīs manual says oil consumption is one more time 1.5 liter....Maybe they realized the oil consumption was very high.

Also check that year by year (practically),oil capacity have been increased....mineīs 6.5 liter,a year later was a liter more...

As you say,as engine looks good,and i donīt leak and smoke not much,because itīs nothing catastrophic,i will live with it...itīs annoying to refill often,but i have no problem to do it.
__________________
---------------------------------------------
85ī5 951
Old 10-08-2003, 10:42 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 01:25 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.