Hello everyone. Just had a 2nd track day at Laguna Seca yesterday and had oil leak on a couple places. Some of which was covered already on this forum, however I could not find one that had all the same leaking area.
Details of the car:
1995 BMW M3
98k miles
RMS Vortech V2 Supercharger kit running 6psi of boost
Euro Oil cooler with flexable aftermarket lines
Headgasket change done at 97k miles with stock OEM headgasket with ARP head studs
leatherz gauge kit with oil pressure (stayed at 60psi on track), oil temp (which stayed under 200F), and water temp (never went past 190F).
Track day:
First 2 session of the day the car ran perfectly fine. However on the 3rd session i was black flagged due to some oil burning underneath the car. Came into the pits and found what seemed like oil was leaking from the valve cover gasket, the valve cover breather line/connection area, oil filler cap, and oil dipstick tube where it connects to the oil pan that was burning on the exhaust.
Things i noticed:
On the supercharger kit, i noticed that RMS connected the crank case breather hose straight to the intake tube before the supercharger without any type of one way valve. How the routing was, air filter, than HFM, then low pressure intake tube to supercharger ( where the crank case vent hose connects to as well as the bypass valve connects to) then supercharger, then RMS liquid aftercooler (where the bypass valve is connected to as well), to throttle body. the supercharger oil feeds from the oil filter housing, then to supercharger, then it drains back to the dipstick tube (which RMS modified to put a drain connection on it).
When i did the headgasket:
I changed everything from orings to gaskets. This includes valve cover gaskets, cam sensor oring, dipstick oring, intake gaskets, head gasket, vanos and vanos gasket, vanos solenoid oring and oil feed crush washer, oil filter housing gasket, oil filter cap oring.
Also there was no visible wear marks on each of the cylinder walls and each of the piston head looks clean with normal carbon build up. Still see the original hone marks on the cylinder walls.
Question:
Seeing out it was leaking in multiple areas, is it possible that the crank case if being over pressurized?
Since the car does not have a oil catch can, would the installation of one would help this is a over pressure issue? also, would venting it to atmosphere better or should i vent it back into the low pressure intake tube to supercharger?
Since this car is a OBD1, I did not notice any check valve on the valve cover breather hose area. PN#11151730407. Would adding one help this situation?
Is it possible for the charge air be circulating back from the bypass hose on the lower pressure intake tube back into the valve cover breather hose that is connected to it?
Sorry for the long Post, any help would be appreciated. thanks!
Not possible but it is. All engines have blowby and the higher the combustion pressure, the more of it you get. The PCV system is designed for 240hp. So you'll definitely want to figure out proper crank venting and how is up to you. Chugging the shit back into the intake is environmentally friendly but not engine friendly. Catch can is easy and clean, you just have the added maintenance of checking/emptying it. The bigger the vent, the better and try to route your breather line with a minimum negative slope, only positive if possible, to prevent a toilet trap and so that any residual oil in the line drains back into the engine. This is easiest with these ARE catch cans that have the inlet at the top (with a typical catch can the vertical positioning is limited by the breather filter on top).
https://drysump.com/index.php/oil-ta...cans/vent-cans
If i do end up routing the return line back into the low pressure intake tube (before supercharger) do u recommend putting a check valve between the catch can and the LPT?
Sounds like excess crankcase pressure.
I run a catch can vented to the atmosphere, and also this oil cap:
https://www.ecstuning.com/b-vargas-t...FQf_4wcdeHABBA
"Be who you are and say what you feel because those who mind don't matter and those who matter don't mind."
-Dr. Seuss
DIY BMW Tools. Charlie For President
That and the mess it will make on the top of the engine from the oil vapor.
"Be who you are and say what you feel because those who mind don't matter and those who matter don't mind."
-Dr. Seuss
DIY BMW Tools. Charlie For President
isnt there a VW part that has an oil separator and breather port built in?
edit: this thing
https://www.idparts.com/oil-capccv-b...er-p-1188.html
just want to update anyone who came across this thread...
I installed a oil catch can due to supercharger getting too much oil on the intake and charge tube, and 1/4 of a 6oz catch can filled up after a 20 min drive.
Feared the rings could be bad so did wet and dry compression
dry:
Cyl (psi)
1) 152
2) 152
3) 162
4) 151
5) 156
6) 75
wet:
1) 230
2) 230
3) 200
4) 240
5) 197
6) 152
Will do a leak down test to further narrow it down to whether its the head or the block. But seeing how I have that much pressure in the crank case, most likely the rings are gone.
Edit:
When doing a leak down test, since its on cylinder #6, do we need the flywheel locking tool to make sure the crank doesnt move or should it be ok without it? Just wondering with the added air would it rotate the crank on its own. thanks
Last edited by EURO M3 CSL; 09-07-2019 at 03:13 AM.
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