I just had Kevin's check valve kit installed on my 97tt and have some questions regarding oil levels and filters.

When one of the oil filters fails what exactly does that mean. I've read you could see smoke on start up indicating a potential oil filter failure. Does that mean the oil is no longer getting filtered and is somehow bypassing the filter. From what I understand when the filter fails oil can migrate to the turbos and consequently cause blue smoke on start up, but with the check valves installed that shouldn't happen. If that's correct, how would I now know if my oil filter has failed?

If I run my oil level right at the bottom mark I don't get any smoke. However, if I fill it anywhere above the 1/3 mark I'll see smoke sporadically on start up. With the check valves installed, can I now run the oil 1/2 to 3/4 or to the top mark on the dipstick and feel confident I won't flood the turbos with oil.

My install was a bit of an issue. The LH turbo had been rebuilt by the PO and I guess when they put it back together the hot/cold side alignment was off a bit. Because of this the check valve needed to be ground down to fit. When I got the car home tonight, with the engine running I could see oil around the brass feed end that connects to the chain housing console. Back to the shop to get that sorted. Hopefully I'll have the car back for the weekend.

One last question, my kit has a 90 on one end of the lines and the shop put that on the check valve end. Is that correct, or is it suppose to be on the feed end, or does it really matter?

Thanks,

 

Scott,

I'm by no means an expert, but that has never stopped me from expressing myself.

Porsche OEM oil filters have a check valve to prevent oil from seeping back into the turbos. The Mahle and Mann and others (I suspect) do NOT have this valve. An oil filter failure would mean that oil has seeped back into the turbo... oil filtration itself is unaffected. Adding the aftermarket check valves is insurance to prevent any possibility of oil seeping back into the turbos. I typically run my oil level at the midpoint or (gasp) even above. I never have any smoking problems.

I can't answer your other questions.

 

Hi Steve,

Thanks for the reply. I didn't think the oil was bypassing the filter, but I didn't really understand what "Failed" meant. I just read the post from ECS Tuning examining the three filters for our cars. It was very enlightening as to the differences between them and also helped shed light on what fails on the filter.

Scott.

 

Internet forum words to live by!

Also make sure you are checking your oil level with the car on a level surface, while it is running and at full operating temperature. With all of the oil cooling I have I need to put a towel over the intercooler to help get up to temp.

 

You should need to grind the check valve. The bolt in the compressor housing can be clearanced if the clocking of the housing is not ideal.

The check valves have nothing to do with the oil filter bypass issue. The check valves STOP the back feed of oil from the hydraulic lifters and migration from oil from the cam housings to the turbochargers when the engine is off.

Why would you want to increase the oil level and put more strain on the oil filter bypass valve???? Your engine clearly runs better when the oil is towards the low level. Keep it there.. All the smoke is going into your CATS.. What about the harm done plugging your cats? I would be more worried about that vs the oil level.

 

Thanks Kevin. I'll keep it near the bottom mark as I have been, but was wondering if I should fill it normally now and just monitor it by the gauge. Not a big deal, just more convenient.

I think the mechanic used the word "clocking" as well in his explanation of why the valve needed to be ground. As I mentioned before, that turbo was rebuilt by the PO so that could explain the clearance issue. They're in now and the leak issue on the other end has been resolved. I’m looking forward to being back on the road tomorrow.

 

Scott I just ordered Kevin's Check Valve Kit too.

Just curious did you replace any other misc items (turbo o-rings etc) along with the kit install?

 

No. I just had the check valves put in.

When I bought the car there was a small clutch shudder that is getting considerably worse. My guess is the rear main seal, but bottom line, I'll be pulling the engine in the next few months and will do several of the "what other things to do when the engine is out" stuff and that may include rebuilding the turbos.

 

before you start rebuilding the turbos I suggest that you just use my modified P-trap return lines.
You will realize that all the oil leak issues around the turbocharger will dissappear.
( There are a few forum messages of members who continued to having leak problems even after a rebuild of the turbos. Probably their turbos were not defective before and the reason is simply the backflow of oil through the turbo scavenge pump from the engine once the engine is shut off)

http://www.zweisteintrading.eu/993_turbo_oil_lines.htm
As a side effect you can also fill up your oil level to maximum again without any issues. This helps oiling and cooling of the engine, especially on the track where you should never go with the oil level at minimum.

Best regards
Andreas

 

You should pay to become a business sponsor if you want to sell commercial products on Rennlist.

 

I am not a commecial product seller. This is a small batch done for myself and some friends enthusiasts. I do live from something else than carparts selling. If some comercial guy wants to take over he can contact me.

This forum is really an unfriendly place. Seems that the only guys hanging around are desperately hoping to making business and if someone else comes up the gang tries to bash out the new guy!

As my background I am a research scientist in physics, so for me it was a pleasure to engineer a solution. I did this a hobby. It really works well and as a 993 turbo owner and enthusiast I offer the few items I have to other enthusiasts. End of the story


Andreas