Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recurrent intermix, any ideas?


Recommended Posts

99 C2 with prior cracked heads. Removed heads, had them repaired. Car ran great until recently noted recurrent coolant emulsification in the oil. This time only have coolant in oil and no oil in coolant (perfectly clean). Preparing to drop engine again and look for recurrent head cracks. Any ideas? Had new oil cooler put in by indy before figuring out the real problem myself with the help of Dharn55.

Link to comment
Share on other sites

+1 to above, do you mean what's on the underside your filler cap?

I've seen a little of this in my AOS and also on the oil filler cap, but it's not coolant (as proved by UOA). Best way to clear that out are some "spirited drives".

Did you have the oil tested (i.e. blackstone) to see if there really is coolant in it? (before pulling the heads again).

Link to comment
Share on other sites

Did you have a reputable shop repair the heads? From what I understand they need to cut out a pretty big piece and start repairing from the inside out. They cant just weld the superficial crack. At least that is my understanding.

I am definately no expert, but there shold not be coolant in oil without oil in coolant. Reason is that the oil pressure is higher than coolant pressure. Of course, when the crack is big enough there will be intermix, but that is intermix both ways.

However, coolant pressure should be higher than oil pressure when engine is turned off hot, but you should still have oil in coolant.

Even though it does sound unlikely that you should have another non-related problem at the same time, I should at least check for other reasons before I pull the engine again.

Thanks,

Johan

Link to comment
Share on other sites

  • 2 weeks later...

Thanks for replies, definitely have coolant in oil. Kept losing coolant (warning light flashing). And when I drained oil it was clearly badly contaminated. I agree dont quite get why no oil in coolant. Gonna pull heads and have them repaired. also will throw in a new oil cooler for good measure. Thankfully its winter in Texas and good work time in my garage.

Link to comment
Share on other sites

You could have a crack in the cylinder liner that opens up when the chamber gets hot

and coolant enters the chamber and some gets burned off -- but when car sits, coolant leaks back into

chamber -- then down cylinder walls into the oil.

Do you have any misfires?

Any coolant in the cylinders or evidence on plugs?

If you do have this scenario -- you really don't want to be driving it as this is the start of the infamous d-chunk failure.

Mike

Link to comment
Share on other sites

You can also boroscope the cylinders per MIke's comment to inspect and read what you're in for before going to far into a repair... definitely pull the plugs and read those too. Would be a lot of money wasted to pull the heads if they don't need repairing, only to find the case has been compromised... in which case it's big decision time on what to do next.

Link to comment
Share on other sites

To give you an idea -- my partner had a customer with a 04 996 that would misfire at start-up but then run fine.

It was a cracked liner --- maybe 1" in length, but deep enough (or wide enough) to catch your finger nail.

The owner had the cylinder boroscoped and saw the coolant, but never saw the crack.

We didn't boroscope that one, but found the crack upon disassembly.

Customer chose to bore out to 3.8 using LN Engineerings Nickies.

Wasn't cheap.

Mike

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.