832ark Posted April 2 Report Share Posted April 2 (edited) Rather alarmingly I’ve found metallic flakes and a tiny sharp chunk (approx 1mm) in my oil drain pan during routine change. I’ve done an autopsy on the filter and found only four barely visible particles which ordinarily wouldn’t worry me on a 98k mile engine. None of the pieces are magnetic and the flakes are microscopically thin, they almost dissolve when you touch them. My first thought was a main or big end bearing but what’s weird is that none of this stuff seems to be being circulated through the oil system which I’d expect in that situation. My next thought is IMS but my engine number seems to have the later larger IMS fitted (although how accurate are the reported engine numbers?) Mine’s 62507154 for reference. Finally, the car runs perfectly, no knocks, bangs, smoke etc. Had a normal spirited drive at the weekend and was performing as normal. Something’s clearly very unhappy, just hoping the damage has been minimised from the POV of getting it rebuilt. Going to get the oil analysis done and see if that can identify the metal. Any suggestions? Edited April 2 by 832ark 1 Quote Link to comment Share on other sites More sharing options...
Nobbie Posted April 2 Report Share Posted April 2 Possibly a bearing shell on the way out? The oil analysis should give you a better idea. Are you sending it to Millers? 1 Quote Link to comment Share on other sites More sharing options...
bally4563 Posted April 2 Report Share Posted April 2 Am I reading this correctly ? The engine has already been rebuilt? If so how did it fail and more so is what you are seeing the fact it was possibly not really flushed if so no worries, may consider doing a oil flush treatment? Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 6 hours ago, bally4563 said: Am I reading this correctly ? The engine has already been rebuilt? If so how did it fail and more so is what you are seeing the fact it was possibly not really flushed if so no worries, may consider doing a oil flush treatment? No, no rebuild. Looks like it needs one Quote Link to comment Share on other sites More sharing options...
ATM Posted April 3 Report Share Posted April 3 Total novice here so just curious.... Would big end / main bearings be magnetic? What could these be if none metallic - piece from a gasket like rocker cover piece of a valve / follower / cam stuff piece of the chain guide type stuff Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 1 hour ago, ATM said: Total novice here so just curious.... Would big end / main bearings be magnetic? What could these be if none metallic - piece from a gasket like rocker cover piece of a valve / follower / cam stuff piece of the chain guide type stuff I’m no expert either but I think main/big end bearings won’t be magnetic whereas IMS will be. Quote Link to comment Share on other sites More sharing options...
Nobbie Posted April 3 Report Share Posted April 3 8 minutes ago, 832ark said: I’m no expert either but I think main/big end bearings won’t be magnetic whereas IMS will be. The bearing shells are usually an aluminium alloy with things like copper and bronze in so the oil analysis can pinpoint where the issue is coming from. I think Miller gives a fault finding guide. Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 46 minutes ago, Nobbie said: The bearing shells are usually an aluminium alloy with things like copper and bronze in so the oil analysis can pinpoint where the issue is coming from. I think Miller gives a fault finding guide. I’ve ordered a sample kit from Miller which should tell me more. It does look to me like the surface white metal of a crank bearing. I’m guessing it’s probably a big end that’s started to break down. Hopefully I’ve caught it before it does serious damage to the crank etc. Are Hartech the go-to people these days or are there others I should talk to? Quote Link to comment Share on other sites More sharing options...
phazed Posted April 3 Report Share Posted April 3 I’m sure I read last year on an American site that it was something to do with guides/tensioners. The consensus of opinion was not to worry too much about it, (either that, or I have a selective memory). Just to add that my 121K miles 986S had practically identical deposits, just three when I drained the oil when I first got in the car. I have now fitted a magnetic sump plug for the future, (which I usually do to all my cars) and I’m not going to worry about it. I am going to track the car and luckily with my memory I will have forgotten about it in a short time and will enjoy it for what it is until possibly that Big Bang day! If so that might be the time for an engine upgrade. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 3 Report Share Posted April 3 Re engine numbers and IMSBs, I spent a lot of time gathering the data for the write up in the Technical section and they are from Porsche documents, either parts catalogues, service documents or Technical bulletins. I have no reason to believe they are not correct. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 3 Report Share Posted April 3 28 minutes ago, 832ark said: I’ve ordered a sample kit from Miller which should tell me more. It does look to me like the surface white metal of a crank bearing. I’m guessing it’s probably a big end that’s started to break down. Hopefully I’ve caught it before it does serious damage to the crank etc. Are Hartech the go-to people these days or are there others I should talk to? Hartech's reputation is solid, unlike your bank balance once you have been there. For a full rebuild there are none better, for bottom end bearings only there may be more cost effective options. 1 Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted April 3 Report Share Posted April 3 1 hour ago, phazed said: I’m sure I read last year on an American site that it was something to do with guides/tensioners. I also remember such comments. And I think despite them being shiny, some flakes turn out to be plastic rather than metal. Helps narrow down what they came from. Good luck with it. 1 Quote Link to comment Share on other sites More sharing options...
nelmo Posted April 3 Report Share Posted April 3 Doesn't look like anything to worry about IMO. I had the big end shells go in a 4-cylinder Ford engine and it made a very obvious rattle - I'm sure our engines would do the same in that situation. Quote Link to comment Share on other sites More sharing options...
phazed Posted April 3 Report Share Posted April 3 Regarding the start up rattle. My engine was drained from oil and left standing for four months. I filled the oil filter and started it up with fresh oil and it regained oil pressure immediately without a hint of a rattle, which I took as being very positive. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 3 Report Share Posted April 3 The cam chains and hydraulic lifters can rattle very briefly on start up as oil pressure rises. Any ongoing rattling that is much more than instantaneous is more of a problem. Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 2 hours ago, ½cwt said: Re engine numbers and IMSBs, I spent a lot of time gathering the data for the write up in the Technical section and they are from Porsche documents, either parts catalogues, service documents or Technical bulletins. I have no reason to believe they are not correct. Thanks, I’m pretty confident then that my car has the larger IMS bearing. Also with these being non magnetic I’m inclined to think it’s something else. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 3 Report Share Posted April 3 1 hour ago, nelmo said: Doesn't look like anything to worry about IMO. I had the big end shells go in a 4-cylinder Ford engine and it made a very obvious rattle - I'm sure our engines would do the same in that situation. Likewise on a Subaru flat 4, it was knocking before silver was detected in the oil. (Those Scooby engines are pretty bulletproof but this one had been well abused by a rally team as a receptionist car before I bought it cheap and ran it for 4 years...) Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 1 hour ago, nelmo said: Doesn't look like anything to worry about IMO. I had the big end shells go in a 4-cylinder Ford engine and it made a very obvious rattle - I'm sure our engines would do the same in that situation. The thing is, last time I dropped the oil 2.5k miles ago there was nothing in it. I’m wondering if I’ve just caught it early before the knock starts. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 3 Report Share Posted April 3 A bearing shell sheds incredibly fine white metal, not grains. The oil from my Scooby looked more like mercury so it is a very fine paste almost. The oil test will tell you much more about possible sources. Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 36 minutes ago, ½cwt said: A bearing shell sheds incredibly fine white metal, not grains. The oil from my Scooby looked more like mercury so it is a very fine paste almost. The oil test will tell you much more about possible sources. I spoke with AMS who said once a big end starts breaking up things get bad pretty quickly, so unlikely. Could be a main though. Quote Link to comment Share on other sites More sharing options...
phazed Posted April 3 Report Share Posted April 3 Out of interest, the three little flakes I found were not in the oil filter, but lying in the bottom of the sump which came to light when I removed the sump to change it. Quote Link to comment Share on other sites More sharing options...
bally4563 Posted April 3 Report Share Posted April 3 I reckon it’s an additive the fact it basically rubs away .. I hope so for you from my arm chair diagnosis Quote Link to comment Share on other sites More sharing options...
832ark Posted April 3 Author Report Share Posted April 3 1 hour ago, bally4563 said: I reckon it’s an additive the fact it basically rubs away .. I hope so for you from my arm chair diagnosis That’s interesting, if you rub it it basically dissolves to nothing although I did find one tiny sharp piece. Quote Link to comment Share on other sites More sharing options...
bally4563 Posted April 3 Report Share Posted April 3 15 minutes ago, 832ark said: That’s interesting, if you rub it it basically dissolves to nothing although I did find one tiny sharp piece. Just saying if it was a con rod bearing or crank bearing, I would not expect to see slivers of material more sparkling dust , and the fact it rubs away between your fingers , hopefully if I’m right you owe me a large drink !! 1 Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted April 3 Report Share Posted April 3 (edited) If you're right he'll probably sit down for a large drink himself. What makes you think additive? Do they have certain ingredients which congeal? Edited April 3 by Menoporsche 1 Quote Link to comment Share on other sites More sharing options...
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