16 replies to this topic

[Alberto]

This can't be good....

 

Decided to change all the fluids on the car.  Using Redline throughout.  Last time I changed my engine oil, I used 2 quarts of Redline 40 and 2 of 30 weight Race oil.  I use a magnetic oil drain plug on my Miata (and other cars too).  If anyone is curious, I got the magnetic drain plug from Dimple Magnetic Oil Drain Plugs.  I actually worked with him 3 years ago to develop the fitment for the Miata, RX7 and Mini Cooper since I own all of them.  He's a veteran owned business and makes his products in the US.  Hope it's Ok to mention that.  I like to support veterans and US businesses.

 

 

Back on topic, I found these metal chunks attached to the magnetic oil drain plug.  The motor was feeling really strong at the last race at Laguna.  I remember thinking of a quote I read on here throughout the weekend - "The motor always feels the strongest right before it goes".  Further complicating the weekend, I made a mistake (early turn-in) at the entry to T4 and hit the inside tire wall causing some minor body damage and screwing up the alignment.  not sure if there is any relationship to seeing these chunks in the oil but figured it couldn't hurt to mention it.

 

 

Anyone have any thoughts on what these chunks are from?  I suspect it would be wise to change the motor before the next event but I really don't feel like it...  Wasn't in the budget either... 

 

[Bench Racer]

Measure thickness and compare to baffle and oil pickup strainer bracket.

[Alberto]

I poured the oil through a tea strainer (don't tell my wife) into an open container so I could look for silt and other debris.  Found nothing beyond the 2 metal shards you can see in the pic above.  The two shards feel rough like iron or pitted steel..  They are pretty thin too.  Also ran a magnet through the oil.  Nothing sticking.

 

Not sure whether to try and drop the subframe to pull the oil pan and see if I can see anything there or pull the motor out...  Thoughts?

 

 

 

If I didn't have that magnetic drain plug, I would have never seen this....  Maybe I should pretend I didn't see it but don't want to break down on track.

[DES4]

Casting flash? But the next obvious question would be "from what?"

 

The whole "engine running stronger just before it lets go" thing might be attributable to an over-lean condition making a few more horsepower while raising combustion temperatures to a point that damages the engine. Or so I have thought. 

[Bench Racer]

Do you have another oil pan to look inside, IIRC, there are some cast ribs inside the oil pan. Parts in your picture look pretty thin, but ya never kow.

[marcusmazza]

I would recommend cutting open the oil filter and making sure there isn't any metal in there. Also, it doesn't take long to pop off the valve cover and oil pan in order to take a look inside. 

 

-Marc

[Dan Tiley]

I'm with Dave on this one.... Looks like casting flash from the block.  These iron blocks have several thin sections where molten iron seeps into the seams in the casting molds.  With the extreme heat cycles that we put them through, it's not all that surprising that these may crack off once in a while and fall into the oil pan.  Good news is that chunks like this will never make it through the pickup screen, so it's not likely that they'd do any damage.  That being said, I'm always a big fan of cutting oil filters anyway.  It's a great indicator of when things are going south... particularly for bearings.  I cut every filter that comes off my engines, as do many of my customers.  

[marcusmazza]

Dan,

 

While on the subject of cutting open oil filters, what do you typically see as far as metal content in the filters for a normal spec miata engine. The reason I ask is I only started cutting my filters open a few oil changes ago, so I don't really have a reference point. There are some small metal pieces (almost look like shavings) present. They are smaller than a milimeter in diameter. I would say on average, I see one or two of these pieces per pleet. They are all magnetic, so I'm pretty sure it's not bearing material. The oil analysis I had run by Blackstone looked pretty good.

 

-Marc

[davew]

It does not look like casting flash to me. Too uniform in shape. But it is definately not from the head, pistons, valve cover or oil pan, They are all aluminum and non magnetic. But Dan looks at the internals of a lot more engines than I do.

 

I agree with Dan, cut the oil filter apart.

 

Dave

[Bench Racer]

 But it is definately not from the head, pistons, valve cover or oil pan, They are all aluminum and non magnetic.

 

 

Dave

  Can I get by with a "well intended".

[Dan Tiley]

Dan,

 

While on the subject of cutting open oil filters, what do you typically see as far as metal content in the filters for a normal spec miata engine. The reason I ask is I only started cutting my filters open a few oil changes ago, so I don't really have a reference point. There are some small metal pieces (almost look like shavings) present. They are smaller than a milimeter in diameter. I would say on average, I see one or two of these pieces per pleet. They are all magnetic, so I'm pretty sure it's not bearing material. The oil analysis I had run by Blackstone looked pretty good.

 

-Marc

 

I generally find nothing.... Once in a while you may find just tiny stray piece of metal that was lodged in a corner somewhere when the block was cleaned, but I'm talking just 1 or 2 total.  Seeing 1 or 2 per pleat (of which there are probably 50-100), is not encouraging.  Hard to say without seeing anything, but one possibility would be excessively worn thrust bearings.  This would cause the the crank to move fore-aft more than it's designed to do, allowing for the connecting rods to grind away at the sides of the crank journals, as well as the crank itself wearing into main caps.  If you want to send me some photos I'd be happy to investigate a little more.  (email: dan@tispeedengineering.com)

 

You can check the crank thrust travel with a dial indicator.  Loosen the alternator belt, and push the harmonic balancer into and out of (fore-aft) the engine.  More than 0.010" would indicate excessive wear.  I'm not sure you'll actually be able to do this in the car with the trans bolted up.... only one way to find out!  I've only done it with the engine on the stand. 

[marcusmazza]

Dan,

 

I may have been overstating the number of pieces. Seemed more like 30 or so in total. Still not good. I'll take some pics and e-mail to you (probably late in the week until I get to it). I'll also check the play in the crank. Thanks for the help. It is much appreciated.

 

-Marc

[Alberto]

Thanks for the input.  Tried to take better pics and a video of the parts.  All I had was my Iphone so sorry if it's not the best.  I suck at taking pics and vids so it would probably look just as crappy with a better cam...

 

I wouldn't call this a "smooth" break as the edges are a bit jagged and uneven.

 

I'm going to cut open the oil filter this evening using some tin snips.  I'll post pics later.

 

Thanks for the input.

 

 

http://youtu.be/iyD0FQLfV1E

 

 

[Alberto]

cut open the Wix oil filter.  bunch of oil came out.  never did this before.

 

there were no other chunks of metal.  however, looks like there is some sparkly shit in there doesn't it?

 

 

[Dan Tiley]

I'm still thinking internal casting flash from the block for the iron "chunks".  No big deal.  The "sparkly crap" looks like bearing material from aftermarket bearings.  Stock Mazda bearings leave aluminum flakes in your filter when they come apart, but some of the aftermarket bearings leave more of a metallic "dust" when things go south with them..... Aftermarket bearings are legal now, by the way, and are generally preferred over the Mazda parts.  Is this an original engine or a rebuild?

 

What really concerns me is the packed material at the ends of the paper element.  Hard to tell from the picture, but is that just glue for the element to the endcaps, or is it bearing material that has collected?  Does it come apart easily when touched with a screwdriver?  I've never cut a WIX filter, so I'm not sure of their construction.

[Alberto]

I pulled the motor out of a 91 with body damage the pax front.  The motor leaked oil like a sieve until I fixed the seals while doing a timing belt but the last Blackstone report was good.  So I assume the internals are OEM.

 

The packed material at the ends of the paper element is glue.  Pretty good glue too.  Doesn't come apart easily at all.  It was a pita to take the filter apart. 

 

So just add some oil and run it, Dan?

 

Thanks for the great input.

[Dan Tiley]

I pulled the motor out of a 91 with body damage the pax front.  The motor leaked oil like a sieve until I fixed the seals while doing a timing belt but the last Blackstone report was good.  So I assume the internals are OEM.

 

The packed material at the ends of the paper element is glue.  Pretty good glue too.  Doesn't come apart easily at all.  It was a pita to take the filter apart. 

 

So just add some oil and run it, Dan?

 

Thanks for the great input.

 

Sure... why not?  Let me know how it goes.  Good luck!