Re: Plastic bits in the oil filter and chain guide pad wear

My 1999 Boxster celebrated her 19th birthday this past July, same month that we did the 90K mile service. Despite MarcW's sage advice to leave well enough alone, I decided to have the water pump and thermostat replaced. Some evidence of minor leakage at the shaft seal but otherwise, the pump was OK. Impeller not missing any bits and the shaft bearings tight. Thermostat looked OK too. Apart from all the usual service items due at 90K, I also had the cam timing deviation checked as I've been finding very small quantities of chain tensioner pad wear products in the oil filter. Deviation was reported to be within spec ... so less than 3 degrees error. I think I can go a while longer before having to replace the pads. I also finally got around to installing a magnetic oil drain plug. My pre-hibernation oil change and end of season service visit is next week, so I'm looking forward to seeing what the mag plug has collected. I'll be examining the removed oil filter as usual.

... the transmission oil flush is also due.
That water pump's seal was ready to let go.
Good call.
Happy Boxstering,
Pedro

Hi Pedro,

The manual transmission oil was indeed replaced.
Cheers,
John

PS: Thanks for providing this excellent forum for all things Boxster!

In the case of a water pump if there is any leak sign that is of course a sign of trouble and then my advice would be to replace the water pump and T-stat.

ASAP.

BTW, Porsche techs have told me it is ok for there to be a bit of leak sign at a water pump that the pump is still healthy. The leak sign must consist of just antifreeze residue -- whitish stain -- on the casting and not very big of a stain either. There can be no signs of wetness nor anti-freeze build up.

In the case of my Boxster's water pump it was not a leak but a noise that had me diagnosing the pump bad and having it replaced. In the case of my Turbo's water pump, on a very hot day and after running around town taking my Mom to the doctor then shopping when helping her into the car after her shopping was complete I smelled hot anti-freeze. Later than afternoon at the dealer an inspection found a greenish blog of anti-freeze residue built up and signs of wetness. This obviously qualified the pump as bad.

Thanks Marc ... actually, I hadn't looked at the exterior of the pump before it was removed ... just thought it was time (19 years). My main concern was age related ... possibility of small bits of the impeller coming adrift and circulating in the cooling passages.

Quote
Indybox
Thanks Marc ... actually, I hadn't looked at the exterior of the pump before it was removed ... just thought it was time (19 years). My main concern was age related ... possibility of small bits of the impeller coming adrift and circulating in the cooling passages.

The impeller is quite robust. The only cases I'm aware of where the impeller has been damaged is when some one nurses a bad pump and the pump bearings develop enough play -- and it doesn't take much -- to let the impeller blades make contact with the block. By design the blades run real close to the block to help the pump be more effective and as a result there's just not a lot of room if the impeller moves about.

But you can change the water pump whenever you want for any reason you want. Be sure you replace the T-Stat too.

... if there are air pockets in the system which make the impeller cavitate and creates minute pitting in the plastic.
With enough cavitation larger pieces of impeller can break off eventually.
That's why its always good to check the coolant level by looking through the tank and not opening the expansion tank all the time which may allow air in.
Sincerely,
Pedro

... all good info ... thanks very much!

PS: Friday scan day snap ... one day late. (My 986 in a 944 sandwich on a 964 fender at a recent Cars and Coffee event)

So ... just to follow up on the recently installed magnetic oil drain plug and oil filter inspections at the year end service last month ...

The oil filter had the usual very small catchment of chewed up plastic bits and no metal as far as I could see. A search for "plastic bits in the oil filter" turned up this Rennlist thread that describes the source. Looks like I have both flavours (brown and black) of plastic bits coming from various chain guide pads. The cam deviation was checked back in July with a max delta value of 3 degrees. Porsche tech said this was within limits and as the engine is not making any unusual noises ... OK to continue in service as is.

Rennlist - Plastic Bits in the oil system info

The mag plug's first inspection only revealed a small quantity of magnetic fines (minute dust-like particles) ... not unusual for a 19 year old engine ... normal wear products.

Car went into hibernation last Sunday ... only 119 days until spring! Looking forward to celebrating my car's 20th birthday next summer.

I think I would be looking at the cam deviation again. The brown particles seems to be a sign of the chain guides cracking and beginning to break up.








Edited 1 time(s). Last edit at 11/23/2018 10:35AM by Lew.
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Yes ... I'll check it again next year to see if there's any change. The picture of the fragments looks worse than it might seem because of the photo magnification ... these are really small bits and not so many as to indicate extensive brake-up of the pad runner area.

Added a new subject line for future reference and another photo from last summer (Saint-Placide church on the north shore of the Ottawa river). Only 116 days until spring ... hold fast!