![]() |
|
|
|
Actual Porsche owner
|
Been thinking that myself. I’m thinking oil issues caused the cat problem, not vice versa.
__________________
. |
||
![]() |
|
Brew Master
|
Quote:
The Cat failure caused the engine issue. Think of it this way. Engine is humming along flowing nicely at 55-60 mph, Suddenly the exhaust is shut off, where does the pressure go? How does that pressure affect the engine internals?
__________________
Nick |
||
![]() |
|
Brew Master
|
Quote:
__________________
Nick |
||
![]() |
|
Get off my lawn!
|
![]() I have always been a data or information geek. Shortly after I turned 100,000 miles on my El Camino I got to wondering about the engine wear. I found a local oil testing company and I started testing and graphing the numbers with PowerPoint. The biggest thing I learned right away was to change the air filter much more often. The silicon levels (sand and grit) were sucked past the air filter and grinding up the parts inside the engine. If you look at the chart, every time the silicon dropped was right after I put on a new air filter. I finally learned that after 100,000 miles of testing things were not going to blow up, and to change the air filter more often. That engine went 300,000 miles before it was just worn out. $1,700 bought me a brand new, not rebuilt but new 350 delivered to me door. Can't beat the Chevy small block for price.
__________________
Glen 44 Year member of the Porsche Club of America 1985 911 Carrera; 2017 Macan 1986 El Camino with Fuel Injected 350 Crate Engine My Motto: I will never be too old to have a happy childhood! |
||
![]() |
|
Registered
Join Date: Nov 2000
Location: AZ
Posts: 8,415
|
Quote:
![]() |
||
![]() |
|
Registered
Join Date: Sep 2009
Location: North of You
Posts: 6,889
|
Quote:
There is more to the story, but without the cat you will never know.
__________________
"A machine you build yourself is a vote for a different way of life. There are things you have to earn with your hands." |
||
![]() |
|
Registered
Join Date: Apr 2005
Location: In the wind...
Posts: 28,538
|
Has the shop even pulled the pan yet to determine if your noise was a bad rod bearing?
|
||
![]() |
|
Brew Master
|
Not yet. We're waiting on direction from Hyundai.
__________________
Nick |
||
![]() |
|
Brew Master
|
Yes one is. No drivability issues prior to failure. Never a CEL. Just one day BOOM cat is gone. The day the second one went he was literally 1/2 mile from home and it just lost power and wouldn't throttle up. The day it failed, he drove the car home from school about 45 minutes away, stopped at the house, then went into town and back. On the way back from town it just puked. The previous time he took off for Lima OH, on his way back the engine just stopped running. Again, no CEL no warnings of any sort.
__________________
Nick Last edited by cabmando; 09-06-2020 at 05:01 AM.. |
||
![]() |
|
Registered
Join Date: Oct 2011
Posts: 284
|
Some of these modern engines with variable valve timing are using the vvt to perform the egr function. Holding the exhaust valve open under certain conditions to dilute the incoming fresh air fuel mixture to lower NoX. You get a lower quality cat converter substrate (Nissan had this happen among others) and it starts to break up and get sucked into the cylinder. This wears out the cylinder and rings and allows burnt oil to get into the cats, causing faster deterioration. It’s a vicious cycle. I highly doubt back pressure damaged your motor. I have had multiple LS based V8s in the shop with failed lifters not allowing an exhaust valve to open that have run for many many miles that way with no mechanical damage. Also they are designed to withstand insane combustion pressures. Also while it’s a much stronger diesel application, Jake brakes perform the same engine braking operation with no damage.
Last edited by Dansvan; 09-04-2020 at 09:31 PM.. |
||
![]() |
|
Senior Member
Join Date: Jun 2000
Location: N. Phoenix AZ USA
Posts: 28,851
|
I work with airplanes (on the side) and we usually do an oil sample every 2nd oil change. Well worth the $$ to keep an eye on what is going on inside.
__________________
2013 Jag XF, 2002 Dodge Ram 2500 Cummins (the workhorse), 1992 Jaguar XJ S-3 V-12 VDP (one of only 100 examples made), 1969 Jaguar XJ (been in the family since new), 1985 911 Targa backdated to 1973 RS specs with a 3.6 shoehorned in the back, 1959 Austin Healey Sprite (former SCCA H-Prod), 2010 Jaguar XF (fast touring car), 1995 BMW R1100RSL, 1971 & '72 BMW R75/5 "Toaster," Ural Tourist w/sidecar, 1949 Aeronca Sedan / QB |
||
![]() |
|
Brew Master
|
Results are in!
Iron 100 ppm universal average 7 ppm Aluminum 90 ppm universal average 3 ppm
__________________
Nick |
||
![]() |
|
![]() |
Unregistered
Join Date: Aug 2000
Location: a wretched hive of scum and villainy
Posts: 54,835
|
|||
![]() |
|
Brew Master
|
Lead and tin were zero. There was no line for brass included in the report.
__________________
Nick |
||
![]() |
|
Unregistered
Join Date: Aug 2000
Location: a wretched hive of scum and villainy
Posts: 54,835
|
points to not being a bearing issue then unless maybe the cam bearings are integral to the head.
|
||
![]() |
|
Brew Master
|
I'm wishing I would have done oil analysis on the first two changes for a baseline. With the short block only having 9000 miles on it, I'm not sure how long to expect really high levels of aluminum, Iron and Chromium.
Forgot to list chromium. sample had 4 ppm baseline is zero for this engine.
__________________
Nick |
||
![]() |
|
Registered
Join Date: Apr 2005
Location: In the wind...
Posts: 28,538
|
Any fuel dilution?
|
||
![]() |
|
Brew Master
|
__________________
Nick |
||
![]() |
|
Registered
Join Date: Apr 2005
Location: In the wind...
Posts: 28,538
|
Well, time to yank the pan and look at that rod.
|
||
![]() |
|
Brew Master
|
That's what I'm thinking too.
__________________
Nick |
||
![]() |
|
![]() |
Thread Tools | |
Rate This Thread | |
|