Notices
996 Forum 1999-2005
Sponsored by:

Scored bores are scaring me off

Thread Tools
 
Search this Thread
 
Old 10-25-2019 | 09:35 PM
  #46  
808Bill's Avatar
808Bill
Rennlist Member
 
Joined: Dec 2016
Posts: 8,051
Likes: 810
From: Kauai
Default

Originally Posted by JTT
pdx, where would one send an injector for flow testing? Your idea sounds very reasonable, if they are accessible and inexpensive enough. This is all new to me, so trying to learn what I can about these injectors. Thanks
Most big name auto parts stores can send them out. NAPA had cleaned and rebuilt mine last year but I'm going to put new ones in soon.
Old 10-25-2019 | 10:02 PM
  #47  
SoCal911t's Avatar
SoCal911t
Rennlist Member
 
Joined: Apr 2005
Posts: 2,052
Likes: 1,535
From: San Diego
Default

Originally Posted by JTT
pdx, where would one send an injector for flow testing? Your idea sounds very reasonable, if they are accessible and inexpensive enough. This is all new to me, so trying to learn what I can about these injectors. Thanks
I plan on buying new injectors for the 996 but I've used an injector service for my '80s BMWs. The owner is great to work with and his prices are reasonable.














Old 10-26-2019 | 03:18 AM
  #48  
pdxmotorhead's Avatar
pdxmotorhead
Three Wheelin'
 
Joined: May 2019
Posts: 1,701
Likes: 400
From: USA/Oregon
Default

I've used the guy up in I believe issaqua Washington,,, most big cities have a injector service company, its mandatory for most diesels and commercial rigs o keep their clean idle status.

I've also used 5-0 motorsports for my jeep ones a couple years ago.

I just googled around for injector cleaning services..

Last edited by pdxmotorhead; 10-26-2019 at 07:12 PM.
Old 10-26-2019 | 07:12 AM
  #49  
Mike Murphy's Avatar
Mike Murphy
Rennlist Member
 
Joined: Aug 2006
Posts: 9,050
Likes: 1,781
From: Chicago, IL
Default

I thought Jake has mentioned at one point that many injector cleaning services aren’t always that great? That some injectors come back worse after cleaning, and for that reason, we should buy new?
Old 10-26-2019 | 09:15 AM
  #50  
bazhart's Avatar
bazhart
User
 
Joined: Nov 2009
Posts: 201
Likes: 91
From: bolton uk
Default

Unfortunately quite a few misunderstandings about these issues which can be cleared up if you would like to read a long detailed report about it from our years of research.

It is available free from admin@hartech.org.

Baz
Old 10-26-2019 | 12:13 PM
  #51  
Flat6 Innovations's Avatar
Flat6 Innovations
Former Vendor
 
Joined: Nov 2010
Posts: 6,968
Likes: 2,295
From: Cleveland Georgia
Default

These injectors can't be effective tested in a lab. The issues that we see are aggravated by engine temperature, especially when the engine is shut off, and fully heat soaked. When the engine shuts down, the engine will elevate in temperature for a few minutes before it starts to cool, all the while the injectors are being asked to hold at least 55 PSI of fuel pressure. With the engine shut off, the fuel within the rails and injectors also heats up, which makes it more difficult for the injectors to hold back.

Fuel leak down often occurs due to this, and the next time the engine is started, it does so with a puddle of fuel within the intake ports, or cylinders, if the intake valves were open on the cylinder at the crank position that engine shut down at.

In short, your lab tests mean nothing in regard to how the injectors function in the real world. We have seen injectors "test" perfectly, yet puddle fuel in the ports that was visible with a long reach bore scope down the intake runners, with the engine hot. During the testing the lab does not use hot fuel to test the injectors, nor do they have them fitted to a hot engine, in an engine bay that averages 140+ degrees F. The lab tests are done at ambient temperature.

This is why injector cleaning, and testing means nothing to me, and hasn't since these discoveries, which we now see all the time.
The following users liked this post:
Mike Murphy (10-26-2019)
Old 10-26-2019 | 07:32 PM
  #52  
pdxmotorhead's Avatar
pdxmotorhead
Three Wheelin'
 
Joined: May 2019
Posts: 1,701
Likes: 400
From: USA/Oregon
Default

Agree,, Cleaning the injectors wont bring a worn out one back, but if you have a rig that does not get used a lot,, "hanger queen"
having the injectors cleaned does help avoid varnish buildup and fuel sludge clogging it,, my theory and its not specific to
Porsche in the least is that a cleaning every other year and new maybe every 80 to 100 K will give you the best overall performance,
I've had enough brand new injectors that were DOA that I'm as concerned about where they are made, and their manufacturing
as I am whether they are brand new. Add yea if you take apart an injector,, you can see quickly that a true full rebuild ain't very likely..
They just are not made to come apart.. I have dismantled the early fat body EV-1 injectors and reassembled them, but that
was young me where time was free and money short..

I use a injection cleaner consistently,, I try and put it in the last tank before an oil change..
And do the change when the tank is almost empty.. I use techron for the most part.

On the road race cars I've worked,, we send the injectors out every season..
over the winter then pickle them with a light oil like a marvel or a marine fogging oil.
Of course we also have 2 or three sets in the tool box..

For the mechanical injection on the sprint cars, they are simple and get cleaned between
each race weekend.. Methanol is just so aggressive your in trouble if they sit..
Old 10-27-2019 | 06:47 PM
  #53  
Mike Mullins's Avatar
Mike Mullins
Rennlist Member
 
Joined: Jul 2002
Posts: 1,334
Likes: 288
From: No. Ky.
Default Same thoughts

Originally Posted by pdxmotorhead
Agree,, Cleaning the injectors wont bring a worn out one back, but if you have a rig that does not get used a lot,, "hanger queen"
having the injectors cleaned does help avoid varnish buildup and fuel sludge clogging it,, my theory and its not specific to


I use a injection cleaner consistently,, I try and put it in the last tank before an oil change..
And do the change when the tank is almost empty.. I use techron for the most part.

.
I think in similar vein and practice the same. I do have very intermitant stumble of one or 2 random cylinders at idle,
I don't see anything on scans, so I need get out the Durametric and see if I see anything.
(I might need help but when I get some time..
Old 09-05-2023 | 11:57 AM
  #54  
Taca2360's Avatar
Taca2360
2nd Gear
 
Joined: Sep 2023
Posts: 2
Likes: 0
Default What do you guys think about this one ?

Idle is sometimes unstable now and sometimes has a mini backfire . Any opinions would be much appreciated!
Thankyou

​​​​​​​https://youtube.com/shorts/9_utLacn6_I?si=hufx9hiMpXAfjXb9

Last edited by Taca2360; 09-05-2023 at 12:04 PM.
Old 09-05-2023 | 02:25 PM
  #55  
pdxmotorhead's Avatar
pdxmotorhead
Three Wheelin'
 
Joined: May 2019
Posts: 1,701
Likes: 400
From: USA/Oregon
Default

Originally Posted by Taca2360
Idle is sometimes unstable now and sometimes has a mini backfire . Any opinions would be much appreciated!
Thankyou

https://youtube.com/shorts/9_utLacn6...fx9hiMpXAfjXb9
How old are your coil packs years count as well as miles. my 03 they were pretty baked at 116K miles when I replaced them...
Old 09-05-2023 | 05:30 PM
  #56  
Taca2360's Avatar
Taca2360
2nd Gear
 
Joined: Sep 2023
Posts: 2
Likes: 0
Default

Originally Posted by pdxmotorhead
How old are your coil packs years count as well as miles. my 03 they were pretty baked at 116K miles when I replaced them...
Can’t remember if I changed the coil packs at some point . I changed the spark plugs probably 2k miles ago. Sometimes the car is left over a month without using it; obviously every time before starting it again I try not to push it and leave it there warming up making sure everything is as it should be. IMS was done at 78 k miles and currently has 98 k miles. I’m worried there’s a scoring on one cylinder I guess I’ll have to use a endoscope to see what’s going on .. There’s 2 things that have my head questioning me if it’s related or not one being the clutch release bearing because not long ago it started to make a heavy tick noise different from what you hear on video after riding and car hot sound is audible when clutch is released on idle, but if I engage the clutch sound (clack,clack) goes away . Second thing is the fuel filter I’m pretty sure that has never been done; making one injector to stick and give a little tick, hickup and misfire . But in other hand what we all worry about is if there’s a scoring on a cylinder ? Or probably a lifter or timing chain tensioner (many factors) that’s why I’m here 😌 to figure out with you experts to help me out based on your experiences what should I do first ? I guess I shouldn’t drive the car cause it’ll make it worst . If I drop the oil with a bore scored cilinder should I see small shavings ?

Thanks you and sorry for my English .

Car is located in Nicaragua

Old 09-05-2023 | 06:06 PM
  #57  
pdxmotorhead's Avatar
pdxmotorhead
Three Wheelin'
 
Joined: May 2019
Posts: 1,701
Likes: 400
From: USA/Oregon
Default

You should drain the oil in to a perfectly clean pan and you might see a bit of metal with any motor,..
But to tell for sure the sump has to come off and do a bore scope... "Its the best way to be sure"

If you have changed the oil and don't have weepy injectors your odds go much lower down on odd of scoring..
Leaky injectors cause bore scoring in anything not just porsches.. The Boxer engine is just more sensitive to it.

DONT let a 996 sit and idle to warm up.. Start it, let it smooth out then drive away gently staying under 3000 rpm till it hits 180F
If you let them idle it takes too long to heat up the pistons, oil etc. .

If available in your area We have a product called Sea-Foam that is a marine engine fuel treatment. A half can in a fresh full tank of gas goes a long way to getting the varnish out of injectors. It forms when gas and oxygen meet without spark and sit around.. I use it in the last two tanks before I change the oil.

Last edited by pdxmotorhead; 09-05-2023 at 06:09 PM.
Old 09-06-2023 | 12:42 PM
  #58  
damage98MO's Avatar
damage98MO
Rennlist Member
 
Joined: Feb 2022
Posts: 672
Likes: 388
From: Annapolis County, NS
Default

Originally Posted by pdxmotorhead
You should drain the oil in to a perfectly clean pan and you might see a bit of metal with any motor,..
But to tell for sure the sump has to come off and do a bore scope... "Its the best way to be sure"

If you have changed the oil and don't have weepy injectors your odds go much lower down on odd of scoring..
Leaky injectors cause bore scoring in anything not just porsches.. The Boxer engine is just more sensitive to it.

DONT let a 996 sit and idle to warm up.. Start it, let it smooth out then drive away gently staying under 3000 rpm till it hits 180F
If you let them idle it takes too long to heat up the pistons, oil etc. .

If available in your area We have a product called Sea-Foam that is a marine engine fuel treatment. A half can in a fresh full tank of gas goes a long way to getting the varnish out of injectors. It forms when gas and oxygen meet without spark and sit around.. I use it in the last two tanks before I change the oil.
"If you let them idle it takes too long to heat up the pistons, oil etc."
I was told that Its not the time to heat up, it's the amount of fuel to air mixture. Just sitting at idle when the engine is cold, doesn't that mean more fuel that washing the cylinders? Also known as running rich...https://mechanics.stackexchange.com/...or%20starting.
​​​​​​The unburnt fuel washes the cylinders, preventing proper lube, and this results in more wear. ie. Bore scoring.
​​​​​​Get your car, any road car, moving once you've started it. At least you're getting some value for your money. I had neighbors who come out, or use remote start, and then have breakfast indoors with the truck running. In NC. It's not even below 30...Sigh. There's a lot wrong with that, but stupid is as stupid does. I'm not the enviro cops, so you know, live and let live. I believe that here in Canada, for years, most parking lots are no idle zones. I see signs all the time attempting to enforce that. But I've seen 1 LEO since moving back, and that one was parked at the digby RCMP. It's the wild West out there. Given the scarcity of law enforcement, I would imagine no idle laws are pretty dang low on the list of priorities. I'm rambling again. It's 'retiree syndrome' 💯🇨🇦❤️
Old 09-06-2023 | 01:56 PM
  #59  
Porschetech3's Avatar
Porschetech3
Rennlist Member
 
Joined: Oct 2010
Posts: 6,509
Likes: 4,924
From: Alabama USA
Default

Originally Posted by damage98MO
"If you let them idle it takes too long to heat up the pistons, oil etc."
I was told that Its not the time to heat up, it's the amount of fuel to air mixture. Just sitting at idle when the engine is cold, doesn't that mean more fuel that washing the cylinders? Also known as running rich...https://mechanics.stackexchange.com/...or%20starting.
​​​​​​The unburnt fuel washes the cylinders, preventing proper lube, and this results in more wear. ie. Bore scoring.
​​​​​​Get your car, any road car, moving once you've started it. At least you're getting some value for your money. I had neighbors who come out, or use remote start, and then have breakfast indoors with the truck running. In NC. It's not even below 30...Sigh. There's a lot wrong with that, but stupid is as stupid does. I'm not the enviro cops, so you know, live and let live. I believe that here in Canada, for years, most parking lots are no idle zones. I see signs all the time attempting to enforce that. But I've seen 1 LEO since moving back, and that one was parked at the digby RCMP. It's the wild West out there. Given the scarcity of law enforcement, I would imagine no idle laws are pretty dang low on the list of priorities. I'm rambling again. It's 'retiree syndrome' 💯🇨🇦❤️


LMAO...no idle zones....That's a new one on me...never heard of that..Thank you !!!

Here in Bama we have a lot of "no wake zones" on the lakes near Marina's .docks, but I can't imagine them ever putting no idle signs in parking lots...

Last edited by Porschetech3; 09-06-2023 at 02:01 PM.
The following users liked this post:
Taca2360 (09-06-2023)
Old 09-06-2023 | 03:40 PM
  #60  
pdxmotorhead's Avatar
pdxmotorhead
Three Wheelin'
 
Joined: May 2019
Posts: 1,701
Likes: 400
From: USA/Oregon
Default

Originally Posted by damage98MO
"If you let them idle it takes too long to heat up the pistons, oil etc."
I was told that Its not the time to heat up, it's the amount of fuel to air mixture. Just sitting at idle when the engine is cold, doesn't that mean more fuel that washing the cylinders? Also known as running rich...https://mechanics.stackexchange.com/...or%20starting.
​​​​​​The unburnt fuel washes the cylinders, preventing proper lube, and this results in more wear. ie. Bore scoring.
​​​​​​Get your car, any road car, moving once you've started it. At least you're getting some value for your money. I had neighbors who come out, or use remote start, and then have breakfast indoors with the truck running. In NC. It's not even below 30...Sigh. There's a lot wrong with that, but stupid is as stupid does. I'm not the enviro cops, so you know, live and let live. I believe that here in Canada, for years, most parking lots are no idle zones. I see signs all the time attempting to enforce that. But I've seen 1 LEO since moving back, and that one was parked at the digby RCMP. It's the wild West out there. Given the scarcity of law enforcement, I would imagine no idle laws are pretty dang low on the list of priorities. I'm rambling again. It's 'retiree syndrome' 💯🇨🇦❤️
I agree There are a ton of reasons NOT to idle a 996 to warm it up.. And almost no reason to do it.
Fueling, Engine warmup all part of a circle of proper care.. If your pistons don't get heat in them they don't
center and seal in the bore as well, this aggravates the fuel collecting at the bottom and soaking the lower side rings .
With a bit of RPM and load it helps keep the chambers from loading up till the heat comes in to help/

The nice smooth drive-away prevents many issues, and causes none.

Boxer engines usually like a hot turn off (Don't let them just sit and idle then turn off, light uptic in rpm to maybe 1500 then cut the ignition.) and a warm start. (Start and drive away slow)
In the ones i've played with, any boxer with a higher performance envelope has some issues with rich at idle. (I started on Bugs, subaru's moved on to a 69 911, and now the 996..)
Hard to make them pull hard at the top end and stay lean at the bottom.


Quick Reply: Scored bores are scaring me off



All times are GMT -3. The time now is 08:42 PM.