996 camshaft deviations and IMS
05-25-2015, 07:06 PM
#16
Instructor
Thread Starter
I too have learned a heck of a lot about this as well. Is there any way to tell from the vin or birth date of july 2000 that this porsche has a single or dual row ims without taking it apart? I do feel better having talked to all of you and that I do have time to make a decision and find a qualified technician to replace the ims. Thanks Joe
05-25-2015, 07:38 PM
#17
Racer
No - you can't tell until you eyeball the IMS bearing cover.
If it makes you feel any better (??) my Feb 2001 build Boxster S had the dual row bearing when I replaced it in 2010. But it's really a crapshoot and you can have either bearing installed because event though you know the assembly date of the car, you don't know the build date of the engine.
If it makes you feel any better (??) my Feb 2001 build Boxster S had the dual row bearing when I replaced it in 2010. But it's really a crapshoot and you can have either bearing installed because event though you know the assembly date of the car, you don't know the build date of the engine.
01-09-2020, 05:33 PM
#18
Rennlist Member
Cam deviations don't indicate an IMSB failure until the bearing reaches Stage III failure. By this point there's already metal laden oil in the engine.
What you need is a set of variocam wear pads. Bank 1 always wears faster than bank 2 and these are the first thing that will give deviations.
If I were pre- qualifying that engine for an IMSR, I'd have to consider this closely, because though the factory spec is 6 degrees, these wear pads wear quickly once they are worn through the epidermis layer of material. As the wear goes deeper and deeper, the surface of the pad is softer and softer. I always consider any issue that may occur down the road, and if we do an IMSR, anything that ever occurs with a cam deviation down the road is going to get that finger thrown at us as fast as lightning.
It might take 60K miles to get to 6 degrees of deviation, but you can double that amount in only 20K more miles.
This is what you'll find.
What you need is a set of variocam wear pads. Bank 1 always wears faster than bank 2 and these are the first thing that will give deviations.
If I were pre- qualifying that engine for an IMSR, I'd have to consider this closely, because though the factory spec is 6 degrees, these wear pads wear quickly once they are worn through the epidermis layer of material. As the wear goes deeper and deeper, the surface of the pad is softer and softer. I always consider any issue that may occur down the road, and if we do an IMSR, anything that ever occurs with a cam deviation down the road is going to get that finger thrown at us as fast as lightning.
It might take 60K miles to get to 6 degrees of deviation, but you can double that amount in only 20K more miles.
This is what you'll find.
And yes, my car has 64,000 miles.
I didn't want you to be right about it, as I cannot believe a design like this would require this level of effort at only 60k miles, but I guess it's the way it is.
01-27-2020, 12:40 AM
#19
Rennlist Member
I just checked my cam deviations for the first time, at 52k miles, with a Foxwell NT530 OBD reader. Cam 1 deviation is zero, and Cam 2 is -3*. Two questions:
- Many rennlisters mention +/- 6* as the allowable range. Is that each cam from 0*, or the spread between Cam 1 and Cam 2. This has never been clear to me. If Cam 1 is at +3*, and Cam 2 at -4*, is that within spec (both less than 6*) or out of spec (spread between them in 7*)?
- Which cam is driver's side / left side?
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