1991 porsche carrera 2

My 96 had the valve guides done by Carlson Porsche under good faith from Porsche. They paid half and the last owner paid half. Done at 62000 miles in 2003. 10k job. Is it common to clean SAI while the motor is out and doing valve guides. I have all the receipts from the work but it is not very detailed. I guesss since Porsche paid for half they dont give line by line cost. I now have 96k and runs perfect with no oil usage in 4k miles. ( I bought it with 92k). I am always wondering If the sai issue will come up or if it has already been addressed. The last owner did do the clutch at the time valves were done. Thanks

CalvinC4S

The valve guides more then likely where replaced due to a SAI fault at 62k. With that said, they must of cleaned them out.

Look close at your paper work, there will be a line that shows owner complaint. Oil consumption, check engine or PDI leak down.

Deadeye

I would replace the check valve the next time the air cleaner box is out for service (plugs, fuel filter etc.) These tend to rust out and fail over time which contributes to SAI issues even with good valve guides.

g_murray

+1
When doing 'enhanced' (regular) maintenance, e.g. changing plugs, wires, fuel-filter, air-filter... get them to install a new SAI Check Valve.
Conventional wisdom, on this forum, is to change it every 30,000 miles AND, of course, to monitor your oil consumption.

Gerry

Quadcammer

If the dealer installed the same crappy factory guides, you may have this problem again at some point.

AOW162435

Or to remove the entire system if you own a '95.




Andreas

1991 porsche carrera 2

After pulling out all the paper work you were 100% correct. They did valves , machined heads cleaned sai. looks like they did the full 9 yards. Replacing the check valve every 15k or so will this prevent sai problems asuming valve guides hold up and no oil consumption. Californina smog so I do have concerns of cel.

C2Cab95

I'm assuming there is a write up... care to elaborate on this? I wasn't able to find it. Thanks!

User 122821

Or add a bypass circuit if you have a '96 and remove the system.

jemsom

I don't want to interfer in your post,
but couldn't you prevent excessive valve guide wear ( and therfore sai problem) with the use of a more appropriate oil ?

there is a post somewhere about motor oil companies having changed drasticaly ingredients in late 90's early 2000's for some (ecological ?) reason I think. Mobil one is one of them.
993 valve guides where certainly not designed with new oil standard in mind.
Just few brands kept old style chimistry.
I personnaly use Motul 300V

Correct me if I'm wrong

g_murray

My 'indy' advised me to switch to Motul 300V also -- from Mobil 1. *I LOVE IT*!

Trouble is -- with 'excessive amounts' of Zinc and Phosphorous (which are GREAT 'wear preventers') -- in the engine oil -- is that they can cause the catastrophic converters to fail 'early' or 'completely'.

MOTORBIKE OILS contain 'high' amounts of Zn and P in *their* oils ...because they can!

Personally, I am biased towards keeping my engine (and valve guides) running with minimal wear and screw the catastrophic converters. You can always replace those 'easily' - coz they're 'external'.

Gerry

Quadcammer

catastrophic converters? little autocorrect humor there.

Let me ask you, why do you love the Motul? What differences have you noticed?

thanks.

vincer77

I wonder how much lubrication the exhaust valve guides receive from oil. With valve stem seals and realizing that the exhaust port is at a relatively high pressure (especially compared to the intakes), I would guess not much. In the old days, lead was a good lubricant.

Kika

you need to find out which valve guides they put in. The OEM ones that came with the car originally, were soft. There are later versions that are better. Look for a parts list.

If the OEM original guides were put back in, then you might have SAI issues eventually. If the better guides were put in, then it is less likely. It is VERY difficult to predict, as there are too many variables involved. but there are some precautions that might help.

1. allow the car to warm up before taking it to high (5k+ rpms)
2. don't take short trips that don't get the engine to operating temp
3. Italian tune up once in a while is a good thing.

Even if the SAI ports get clogged, there ARE a options other than a complete top end. i.e. the bass guitar string roto rooter. I was having SAI clogged port issues about 2 years ago, and did the bass guitar cleaning, and haven't had a CEL since.

trophy

https://rennlist.com/forums/993-foru...moval-diy.html
https://rennlist.com/forums/993-foru...e-removal.html


I have been using Motul almost exclusively in my car for over 9 years (PO used it before me). I did try a different brand for one fill and found an increase in oil.engine temperature over the Motul. I have had oil analysis done by Blackstone and it has alwys come back favorable (even after an extended interval).

My car sees over 30 track days a year and has done so for 10 years, my oil consumption is below factory specs. As far as I am concerned it is worth the investment.....