kkim

Ryan,

I would not wait until the CEL comes on to start doing something about it. If you have 45K, you should do something now if nothing has ever been done w/ regard to maintaining the system. Just be thankful there is a DIY procedure on flushing the ports. Prior to that, people were taking their cars to mechanics who pronounced their valve guides worn at the tune of 5-6k to "fix".

I would flush the ports to get some baseline on how clogged they are at your mileage. Change the SAI valve at the same time as it is most likely rusted as hell at this point. I would recommend, as been stated by others, to change the SAI valve at a regular interval that you are comfortable with... I've read figures anywhere between 15-30K recommended. Surely, 45K is too long, IMHO.

Anxiety? Not anymore, as you can proactively do something about it. If you wait too long, the ports can get plugged solid, which is something you want to avoid to prevent having to tear the engine apart to fix.

Good luck... parts for the DIY flush run less than $200.

f_scaife

What is the P/N for the SAI valve?

epj993

Part number is: 993-113-250-03. Mine was $63 at the dealer.

zffnhsn

Whoa! The CEL is not exclusive to a SAI restriction condition. It could be a failed oxygen sensor or a fuel filler cap gasket.

epj993

BTW, if you do the flush you'll also need these parts:
(6) exhaust seals, p/n: 993-111-195-00
(12) exhaust lock nuts, p/n: 999-084-052-02

Lorenfb

Check here ( www.systemsc.com/pictures.htm) for some additional info on SAI CELs.

luv2ride

Thanks for all of your helpful info. Although I still have anxiety. So keep it cool, do a flush and replace the sai valve frequently. Good sound advise. I will take a pic of the under carriage and see if the cover is on or not. What should I be looking for? I also have all of the records and I'll see if the PO did anything (I purchased car at 42k). Kelly, do you have the DIY procedure on how to flush? Can my shop do it? Thanks again.

Ryan

Traffic53

hey man- thank you very much for this link. this is good reading.

ecobb993

SAI CEL is really nothing to be "anxious" about. Just get the little pocket code scanner from Pepboys and keep in the door pocket. It takes just 30 seconds to check the code and erase it. You don't even have to shut of the engine.

Every couple months or so I get the silly light, pull over when it's convenient, plug in the scanner, push the "read" button, make sure it's the dreadded code, push "erase?" and a few seconds later pull back on the road.

When your engine really needs it, have the guides done and all the ports cleaned. In the meantime, "don't worry - be happy" - and carry a pocket scanner.

luv2ride

The tray was removed at 23k. spoke to the PO and things have been cool for a while. The temp for him and I never hit past 9 oclock. we spoke in detail of the cars heating past de's (5) ect. Should I still be concerned and do a flush and replace the sai valve?

epj993

It's good that the tray is off and oil temp stays normal. But, as Kelly stated a few posts up it would probably be wise to do the flush while you're not completely clogged and get a baseline. Regular SAI check valve replacement & running as cool as possible (along with the other suggestions) will extend the interval to the next flush. At 45K, you're due.

kkim

To me, this is good sound advise. I bought my car 2 years ago w/ 46k miles and was happy the CEL light wasn't coming on. I mean, nobody wants to do any more maintenance on the car than they have to, right?

Since that time, various warnings would pop up on the board on changing out the SAI valve, but hey... my CEL wasn't coming on so those warnings weren't for me... or so I thought. Later, Rob Kwate did the SAI DIY that is now posted on P-car.com. http://p-car.com/diy/sai/1/sai.htm "Hmmm... looks like something I should try", I say to myself... "I'll get to it later".... I mean, I couldn't be one of the unfortunate few to have SAI problems, right?

Fast forward to about 60k and lo and behold... "CEL!!!" I start thinking... "why? oh, why me, Lord!!" Yeah... right... I had been warned.. I had read the posts and the DIY... the car was in the range where it has started to have this problem... I had been warned, but refused to listen. Instead I deferred maintenance and this is what I got for my actions... https://rennlist.com/forums/993-forum/224219-need-help-diy-sai-flush-problem.html

I was lucky I was able to "unstick" the clogged port. If I hadn't the heads would have needed to come off to manually clean out the carboned up, convoluted passages.

Where are you located? If you live in a state where you don't have emission checks, you may think twice about if this should be even a concern for you. As stated earlier, the clogged ports doesn't harm performance, but good luck if you ever decided to sell to someone in a state that does. Wait too long and if/when you you decide to do the flush, you nay end up having to do a lot more than you bargained for.

If it were me back at 46k, I wouldn't have waited knowing what I know now.

Good luck whatever you decide to do....

C. Eastwood.... "Feeling lucky, punk?"

Martin S.

Absolute yuk...nasty. Hergie from Hergesheimer Motorsports in Lake Forest, CA recommends what we see above: Change the SAI check valve every 10-15K miles and rev it high on a regular basis.

I drive the wheels off my car, whenever possible, on the track of course. The car burns very little oil.

I am going in for my smog test today, wish me luck!!!!

aam993

This approach will NOT work for OBDII(96-98) 993 if once in a while you need to pass state inspection. For state inspection all OBDII codes, including SAI, has to be in READY state, while if you recently manually reset the computer(or disconnected the battery for that matter) it will be in NOT READY state.

autobonrun

I think all the comments so far are valid and make lots of sense. I plan to get a SAI valve today since I don't know when/if the previous owner changed it, and I've only had my 96 C4S two months.

However, here is my take on the problem. Most of the suggestions are related to how to prevent the carbon from building up. I think there is another step that needs to be taken, and that is to limit the amount of carbon formed in the first place. Carbon is a natural result of combustion but the amount produced is dependent on how complete is the combustion. I think we can reduce the overall amount of carbon by 1) using a clean burning fuel and 2) keeping the car tuned up so that combustion is as complete as possible. To address the clean fuel issue, I only use one type gasoline in my car and that is from Quiktrip. They are not in every state but from what I have researched, they produce one of the cleanest burning gasolines availables. Another source of carbon would be any oil that gets by the seals and into the combustion chamber. Not much that can be done about that except a rebuild so I'll focus on the other two items that I can control.

I also think that both reducing the heat and driving the car hard will help keep the carbon from building up. I don't think either of these is a legend. In order to build up to a level that will block passages, the carbon has to stay in place long enough and at a high enough temperature to form a solid. Higher air velocities will help dislodge any particles before they can form a solid. In addition, reduction in heat will help keep the carbon from "coking".

This is my opinion. I'll know in several years whether this works or not.