New to Forum.
I am having a 97' 993 engine rebuild done (carbon removed and new valve guides) . Somewhere in this forum I read some things a owner should have done while a top end engine rebuild it being done. For example are there parts/seals that should replace while engine is out. I only want to go through this once. Please I need some quick advice. I am not going to race this car.

Ralph (rlsammax)

 

There are several threads around this, I would do some searches and browse through them. You will get a number of opinions from a few replaceables to replacing the heads/cams/etc.

An example of this for instance:

https://rennlist.com/forums/993-foru...e-top-end.html

It really comes down to how **** you are and how deep your pockets are.

I would focus on things are are impossible to get to without the heads off (like the through bolt O rings), and then sort through the others (like replacing the P/S belt, or cleaning the injectors, etc).

If you start and post a list, you will get a lot more comments too..

Cheers,

Mike

 

Looks like there's a problem with the forum Search database at the moment. If your quest is urgent, you can try this workaround using Google search:

Enter your search term in google, followed by "site:forums.rennlist.com/etc" like the example below where I'm searching for info about oxygen sensors (substitute your own search terms):

"oxygen sensor" site:https://rennlist.com/forums/993-forum/

 

BTW Mike's suggestion on the case through-bolt o-rings is a really good one, wish I had seen this referenced when I was doing my top end rebuild.

Of course, it might have been noted in one of the pre-2013 threads but I might have ignored it because I didn't plan to remove pistons & cylinders. Ended up removing P&C's to install new cylinder base seals because I forgot to put hold down bolts on the pistons after removing the heads, and a couple of the pistons lifted off the case when I rotated the engine.

Anyway, I didn't think to replace the case through bolt o-rings at that point, and now it looks like at least one of 'em is leaking a little.

 

This was my starting point:

- Aftermarket Phosphorous Bronze Valve Guides
- clean SAI ports:
- Main Seal
- Valve Lifters
- VRAM intake Gasket
- Chain Case Gaskets
- R/R Engine Sound Pad
- Clean fuel injectors
- Chain Rails
- Engine Case Thru Bolt O-Rings
- Cylinder to Case O-Rings
- Power Steering Belt

- Distributor Belts/Distributor Bearings
- Alternator & Bearings

 

If you need any price quotes for some parts, just shoot me an email.


-Jason

 

Hi Ralph, Just curious, what led you to a top end rebuild. Also, how many miles are on the car. This could help you determine what's needed for a "while you're in there" list.

 

+1, and:

New valves, depending on wear
Spark plugs
Spark plug wires, set (easy with engine out)
Distributor cap & rotors
Valve cover gaskets
Alternator brushes / regulator
Oil temp sensor
Oil pressure sensor
Backdate cam timing gear from friction to pin type
Gaskets for intakes (at heads)
Exhaust gaskets (at heads & cat/muffler)
Belts for alternator, fan, AC
Clutch, if necessary (friction disc, pressure plate, pilot & throwout bearings, fork, shaft w bearings)
RS flywheel, if within budget

 

Just got the car. Has 25,000 miles on it. The check engine light came on. SAI issue. So the dealer is paying for fixing. BUT he is only paying for cost of engine removal….clean out the carbon. So I am paying for the new valve guides while the engine is out. I figured I might as well have it done rather then some date down the road. This car was babied thus the carbon build up. Hope that answers your question.
PS. I should have my portion of the cost by tomorrow. So I also asked "What else should I do while the engine is out.

Ralph

 

There is a BIG difference in the cost between pulling an engine and rebuilding the top end -> I am willing to bet at dealer prices, they will more than recoup their costs by charging full rate on parts and labour. And "cleaning out the carbon", which I assume is cleaning the SAI passages, is a very different piece of work than a valve guide replacement.

BTW, what was the key indicator used to diagnose you needed a top end done?

If I was going to do a major piece of work like a top end, I would get quotes from at least two or three shops and decide, based on trust, skill and price. I would not bother getting a quote from a stealer, almost all of the mechanics in a normal Porsche dealer did not have hair when these cars were made. The real experts are in the smaller focused independents.

Just my two cents anyways, its just my opinion .. good luck!

Cheers,

Mike

 

Besides the engine work, get inside the engine compartment and clean it up.

Even one that looks clean with an engine in it can benefit if you are into clean anyway.

 

Uhh, you're rebuilding the top end of an engine with only 25K miles because you got a CEL light for SAI?!?

That doesn't make much sense to me. They can be totally unrelated.

A good mechanic charges about $800 to clean out clogged carbon that causes a CEL light due to SAI issues.

That same mechanic charges about $10K to rebuild the top end and install aftermarket valve guides.

I'd imagine both will solve your CEL/SAI problem, but only one (the cheap one) is directly solving the problem you have.

I've rarely, if ever, heard of a 25K mile car that needs a top-end rebuild.

Sounds like the dealer thinks it's got a huge sucker fish on the line. I'd not take the bait and go get some more knowledge and information from second opinions. Preferably from an independent mechanic with a deep understanding of 993s.

Don't needlessly throw away thousands, when hundreds may solve your problem.

Good luck

 

+1 to what others have already said - Holy carp, that's low miles for a top end rebuild.

Could be other reasons for SAI CEL, for example see post #27 in this recent thread:
https://rennlist.com/forums/993-foru...top-end-2.html

Even if SAI cleanout is required, may be less invasive ways not requiring engine drop, see for example:
https://rennlist.com/forums/993-foru...-cleaning.html

Further to Vorsicht's and Mike J's excellent questions, ie how were worn guides diagnosed, oil consumption is usually the best clue that valve guides are worn. There is also a more definitive check for worn valves described here by Steve Weiner of Rennsport:
https://rennlist.com/forums/993-foru...l#post11155637

I take back almost everything on the list I supplied above, except maybe spark plugs and distributor cap / rotor. Oh, and maybe do the fuel and air filters, forgot those. Other than these, I am hard pressed to imagine anything else would be needed at that mileage.

 

Ralph!

I am glad you came to this forum. A top end is not required until oil consumption reaches 1 quart per 800 miles. It is highly unlikely that your car meets this condition. In fact, many cars get well over 100,000 miles before needing a top end and some get over 200,000!

Please ask the dealer to give you the specific engine fault code. It will be something like P1401. Then come back here and report. We'll help on the next step.

If it really is clogged passages and the dealer is willing to pay to have them cleaned out then that is all you really need to do.

One other thing that would be good to know is when the car was last smogged (if ever) and what the values are from that report. I realize you may not have any of this info but it would be nice to know.

Also, this dealer seems odd. I believe some Jiggery Pokery is going on.

 

Ralph - you just bought the car? No PPI? The dealer is Sloan? Are they doing the work?

For reference, here is your intro thread:

https://rennlist.com/forums/showthre...errerid=136628

(BTW - your other cars are awesome!)

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