PPI Results In - Can I get some advice?

[hopkinskid]

Again, this is posted on Rennlist, so I apologize to anyone who reads this twice.

Car - 1983 911 SC Targa, 117k miles.

First off, I got the PPI done at Heyer Performance in Mountain View by Tony. Tony was very informative, very honest, and checked the car thoroughly (test drive, etc, etc) = PPI took 3 hours (because we talked a great deal and he had to do some additional checks, mentioned later), and he was kind enough not to charge me 3 labor hours.

The car had some very minor "cosmetic" problems: torn driver's seat, tiny leak in targa, loose driver's side mirror, needs new turn signal, etc, etc (minor stuff that I can deal with later). It's not cherry, but overall, the car is in good condition. But then came the compression test:

1 - 155
2 - 160
3 - 155
4 - 150
5 - 150
but........
6 - 135

Tony was nice enough to check the intake, do a valve adjustment and a leakdown on #6 - 25%.
A little coming out of both exhaust and intake.

Can I get some advice? This car is almost "perfect" for me - all updates (spring centered clutch, carrera tensioners, popoff valve, new alternator, 24 new head studs in 1996, etc), a nice 911 I can start with, decent mileage, tranny/clutch in decent condition (synchros good, shifts good), and so forth.

If I were the owner of this car, I would suck it up and just drive it. I would ignore the 135 and eventually get a valve job ($3-3.5k) two, three, four years down the line...maybe never. But as a potential buyer, I have no idea. I could negotiate this problem into the final purchase price, but should I even bother? If I were to purchase the car, I was recommended to drive it hard (like a Porsche) for 1-2 thousand miles - the previous owners never drove the car hard, and used it as their 3rd/4th/weekend car. So drive the car like it was meant to be driven....and then get another compression check again. Maybe the 135 will be worse, maybe the same, maybe better. What are the chances of me facing a valve job 1 year down the line? I can deal with a $3-$3.5k job 3 years down the line, but not so short-term. Besides, again I could try to negotiate the owner's asking price considerably.

In addition, this was the same car that had all the work done in 1996 - the car had a valve + major job - remove/install engine/tranny, complete valve job, replace valve guides, replace all 24 head studs, etc. In addition, as recently as April 2000, a PPI showed no problems with the compression (170-175 on all cylinders).

I was thinking of offering $13.5-$14.0k if the PPI was satisfactory. However, with the #6 problem, I have no idea. Maybe offer $11.5-12k, and just drive the car until it needs a valve job. I'm not sure. I would greatly appreciate any recommendations, advice, information, stories, or scenarios.

Thanks!
Hopkinskid

[82SC]

wow...you are offering quite a bit

I think a solif mechanical and near perfect SC should be valued at about 15-17 depending on milage.

clearly the interior is not perfect and the engine does have some bugs...

I paid 10.7K for an SC
1982
160K miles
engine and tanny solid
interior was fine, but the seats were shot...but useable...
no updates...except clutch
and the alternator was shot

I think I should have gone done to 9.5K but that was a stretch from her original offer of 13K

use the engine prob to deal down or keep looking...

I am no expert but 12K and lower is what I would look to offer...just because the updates are in place...
i guess the recent engine work leaves the current owner with a desire to get some of that back...

[rstoll]

Negotiate for 12k, then invest in a bottle of Techron to clear the carbon out of #6. Have fun!

[pbs911]

Minor stuff gets expensive. I would have some concern regarding #6. Also plan on about 500 + for a targa top redo.

I have to ask, why did the compression drop so significantly so fast, especially if the car was rarely driven?

As a reference, I paid 10K for my 78Sc with 35K on a fully rebuilt motor and trany. It needed paint ($4K since I R&Red the parts. The interior was very good except for the seats. They were a grand.

Don't rush in an buy the first one. The motor is probably the most important part of the car. With the infor you gave, and the car is worth 13K to you, I would offer a price low enough to redo the vavles, at least on #6.

My .02

[nhromyak]

What did Tony say about the #6 being low?

What were his thoughts?

Tony's a great guy. His team (dad included) are great too.
I could talk to any one of them all day. But then, my car and everyone elses wouldn't get done!

Did Heyer do the valve job in '96? If not, who?
Whoever did the valve job, ask their opinion on the #6 low compression.

It sounds to me like the #6 has some carbon buildup. But, boy what a chance that would be...

My dad (80sc) and I (85 Carrera) have personally experienced where (as you say) DRIVING THE CAR makes all the difference. If the PO (existing owner really) didn't take the engine above 4K, I would lean towards carbon buildup.
My dad drives to Laughlin NV (300+ miles ~80MPH) about once every two months. He SWEARS the car runs better by the time he comes back. The rest of the time it is his daily commuter and he doesn't like to hit 3k around town (wherever a retired person goes daily, I don't know)!

But again, that's a chance. What is your feeling on the car and the PO.

Good Luck!

[Leland Pate]

I too would be a little wary about the #6 low compression. If it just recently had work done on it I would be even more curious. I know that sometimes compression tests can be decieving, (just ask Warren) to say the least. I might suggest having someone else run another compression test on it...different day, different shop... who knows.

Oh, and I agree with 82SC, I paid 10K for my car.

[Early_S_Man]

Hopkinskid,

Please read the carbon clean-out procedure I gave using Berryman B-12 Chemtool in the following thread:

http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=52803&highlight=B12+Chemtool+carbon

I believe Techron was used instead, but the procedure brought ALL of the cylinder's compression up to 150 psi!

If you can get the current owner, or a shop to do it with the owner's sanction, you may be in good shape ... otherwise, I believe the engine will need another top-end job SOONER than 2 to 4 years down the road! Perhaps as soon as next summer and 90 degree weather hits ... a single long trip can burn valves when there is an existing 'contributing' condition in hot weather! Good luck!

[hopkinskid]

82SC - Thanks for the pricing tip. It's tough up here in the Bay Area....all these other cars around priced at $16, $17, and 18k. So I guess I was under the impression that $14.5k was a good deal for the car, but thanks for your tip. I'll see what the owner says to $10.5k-11k!

RStoll - yup, it seems like people swear by that stuff (techron).

PBS911 - I guess you're talking about how one shop stated 180 last year, and this shop showed different numbers. I asked several people, and they talked about several factors, including the precision of gauges, precision of work, etc. I personally think 155-160-165 is much more realistic, but I was told just as long as the compression was high and consistent, that would be fine. Too bad about #6....the rest looks ok. Thanks for the tip about not rushing to buy one. If I was buying on impulse, I would have bought the first 911 I saw. Question....is there a process to redo just the #6 valve???

Nhromyak - Tony was great to work with. He checked everything (and I mean everything)! He pointed out immediately that #6 was low. Since he felt that the car didn't have it's valves adjusted/15k maintenance work done for some time (he was right, I think 20k-25k miles), he did a valve adjustment on #6 (it was loose). He then performed a leakdown....25%. We talked about several possible scenarios....1) whoever did the last valve job in 1996 didn't do a good job; 2) since the car was not driven to even half its potential (not to be sexist, but the previous 2 owners were women and they treated the car "nicely"), we talked about possible carbon buildup; 3) he told me that if I were the owner, I should run the car hard for 1-2k miles, treat with fuel additive, and then recheck the compression; 4) we really didn't talk about a valve job, since he didn't want to push that type of work.

Heyer did not do the valve job in 1996. It was a place in San Jose called P.A.C. I remember looking over the work order very closely, but I forgot the complete name of the place. But I still have their contact info.

I had the current owner drive around for about one hour...definitely not one of those "high-schooler in Mustang" types. Smooth acceleration, double clutching, not too fast, not too slow. Her other car is a small Toyota stick, and I'm pretty sure she drives both cars in the same manner. In the past 15 months, she has driven the 911 about 6k miles. I was actually relieved in her driving style, but people did tell me that they would rather have a "track-type" owner sell them his or her Porsche, compared to a "know-nothing-about-911" type owner.

I like the car. It's not going to win any shows, but I feel that it'll be a good start for me. The owner is also very helpful and pointed out every imperfection; I kinda feel bad for her, since she was under the impression that the car had solid compression numbers. Again, there are minor imperfections that will probably add up to $1-$2k, but #6 is a major problem for me. One part of me says:

Negotiate with the owner, maybe get the price down to $11.5k-$12k, drive the crap out of the car and have fun, read up on the carbon issue, and maybe end up getting a $3-$3.5k valve job in three years.

Another part of me says:

Man, look elsewhere. It's not worth the risk and problems. There are many 911SCs out there, so I should keep on looking for the ONE.

Anyone: I'm trying to read up on carbon buildup. Any tips on solving this problem?

THANK YOU ALL.

[nostatic]

Why weren't the valves adjusted for 20-25K? That right there would scare me...it indicates a lack of attention (or money) on the part of the owner.

There are plenty of cars out there...especially in the Bay Area (and in SoCal too). If you really love this car, I'd offer $9-10K, using the #6 and leaking Targa top as reasons. If you get it for that, then you can rationalize doing a top end job (which *really* shouldn't be necessary so soon after a rebuild...that's another red flag).

I think you should keep looking though... As far as prices, people may be asking that, but I seriously doubt anyone is paying that. Down here, there are plenty of late 80's cars that are priced in the low $20's and not going anywhere. They aren't the greatest examples, but it is indicative of the market.

[Early_S_Man]

hop ... try looking immediately above your last post!

[hopkinskid]

Leland Pate - I was thinking the same thing of taking it for another PPI (I have full confidence in Tony's work); just because I'm so damn interested in this car and I think it would be a nice $100 investment to get another test. I know the compression is low on #6, but doesn't the 25% leakdown on it pretty much seal it (no pun intended)? Even if I have some other guy check the compression, and it's a tad bit higher and closer to the other numbers (150-165), what about the leakdown? I'm sorry, I'm not the most technical guy in the world, but I watched the leakdown test (100 psi in, 75 psi retained), so I know there's leaking from the exhaust and intake.

Early_S_Man: Would the carbon clean-out procedure possibly fix the leakdown numbers? Again, I apologize for being new to this. I kind of understand how carbon buildup may cause low compression, but would it also cause the 25% leakdown figure on #6?

Nostatic - I too wondered why the valves weren't adjusted, oil, fuel, air filters changed, sparkplugs replaced after such a long time (25k miles). I attributed it to the fact that the current owner doesn't know very much about the maintenance procedures for a 911. She took great care of the car, drove it 2-3 days a week, kept it in a garage, and had the oil changed every 3k miles....just like you would a normal car. When I asked her when the valves were adjusted last, I had a sense she didn't know what I was talking about. However, she was the owner of the car for 15 months, and about 9k miles. The owner before her maintained the car properly, and had the major maintenance done 12-15k before she sold the car. I suppose it was one of those "things" where the previous owner assumed that the current owner knew a great deal about Porsches, and assumed that the work would be done immediately after purchase.

[Early_S_Man]

hopkinskid,

Yes, if it is just carbon under the valves ... and if no damage has been done yet to the exhaust valve, then I would expect the 'pour through/soak' treatrment with B-12, Techron, or 'Marvel Mystery Oil' to improve both compression and leakdown numbers to the same as the other cylinders. I have had good luck using the B-12 Chemtool (rercommended by Porsche for use on MFI engines) and others have reported similar success restoring compression and leakdown numbers by using the same method and Marvel or Techron!

[StuttgartDavid]

H:
1) I vote for the decarbon, drive, and retest, but only because you seem captivated by this car. (Good luck trying to convince the current owner that sustained full throttle at 6000rpm in fourth gear, uphill under full load is good for her car . . . by the way, make sure the timing is not overly advanced before you do this, and fill it with very good gas.)
2) The fact that Tony said the #6 valves were loose isn't good news, though not as bad as if he had said they were tight. These are the conditions where you are more likely to burn exhaust valves.
3) Note that this engine had recent extensive work, yet it did not solve all its problems (and may have even induced some of them). I take this as confirmation of my opinion that rebuilds are no guarantee of security, and if done wrong, can often make things worse rather than better.
If a 911 engine has survived to high miles without work, this should be taken as a confidence booster, not a bad sign. Both electronics and Porsche engines fail, if they are going to fail at all, quite early in their life. If the thing has made it past 100-150k miles without failure, it is sure confirmation that the factory assembled it right in the first place, that the parts were properly broken in, and that the pieces, even if slightly worn, are wearing in proper relation to each other and are likely to continue to do so harmoniously for a long time. It is like actuarial tables for life insurance - even thought the average life span for the entire population may be 70 years, if you make it to 80, your life expectancy increases and you are statistically much more likely to make it to 90 than you are to die soon, because you have proven that you don't have many of the problems that kill most people early.
Any attempt at rebuilding upsets this established balance. Even if done absolutely correctly in a properly clean environment and followed by a proper break in regime, you still face the possibility that some of the parts will not bed in properly, or will have undetected manufacturing or assembly flaws. Few mechanics can do it better than the factory, and even then they face essentially random and uncontrollable risks on run-in.
My advise is to keep looking - there are many cars out there. Also, why a targa? Unless you need it for the George Hamilton tan, or as a sexual aid, buy a coupe - stronger, lighter, faster, and longer lasting!
-David
1974 914 2.0 track tool
1982 911 SC daily driver (175k and counting, heads never off)
1968 911S vintage racer under construction

[hopkinskid]

This may sound like a dumb question, but is there a sure-fire way to see if this is a carbon problem? Or will I have to take the decarbon, drive, restest, wait-and-see approach? If I can get this car for around the $11.5k range (in anticipation for a valve job), I wouldn't mind too much about "waiting and seeing". But is there any other way to see if this is a carbon issue?

StuttgartDavid - yes, I am definitely captivated by the car, but I will not buy on impulse. If that was the case, this car would be in my garage right now, and I would be crying to you all because I paid the full amount. Man, it sure is tough not buying 911SCs on impulse, especially around here (bay area), where every single one of them looks great. But this specific car is definitely what I'm looking for....all updates, not-too-high mileage, tranny/clutch in great condition, etc. Even the guy who did the PPI felt that this was a great little car, until the compression test.

The 1996 work was done because a leakdown showed 35% on #3. Mechanic found broken stud, so the rest is history (24 replacements, replaced valve guides, valve job, etc). It is suspicious that after 35k miles and 5 years, #6 shows signs of another valve job. The broken stud may have been to user error (I cannot confirm this), but other than that, the engine has performed flawlessly. If I get this car, I do hope that I have one of those exmaples where the engine goes 250k-300k, with a valve job in between, or something like that.

Why Targa? Well, not to sound like Forest Gump, but there are some things that I remember from childhood, and some things that I have forgotten. I don't remember my first couple Christmas's, or the moment I was born, and I don't remember the name of the girl that I first kissed in preschool. But I do remember being 4 years old and standing behind the driver's seat with the wind blowing through my hair as I rode in my uncle's 1972 911S Targa, having the time of my young life. After that, I've been sick with this thing called Porsche fever. And being in California now, I just have to have a Targa. I'm one of the few people who thinks a Targa looks better than a coupe (no offense).

Hopkinskid

[Jdub]

Hop:

This is tough. Do you assume that you can bring the cylinders back up to spec. via driving or are you looking at another valve job on the car?

I don't mean to question your mechanic, but I would at the very least find someone else who can again confirm that you have wiggle between your valve stem and guide. If this is the case, then you have problems as the guide will not wick the heat from the stem, which is bad.

OTOH, I paid 5.5K for a '78sc Targa with all the upgrades you mention, but had a bad 1st/2nd and had a comp in the #1 equal to what you are seeing. It was brought back to life by Techron runs and daily use. The 915 was rebuilt, and I performed the rest of the bits and pieces on the car (including rebuilding my own Targa top at a cost of about $175.00) so you can see that it can be done cheaply.

I think that you must really concentrate on that valve "problem" so that you can rest assured when you purchase this car. If it turns out that a valve job is needed, then use this fact to bring the price down around $8-9K IF the owner will swallow that figure. That would be a sweet deal.

Jw

[StuttgartDavid]

H: Understand the targa desire. Since you like this car so much, I don't see this #6 problem as a dealbreaker, as I also suspect the carbon issue. To answer an earlier question, yes, you could fix just the #6 head/ valves if it turns out to be a structural problem. That's the beauty of the 911 separate head design. 30k miles after a valve job, the others shouldn't need anything - any failures here will be due to material failure or malpractice. Practicality of doing only one bad head depends on if you can do the work yourself. A shop costs so much for the R+R and teardown/ reassembly that often the "may as well do it all while we're here" mentality starts to make sense. On the other hand, if you do the R+R of the motor yourself and bring it by pickup truck for benchwork at your shop, or do the teardown and reassembly yourself (pretty simple to pull just one head, except for resetting the dreaded cam timing), it could be quite cheap - only the machine shop services.
However you handle the work, I would abuse the PO must more than $11.5 if #6 does turn out to be more troubled than simple carbon.
But first, try the direct application of Berryman B-12 described before, followed by charging up the Sierra Nevada at speed and rpm with a tank full of ultra-highly concentrated Techron and high octane gas (and spot-on ignition timing). That should fix any carbon worries and rebuild your confidence in the car. Come to think of it, do that yearly with whatever car you wind up with!
Good luck, and remember - You can't go wrong with any Porsche, only more expensive!
D

[nhromyak]

Then again, if you REALLY like the car. Get it! and deal with it!

I got mine in Bakersfield CA. It was near my parents house. It was in the mid to high range for $16k at 119k miles. The owner would not budge on the $. I was down for the weekend and took a chance and got the car (no PPI, didn't even hear about them before I joined this forum, no compression checks, no time - weekend). No regrets after 11K + miles.

I know the Bay area is more $. That's where I was living at the time.

If you don't get it. Keep your eyes open and keeping searching classified in all the smaller areas (Bakersfield, etc.)

I didn't read that there is a valve guide wear problem in the above posts, however if there is, then you WILL need a valve job soon.

Good Luck!

[Jdub]

Shoot; what did I infer from this thread? My apologies for the loose valve guide-to-stem assumption!

So my post was based on this. If no sideways wiggle was found by your mech. on the valve(s) than please ignore my ramblings.

Now if this is a pure carbon buildup problem, with no "bad" valve wear than I'd recommend hammering the owner on price and take it from there. As other posters have said it is only a case of driving the car to right it.

Again, my apologies!
Jw

[Early_S_Man]

To hopkinskid and others that don't BOTHER to read the entire thread or threads I post a link to:

The 'carbon' problem under a valve is not something you put Techron in the gas tank and drive for miles or weeks to see if the problem will go away! The procedure I posted was for a carbed or MFI car ... CIS will be a bit messy, as you will need to remove the air filter and pour the B-12 Chemtool into the air box in the general vicinity of the intake runner for cylinder #6. Be sure to unplug the red fuel pump relay AND the 6-pin connector to the CDI-unit ... BEFORE you start pouring a HIGHLY-FLAMABLE liquid into that airbox!!! It will require an assistant to accomplish the procedure and compression test!

If you do the procedure I posted, the problem will either be solved or not ... the next DAY you will know whether the problem is fixed! Less time, total, than this thread has been going! ZERO miles have to be driven ... waiting for an answer!

If you can't handle doing a compression test with a gauge that requires you to remove all of the spark plugs and manage to thread a hose and fitting into a 911 cylinder head ... maybe you don't need to be considering a purchase of one of these cars!

[dtw]

I've read the whole thread/links Warren- so please don't bite my head off.

Looks like all the pricing/mechanical advice has been given, so i just want to know one thing- is the woman who actually knows how to double-declutch single? Would she consider a relocation to North Carolina? Meeeeoooowwrr.

Good luck with the SC. Keep a level head.