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By Crumpler
#99533
I have nothing to back this up but my thoughts are that the market has not moved upwards for the traditional 928 that is sorted but has miles and needs some love.
Probably there are outliers, and early and late MY with low miles would still command a premium.
I haven’t seen any eye popping sales on BAT, and I thought I read that BAT was having some 928 fatigue, but I confess I haven’t been looking since I stripped the 86.5 for the track. Part of me doesn’t want to know;)
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By worf
#99625
928s have been increasing in value since the late 00s. An S4 auto that you couldn’t give away in 2005 for $7500 now fetches $20k+, is 15 years older, and thus in worse shape than it was when it was 1/3 the price.
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By Sazerac
#100384
Yes, the market has moved up.

Just another reference point. I got my 90 GT like new with 30k miles on it in 2011 for 30K. Impossible to find something like that now. A 100K GT that's decent can hardly be had for that now.
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By Ghosteh
#102446
Correct me if I'm wrong, but I think we saw a substantial jump in values over the last few years, but it may have slowed down to a slow trot over the last few months. At least I haven't seen any "wow" results on BAT or the auction reports like last summer.

I do think other collectible cars are still rising also, so maybe we're just floating along with the market in general, and not out front setting the pace. Too bad, because when I see how crazy 911SCs have become, it makes me wonder when people are going to wake up & see the 928 as every bit as good of a car.
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By checkmate1996
#103369
BAT recently sold an 84 euro which needed a significant amount of work (e.g. interior and WB/TP) for IIRC $45k....
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By worf
#103379
checkmate1996 wrote: Fri Sep 10, 2021 8:41 am BAT recently sold an 84 euro which needed a significant amount of work (e.g. interior and WB/TP) for IIRC $45k....
BAT has become the place where lipstick is placed on 928 pigs. Sellers knowingly selling TBF cars, etc., and some on forums complaining bitterly about anyone that attempts to illuminate the information asymmetry between buyers and sellers.

So… I guess that’s good?
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By checkmate1996
#103388
In this case, the seller appeared to do a good job being as transparent as one can tell with all the needs required and the interior spoke for itself and it still sold for $45k; which i think is good. I mean 911s of the same vintage/condition sell for >$45k all day long. Given the quality of these cars and road handling capabilities especially compared to a ferrari 308 and other similar super cars during that era, they are due. The gray market twin dizzy euros are a special car and should climb with them being the niche within the niche...
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By worf
#103408
checkmate1996 wrote: Fri Sep 10, 2021 9:24 am In this case, the seller appeared to do a good job being as transparent as one can tell with all the needs required and the interior spoke for itself and it still sold for $45k; which i think is good. I mean 911s of the same vintage/condition sell for >$45k all day long. Given the quality of these cars and road handling capabilities especially compared to a ferrari 308 and other similar super cars during that era, they are due. The gray market twin dizzy euros are a special car and should climb with them being the niche within the niche...
Agreed and can’t argue with any of that… at least in a context of “air-cooled 911 prices are illogical.” :tongue:

Twin-dizzy with needs goes for more-or-less sticker. Near-perfect S4s sit waiting for a buyer for a long time at 1/2-MSRP in the private market while TBF S4s are sold on BaT for 1/3-MSRP.

I always tell folks that I have no idea what their 928 is worth and that I can only tell them approximately how much it will cost to make their 928 meet their expectations (whatever those might be.)
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By linderpat
#103417
worf wrote: Fri Sep 10, 2021 8:59 am
checkmate1996 wrote: Fri Sep 10, 2021 8:41 am BAT recently sold an 84 euro which needed a significant amount of work (e.g. interior and WB/TP) for IIRC $45k....
BAT has become the place where lipstick is placed on 928 pigs. Sellers knowingly selling TBF cars, etc., and some on forums complaining bitterly about anyone that attempts to illuminate the information asymmetry between buyers and sellers.

So… I guess that’s good?
OK Dave, do you have an example of a BaT car being knowingly sold with TBF? I follow that site very closely, and I have yet to see that. For the record, I do not at all disagree with your call out for end play check on each auction of post 85 auto box cars. I agree with you. You also do it at or near the beginning of an auction. All perfectly appropriate for a known issue.

I objected to GB killing a guy's auction with less than a half hour to go. That was a very specific thing. I understand the arguments about head pitting, and low mile cars - I am an engineer too BTW. But I also know that each car is its own case, and the question is what is the maintenance history, as that is the tell as to whether there is a potential problem. These things are dealt with before the auction is in the final run. Now if I had evidence that a particular car was subject to a hidden defect that I knew about, I'd raise it even with a minute to go. It's about timing and about specifics.

For everyone else following along, I'm the guy Dave is calling out. I wouldn't characterize it as bitterly complaining either, but whatever. :beerchug:
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By worf
#103768
linderpat wrote: Fri Sep 10, 2021 11:24 am For everyone else following along, I'm the guy Dave is calling out. I wouldn't characterize it as bitterly complaining either, but whatever. :beerchug:
You are not the only example of BaT denizens displeased with some of my posts. BaT itself (either via human intervention or trained filters) has removed comments I have made on the subject of TBF in several 928 auctions.

It is reasonably clear to me, that with the new ownership, BaT is a different place now.

I didn't call you out by name here. But, you've opened the topic.

linderpat wrote: Fri Sep 10, 2021 11:24 am OK Dave, do you have an example of a BaT car being knowingly sold with TBF? I follow that site very closely, and I have yet to see that.
The TBF '90 that sold this spring changed hands too many times too quickly. I have 'off-the-record' first-hand accounts from several folks that make me very suspicious that the general condition of that 928 wasn't known (if not known, strongly suspected) when it was offered for sale.

linderpat wrote: Fri Sep 10, 2021 11:24 am I objected to GB killing a guy's auction with less than a half hour to go. That was a very specific thing.
I was totally oblivious to that auction having already made the decision to refrain from posting on most 928 auctions. (Especially auctions for 87+ automatics.)

Therefore I had no knowledge whatsoever of anything GB posted to the auction that wasn't illuminated in that thread.

As a result, I was completely flummoxed by the acerbic content and tone of your posts after my first one or two short posts. Especially after my long post, I felt that your tone was undeserved.

In fact when I realized that your comments to me had nothing at all to do with the content of my posts in that thread but with someone else's posts on BaT, I had to entertain the notion that perhaps you were 'happy' with the information asymmetry between 928 buyers and sellers and that's why I was painted with the same broad brush.

Rest assured that from now on, I will not make any negative posts about 928s on BaT even when I see something catastrophic or obviously misrepresented. And nothing to do with your posts in the thread on TOS. It's a decision I made prior to that thread appearing.

I'm the one that has to field the phone calls and e-mails from 'successful' BaT buyers. So, it's best for me to no longer have a presence on BaT so that I don't have to answer the question of "Why didn't you post (on my auction)!?!?"

Damned if I do.

Damned if I don't.

The best 928s are no longer offered on BaT anyway. The exchange of the very-worthwhile examples has reverted to the private market.

And yes, in answer to one of your TOS posts: every 928's head gaskets are rotting away. Even the head gaskets I installed last year are rotting away. I expect them to need to be replaced in 20 to 25 years or so. But, any 928 running factory-installed head gaskets is a time bomb that I think has a good chance of going off in the next 10 years. And since the earlier heads are more resilient than the later heads, the bombs will be synchronized.
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By linderpat
#103825
worf wrote: Sun Sep 12, 2021 1:08 am .......

And yes, in answer to one of your TOS posts: every 928's head gaskets are rotting away. Even the head gaskets I installed last year are rotting away. I expect them to need to be replaced in 20 to 25 years or so. But, any 928 running factory-installed head gaskets is a time bomb that I think has a good chance of going off in the next 10 years. And since the earlier heads are more resilient than the later heads, the bombs will be synchronized.
As I pointed out previously, that was never a question raised by me, or my point. Obviously head gaskets are a wear item and need to be replaced over time. I am not a total idiot (soome would argue this of course :evilgrin: )

My point - and for one more time to be stellar clear - is that I have questions about the incidence and seriousness of the pitting of the heads from coolant seepage around the gaskets in every case on a low mileage car (or any mileage for that matter). That is being painted as the newest most serious issue confronting us, and make the cars a lot less desirable.

Now that has been clarified on rennlist that it is an issue mostly associated with the 87+ engines. My point is that one cannot make a blanket statement about it - the condition, which obviously exists in certain cases (I've seen the pictures too), is dependent on a number of factors including maintanence history and coolant used, etc. If you and Greg are saying none of that matters, and that pitting will occur no matter what, then I would not touch a post 86 car and never recommend to anyone to buy one. They are ticking time bombs in need of replacement engines, and that is an unacceptable defect. I have a hard time believing that this state of affairs is actually the case. I have seen pictures of blocks where no pitting has occurred under circumstances where one would have expected it.

Anyway, from my standpoint, this subject probably has run its full course. Notwithstanding this, I have the highest regard for you, Greg, Stan, Sean, Pete and a few others, that keep these cars alive and us plebes with enough knowledge to keep them on the road. :beerchug:
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By SeanR
#103830
I stopped posting on any BaT auction that I didn't have personal knowledge of the car. Not worth the trouble or the nasty messages I got from owners saying I wasn't helping. Now I do get a number of calls/e-mails asking my opinion on certain cars and off the auction I have no issues answering questions posed to me. It's not up to me to guide potential owners with answers to questions not asked. If they want an opinion they will contact me.

There are a few guys on Rennlist who do their own work and it is freaking terrible work. Things look nice and pretty but if you look at the details on what they are doing, I wouldn't pass that work off as anything good. One guy in Houston is a prime example, likes to clean stuff but then does chincy shit instead of doing it right, posts his car up on BaT and people rave at how good it looks and it's hard not to pipe in about how wrong so many things are.

Personal experience on head gaskets, the 1990+ cars are the worst. I don't know if they used a different material on the gaskets but everyone I've had to tear down required welding on the heads because of it. Most are low mile examples that just sat. Took down an '80 Euro with 100k on it a couple months ago and while the gaskets were 40 years old, they looked pretty damn good, and that's usually what I find on the early cars.
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By checkmate1996
#103893
Being a long time follower of BAT, it seems to me that every marquee has their issues. For example, Air cooled 911s tend to leak oil if you change the seals the out. But no one cares. It seems “accepted”. Even 996 models are sky rocketing in price even with all their known issues. So, are we just really our own worst enemy when it comes to 928s?
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By checkmate1996
#103896
Being a long time follower of BAT, it seems to me that every marquee has their issues. For example, Air cooled 911s tend to leak oil even if you change the seals the out. But no one seems to care. It seems “accepted”. Even 996 models are sky rocketing in price even with all their known issues. So, are we just really our own worst enemy when it comes to 928s?
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By worf
#104168
linderpat wrote: Sun Sep 12, 2021 11:26 am As I pointed out previously, that was never a question raised by me, or my point. Obviously head gaskets are a wear item and need to be replaced over time. I am not a total idiot (soome would argue this of course :evilgrin: )
I think the 'conversation' is getting muddled by conflating head gasket deterioration and head pitting.

linderpat wrote: Sun Sep 12, 2021 11:26 am My point - and for one more time to be stellar clear - is that I have questions about the incidence and seriousness of the pitting of the heads from coolant seepage around the gaskets in every case on a low mileage car (or any mileage for that matter).
I understand this - that you are skeptical that every single 928 has deadly head corrosion. That's fine. I've never written that.

What I have written is that it is 'time' to replace head gaskets fleet wide because:
a) for early cars can we expect head gaskets to last for 40 years?
b) for later cars we know - strongly suspect at least - that their heads are more prone to expensive-to-fix corrosion.

linderpat wrote: Sun Sep 12, 2021 11:26 am That is being painted as the newest most serious issue confronting us, and make the cars a lot less desirable.
This I don't understand. Either knowledge is good. Or knowledge is bad. Or you do not believe what is being posted?

Or you believe that this is some unique-to-928's issue?

From talking with 'my guy' that does reconstructive work on everything from my client's heads, to Ferrari cylinder blocks, to one-of-one parts for Bugattis, deterioration of "plain" aluminum castings is not at all unique.

linderpat wrote: Sun Sep 12, 2021 11:26 am Now that has been clarified on rennlist that it is an issue mostly associated with the 87+ engines. My point is that one cannot make a blanket statement about it - the condition, which obviously exists in certain cases (I've seen the pictures too), is dependent on a number of factors including maintanence history and coolant used, etc.
Again, the only unqualified blanket statement I've made is that head gaskets cannot be expected to have a design lifetime in excess of 30 years.

The corrosion damage is a separate, but related issue.

linderpat wrote: Sun Sep 12, 2021 11:26 am If you and Greg are saying none of that matters, and that pitting will occur no matter what, then I would not touch a post 86 car and never recommend to anyone to buy one. They are ticking time bombs in need of replacement engines, and that is an unacceptable defect. I have a hard time believing that this state of affairs is actually the case. I have seen pictures of blocks where no pitting has occurred under circumstances where one would have expected it.
I've never made such statements vis-à-vis corrosion and you are applying a too-broad brush. First don't conflate block corrosion with head corrosion. Next realize that the 'time bomb' issue has two manifestations and that head corrosion is actually the least serious manifestation.

A deteriorated or 'popped' head gasket can damage the cylinder block.

Serious head corrosion just makes the heads more expensive to repair...

... unless the head corrosion is allowed to proceed to the point where the manifestation is just like a 'popped' head gasket.

I advocate head gasket replacement for the early cars for the first reason and for later cars for the second reason.

My many discussions with 'my guy' along with the TOS threads have brought me to the opinions I hold and have posted.

In particular:

- the later heads (90+) are more porous than the earlier heads. It is the porosity of the castings that makes the later heads more expensive to repair and ALSO what causes them to exhibit far more deterioration due to crevice corrosion when coolant is allowed to 'go bad.'

- ensuring that the additive package in the coolant is refreshed on schedule will limit corrosion.

- nothing we do will enable head gaskets to last indefinitely.

- a 928 engine 'marinating' in old coolant without being operated will exhibit less deterioration than a 928 with old coolant that is circulated due to once-per-month "warming up the fluids" operation. (All other things equal.)

- and last but not least, very few 928s that arrive at my shop come with since-new records that enable an educated guess as to the health of head decks (for '87+ where head deck health rather than gasket age is the concern.)

I have seen a set of garage-queen low mileage GTS heads with insufficient corrosion to warrant the expense of 'decking.' But, those heads came with records of on-schedule coolant changes, or long periods of dormancy immediately followed by a coolant change.

And of course, there's the '89 that *sat* for 14 years with the same coolant that required no welding.

A mid-mileage '91 with 20 years of records and no coolant flushes that was 'warmed up' once a month that required significant welding.

All the 32v heads I have seen with my own eyes exhibit head health consistent with the bullet points above to the extent of records (or previous owner stories) provided.

SeanR wrote: Sun Sep 12, 2021 12:21 pm Personal experience on head gaskets, the 1990+ cars are the worst.
The 90+ heads suck because of the casting porosity. 'my guy' has done enough heads for me now, that this is a hill I'll die on.

SeanR wrote: Sun Sep 12, 2021 12:21 pm I don't know if they used a different material on the gaskets but everyone I've had to tear down required welding on the heads because of it. Most are low mile examples that just sat. Took down an '80 Euro with 100k on it a couple months ago and while the gaskets were 40 years old, they looked pretty damn good, and that's usually what I find on the early cars.
I'm not sure exactly why, but what you wrote above and/or exactly the way you wrote it, make a mental gear turn in my head.

How many places in PET (or at least old PET) do we see "gasket" and on the next line down "gasket (without asbestos)?"

I did a few minutes of googling...

In 1987 the US passed a law required all automotive stuff to be asbestos-free. No doubt this came after Europe did the same thing.

Asbestos was used in automotive gaskets.

Was it ever used in 928 head gaskets? If so, when did it stop?

If 928s stopped using head gaskets with asbestos in MY'87, or '88, or '89, would that further explain why we see 16v head gaskets that look better than 10-year younger 32v head gaskets?
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By Sazerac
#104563
worf wrote: Tue Sep 14, 2021 12:53 am
.....

- the later heads (90+) are more porous than the earlier heads. It is the porosity of the castings that makes the later heads more expensive to repair and ALSO what causes them to exhibit far more deterioration due to crevice corrosion when coolant is allowed to 'go bad.'

- ensuring that the additive package in the coolant is refreshed on schedule will limit corrosion.

- nothing we do will enable head gaskets to last indefinitely.

.....

Asbestos was used in automotive gaskets.

Was it ever used in 928 head gaskets? If so, when did it stop?

If 928s stopped using head gaskets with asbestos in MY'87, or '88, or '89, would that further explain why we see 16v head gaskets that look better than 10-year younger 32v head gaskets?
Unfortunately, this is the wrong thread to have such an interesting discussion about things that are more technical in nature and don't really affect the value. I just picked out a couple of the interesting points here.

1.) This also looks to me like crevice corrosion that is significantly related to material properties of head gaskets, aluminum casting inconsistencies, coolant, etc. Despite the noise level "over on the other site" by certain very loud vendors, I vote crevice corrosion.

2.) I have been saying for a long time as well that the head gaskets could play a role. My first hypothesis was that manufacturing tolerances with base materials could be a problem, but about 4 months ago I also became aware of the asbestos issue. It is possible that the older head gaskets were simply better. This would mean that new head gaskets might not last as long as the originals. Who knows? It will take years to get data.

If you recall, the longest thread "over on the other site" was started by somebody with a recent HG change that had already had pitting that started after he went back in 3 years later for other reasons. Many people blamed it on the coolant G05. I didn't buy that. This is definitely a complex problem with lots of variables.
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By Fox_
#104614
^^^This thread went better than I'd ever expected.

For a short while I had a job that involved aluminum work boats and salt water. Given any opportunity for a galvanic reaction, they rot QUICK. I'm not trying to say that's what is happening here, just that given the right conditions aluminum disappears....

With more and more engines made of aluminum these days, has anyone tried to talk to a head gasket manufacturer?

And another short clip https://www.youtube.com/wa[…]

Great thread :rockon: I thought it was a gre[…]

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Panorama September 2021

great representation ~!