Jeff323

Hello everyone,
This is my first time posting. I am looking for some advice on the potential purchase of an '89 C4. I've never owned a Porsche before, but it's been a bucket list car for me for a very long time. I've owned many German cars over the years, but now may be the time to take the plunge into the Porsche world.

I've tried to do a lot of research on 964's and especially C4's recently and think I'm fairly educated now, but having never ownened an air cooled 911 before I'm still a bit concerned and don't want to make a big mistake and get the wrong car. Admittedly a C4 wasn't my first choice (mainly from a maintenance and complexity standpoint), but I'm not opposed to owning one either if it's a good car. The story with the car in question is its owned by a friend of my wife's and because he knows I'm a big German car fan he randomly offered the car to me the other day. It sounds like I might be able to get it for under 30k too, so while a C4 scares me, the price makes it potentially worth it. I will be seeing it for the first time this weekend, but here's what I know so far...

It has a little over 160k miles on it, but the engine was completely rebuilt a few thousand miles ago and a new clutch was also installed.
A new windshield was installed recently as well and any rust that was found (very little from my understanding) in the channel was also repaired. It's said to run and drive very strong and to present itself as a good clean driver's car, but not concours quality.

Known issues are:

1) ABS light is on on the dash (I'm aware of the ABS and AWD issues these cars can have so that's a concern for me).

2) A/C doesn't work (not a big deal really).

3) HVAC blower motor speed has a mind of its own

4) Driver's seat side bolster is ripped or seem is split

5) Passenger lower molding is loose (clips broken or missing)

6) Fuel vapor smell coming from the tank (sounds like a filler neck would fix this)

I may be forgetting something but I think that's most of it.

I'm a competent mechanic and I am currently restoring an 81 BMW 323i that I've owned for 20 years. I am also a helicopter mechanic, so I'm very capable of doing any work or maintence this car may need, but I'm also not looking to break the bank on repairs or get into another restoration project. I would not purchase the vehicle before getting a PPI done, but before that do you have any tips for me and what I should be looking for and concentrating on this weekend when I look at it? I know oil leaks are an issue on the early cars, but does a rebuild now mean I should be a lot safer from that issue now?

Thanks for any help and insight you can give!

Mixter

964's are great cars and you won't be making a big mistake with a C4. Problems with C4's are rare. Maintenance is relatively easy. It just takes a little more time and a few more steps to bleed the system.

greg1990964

Sounds like you're pretty well
Educated and lined up to buy or not. Look forward to hearing what Happens with your sale. PPI is always a good uses depending on seller and asking price. My collection would not exist if I had I insisted on it. A few (one) seems to have a problem with buying cheap and rolling the dice. Good luck, we are are here to help.

Jeff323

Thanks guys. So what's the concensous on potential oil leaks on a rebuilt and resealed engine? I realize there's no way to perminently eliminate any possibility, but when one is rebuilt these days does that make them about as reliable as any other 911 engine with regards to leaking?

cscrogham

As a victim of the 964 Carrera 4 love/hate curse, I can give you some insight on your list.
1. Prob hydraulic pump, see if it is leaking between the connections. They are about $1900 new (wouldn't trust a used one). C4 needs this working for not only brake pressure and proper pedal feel, but also diff locks etc. It runs everything.
2. Don't think like I do "No big deal" turns into thousands of dollars, the front fans alone are a grand EACH!! URO sells a decent replacement but still several hundred plus a monumental pita to change. Prob related to #3, get the condenser update for front fan, convert to 134, get new fans, check operation of rear engine fan (at which point you will find the really access panel will be welded to the post, etc).
4.There was a great nearly new set of Sport Seats (the BEST seat) for sale here not long ago for a few thousand, I would do that before trying to repair. If you are lucky you have black interior, mine was grey and I was lucky enough to not have significant rips or tears so had them re-dyed which turned out looking great.
5. They are a few bucks each and a piece of cake, get enough to do both sides, when you remove again for inevitable oil tank/fitting/thermostat leak they will break again hardest part is getting the seal to line up properly.
6. Try filling up half way

Good luck! C4's are great cars!
Cole

me964

well, with your mechanical background, potential problems will be easy peasy
at least a lot easier than for most of us ...


1) buy the C4 ABS/PDAS tester from Michael (very soon to be in production)

https://rennlist.com/forums/964-foru...-interest.html

https://rennlist.com/forums/964-foru...or-orders.html


2) not urgent for now, (took my a/c belt off 8 years ago and never looked back)

3.) probably minor electrical issue

4.) ask your local automotive/aircraft leather/interior guy

5.) minor issue

6.) has to be adressed, check tank ventilation and hoses



the price for that 964 seems to be hot (you won`t get that car overhere ín europe for the aforementioned amount)

Jeff323

So I got to look at and the car today and take if for a drive. Overall it presents itself pretty well and is as described, a nice driver. Some cosmetic work and elbow grease could easily bring it up a few notches in the looks department for sure I think.

As for the mechanicals, the engine sounds and pulls real strong. I did notice there seemed to be fluid around where the power steering reservoir is, so there probably is a leak of some sort.

The ABS and AWD warning lights that come on appear to be intermittent. He told me he thought they may be related to hitting bumps in the road so he's thinking its a wiring issue, not sure I buy it but it did happen with me in the car so maybe faulty sensors or possibly a bad ground ? After talking with the owner it sounds like he has never changed the brake fluid in the 5 years he's owned it either though which I told him was a big no no, especially with these cars given the AWD system. I don't think he's put a lot of miles on it during his ownership, but it still is way overdue and not good to hear.

The other big thing that bothered me was the clutch is said to be fairly new (within the last 10k miles it looks like) but the engagement point is very high. So high in fact that I was having a little trouble making smooth shifts with it. It didn't seem to slip at all, but this concerned me a lot. Is it possible that whatever hydraulic issue the car is having is also affecting the clutch bite point? Other than that I didn't notice much else that seemed off or unexpected aside from maybe the brake rotors feeling like they were warped very slightly.

Not really sure what I want to do next. Part of me says to wait for a better example to come along, but then I'm not sure I'll find another one at a similar price. So providing a PPI doesn't raise any larger red flags I still may come out ok with this one. Tough call for me.

ezinternet

I've got concerns about this car as described. If the car has cosmetic defects and leaks, then it could lead me to wonder if the owner wasn't keeping up with mechanicals either.

Porsche made incremental engineering improvements to the 964 over the years - fixes and some different parts (e.g. suspension). You would be buying the V1.0 version.

- For example, does the car have the distributor vent hose update? If not, then it's an indication to me that decisions on maintenance weren't taken with a view to longevity.

- Similarly, there was a factory update to the gas filler hose/system. Was that done? Was designed to fix the venting/gas smell problem.

- What details do you have on the engine rebuild: who did it, what parts were replaced as opposed to refurbished, how much was spent?

I'd be cautious with jumping into a high-mileage car if the service philosophy was oriented to fixing what broke rather than proactive preservation.

You might be playing catch-up on repairs needed; and even with you doing the labor it could be expensive.

LM964

Does the AWD/ABS light go out once past 2,000+ rpm? If so it sometimes points to a battery voltage drop detected by the PDAS control. I had this for quite a while but the indicator lights would always go out (and stay out, even when idling) once past the 2k rev range for the first time. Never bothered me as I knew everything was working just fine. Eventually changed the battery and all good - no repeat (apart from the usual start up procedure until moving).

Completely flush and refill clutch/brake fluid. I did this when clutch and gear selection became 'sticky' and it changed everything (I collected 3 jars of black thick old fluid drained from clutch salve cylinder). Proably worth checking pedal adjustment/movement down in the pedal box - the rubbish footwell carpet also rides up and gets in the way of free movement occasionally (I cut all this right back).

Blower/aircon fans etc controlled by the CCU. If this plays up (and it does) then Tore is the guru here - checkout any of his threads and his site for full detail. In some cases a faulty CCU will also not pass a signal to the oil cooler fan either (low or high speed). After a good drive what's your highest oil temp reading on the gauge?

Passgenger moulding - not urgent or critical, unless you meant the interior passenger side lower dash moulding (protects passenger knee caps in an accident!).

Seat can be recovered or even repaired/patched easy enough by professionals.

Fuel smell, if from the filler area, should be straightforward to replace the whole filler neck. Check too the overfill drain is not blocked etc.

It's a 26/27-year old fine piece of Porsche engineering. However, it does need fettling and is a bit of an ownership lifelong project. If the price is right (and not on the tail of silly recent valuations) then it seems your more than capable of bringing it all together the way it needs. Once mechanically sound and safe, just keep using it. Dont be put off by too many oil leak stories - out the factory it's consuption value was 1.5 litres / 620 miles (which is quite high in the big scheme of things these days). Unless your getting constant driping from the crankcase or having to top up more than the factory value, I wouldn't worry about it. A high quality race/performance oil is a real treat for the engine and I find the harder I drive it the better it gets

Jeff323

I don't really recall seeing the distributor vent hose update. If I had to take a guess I'd say it probably isn't there. I saw the receipt for the engine rebuild and it listed new rings and bearings and a complete valve job with arp head bolts. Total bill was about $8200.

bweSteve

$8,200 full engine rebuild is inexpensive IMO. As EZ asked, who/what/when did the engine rebuild. Knowing the builder can tell a lot too.
My 964T engine was rebuilt 15 yrs ago, and I have not had a single engine leak over those entire years. Dry as a bone & running strong. So more details in that dept would help justify the price point.

LM964

Vent kit is cheap Jeff. £15 here in the UK and pretty straightforward to fit if you're a bit DIY handy.

Yup, any story the receipts can tell would really help, as is the rep of the garage/builder. Dates, specific parts/items etc. If not too long ago the garage/engine builder would still have their own records that may have more info for you. The cost you mention is typically a rough average for a top-end build these days, but depends when yours was done. You have a leak down test done on the cylinders yet? Readings for them would help.

tbennett017

These are all issues I have addressed on my car. Competent/can-do attitude and help of members here will get you through. Get a copy of Adrian Streather's 964 Companion book and read up on the maintenance and how the PDAS system works.

Maybe a bit of hyperbole on the fans. True they are expensive but but sounds more like fan resistors or other cheaper problems. The biggie is the PDAS issue, but check too that the brake fluid reservoir is full. The pickup for the clutch is higher than the brakes, and I wonder if you are simply low on fluid, causing your concern with the clutch takeup and the bump-induced warning lights. (Cheaper fixes are better, no?) This car is complex, but I have found over time that I have to resist the tendency to make problems bigger than they are through worry. You'll get the hang of it.