Question about 1990 Porsche 928

2 Answers

My 928 GT

When I initially got my 928 GT, I got it at a great price, assessed value from an appraiser was nearly double what I paid for it!

now, there are the obvious electrical gremlins, but the body is in great shape, and for the most part it runs exceptionally well.

Now, here are my two problems, for the most part, the engine has run great, but sometimes runs a little rough, and after running it through a high pressure wash, it stalled out, couldn't figure out why at first, ultimately determined water got in through the intake, popped off the air filter, which I discovered had a sizeable crack in the seal (had already made plans to get it up to a Porsche mechanic in Calgary to fix the few things wrong with it), found that debris had gotten through the crack, and was sitting on the screen, I removed the debris (and later put silicon sealant on the crack to reduce the problem until I can find an air filter for the car), assuming smaller debris had gotten through the screen....started the car with the air filter off....after a few tries it quickly roared to life...problem solved, however with the debris, I suspect the engine has gotten some **** in it, as it hasn't been running perfectly....will an engine shampoo solve the problem? or am I looking at some costly repairs?

Now, the other thing (and I suspect it's connected to the diff. issue), when I got the car, PSD light was on, meaning the PSD had been disengaged due to some problem.....that was one of the things I'd planned on getting fixed in Calgary....now, one thing I absolutely LOVE about my 928, is that while it might not corner quite as well as some other cars I've owned or driven, it's an AMAZING drift car....NEVER experienced a car that was so easy or precise to control while sliding sideways at high speeds.....anyway, one day when I took a female friend of mine for a drive, I drifted a few corners, and found that around the 4000-5000 rpm mark there was significantly less power than normal, and a great deal of vibration in the shifter accompanied by a bone chilling rattle that sounded like gears grinding behind me....also, tires weren't spinning like usual, not entirely clear on the drivetrain setup of the car, but from what I understand of it, this is a good sign the differential is going.....is this the case? will the Diff (which I understand is amazingly durable in this car) need to be replaced? or will a simple rebuild do?

plz....I need to know what kind of expenses I'm looking at here...so I can budget....(I do have approximately $4000 to put into the car, but there are other things I'd like to get done as well.)

Posted by on

  • 2 more comments 
  • jhudes Oct 15, 2008

    Engine shampoo is what I've heard it referred to when they pop off the valve cover, and give the internals of the engine a good cleaning.....typically costs about $150-300, and in my experience, makes the engine run a lot better.



    The PSD light is the warning light for the PSD (as I'm sure you know, Porsche's version of an electronically controlled Limited Slip Differential).

  • jhudes Oct 15, 2008

    Engine shampoo is what I've heard it referred to when they take off the valve cover and give the internals of the engine a good cleaning.....generally costs $150-$300 and in my experience, makes the engine run alot better (witnessed in an EF Civic Si used for rally racing....dialed in a 4 hp increase, and better fuel economy and crisper, smoother engine idle, and crisper sound at higher revs).



    The PSD light is the warning light for the PSD (as I'm sure you know, Porsche's version of a Limited Slip Differential).

  • jhudes Nov 01, 2008

    thanks, lol, I'm not too concerned about cost, I intend to keep it as a show car rather than a daily driver (it's a great drift car btw), so maintenance will not be so bad. I was well aware of the electrical gremlins, but after finding one in such decent condition, at the price, I had to get it. I've already had offers double whatI paid for it from some true car enthusiasts, so worst comes to worse, I can always sell it (though I'll have to do it at the right time).



    The crack was in the air filter, not the intake.



    Yeah, it's going to Two-Square in Calgary in the next week or so...the mechanic I've been speaking to has owned several 928's and seems quite passionate about them.



    Thanks for your input. Out of curiosity, would it be a feasible modification to move the fuse box/relay panel to a better protected location?

  • yadayada
    yadayada May 11, 2010

    What is engine shampoo? What is a PSD light? To much info, short sweet and to the point, thanks

×

Ad

2 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

I just bought a 1990 928s4 and it also has the PSD light on, meaning the PSD had been disengaged due to some problem....
I was wondering what jhudes on Oct 15, 2008, found out about the problem, and what work was done to fix it, and the ultimate cost
Please respond!

Posted on May 06, 2010

Ad
  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that hasĀ over 10 points.

    Mayor:

    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 18 Answers

Let me give you my heart felt feelings of sadness for you. I love the 928's. They are positively one fo the best touring / GT cars ever produced. But they have a huge failing, the electrical system. I worked for Porsche for 15 years and I have seen some wild S**T in those electrical systems. Why Porsche decided to put the fuse / relay panel right below a huge hole in the cowl that will, someday leak, is beyond me. The 928 is the most expensive Porsche to own now. You know just try to find parts and when you do they are gold. As a mechanic I had to finally sell my 928 GT S4 because I could not keep it. But I can keep my Lotus Esprit S4 and Hummer H1 because the 2 of them did not cost as much to keep.

Doing a 'top end' cleaning, if this is shampooing will always be a good thing. Also if there was a crack in the intake after the MAF sensor (thing with screen) the previous owner whould have to have the diaphram adjusted (little hole in the middle of the octipuss) to compensate. This takes a special, very long allen on a swivel end to adjust. Again this has to be done be a qualified mechanic.

Unfortunately without having my hands on the car I really have to say get it to a qualified person and leave it there. A true "friend of Porsche" will work with you and try to keep costs down by working on it in down time. There are a lot of prople that dont know the 928 find an old time Porsche guy that just loves the cars. Good luck.

Posted on Nov 01, 2008

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

Which one is a better car with fully loaded features and performance, a Honda City 2017 or a Verna 2017?


Both the Sedans are a high class model, which having good mileage, superior looks and best in class interior features. Here, I highlight the comparison of both the sedan diesel variants having same price, so to make your decision easy, have a look

Hyundai Verna (Diesel)
=> The Hyundai Verna Price is 11.40 Lakh
=> It has 1.6-litre 16V U2 VGT Diesel Engine which produces 126.2bhp of power and 260 Nm torque.
=> It has the Mileage (ARAI) of 21.02kmpl with 4 values per cylinder.
=> Top speed is 196 km/hour and 0-100kmph within 10.5 seconds.
=> It has 6 Speed automatic type transmission with 1582cc engine displacements
=> It is a family car which has the seating capacity of 5 people along with the 480 litres of cargo volume & 45Litres fuel tank capacity.

Honda City (Diesel)
=> The Honda City price is 11.47 Lakh
=>It has 1.5-litre 8V TDCI Diesel Engine which produces 99bhp of power and 215Nm torque.
=>It has the Mileage (ARAI) of 25.6kmpl with 4 values per cylinder.
=>Top speed is 160 km/hour and 0- 100kmph within 12.5 seconds.
=>It has 6 Speed manual type transmission with 1498cc engine displacements
=>It is a family car which has the seating capacity of 5 people along with the 510-litres of cargo volume & 40Litres fuel tank capacity.


verna vs city-phdmgusq2wrosyx4u3bnlx0j-5-2.jpg After comparing the features and specification of both the sedan, I will suggest you to go with Hyundai Verna 2017.

Aug 29, 2017 | Hyundai Cars & Trucks

1 Answer

I need 3 regulators for 3 of my windows, a timing belt, and a water pump...trade it in or fix it up and keep it..almost paid off...


if you trade it in, its up to the dealer to spot the problems when they do a appraisal for the part exchange price,KEEP YOU MOUTH SHUT.if they offer you a fair price then you decide.its not like your selling it to a friend is it.....if the price is low then walk and make the decision after pricing up the parts and if you can do the job yourself all the better, if not you have the choice of where you buy the parts.genuine or pattern......and who does the job of fitting them.

Jan 31, 2011 | 2003 Volkswagen New Beetle Convertible

1 Answer

I believe the motor has blown. I'm not sure what to do with the car or how to go about getting a good price for it. the inside is in a tidy , clean condition and there is a minor dent at the left rear of...


I would find a shop that will perform some economical but enlightening tests to determine the extent of the damage and the cost of repair. The value of a non-functioning car greatly reduces the buyers market for it. Place some local ad's for it as a mechanics special to test the local buyers for what it may be worth. Then, taking that number, add in the cost of the repair, and if this number is greater than Blue Book Value (KBB.com), then sell as is. If however it "books out" at a number higher than the cost of the repair and broken sale price, then it may be worth investing in the repair in order to sell it solidly at book value as it would have the new repairs to the engine.

Of course so much of this is contingent upon your local market and that car's popularity in your area. Most of the time with cars nearing ten years old the best value in the car is to just keep it running. Either way the basic formula above will help to keep you from loosing money.

Nov 01, 2010 | Subaru Impreza Cars & Trucks

1 Answer

I have a 97 grand am gt with 3.1 idles fine but normal acceleration and cruise is nearly impossible. Bogs down at all speeds. Hard acceleration is fine goes good.


I had the same problem with my 89 grand am it was caused by a faulty crank position sensor. Initially it would cut out when accelerating and eventually wouldn't start at all, replaced the sensor runs great again.

Aug 22, 2010 | 1997 Pontiac Grand Am

1 Answer

I paid 8388 dollars for 2001 mustang convertable manuel shift is this reasonable


yes this is a comparable price. engine and trans really hold their value plus the addition of the convertible top. you did ok.

Apr 06, 2010 | 2001 Ford Mustang

1 Answer

Porsche 928 s4 - Transmission whining


tourque tube bearing need replacement. $672.00

Jun 29, 2008 | 1988 Porsche 928

Not finding what you are looking for?
1990 Porsche 928 Logo

744 people viewed this question

Ask a Question

Usually answered in minutes!

Top Porsche Experts

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

ROBERT GARCIA
ROBERT GARCIA

Level 3 Expert

917 Answers

yadayada
yadayada

Level 3 Expert

78267 Answers

Are you a Porsche Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...