944 turbo common question
 

Hi guys,
I may have the opportunity to get a 944 turbo for about 7000$, except I still haven't seen the car. I own a 944 already and know of the common problems such as belts, water pump and obviously like any other standard car, tranny and clutch. However, I have never owned any vehicle that has a turbo in it, and therefore I was curious as to how I can tell if the turbo is working. At what speed does the turbo kick in..or is it's presence always felt? (I've heard of cars that have turbo that kicks in only after 60mph for example). Also, how can I tell if the turbo is functioning properly? Is there any other important things to look out for? I know the car has no rust, and will be inspected by a porsche garage...but I just want to be sure.
Another detail I was curious on, was do all 944 turbos come with seats that are more sportier than the 944 NA? It seems as though the 944 turbo setas are more of a hip hugger than the NA cars.
Any information would be appreciated!
Thanks a lot,
Mike

Porsche seats have stayed pretty much exactly the same through most of the years. The differences are in the many different leather/vinyl/cloth combinations you could order. Another difference is the amount of power and heating controls the seat has. Some are four-way power, seven-way power, etc..

The turbo on our cars are controlled by a computer and the accelerator position. There is a guage beneath the tachometer that reads 0 - 2 BAR. Further down your foot is on the accelerator the higher the BAR will rise and the more boost you have. Full 2 BAR is achieved on a stock turbo at about 3500 - 4000 RPM and with the gas pedal floored. There are chips you buy that work very well at allowing the full boost to kick in at lower RPMs like 2500 - 3000. This really makes a difference.

Don't worry, you will feel the turbo when it kicks in. It is quite a sensation.

Mike the seats you are talking maybe sport seats, they have larger side bolsters.

The bar guage shoul read about 1.8 at full boost. The best way to see and feel the full boost is in third gear floored from 3500 to 5500 rpm. If it is your first time you wont be looking at the guage but you will be hooked.

Here's one to peek at:
Take the dipstick out, look at it about halfway up. If it's brownish in the middle area, the car has had its share of hard driving. A clean dipstick would show good maint. (Of course it could mean a replaced dipper) The dipstick tube runs right down past the turbo.

Sport seats, an option on both turbos and n/a's, are the ultimate factory "hiphuggers". They are very desirable.

[Long but hopefully helpful.]

Mike,

The one thing I would add is be VERY through about checking ALL the intake and vacuum line rubber.

Turbos are very susceptible to loosing power due to even a small hairline crack in an intake boot or vacuum line etc. And due to the extreme heat under the hood of a turbo, the rubber WILL become brittle and crack over time.

At idle or normal driving with negative or moderate pressure in the system everything may seem fine, but as soon as you get into positive boost, the problems will begin to show.

The best way to check the intake boots is to look for the tell-tail oily residue on the rubber. (If you were to take off one of the intake boots, you’d see there’s a lot of oil inside. This is normal, but if there’s a crack, oil will seep out under pressure leaving the residue on the outside.)

Also, inspect ALL the intake boots by squeezing the rubber. It should be somewhat soft and pliable. Look closely at all bends and joints in the casting of the rubber. These are the places fractures are likely to occur. Also another indication is excessive bulging in the intake boots. Sometimes the opposite can happen and the rubber becomes TOO soft..

I found that even though all the rubber in my car LOOKED perfect, it wasn’t until I examined them closely that I saw the cracks. And even though I THOUGHT the car was running just fine, it wasn’t until after I replaced all the rubber that I realized how much power I had been losing.

One good way to check the vacuum system is to turn on the heater and see if it works properly. If it doesn't come on or if once it comes on, it wont turn off, that's a good sign the vacuum system has a leak somewhere.

Oh, one last thing, though they don't often go out, it's still not a bad idea to check the waste gate. This is pretty easy. When you first start the car, (BEFORE driving it) let it idle for a moment or two and then reach under the car (on the passenger side) and feel the small bypass pipe that comes off the waste gate and goes into the exhaust after the catalytic converter. If the waste gate is operating properly it should remain closed and the pipe should be cool to the touch. If it's hot, then the waste gate is stuck open.

If the owner was driving the car just before you look at it, the bypass is likely to be hot, so give the car a few minutes to cool down before checking it.

Also, after driving the car, check it again. (Of course, be careful not to burn yourself) If the bypass is still cool, that means the waste gate is stuck closed, this too can be an indication of a leak in the vacuum system.

FYI- Some people may deliberately detach the vacuum line to the waste gate to keep it closed. While this may seem desirable, (because you’ll get quicker spool-up and more boost) the waste gate is there for a reason…. To prevent you from over-boosting and blowing up your motor.

Good luck, hope this helps.

Hey Doc:

I noticed that the vents in my car always have air coming out of them, even when the fan knob is at zero. I noticed in your reply that this may indicate a vacuum leak? Also, the fan blower doesn't work on 1, 2 and 3, but works on 4. I'm guessing that's the resistor? Where exactly is this resistor? Thanks,
S

Yes, that's right, the fan IS ALWAYS blowing. In the #1 position it gives me just about the right amount of air. If it's too much, I just send it all towards my feet.

Mike, you didn't say what year this 944Turbo is? For the '86 951s, you can get decent condition ones for $4500-6500. For $7K three years ago, I got a MINT condition 951 with leather seats, optional Fuchs wheels, new tires, Saratoga glass sunroof, recent service, etc. There were more '86 951s made than all the succeeding years combined, so their prices tend to be lower.

The newer '87-88 951s can be had in decent shape for $8000-10000. THe limited edition '88 TurboS and all '89 are usually in the $10-13000 range for good samples.

So I'd take my time and shop around. Definitely take it to a Porsche-knowledgeable shop for a full pre-purchase inspection. Have them check the compression, condition of belts, ball-joints, brakes, clutch, AC, etc.

It's SO much better to pay an extra $1000 or so for these maintenance items in tip-top shape or else it can easily cost you $5000 in repairs.

SM,
Danno's correct, The fan will always blow (at least a little bit) even when it's in the off position.

As for the problem with the other positions, it just so happens I recently noticed the same thing. However since my car is a track car... it's not a big issue for me so I haven't really worried about it. I'd be interested to hear what you find. I would suspect you could spray some electronics parts cleaner in there and work the knob back and forth to fix it. Usually the "pot" gets dirty over time causing the problem.