Several Questions
 

I have several questions about my 1988 base N/A. I'm going to split my post into two sections. The first part will be entitled Why? and the second will be called ZOMG what's going on???.

Why?
1. Why does the little inline 4 in my N/A need a balance shaft? My VW Golf has an inline 4 diesel engine and it doesn't use a balance shaft. I'd assume with a diesel engine it'd need something to cut down on vibration, but it's just bolted in there.

2. What's the point of the 21 gallon tank? It seems like a bit much. Is it to add weight to the rear of the car so it's balanced better?

3. Why did Porsche put 2/4 at the half tank mark instead of 1/2 like every other car in the world? Was simplifying fractions unheard of back in the 80's?

4. What's the point of the rubber boot under the shift boot? I believe they call it the "inner shift bellows"?

5. Why does the little 4 cylinder engine need over 6 quarts of oil? It's not an oil cooled engine, right? I don't think my dad's truck even uses 6 quarts and it has 4 more cylinders...

ZOMG what's going on???
1. My N/A seems to rev very slowly while accelerating. Even with the pedal to the floor it takes its sweet time to rev (I'm not lugging the engine). This is my first gasoline powered N/A car (the only other car I've owned/driven is my turbo diesel Golf). Is it just an N/A thing?

2. My fuel tank gauge is way off. I filled my tank beyond full the other day and it says I only have 3/4 of a tank? Also, the needle bounces while driving.

3. I have a grinding nose coming from behind the engine just before the shifter when I coast in gear. It goes away if I accelerate/put it in neutral. I believe my car still has the original rubber centered clutch disk. Could it be the clutch, or are my torque tube bearings dying?

4. I have to crank my car for a few seconds before it fires up. My battery is almost always super weak or dead (I need to replace it), so the engine turns kinda slow. Could the slow turning engine make it take those extra few seconds, or could there be something else causing my engine to take longer to start?

Thanks,
Jeff

Hi Jeff,

I saw your first post-welcome:
http://forums.pelicanparts.com/6615175-post1.html

Why?

1. The 4 cylinder is half of the 8 cylinder 928.
If you took the BB balance belt off the fuel rail would vibrate at idle and the oil pickup tube might crack. Just a few of the problems.

2. Gas tank. Correct

3. Designer was from Germany and ROW prefers 2/4.

4. Sound deadener just like the foam sound absorber below it.

5. EDIT --6 quarts of oil are for improved lubrication at high RPM-overhead cam and crank prone to eat bearings.

ZOMG

1. The throttle body cam is designed for fuel economy. A new version of the throttle cam is available

2.. Clean the fuel tank sender.

3. Rubber center clutch? You must have gotten a good deal. You and your father will spend a couple of weekends on your back changing the clutch and have a first aid kit.

2nd EDIT--I reread your original post. Transmission?
http://forums.pelicanparts.com/6633435-post16.html

4. Get The alternator/regulator/battery checked before it distroys the car computer DME.

Yes and also may have a leak down fuel problem.

Read Clarks Trouble Shooting page. Better read everything on Clarks.

Troubleshooting - Engine

GL
John

I'll add a little bit.

Without the balance shaft, at sub-4k RPMs (normal street driving), things would break. If you decide to run solid motor mounts and no balance shafts, things do vibrate enough to break. These engines, by design, develop a large resonance at 2k and 3k RPM.

The rubber boot, aside from sound dampening, is also a heat insulator. Without it a lot of heat passes through.

Technically, all engines are oil-cooled. Most, if not all, engines are designed to have some amount of oil cooling system. On the bottom of the oil pan there are a row of maybe twenty fins - this works just like a radiator by creating more surface area.

As for the slow RPM increase, well, there isn't a Turbocharger! The stock throtttle cam does do something, but for the final 75% of throttle travel its the same ratio as the aftermarket one. Only the first 25% or so is a different ratio, done for easier driving in traffic, etc.

Take care!

The differences in vibration and resonance dampening between the 944 and the VW are different in the fact that the VW has a Vibration Dampener attached to the front of the crankshaft - looks like a solid "V" belt pulley, of course without a belt. This type of dampener is proven to work, but not near as well as the counter rotating balance shafts of the 944s.

So is that why it's slanted? They just took it, cut it in half, and called it a day. Obviously there's more to it than that, but I just simplified it a bit

Hmm that's odd.
I see. I need to replace the foam under it. It's all dry rotted and gross :(

Pfffft, who cares about fuel economy? I've seen the new throttle cams and I am defiantly going to pick one up once I recover from the $3000 I just spent on a lift and parts.

I got the car for $3200 ($3000 for the car and the other $200 was for the PO being super nice and dropping it off at our house). It came with service records (almost all services were done at a NAPPA Auto Parts store :eek:), owners manual, a Porsche calendar from 1988, an extra set of rims, and some other goodies.

I've seen clutch replacement threads and it does not look fun :( I've replaced the clutch on my Golf an I thought that was bad, but the procedure for the 944 makes replacing my Golf's clutch seem like a walk in the park.

I need a new/rebuilt transmission, or have this one rebuilt. I've gotten quotes and no matter which I choose it will still cost me in the $1800-2000 range :(

How would a dying battery destroy the DME?

Thanks! I'll check that out!
Does the compressed air from the turbo help force the pistons down, resulting in a faster revving engine or something like that? It mainly has a hard time picking up RPM's while accelerating up a hill. This is with the pedal to the floor, not just leisurely driving around town. I don't just mash the pedal at 2000rpm, I usually wait until around 3600-4000rpm when the power starts to kick in to give it full throttle.

It's not like I'm trying to race or anything. It's just something I noticed. I really don't mind how slow the car is (well, it's not "slow", but it isn't "fast"). I also like RWD A LOT better than the FWD in my Golf! :D

I've never noticed anything like that on my Golf. I'll have to take a look and see.

Sorry for all the ninja edits yesterday. After posting this more and more stuff kept popping into my head throughout.

The 2/4 makes sense to me, if not just for aesthetic reasons.

the rubber inner shift boot also acts as a seal to keep noxious fumes from entering the cabin

The turbo increases air density and makes the engine more powerful. Airplane engines lose power as they climb because the air is less dense. Turbo or Super charged engines make the air denser so the engine thinks it's at a lower altitude, thus making "sea level horsepower. When the turbo cuts in (typically at higher rpm's) you're actually creating denser air for the intake and creating more horsepower. If you've heard the term "turbo lag", it refers to the turbo not doing it's thing until the higher rpm turns the turbo faster.

your 944 has no HP to begin with and certainly less TQ thn your diesel. Of course it will feel different when driving than the Golf. Maybe search for HP/TQ charts to compare the two motors to see what I mean.

What you need to do is find another (local) 944 to ride/drive in to see if what your car does is much different.

21 gallon tank -excellent - means 400+ miles on a tank. Germans, of course, put large tanks in cars built for crusing long distances at high speeds. Early 944s, iirc, only had 18 gallon tanks?

imho, all 944s are "slow starters" that sound lazy... indeed, its possible you have an electrical issue, but again, comparing to another one might be a better solution.

Yeah, I've heard of turbo lag. It's one of the reasons I stayed away from the 951 (I hear the lag is awful). Plus I'm tired of the annoying "oh **** the turbo just kicked in!" surprise.

The only thing I like about the diesel is the torque and how I can blow soot on tailgaters (I don't blow soot to "show off" or anything like that. Just on annoying people riding my ass). This may sound odd, but I kind of like the lack of power in my N/A.

I've only seen one other 944 (or maybe it was a 924? I saw it from a distance without my glasses on) in my area in the 19 years I've lived here. Does anyone on here live in Sykesville MD? I think my lowish power is due to my engine needing some routine maintenance.

I don't mind the 21 gallon tank. I was just wondering why they chose such a big tank.

One thing I do not like about my N/A is the brakes. While trying to slow down for a stop sign at the bottom of a steep hill the pedal just kept sinking further and further to the floor with minimal slowing down. I tried to use the e-brake to help, but it didn't do squat. Luckily I managed to stop without going through the intersection. I can still lock the wheels if I haven't used the brakes much/at all (which is actually kind of fun for some reason. I don't care if I wear flat spots in these crappy K-Mart tires the PO put on), but they fade horribly.

It sounds like you need a brake master cylinder. The sinking of the peddle is because your master cylinder is bypassing internally.

It's either that or the brake fluid has not been serviced in years. So it's full of air and water which is typical. Change out the fluid completely with Super Blue and bleed the system.

+1 on flushing the brake system.

The proper way to do that is to drain the fluid reservoir then fill with DENATURED ALCOHOL (available at Home Depot, Lowe's etc), then bleed each brake circuit until the alcohol runs clean and clear, then refill and bleed with brake fluid. When you bleed the brakes, always start with the right rear wheel (furthest from the master cyclinder) and left rear, right front and finish with the left front.

ATE Super Blue is a good fluid to use at this time , because the blue color will get fairly dark when the alcohol is gone.

Morning Bob...A bit off topic, but are you going to the Friends of Steve McQueen Car Show at Boys Republic in Chino today?

Definitely get those brakes up to par. Stopping is more important than accelerating.
Does sound like you need some servicing on the car, should accelerate better than you describe.

Fluids/oil are on my list of many things to do. The first thing I need to get done is the timing belt/water pump/balance shaft belt/rollers.

Any thoughts on this? How would a dead/dying battery hurt the DME?

Bad alt/reg can cause line spikes...those can be death to the DME

I see. I think it's just the battery. It's some 15 year old crappy NAPPA Auto Parts battery one of the PO's put in. I'll try either a genuine Porsche battery, or some other sort of high quality battery and see what it's like. If a genuine Porsche battery is unbelievably expensive (like everything else is on this car...), then does anyone have any recommendations?

I had dead/weak battery issues with my Golf as well. I replaced the Walmart brand battery the PO put in with an OEM battery and I was good to go after that. Hopefully the same thing will happen with my 944!

Thanks for the help everyone! I just need to save up another 500 million dollars and I can get crackin' on my 944! :D

Interstate battery....Porsche is about twice the price as an Interstate.

Sykesville MD - Part of the world covered by the Chesapeake PCA region.. Also, large NOVA/DC/Baltimore contingent of porsche folks hang out here (Dorkiphus.net - NOVA/DC/MD Porschephiles).