My First 944

[Nehmaiz]

Today i became the proud owner of 2 porsches, my second one being a 1989 944 automatic 3 speed tranny.

Some known issues about the car:

original Engine caught fire, another engine was sourced from a same year model. both Japanese origin cars.

current chassis number is WPOZZZ94ZKN401651, when i use Scouser's Vin Decoder it shows the car had the 3.0L DME Engine.

The donor car's Chassis number is WPOZZZ94ZKN404260 which shows that the engine was a 2.5L DME Engine... i thought 89 models did not get 2.5L engines!?!

Now the previous owner of the car says he's sure it's a 2.7L engine... i tried to check the engine number but could only find the crank case number 944.105.250.7R

89 model 944 cars should have the engine number on the rear right hand side of the engine, but i couldn't find any other code.

2) the car vibrates a lot when idle and when in reverse gear... i read about rough idles on 944s, but this one shudders bad, not sure if it's normal.

3) when on the highway cruising, there's a rattling coming from under the shifter area, sounds like it's coming from the tranny..

i expected the car to have some issues, i'm just hoping it's nothing major like a full transmission change.

any feedback on the above would help.

Thanks

[wvicary]

1- If it's a single cam engine then it's the 2.7 L, the 3.0 L has a twin cam engine which is very wide when compared to the single cam.

2- The balance shaft belt can break which cause excessive vibrations as does collapsed engine mounts.

3- Inspect the heat shields around the exhaust system.

[Nehmaiz]

1- If it's a single cam engine then it's the 2.7 L, the 3.0 L has a twin cam engine which is very wide when compared to the single cam.

2- The balance shaft belt can break which cause excessive vibrations as does collapsed engine mounts.

3- Inspect the heat shields around the exhaust system.

it's a single cam engine, so as per your answer it should be a 2.7L, but how do i know it's not a 2.5L as the vin decoder says?

i will check all of the above, many Thanks for your input!

[wvicary]

There is also a serial number on the engine block that will give you details. i can't remember where it is on the 944 but I think it's located on the left rear of the bell housing near the access window for the timing marks. I'll try and verify the locating tomorrow.

[Nehmaiz]

Thanks Guys,

i can say most of the work needed on the 944 is probably finalized, only issue is that the vibration is still there.

i've checked engine mounts and transmission mount when engine and gearbox were pulled down, they are perfectly fine. as suggested believe the next possible culprit is the balance shaft belt... however, the garage is quoting me 6 hours of labor just to open up the the balance shaft and check if it needs repair...

is that true, do they really need 6 hours to get to the balance shaft?!? is there a way i can do it myself and check it's condition? i don't want to end up paying 500$ just for checking if the balance belt is ok!!

Cheers

[wvicary]

You can easily check the condition of the balance shaft belt. Several 10mm head sized bolts retain the upper timing belt cover, remove these bolts, pull the cover back and you can see the balance shaft belt.

How did you determine the engine/transaxle mounts are "fine"?

[magcuda]

The motor mounts are hydraulic and collapse, this causes a vibration at idle.

If you raise the idle a little does the vibration go away?

[Nehmaiz]

@Wvicary:

the balance belt is not broken, that's for sure... believe that it's not timed well with the timing belt and that's what's causing the vibration i guess...?

regarding the mounts, they did not appear deformed and are in tact... what else should i look for?

@Magcuda

how do you determine of the mounting has collapsed?

if you raise the revs a bit the vibration goes away.

a little more info about the vibration: when you start the car in P it's there but the car doesn't shudder heavily... if you turn on the AC the shuddering increases, and when you put reverse gear the shuddering is at the maximum.... My GF jokes and says it's better than a vibrator!!

Thanks for the help guys, appreciate it.

Edited July 22, 2011 by Nehmaiz

[magcuda]

I have attached 2 bulletins, 1 is for the old style mounts and the other one is for the new style mount

Usually the balance being out of time is really felt at about 3200 rpm

CHECKING_MOTOR_MOUNTS.pdf

NEW_STYLE_MOUNTS.pdf

[Nehmaiz]

I have attached 2 bulletins, 1 is for the old style mounts and the other one is for the new style mount

Usually the balance being out of time is really felt at about 3200 rpm

Thanks Macguda,

Checking Mounts diagram in the first attachment is very interesting!

if it's not the mounts and not the balance belt timing, what else could it be??

Edited July 22, 2011 by Nehmaiz

[wvicary]

I would bet good money that the mounts have failed.

[Nehmaiz]

well in all honesty My 944 experience is turning out to be a nightmare...

i took the car yesterday from the indy only to get to the nearest petrol station and notice that it has spilled all the coolant and was overheating...

they fixed the balance belt timing and vibration was reduced 75% when AC is off... funny enough when AC is ON the vibration is much more... so there must be something related to the AC Compressor...

[wvicary]

I have seen a failing cooling fan cause a vibration. There are two fans, one is the main cooling fan and the other is the A/C cooling fan. I also recommend replacing the motor mounts.

[magcuda]

If you raise the idle slightly does the vibration get better?

If yes then the mounts are toast

[Nehmaiz]

If you raise the idle slightly does the vibration get better?

If yes then the mounts are toast

Thanks for your input guys, it seems like vibration is the least of my worries now... the coolant hose burst the other day straight after taking the car back from the workshop, so i took it back and they said that the coolant hose was old and worn thus cracked quickly under pressure, so they replaced it the hose.

i took the car again yesterday only to get home and notice the temperature gauge almost at the red point, so i stopped the car and turned off the engine, that's when i heard the coolant river falling on the floor again... the pipe burst again!!!

so now i'm thinking it's probably a blown head gasket that's causing extra pressure into the coolant system, or (Hopefully) the coolant tank's cap is leaking air into the coolant system.

any thoughts on this problem? i really enjoy this car, and actually think it's a beauty to drive, but if it's this unreliable i might just sell it off and stick to my 996...

[wvicary]

I suggest you find a new garage to service your vehicle.

[Nehmaiz]

Well I Just bought my 3rd baby, and 2nd 944 in the stable, an absolutely immaculate and all original 944 S2 with full service history.

93K KM on the clock...

can't wait for it to be shipped over.

cheers!

[wvicary]

Nice looking motor.