944 Turbo Vibration Problem
Discussion
I own a 1986 model LHD 944 Turbo with manual transmission. I live and work in Dubai, United Arab Emirates and the car is serviced by a well-known independent Porsche centre.
The problems with my car started after the water pump failed earlier in the year. As you would expect the car started to overheat but fortunately when the red warning light came on, I was able to pull over to let the car cool down. However, I foolishly thought that the problem was a blown fuse as I couldn't see the fan cutting in. Having checked the oil level, topped up the coolant and then let the car cool down, I decided to drive it the 2 or 3 miles to the Porsche centre later that evening. With hindsight I should have perhaps got the vehicle recovered there on a low loader, as within 1 mile of starting from cold, the car's water temperature went into the red necessitating another stop to let it cool down. By the time I had managed to limp the car to the service centre, one of the top water hoses had split sending steam gushing out under the passenger side wing.
The service centre thought the problem could either be the water pump or the head gasket. The water pump was inspected and was found to have seized solid. With a new water pump fitted, the engine was pressure tested and seemed to be no worse for the incident.
However, when I picked the car up form the service centre, I noticed a vibration in the transmission that could be felt through the gear lever and steering wheel at idle. Also when accelerating into the turbo zone (3,000 rpm+), there was a loud vibration that felt like it was coming from the exhaust. The car was returned to the service centre where it was diagnosed that the engine mountings had deformed, leading to part of the exhaust manifold touching the chassis. Replacement engine mountings were ordered and fitted. Whilst the engine is apparently sitting properly on its new mountings, the vibration in the transmission is still there and the exhaust system is continuing to show signs of vibration and has now started to blow just in front of the main silencer (non-cat model).
The service centre is confident that that the engine is running correctly but cannot explain the transmission or exhaust vibration. Needless to say the car is no longer enjoyable to drive and unless I can get the problem fixed, I am seriously thinking about selling it, which would be a real shame. Any thoughts?
The problems with my car started after the water pump failed earlier in the year. As you would expect the car started to overheat but fortunately when the red warning light came on, I was able to pull over to let the car cool down. However, I foolishly thought that the problem was a blown fuse as I couldn't see the fan cutting in. Having checked the oil level, topped up the coolant and then let the car cool down, I decided to drive it the 2 or 3 miles to the Porsche centre later that evening. With hindsight I should have perhaps got the vehicle recovered there on a low loader, as within 1 mile of starting from cold, the car's water temperature went into the red necessitating another stop to let it cool down. By the time I had managed to limp the car to the service centre, one of the top water hoses had split sending steam gushing out under the passenger side wing.
The service centre thought the problem could either be the water pump or the head gasket. The water pump was inspected and was found to have seized solid. With a new water pump fitted, the engine was pressure tested and seemed to be no worse for the incident.
However, when I picked the car up form the service centre, I noticed a vibration in the transmission that could be felt through the gear lever and steering wheel at idle. Also when accelerating into the turbo zone (3,000 rpm+), there was a loud vibration that felt like it was coming from the exhaust. The car was returned to the service centre where it was diagnosed that the engine mountings had deformed, leading to part of the exhaust manifold touching the chassis. Replacement engine mountings were ordered and fitted. Whilst the engine is apparently sitting properly on its new mountings, the vibration in the transmission is still there and the exhaust system is continuing to show signs of vibration and has now started to blow just in front of the main silencer (non-cat model).
The service centre is confident that that the engine is running correctly but cannot explain the transmission or exhaust vibration. Needless to say the car is no longer enjoyable to drive and unless I can get the problem fixed, I am seriously thinking about selling it, which would be a real shame. Any thoughts?
I posted your question on the UK 944 list
www.titanic.co.uk/944 and got the following:
Sounds very much like the balance shafts are out of kilter. This would cause
dreadful vibrations throughout. Possibly if belts have been changed/adjusted
they've got the balance belt skew-wiff. God forbid it should be that the
cambelt is out of adjustment!
Only other thing I can think of is if there's a duff spark plug, but the
missing should be obvious.
Vibrations.
If the specialist had to replace the water pump then
the belts had to be removed. Maybe they are not back
on properly?
If the engine mounts are new, then maybe he can now
sense vibrations from gearbox mounts.
Could the manifold or exhaust be damaged due to the
collapsed engine mounts.
All I can think of
>> Edited by dmsims on Saturday 8th June 11:50
www.titanic.co.uk/944 and got the following:
Sounds very much like the balance shafts are out of kilter. This would cause
dreadful vibrations throughout. Possibly if belts have been changed/adjusted
they've got the balance belt skew-wiff. God forbid it should be that the
cambelt is out of adjustment!
Only other thing I can think of is if there's a duff spark plug, but the
missing should be obvious.
Vibrations.
If the specialist had to replace the water pump then
the belts had to be removed. Maybe they are not back
on properly?
If the engine mounts are new, then maybe he can now
sense vibrations from gearbox mounts.
Could the manifold or exhaust be damaged due to the
collapsed engine mounts.
All I can think of
>> Edited by dmsims on Saturday 8th June 11:50
AND
There is cam that automatically drops 180 degrees when the belts are
removed, if the mechanic who fitted the belts doesn't know his Porsches then
he will fit the new belts in effect 180 degrees out of time, have heard of
this problem happening on 944s a few times, this would cause the symptoms
and I feel 99% certain that this what it will be.
There is cam that automatically drops 180 degrees when the belts are
removed, if the mechanic who fitted the belts doesn't know his Porsches then
he will fit the new belts in effect 180 degrees out of time, have heard of
this problem happening on 944s a few times, this would cause the symptoms
and I feel 99% certain that this what it will be.
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