Survey: Tyre pressure warning system.
11-27-2002, 09:49 PM
#1
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Survey: Tyre pressure warning system.
If your car has the notorious RDK tyre pressure warning system (MY 89 - 93)please post whether it's-
A Disabled, or
B Working.If so how reliable?
Also-
C Is it worth having?
D Any other comment on topic.
Colin
89GT (with disabled RDK)
A Disabled, or
B Working.If so how reliable?
Also-
C Is it worth having?
D Any other comment on topic.
Colin
89GT (with disabled RDK)
11-27-2002, 10:12 PM
#2
Burning Brakes
When I first got my 90GT the warning system would falsely register low air pressure in two tires. I bridged the system so that it would no longer give any reading, false or otherwise.
So when it came time to upgrade to 17" wheels, it didn't matter if they didn't have tire pressure sensors. (If you use wheels without sensors, the system will give low pressure warnings for all wheels.)
BTW, Porsche must not have thought much of the system, as they stopped using it in the (I think) 94 GTS.
YMMV.
So when it came time to upgrade to 17" wheels, it didn't matter if they didn't have tire pressure sensors. (If you use wheels without sensors, the system will give low pressure warnings for all wheels.)
BTW, Porsche must not have thought much of the system, as they stopped using it in the (I think) 94 GTS.
YMMV.
11-28-2002, 04:34 AM
#3
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My previous 928 - a '91 GT - had the system working. It was very sensistive, so I always ran with higher tire pressure than required.
The S4 has 17" wheels, and the system is disabled. Do I miss it? Not really. Would I like to have it, if it worked better? Yes.
Tire pressure monitoring systems are having a big comeback in Europe right now. I'm not sure, which brands use it other than Renault. I hear the NHTSA here in the US is considering to make these mandatory on new cars in the near future. A result of the Ford Explorer tire deasaster...
The S4 has 17" wheels, and the system is disabled. Do I miss it? Not really. Would I like to have it, if it worked better? Yes.
Tire pressure monitoring systems are having a big comeback in Europe right now. I'm not sure, which brands use it other than Renault. I hear the NHTSA here in the US is considering to make these mandatory on new cars in the near future. A result of the Ford Explorer tire deasaster...
11-28-2002, 05:03 AM
#4
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When inflating the tires to the maximum of 3 Bar (43.5 PSI) It gives me the warning “REIFEN DRUCK”. When I (over)inflate them to a pressure of 3.2 Bar (46.4PSI) the warning is gone. Not the best solution, but I leave it at that for now. Does anyone know if the RDK system can be calibrated?
As the colder weather slowly is making it’s entrance here in Holland, I will be mounting the winter tyres (on phone dials) pretty soon. Problem then solved for the time being.
As the colder weather slowly is making it’s entrance here in Holland, I will be mounting the winter tyres (on phone dials) pretty soon. Problem then solved for the time being.
11-28-2002, 10:06 AM
#5
Burning Brakes
To the best of my knowledge, the RDK system cannot be calibrated. Perhaps cleaning/lubricating the transmitters and sensors may help to improve the signal and read-out.
Running with over-inflated tires isn't good for the ride or the life of the tire. Under-inflated tires get ruined too soon as well, and may be dangerous while braking or cornering at the levels designed for a 928.
A few years ago, Kim Crumb was using a tire pressure monitoring system that was independent of the RDK. It comprised a cabin rearview mirror that had readouts for each tire. The sensors - transmitters were in the valve caps on each tire. The best feature of the system was that it could tell you the pressure of each tire while the car was moving. With such a system, one could tell the change in pressure due to driving style, road conditions, or ambient temperatures. I think Kim said the system would soon be available for about $250. To date, I haven't seen another system like it. YMMV.
Running with over-inflated tires isn't good for the ride or the life of the tire. Under-inflated tires get ruined too soon as well, and may be dangerous while braking or cornering at the levels designed for a 928.
A few years ago, Kim Crumb was using a tire pressure monitoring system that was independent of the RDK. It comprised a cabin rearview mirror that had readouts for each tire. The sensors - transmitters were in the valve caps on each tire. The best feature of the system was that it could tell you the pressure of each tire while the car was moving. With such a system, one could tell the change in pressure due to driving style, road conditions, or ambient temperatures. I think Kim said the system would soon be available for about $250. To date, I haven't seen another system like it. YMMV.
11-28-2002, 05:31 PM
#6
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Hi,
On my '91 GT, the warning system is reliable insofar as it provides a reasonable warning of what seems to be tiny losses. Problem is that the seal around the valve on at least one of the wheels leaks....
Chris M
On my '91 GT, the warning system is reliable insofar as it provides a reasonable warning of what seems to be tiny losses. Problem is that the seal around the valve on at least one of the wheels leaks....
Chris M
11-28-2002, 06:33 PM
#7
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90S4 and 93GST both systems worked great. I like it very much.
When I had it shut off: On my '90 I had upgraded the wheels so it was jumpered. Had a tire pressure loss coming down a mountain - slow leak. Doing speeds around 200 km/h.
Lucky that during re-entry (and not high speed) into Seattle I suffered a catastrophic failure of my rear Toyo. One night in the hotel, $150 towing (rip off), $200 tire fix, all could have been saved by RDK.
Sure it was deleted for 94, but I believe tire pressure sensing is back on most high end products.
If you drive like an autobahn, it's worth it.
When I had it shut off: On my '90 I had upgraded the wheels so it was jumpered. Had a tire pressure loss coming down a mountain - slow leak. Doing speeds around 200 km/h.
Lucky that during re-entry (and not high speed) into Seattle I suffered a catastrophic failure of my rear Toyo. One night in the hotel, $150 towing (rip off), $200 tire fix, all could have been saved by RDK.
Sure it was deleted for 94, but I believe tire pressure sensing is back on most high end products.
If you drive like an autobahn, it's worth it.
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11-28-2002, 06:44 PM
#8
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As i'm running an earlier car I don't have the RDK system but I would fit one of the after market systems when I finally get round to getting new 18" wheels. 
Don't know which but there seems quite a wide choice.
Cheers
DaveW
Don't know which but there seems quite a wide choice.Cheers
DaveW
11-29-2002, 12:38 AM
#10
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I restored mine- PO had removed the central control unit & Phil T sold me one at an exceptional price (thanks again, Phil). Works fine.
The rearview mirror read out unit has been on the market for some time- and a couple of others.
Donald
The rearview mirror read out unit has been on the market for some time- and a couple of others.
Donald
12-03-2002, 12:10 PM
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B - On my '93 works great and I love knowing at high speeds all systems are AOK! Keep the pressure at 36PSI all the way around.
Interesting thing I've noticed over the years - in the Summer (Dallas 95-100+ deg.) the tires need to be topped up maybe 1 or 2 times/mo. but in the Winter (30-70 deg.) no problems for 4-5 months. The only thing I can figure is that tires "breathe" a little more when they get hot. I've noticed this on my other cars too.
Interesting thing I've noticed over the years - in the Summer (Dallas 95-100+ deg.) the tires need to be topped up maybe 1 or 2 times/mo. but in the Winter (30-70 deg.) no problems for 4-5 months. The only thing I can figure is that tires "breathe" a little more when they get hot. I've noticed this on my other cars too.
12-04-2002, 11:39 PM
#12
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There hasn't been enough response here to assess the situation with any accuracy so I thought I'd boot it back up the board and try again.
Up to now it seems that about 50% of respondents have serviceable RDK systems with the remainder split between 'disabled because unserviceable' and 'disabled because of wheel change'.However I get the impression that most drivers approve of the concept.
IMO it's a very worthwhile safety feature. I only wish there was an easy way to fix the bloody thing!
Colin
89GT
Up to now it seems that about 50% of respondents have serviceable RDK systems with the remainder split between 'disabled because unserviceable' and 'disabled because of wheel change'.However I get the impression that most drivers approve of the concept.
IMO it's a very worthwhile safety feature. I only wish there was an easy way to fix the bloody thing!
Colin
89GT
12-05-2002, 10:49 AM
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Apparently, some cars have the 3.0 bar sensors and some have the 2.5 bar sensors. Mine is 2.5 bar and I agree that that I wouldn't like 44PSI either. Another issue is repair if a sensor gets damaged. The sensors aren't cheap. If you get your wheels repainted you need to remember to remove the sensors and you need to make sure your tire man knows about them and knows what not to do while mounting tires.
Randy
'93
Randy
'93
12-05-2002, 11:32 AM
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91S4 works fine, in hot weather (100F) it sometimes gets a bit tempremental.
Key is to get the tire pressures done in the garage before you drive anywhere, even a 2 mile stint to the nearest garage for compressed air is enough to warm the tires up and mess with what pressure you need to put in the tires.
Chris
Key is to get the tire pressures done in the garage before you drive anywhere, even a 2 mile stint to the nearest garage for compressed air is enough to warm the tires up and mess with what pressure you need to put in the tires.
Chris