90 C4 - steering noise, PDAS (only) warning, unstable idle...
02-10-2014, 06:13 PM
#1
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90 C4 - steering noise, PDAS (only) warning, unstable idle...
I'm a fairly new 964 owner (coming from a 87 3.2 and various VAG cars..) and have had my 90 C4 for just over a month now.
Its a proper winter here so I haven't gotten to drive it a lot, but have encountered a bunch of small-ish problems which might not be related, but they all came up in a very short time frame so I'm not sure whats going on.. Apologies in advance for some possibly strange terminology as english is my third language - my car lingo is divided between my native language and english with a little bit of german here and there, so its a bit of a mess
first a bit of background - the car has 140k kilometers on it, so about 87k miles. the engine has been taken apart and reassembled recently by a skilled shop in Germany, but the car hasn't seen a lot of miles since then, probably a few hundred. it has a cartronic chip and exhaust. all fluids are new given the recent overhaul.
Problems:
1. When I first drove it, it ran well apart from a somewhat unstable idle. The car would start up nicely, but when I lifted the clutch it kept stalled and I had to give a lot of gas to keep it running. When just idling still, it will sometimes idle evenly at 700 or so rpm, sometimes it will jump between almost 500 (close to choking) and about 1200. And occasionally it will stall at ignition - rpm's fire up and straight back to 0. There seems to be no pattern to this, it will sometimes happen when the car is cold, sometimes when its hot. Even after driving for 30 minutes and letting it sit running in a warm garage for a couple of minutes, it can still fluctuate, or it might run quite evenly.
At first his was the only issue there was, otherwise it felt and drove great. I started trying to fix the idle by cleaning the ISV and resetting DME by disconnecting the battery. This seemed to help a bit, but not a lot. I mean, at first I thought it solved the problem but then I realized it didn't, because like I said, the problem seems somewhat irregular, but it persists.
2. Before I had a chance to do anything further (was planning on checking o2 sensor cleaning air flow meter next), I just noticed that there is a strange noise when I took off with the car. its most notable when I turn and accelerate, for example in an intersection or simply maneuvering in the garage. but then I realized I can also hear it when the car is still and I turn the wheel. its hard to describe the sound, but if you compare the idle sound to an angle grinder, this noise is like the grinder lightly touching steel or whatever you are grinding, and it comes as soon as I turn the wheel. sorry, can't think of a better comparison... I'm guessing this might be related to power steering? I thought it could be a driveshaft issue but then it occured when the car wasn't moving. After noticing this, I decided to drive for a bit, and the noise isn't noticeable when driving at a steady speed.
3. After going for about 25 minutes at max 50mph, the PDAS warning light came on. Just the interlocking symbol and the general warning light, no buzzer. I drove another 10 minutes to my garage, and the next time I started it the warning lights were gone. I've only done a 5 minute drive after that so I don't know if the alarm would come up again after another slightly longer drive.
4. And one more thing... After parking in my garage today, I noticed a couple of drops of oil behind the passenger side rear wheel, and there was also a pretty noticeable smell of oil.
So, any ideas on how to start decyphering this? I just noticed issues 2-4 today, so I haven't really had time to do anything yet, but I figured I would need to at least check:
- where the oil is dripping from
- brake fluids because of the PDAS problem
- power steering fluid and belt for the steering sound
- aforementioned fixes for unstable idle...
I'm thinking of taking it to a proper shop, but would like to hear some thoughts in the meantime. I'm ok with basic maintenance but I don't have a ton of time right now and I feel like the number of issues might be extending beyond my technical skills.
excuse the lengthy post
Its a proper winter here so I haven't gotten to drive it a lot, but have encountered a bunch of small-ish problems which might not be related, but they all came up in a very short time frame so I'm not sure whats going on.. Apologies in advance for some possibly strange terminology as english is my third language - my car lingo is divided between my native language and english with a little bit of german here and there, so its a bit of a mess
first a bit of background - the car has 140k kilometers on it, so about 87k miles. the engine has been taken apart and reassembled recently by a skilled shop in Germany, but the car hasn't seen a lot of miles since then, probably a few hundred. it has a cartronic chip and exhaust. all fluids are new given the recent overhaul.
Problems:
1. When I first drove it, it ran well apart from a somewhat unstable idle. The car would start up nicely, but when I lifted the clutch it kept stalled and I had to give a lot of gas to keep it running. When just idling still, it will sometimes idle evenly at 700 or so rpm, sometimes it will jump between almost 500 (close to choking) and about 1200. And occasionally it will stall at ignition - rpm's fire up and straight back to 0. There seems to be no pattern to this, it will sometimes happen when the car is cold, sometimes when its hot. Even after driving for 30 minutes and letting it sit running in a warm garage for a couple of minutes, it can still fluctuate, or it might run quite evenly.
At first his was the only issue there was, otherwise it felt and drove great. I started trying to fix the idle by cleaning the ISV and resetting DME by disconnecting the battery. This seemed to help a bit, but not a lot. I mean, at first I thought it solved the problem but then I realized it didn't, because like I said, the problem seems somewhat irregular, but it persists.
2. Before I had a chance to do anything further (was planning on checking o2 sensor cleaning air flow meter next), I just noticed that there is a strange noise when I took off with the car. its most notable when I turn and accelerate, for example in an intersection or simply maneuvering in the garage. but then I realized I can also hear it when the car is still and I turn the wheel. its hard to describe the sound, but if you compare the idle sound to an angle grinder, this noise is like the grinder lightly touching steel or whatever you are grinding, and it comes as soon as I turn the wheel. sorry, can't think of a better comparison... I'm guessing this might be related to power steering? I thought it could be a driveshaft issue but then it occured when the car wasn't moving. After noticing this, I decided to drive for a bit, and the noise isn't noticeable when driving at a steady speed.
3. After going for about 25 minutes at max 50mph, the PDAS warning light came on. Just the interlocking symbol and the general warning light, no buzzer. I drove another 10 minutes to my garage, and the next time I started it the warning lights were gone. I've only done a 5 minute drive after that so I don't know if the alarm would come up again after another slightly longer drive.
4. And one more thing... After parking in my garage today, I noticed a couple of drops of oil behind the passenger side rear wheel, and there was also a pretty noticeable smell of oil.
So, any ideas on how to start decyphering this? I just noticed issues 2-4 today, so I haven't really had time to do anything yet, but I figured I would need to at least check:
- where the oil is dripping from
- brake fluids because of the PDAS problem
- power steering fluid and belt for the steering sound
- aforementioned fixes for unstable idle...
I'm thinking of taking it to a proper shop, but would like to hear some thoughts in the meantime. I'm ok with basic maintenance but I don't have a ton of time right now and I feel like the number of issues might be extending beyond my technical skills.
excuse the lengthy post
Last edited by bdc1; 02-10-2014 at 07:23 PM.
02-11-2014, 01:02 AM
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Clean the air flow meter only with MAF cleaner. Anything else will ruin it. Check for vacuum leaks, get rid of the cartronic chip and replace with a steve wong or steve weiner chip. Flush your power steering fluid with CHF-11.
02-11-2014, 02:27 AM
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Are your levels ok? check your power steering fluid level and your brake fluid level.
For me the grinding noise is solved it was a leaky (really leaky ~1l/month) return hose, so the power steering was compressing air.
For me the grinding noise is solved it was a leaky (really leaky ~1l/month) return hose, so the power steering was compressing air.
02-11-2014, 11:59 AM
#4
Rennlist Member
Yes, noise in the steering may be air in the system. First look at the fluid reservoir (right side of engine bay) and ensure that you have fluid in there.... then a flush/fill is a good idea with new... mine was making noise and it went away with fresh fluid. Though be aware that I had to replace my steering rack soon after as the seals had worn.