chirpping sound 90 SE
Discussion
Ok here is another small thing, on start up and idaling there is a "chirpping" sound which seems to be comming from the front of the engine. I thought it was the vacume pump but i replaced it and the noise is still there. after about 4 minutes of idealing the noise seems to go away as the engine heats up.
Chris
90 SE
Chris
90 SE
Probably, almost definately, EPBV (exhaust back pressure valve).
Restricts exhaust flow for emissions reasons until warm. Chuck it away and block the vacuum pipe up. You can get spacers to replace it from the usual sources.
Edited fur spelin!
>> Edited by scotty2 on Wednesday 23 November 17:58
Restricts exhaust flow for emissions reasons until warm. Chuck it away and block the vacuum pipe up. You can get spacers to replace it from the usual sources.
Edited fur spelin!
>> Edited by scotty2 on Wednesday 23 November 17:58
Get about a metre of heater hose and use it like a stethoscope (in one ear only, obviously), around the front of the engine when it is making this noise. You will know when you have found the source of the noise.
If it's coming from the front, I expect it will be water pump, cambelt tensioner, alternator or PAS pump if you have it. Maybe even aircon compressor.
Paul.
If it's coming from the front, I expect it will be water pump, cambelt tensioner, alternator or PAS pump if you have it. Maybe even aircon compressor.
Paul.
It's the vacuum pump.
A squeeking pump is not the sign of a failing pump, it's the sign of a vacuum leak in part of the vacuum control system.
What you have is lost vacuum in the system, when there is no resistance on the pump diaphram the pump squeeks, as vacuum is drawn, the squeek goes away.
I would recommend that you check the heater control lines, they are small enough that if one is loose it will give this symptom.
A squeeking pump is not the sign of a failing pump, it's the sign of a vacuum leak in part of the vacuum control system.
What you have is lost vacuum in the system, when there is no resistance on the pump diaphram the pump squeeks, as vacuum is drawn, the squeek goes away.
I would recommend that you check the heater control lines, they are small enough that if one is loose it will give this symptom.
As you describe it, it's hard to tell if it is a loud chirping (like a heatshielt rattling against something) or a soft chirping (like John said, a vacuum system leak)...
I have also heard a soft chirp (or pffft pffft) when the line from the crank case breather to the intake manifold has a hole in it or is disconnected. Same sound for any intake manifold leak.
As someone said you can get a chirping rattle from the EBP valve below the cat, or if the parking brake cables touch the muffler...
Since it seems to go away once the car is warm, I would look at the heat shield rattles first (front of the engine as you said). You might also look at the retaining clips on the exhaust manifold. You might have lost a stud and the retaining clip is dangling and rattling against something.
Actually after thinking about what Squelch said, and how you said it only lasts a few minutes... You may have a leak at the throttle jack capsule. It only draws vacuum while the engine is cold. If there is a leak there, then the vacuum pump will chirp for that time that the solenoid is energized.
Travis
Vulcan Grey 89SE
www.lotuscolorado.com/vulcangrey/
>> Edited by lotusse89 on Thursday 24th November 17:05
>> Edited by lotusse89 on Thursday 24th November 17:09
I have also heard a soft chirp (or pffft pffft) when the line from the crank case breather to the intake manifold has a hole in it or is disconnected. Same sound for any intake manifold leak.
As someone said you can get a chirping rattle from the EBP valve below the cat, or if the parking brake cables touch the muffler...
Since it seems to go away once the car is warm, I would look at the heat shield rattles first (front of the engine as you said). You might also look at the retaining clips on the exhaust manifold. You might have lost a stud and the retaining clip is dangling and rattling against something.
Actually after thinking about what Squelch said, and how you said it only lasts a few minutes... You may have a leak at the throttle jack capsule. It only draws vacuum while the engine is cold. If there is a leak there, then the vacuum pump will chirp for that time that the solenoid is energized.
Travis
Vulcan Grey 89SE
www.lotuscolorado.com/vulcangrey/
>> Edited by lotusse89 on Thursday 24th November 17:05
>> Edited by lotusse89 on Thursday 24th November 17:09
Does it happen when you pump the brakes when stationary? Mine did this and it took hours to track down. If it's the same situation, there is a rubber pipe that exits on the chassis rail towards the rear left hand side wheel. It is the exhaust for the vacuum circuit or something. See if it comes from here by sticking your thumb over the top and seeing if the noise stops. The rubber pipe is quite large guage - much bigger than the ones running to the bits and bobs in the boot area for example.
Jason
'89 SE
Jason
'89 SE
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