Irritating high-pitch noise

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Oct 07, 2014 7:27 pm

Is that passenger side Simon?
Is it only when the a/c is on, or is it actually just when the vent fan is running (with a/c switched off)?
Does it make any difference where the vent selector is set to? (i.e. windscreen, footwell, face etc)

If it's pass side and only when vent fan running (a/c on/off makes no difference) then my thoughts would be either something stuck in the vent fan impeller, or the ducting that runs across between the heater unit and the side of the dashboard is dislodged/the foam seals at the ducting joints has perished and the joint is loose.

If you can get it to stop when the vent fan is still running but the vent selector is in a particular setting, it's likely to be the ducting, so check that first. If the selector makes no difference, then it could be the impeller.

To access the vent fan impeller you remove the scuttle panel trim and then a secondary baffle trim and you can see directly into the fan. Check pics in my Ukdm build thread, or in Pushki's build thread to see what the area under the scuttle panel looks like.

Post by **simonc** » Wed Oct 08, 2014 1:24 am

Morning Iain, yes sir it's the passenger side. As I said it's kind of coming from the speaker area and is this bloody annoying whistling kind of sound. It is definitely to do with the air-con because when I switch the air-con off (but keep the fan running) the whistling does stop.
It's also annoyingly intermittent and my "cure" (other than sat in a bloody Prelude sauna) is to turn up the fan then turn it down then turn it up again. Twice I've actually walloped the dash on that side in sheer frustration. It worked - for a while.
There is another little detail insomuch that the right hand vent of the two in the centre does not push out as much air as the one on the left ( if you get what I mean).
Thanks so much for the information and of course this needs looking into and fixing as it is a highly bloody irritating noise. I will dig up your thread as well as Pushki's and add it to my list of things to do.
As an aside Iain I have a monster new addition to my profile listing a catalogue of horrors that have had been driving me to distraction these past few weeks. The story I will be telling will make your hair curl due to the lies, shoddy advice, bodge fixes, counterfeit parts, third-rate workmanship culminating in horrendous consequences. I'm putting it all together now as it's become a massive and seemingly, unending story.
I do thank you for this info. However Iain, it's finding someone out here with half a brain who'll do a job without breaking something else! Watch this space.
Best regards
Simon.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Wed Oct 08, 2014 8:42 am

Hmmm... Right, in that case if it only makes the noise when the a/c is on, it isn't something stuck in the fan impeller.

something shrinking in the cold air when the a/c is on maybe?

mercutio · Post by **mercutio** » Wed Oct 08, 2014 7:22 pm

wurlycorner wrote: something shrinking in the cold air when the a/c is on maybe?

is that the excuse you give Lisa

Post by **simonc** » Thu Oct 09, 2014 8:34 am

@wurlycorner What is interesting Iain is that if I am on a long run, say to Singapore, I notice that the air-con just about gives up the ghost after three hours or so of running. The fan is still on , there's no horrible noises or creaks, rattles etc, it is like it's just run out cooling power and slowly begins to blow lukewarm air through the car. Given last Monday was an exceptionally hot day, the cabin temperature is bordering on "Broil".

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Oct 09, 2014 9:51 am

Low on gas then, or needle valve sticking (i think there's one in the drier)?
That could cause a hissing noise in the pipework, which does enter the cabin above the passenger footwell.
Time to get the aircon checked and serviced by someone that knows what they're doing I suggest...

Post by **simonc** » Thu Oct 09, 2014 9:59 am

Yes mate you're right and this is yet another job on the agenda. Luckily, I have a client whose husband runs his own car air-con business. I used him to service the Del Sol and he did a good job so he's on the list to visit. Wish me luck.