Cold start trumpet sound

I like to think that my car is trumpeting my return. My wife thinks its farting at me...

When I start the car when its cold (first start in over 8 hours) the car will make a trumpet sound for maybe 5 to 10 secs. And by trumpet I mean what I would sound like if I picked one up and attempted to play (and got a note out). It raises in pitch across the 5-10 sec and then stops. Anyone ever heard of this before? The only think I can think of is that I have some kind of exhaust leak that seals up pretty quickly after starting.

thanks,
Aaron

 

What year is your car and do you only hear it when it's cold?
Does the trumpet sounds out of tune? if it does it needs a tune up, just kidding

 

Ha!! No its perfectly in tune. Well, at least I could not do any better...

Its an 85 308 euro. It does have an aftermarket exhaust, a Larnin I believe. Its also really hard to determine where the sound is coming from. I had my wife start it while I had my nose in the engine bay. Perhaps I should put it on jackstands and crawl under it.

Aaron

 

I've heard that sound too, my first (the red) GT4 used to make it every so often. No idea what it was, but it never seemed to bother anything!

Cheers,
Aaron
'82 GTSi

 

Did you check your belts and pulleys for tension and glazing?

Maybe you ran over that damn AFLAC duck!!!!!!!



Jim

 

I didnt see any feathers when I was checking the belts. The belts seem fine. Although I dont know if the tension is right, but seems fine.

I have attached an mp3 that has the sound. Just incase anyone is interested in hearing it. Im not too worried about this. I just find it interesting.

Also usually the sound is a consistent note that increases in frequency for about 5 secs. This mp3 plays 2 short notes.

Aaron
View attachment trumpet.MP3

 

I have the same thing on my 328....only happens during the winter...strange...

 

I listened to your mp3 file a few times and it reminds me of The Little Rascals episode where Wheezer and Stymie bake a "surprise cake" with all sorts of things inside. The rubber glove in the cake made the same sound:
View attachment Wewow.wav

 

I'm sure my post was absolutely of no benefit to you, Aaron.

 

I'm sorry I'm not contributing here but LMAO! reminds me of people fitting duck calls to their blow off valves on STIs etc

 

From all the information that I see on this post. Personally I would look at the the cold start injector or the Injector Vac. lines as Barry said " sounds like a rubber glove" or Rubber Hose. Just a thought, next time you start the car clamp off the vacuum line to the injector once it starts to trumpet see if that takes away the sound.

have fun.

 

'83Qv, I have a similar sound at times. But I thought it was comming from the f/i accumulator.

Hack

 

Too Funny

 

The exact same sound happens on carb'd cars once in a while, don't ask me how I know.

 

Mine's carbed. Never heard this sound though... Might have something to do with the emission control stuff?? I don't have that, and all that air pumps, canisters, hoses, test tubes and what have you might create all sorts of funny air flows, and thus options for strange sounds...

Hans

 

I'm sure that's all it is.

As with Hans, my carbed car has never made a noise like that either. I do get a vacuum closing "thump" when I shut down after a highway drive.

 

Ill try this in the morning and see what I get.

Aaron

 

Its done that for years and infact from when I first got it. I did a seach on the old fchat archives and several guys had the same thing-the oil cooler inlet moulding vibrating. have your wife hold her hand on the moulding at start up and see if it stops.

 

Hey, your car sounds great.
Except from that trumpet noise.
First I thought this was a joke, but it isn’t, is it? lol.
Tell your wife to start the car, put a finger on the cold starting injector and feel if it is vibrating a lot.
Next test is to disconnect the electrical connector from the injector the same second the car starts to see if the sound disappears, my imagination tells me it comes from the injection system.
The reason is, when we were playing with the old Volvo 240 turbo, we increased the fuel pressure to get more fuel to the engine and at a certain point we got similar sounds from the injectors due to the higher pressure.
Can’t hurt to test it.

 

its not the injection, see above, it happens to carb'd cars also

 

I may have posted one of those messages/replys in the old F'Chat...

I can definitely say that it is a combination of the oil cooler duct and oil cooler itself, that resonates with the flow of cold oil through the cooler.

I installed a B&M cooler (with a custom-made duct to fit it) a few years ago and as this one is larger and more efficient than the original cooler, it trumpets for a bit longer and a bit louder!

 

Exactly what Peter said on my car as well(GT4).I replaced the oil cooler on my car as well and it does it every once in a while on start up.It sounds like the oil draining out of the cooler after shutdown and rushing though on start up.I've replaced the three rubber mounts that mount the oil cooler as well and it didn't stop it

 

My car 86 328 makes a very hi pitched trumpet sound as well.. cold start valve moving around... only does it when its below 50 F.... does not seem to affect anything... my mechanic said leave it alone... dont think its a major issue.

 

My '83 QV Euro does this noise every time I start it (hot or cold). I have no smog equipment on it either. Mine only lasts about 2-4 sec. right after the engine catches on start up. It does not seem to affect anything on performance and I never hear it again till re-starting. I thought it might be a loose pulley belt slipping momentarily or (I shutter to think) one of the cam belt tensioner pulley bearings.

So, the concensus is that it is something with the oil cooler then - and there is no solid remedy?

 

My 75 GT4 does it about 80% of the time on cold start and I've always been a bit concened, but it's nice to finally have what looks like an answer.

A search of the older threads found this one to have a good explanation:

http://www.ferrarichat.com/discus/messages/256120/255902.html

Based on this description, it would be interesting to know if oil viscosity might not have a little to do with it.

Are those of you who have experienced this noise running 20-50 or lighter oil?