Oil Pump Noise 308 - New Second hand oil cooler

Hello Tom,

which of your cars ? Since you're in Europe and there's a GTB among your profile cars. Is it this car and is it drysump ?

There have been several discussions about oil cooler / oil lines noise. Here are two examples. One started by me.

I myself have experienced a change in noise level after replacement of drysump oil lines and oil cooler.
I haven't purchased the lines from Superformance, since I have a drysump car and they weren't available back then, but had them custom made from a company who does aviation gear. Today Superformance also stocks drysump lines.

I have this noise since 3 years now. It goes away after a few minutes after engine start and I let it alone. Never experienced any problems.

I suspect the inner material of the lines for being the reason. They are made of Teflon and not rubber. And Teflon seems to have different noise transition characteristics. So the vibrations from the oil pump- in case of drysump both pressure pump and scavenge pump - are forwarded to the drysump oil tank, which acts as a resonator.
Just my theory, which is confirmed when I turn my ear as near as possible to the open oil tank neck.

Other comments and suggestions here:

http://ferrarichat.com/forum/showthread.php?t=174725&highlight=oil+cooler+noise

http://ferrarichat.com/forum/showthread.php?t=236242

Best Regards from Germany

Martin

 

Some of the coolers have the fluid transfer tubes sticking proud of the header tank inside and some are flush with the tank.

The noise is caused by cavitation of cold, thick oil trying to turn the corner into the coolers with the lines protruding past the header tanks. Once the oil becomes thinner, the noise goes away. A nuisance maybe but not a concern point.

We have found some of the coolers had the lines flush on one side and protruding on the other. In that case, flipping the coolers where the flush tubes are on the inlet side will eliminate the noise.

 

Look inside the old cooler on the inlet side and compare that to the replacement cooler. You will visually see the difference between one that is quite and a noisey one. In the early 80's when availability was easy we used to order three at a time, cherry pick and return those with the tall tubes as owners hated the newly created noise.

 

take care of the fittings regarding repeated torquing down and loosening the aluminium threads.
I back then preferred getting used to this new sound instead of endless fiddling with the aluminium fittings with questionable results.
And I forgot to mention; first I installed a new oil cooler with my old lines. No sound. Then I replaced my lines with the new teflon ones.... Sound.
Back then I read that posting from Dave in the older thread - I read a lot of postings prior to replacement of lines and cooler - and checked whether the tubes protrude into the housing. They are both flush with the inside of the cooler, so I could exclude this possibility. Nevertheless I got that sound.
I don't know, what oil cooler you have; I have the one Superformance stocks - german product AKG - and it is not possible to simply flip it upside down. The oil cooler duct wouldn't fit anymore.

Best Regards

Martin

 

Tom when I had my GT4 I experienced the exact same symptoms after replacing my oil cooler.It only made the noise during start up and within a minute it would go away.

 

Your welcome, glad it worked out for you. We have gone through a good many coolers over the years, this is not a new problem.