Is this fan noise OK?

twobone · twobone's Garage

Now that my CIS is fixed I can actually hear my engine.

I'm hearing a "whackatta - whackatta" type noise that sounds like its coming from the fan area.

It does not sound like valve noise

On an 3.0 ltr, is that a normal sound?

Rot 911 · 04-17-2006, 10:08 AM

Sounds, literally, like the fan is hitting the housing. Either loose alternator bolts, bad alternator bearings or cracked fan housing.

Motorhead-45 · 10:59 AM

That area is very near the chains and tensioners. Get a mechanic's stethoscope and isolate it. You could also briefly, very briefly, remove the fan belt to determine whether it's the fan or not. A cold engine without a fan for 15-30 seconds shouldn't be a problem. If the "whackatta - whackatta" goes away then you know it's in the fan assembly. If it doesn't, then you need to look elsewhere. Noise travels!

dan79brooklyn · 04-17-2006, 10:49 AM

Is the fan spinning smoothly?
Does it look like it is out of balance?
My car was making a noise from the fan and the pulley nut hole
(sorry bad description) was rounded off and was wobbling.
Hope that's helpful...?

jester911 · jester911's Garage

Check the fan and housing for scratchs/gouges. I had some sort of debris that got caught between the fan and housing and dug in causing a big burr that would catch the fan blade slightly.

I took sandpaper from coarse to fine to sand out the burr and it has been good for 3 years or so.

twobone · twobone's Garage

Weird, I had the valves adjusted less than 3,000 miles ago by a shop I trust....hmmm

My local (now very trusted) mechanic Frank used a stethoscope thingy and diagnosed it as rocker #6.

$40 CDN later, he adjusted it and I'm back on the road.

He suggested that I get them all adjusted as #4 was off too.

What makes a valve set to go out of sync so quickly?

Do the adjuster mechanisms wear out?

DaveE · 04-17-2006, 05:25 PM

If you think it's the fan or alternator you could just take off the belt and spin the fan by hand without running the engine. Should be nice and quiet.

Motorhead-45 · 04-17-2006, 05:30 PM

Quote:

Originally posted by twobone
$40 CDN later, he adjusted it and I'm back on the road.

Man....I sure wish I had someone local who would even think of looking at my car for $40, much less repair it for that price!

Sounds like the beginning of a good relationship. Stick with that mechanic!

twobone · twobone's Garage

Ya, Frank charges $55 CDN an hour...partly because he is not a licensed mechanic by trade. However he has been working on Porsche 911s for ages and has been running race cars. I trust his judgement. He has not led me wrong yet. Also he is a 5 minute walk from home.

I think I might adopt him

Man....I sure wish I had someone local who would even think of looking at my car for $40, much less repair it for that price!

ianc · 04-17-2006, 11:33 PM

Quote:

What makes a valve set to go out of sync so quickly?

Imperfection in the original adjustment?

A sudden change in the usage of the car? If the car had sat for awhile, you might (with regular use) have burned a lump of carbon off a valve or seat that would open up the clearance...

ianc