Sweet smelling smell

[jpspringall]

I've noticed recently that after running the car for a while that there is a sweet smell coming from what i think is the alternator (the circular silver unit attached the right of the engine as you look at it from the back). From a bit of googling it appears that it could be burning out: http://www.ehow.com/list_7224588_tips-delco-alternator.html.

The reading on the dash says ithe battery charging at 14 volts.

I've had a look round the car and cant see any leaks, and coolant level isnt dropping so dont think it's antifreeze which was the other suspect.

Just wondering if anyone has had a similiar issue, should it be something i should be worried about (knock on effects) and any ideas on how much a replacement would be.

Cheers

James

[Justin]

Check that it isn't the sweet sweet smell of success.

http://coachhonea.files.wordpress.com/2011/01/great_success.png

[Kaz-kzukNA1]

Hi, James.

Finding the source of smell is not an easy task because of several reasons.

If you smelt it inside the garage after you drove your NSX, it could be from the front compartment and not from the engine bay or vice versa.

When the radiator fan or A/C condenser fans are operating, they can easily transfer the smell from forward/centre section of the car to the rearwards.


At the bottom of the radiator, you may see seepage of coolant that is too small to cause any drips on the floor or change in the coolant level yet enough to cause some smell.

Even after it dried up, it will still make the same smell until it is thoroughly washed off.

Radiator is a consumable parts, by the way.


‘Sweet smell’ is also a kind of difficult one to understand.

For me, brake fluid is more like sweet smell than the coolant but probably it’s just me…


I don’t think you can judge the condition of ACG by the smell.

In Japan, the ACG failure on NSX was very rare but a few cases started to emerge.

Having said this, rebuilt unit with core exchange is quite easy to get hold of at reasonable price in Japan so most of the high mileage NSX owners normally replace their ACG unit before any failures.


About a year ago, I overhauled my ACG.

http://www.nsxcb.co.uk/showthread.php?6286-NSX-Health-Check-Service&p=75266#post75266

Same link can be found in my ‘NSX Technical and Service Index’ thread in the ‘Sticky’ area of ‘Technical’ forum.

You can’t judge the condition of ACG based on the mileage but even after 16 years and nearly 130K miles, the electronics component such as brush module, rectifier, regulator, rotor, stator, etc were all fine.

The brush was worn but still had enough length to cover lots and lots of miles.

The only thing I noticed was the big rattle at one of the bearing but even so, it didn’t make any noticeable noise while it was running on the engine.

There is a proper way to test the ACG but as a quick check, if your volt meter on the dash is showing steady reading at idle rpm with both high/dip head lights On, A/C fan at max speed, rear hatch glass defogger On while making your door window up and down several times, then your ACG is very likely to be fine.

There is a coolant seepage hole/pipe from the water pump at the timing belt lower cover below the ACG and above the crank pulley.

It is normal to see tiny amount of seepage there over many years/mileage.

You may see build up of coolant corrosion around the fixing bolt area of thermostat cover.

Both will make some smell but far too small to change the coolant level.

If you haven’t replaced your coolant hoses over the last 8 – 10 years, you may have corrosion at the pipe connection point under the hose but impossible to see it from outside.


If you have any doubt with your cooling system, just ask your nearby garage to carry out the pressure test.

If your coolant hoses are really old, then best to replace all of them.


Not much help I’m afraid as I’m not sure whether the smell is from the coolant or something else….

Kaz

[AR]

Bit of an odd one but have you checked the pipe that goes to the oil cooler?

[Nick Graves]

If it's a sort of caramelly-smell, it could be the shellack cooking off the ACG windings. There's a very distinctive bitter-sweetness to frying electrics. Mind you, the amount of Renaults with horribly whiney, smelly alternators that go on for years, I'd not worry too much.

anti-freeze has a very sweet smell - think of the ****tiest, instant-headache white wine you've ever had. It could conceivably be a slight weep from the hot-spot, fast-idle thingy into the valley of the V, if the smell is up top. But you'd notice the coolant drop eventually.

I think sweet-smelling brake fluid probably IS just you, Kaz! It's got a very dry white wine smell (Viognier or somesuch) to me. Maybe my whole world just smells like wine, though...

Probably all you can do is give the engine bay a (gentle) hose down & dressing & polish with an old T-shirt. I find interior plastic dressing brings it up a treat, whether on composites, crackle paint or ally. At least if it's clean enough to eat yer dinner from, you will be able to spot any weeps/wonky bits a lot easier. Might even was away the smell...

[jpspringall]

Hi Nick,

Would shellack cooking off the ACG winding linger for a while? As it does linger for a couple of hours.

Kaz,

How difficult would be to get a rebuilt unit with core exchange from Japan, as by the looks of it a new one is about £850.

It's booked in for some new tyres @ Honda so i'll get them to check it over then.

Cheers

James

[Kaz-kzukNA1]

Hi, James.

I haven’t searched the UK market but this ACG is not NSX specific so I’m quite sure there will be some companies offering refurbishment service in UK.

In fact, most of the refurbishment services in Japan are on a core-exchange basis so you will need to send in your existing ACG to them.

Considering the weight of the ACG and also the warranty policy on the refurbished parts, probably it is not cost effective to do so outside of Europe unless the price is really good.

Kaz

[Kaz-kzukNA1]

By the way, it's not that common to have ACG failure on NSX (yet) so I hope your Honda garage will find the source of the smell...

Kaz

[jpspringall]

Cheers Kaz,

Will let you know what happens.

I've not forgotten about my CCU - just a case of finding the time.

James

[Sudesh]

I think as Kaz mentioned, I would do a proper check on the alternator, but the test he mentioned is a good guide.

Any good alternator/starter motor repair company should be able to refurbish the alternator for less than £100. I have a local company repair a more modern water cooled alternator for £75

An off the cuff thought I had was; is it possible that maybe something caught your exhaust? A bag or god only knows what else. I cant say I have ever smelt a "sweet" smell from my work on NSX or other cars. But we all have our take on smells lol

[jpspringall]

Cheers Sudesh,

I did the test that Kaz mentioned, and seemed OK, so i'll get it checked out when the tyres arrive.

Hopefully it wont be serious, just dont want to risk being stuck in the back end of nowhere.

James

[Nick Graves]

It could do; IF you have a short developing in the winding, it's quite a big lump of copper (like a good pan!) the could stay hot for a while. Especially where it is placed.

I still think it's unlikely though; I'm sure a full-electrical load test would either kill it or cure it!

[nigel]

The anti-freeze used in most cars has a sweet smell.
I won't tell how I know but some farmers use "anti-freeze" to attract rodents that have become pests as it will do them in after a short time.
Do check your cooling system and if the smell seems only to be in the drivers compartment odds are the heater core has gone off.
Just a thought.

Cheers
nigel

[Nick Graves]

:D

Years ago, huge numbers of BMWs were suffering from bottom-hose failure in Bavaria.

BMW were a bit mystified, until they worked out the local pine martens could smell the anti-freeze & were eating through them.

They now have more extensive undershields.

[WhyOne?]

That is a seriously crap fact Nick!

[jpspringall]

Though a very quick way of getting asked to leave a dinner party.

Still waiting for car to go to honda as tyres havent arrived yet, so no diagnosis as yet.

James

[Nick Graves]

Apparently, they like rubber car aeriels too these days.

For €200ish, you can now have an electronic deterrent fitted...