Talk Morgan

Ammonia smell..

Posted By: NickCW

Ammonia smell.. - 31/05/19 07:41 PM

So curiously today I have started to smell Ammonia quite strongly under high load full throttle, i.e. 3rd/4th gear foot down at around 2.5/3k rpm.

I recall reading somewhere that this is often from old/broken catalytic convertors, however it is coming into the cabin from what smells like the engine bay so I am unsure as to what it is. Usually I get a bit of a strong petrol smell (like the engine is running rich), which I have been told is normal. I have had all fuel lines and connections checked by two Morgan dealers as I was paranoid about a fuel leak so I know it can only be the engine running rich..

Any thoughts/suggestions?
Don't want to poison my pregnant wife when driving ideally! hide
Posted By: DavidR

Re: Ammonia smell.. - 31/05/19 09:24 PM

Nick, just a thought do you usually use the same brand of fuel?

A google search throws up either the effect a rich running engine has on the catalyst when the engine is cold or mould in the aircon, but I would expect that to be more constant rather than throttle sensitive.
Posted By: NickCW

Re: Ammonia smell.. - 31/05/19 10:40 PM

Interesting question as I usually always run on Shell V-Power 99ron, however currently I am on holiday in the Malverns and the local station is a BP, so have been running it on 97ron ultimate.
Air con was off and is clean so no smells there, how odd..
Posted By: waikiore

Re: Ammonia smell.. - 01/06/19 01:23 AM

Interesting stuff, as I often have a smell of burning - like a just lit match, very worrying when I first bought this car and thought the woodwork was on fire but after very thorough checking nothing has changed and it still occasionally does it ?
Posted By: Alistair

Re: Ammonia smell.. - 01/06/19 08:44 AM

There is a lot of cow poo on the roads in that region. Are you certain the locals have not left a deposit on your cat's which is being burnt off ?

I had that in the area around RAF Coningsby where I got a load of cwap on the exhaust/pipes. The smell was quite strong but made worse on full power moments as the pipes got hotter.

I ended up putting it up on axle stands and jet blasting (very very carefully!) down the pipes.
Posted By: NickCW

Re: Ammonia smell.. - 01/06/19 12:09 PM

Originally Posted By Alistair
There is a lot of cow poo on the roads in that region. Are you certain the locals have not left a deposit on your cat's which is being burnt off ?

I had that in the area around RAF Coningsby where I got a load of cwap on the exhaust/pipes. The smell was quite strong but made worse on full power moments as the pipes got hotter.

I ended up putting it up on axle stands and jet blasting (very very carefully!) down the pipes.


Now this is an avenue I did not think about! Quite possible and would explain why it was worse on full throttle.
I shall have to get the hose out when I am back, to be honest it needs it with a week of bug splatter and rain! drive
Posted By: Alistair

Re: Ammonia smell.. - 02/06/19 07:25 AM

Stick it up on a kwik-twit ramp and walk under very carefully!
Posted By: NickCW

Re: Ammonia smell.. - 03/06/19 12:58 PM

Soft hat at the ready!
Posted By: howard

Re: Ammonia smell.. - 03/06/19 08:42 PM

A cat has been sleeping on your warm bonnet and has peed on the engine.
Posted By: twotribes

Re: Ammonia smell.. - 03/06/19 09:40 PM

Originally Posted By howard
A cat has been sleeping on your warm bonnet and has peed on the engine.


Is that what your Lotus dealer used to tell you? - do Elises still smell of trimethylamine/urea - or as a boat owner, did you not notice the smell of fibreglass? boat
Posted By: Ray

Re: Ammonia smell.. - 03/06/19 10:15 PM

I once had an Escort that would periodically chuff out a strong smell of H2S. It uesed to cause some interesting arguements between the passengers.
Posted By: howard

Re: Ammonia smell.. - 04/06/19 07:13 AM

Originally Posted By twotribes
Originally Posted By howard
A cat has been sleeping on your warm bonnet and has peed on the engine.


Is that what your Lotus dealer used to tell you? - do Elises still smell of trimethylamine/urea - or as a boat owner, did you not notice the smell of fibreglass? boat


Fibreglass? I love the smell of styrene from fibreglass, but thats not a bit like ammonia.
Posted By: twotribes

Re: Ammonia smell.. - 04/06/19 03:03 PM

Originally Posted By howard
Originally Posted By twotribes
Originally Posted By howard
A cat has been sleeping on your warm bonnet and has peed on the engine.


Is that what your Lotus dealer used to tell you? - do Elises still smell of trimethylamine/urea - or as a boat owner, did you not notice the smell of fibreglass? boat


Fibreglass? I love the smell of styrene from fibreglass, but thats not a bit like ammonia.


Depends what monomer is used in the resin - polyester, epoxy, styrene or typically a mix depending on whether you want flexible/strongest/cheapest.

Epoxy is strongest but least flexible - so maybe that's why styrene is used for boats (or because people will pay more for the 'new boat smell' laugh2).

My wife flat refused to entertain a Lotus because the luggage space "smelled of wee" - so I'm guessing Lotus use(d) a high epoxy mix and not all the amine hardener (NH3) forms bonds with epoxy groups on each resin molecule, some reacts with water in the air to form ammonia (NH4).

Peter J could probably tell us whether that's a Bronsted-Lowry or Lewis Acid Base reaction. All I know is I didn't get my Lotus!
Posted By: howard

Re: Ammonia smell.. - 05/06/19 10:35 AM

I very much doubt that Lotus used anything other than the cheapest polyester resin just like all but a small number of high end race boat builders. When you get to epoxies you start using autoclaves and I never saw any of those in the Lotus factory. Yes the amine hardener does deteriorate with time and stink of ammonia but I have never found the resulting epoxy laminate smeel that way even when as a fully fledged cheepskate, I continue to use stinking hardener.

To go back to the OPs issue , I remember when domestic light fittings stank of amonia as the bulb heated up. The problem was the urea formaldehde resins they were made from. I wonder if the OP has some component in that plastic in his engine bay. I think its also used in particle boards if MMC have started to move away from trees.

The other possibility is some silicone sealant .
Posted By: CooperMan

Re: Ammonia smell.. - 05/06/19 12:47 PM

Originally Posted By howard
To go back to the OPs issue , I remember when domestic light fittings stank of amonia as the bulb heated up. The problem was the urea formaldehde resins they were made from. I wonder if the OP has some component in that plastic in his engine bay. I think its also used in particle boards if MMC have started to move away from trees.

The other possibility is some silicone sealant .


MMC use MDF in place of plywood in some locations, problem is it often contains Formaldehyde
Posted By: Philippo

Re: Ammonia smell.. - 05/06/19 09:05 PM

Hello Nick

I regularly got a smell of ammonia on my Aero S1 at high load full throlle and this for the whole 10 years and 30,000 miles that I owned it. I recall someone telling me it was to do with the cats (maybe the chap that sold it to me) and I never worried about it.

Cheers
Posted By: NickCW

Re: Ammonia smell.. - 07/06/19 11:58 AM

The smell (for now) seems to have gone, no traces of poo or resin bodges so not entirely sure.. perhaps the cat wee'd on the exhaust?

Either way maybe it is an excuse to get some sports cats.. innocent
Posted By: NickCW

Re: Ammonia smell.. - 07/06/19 11:58 AM

Originally Posted By Philippo
Hello Nick

I regularly got a smell of ammonia on my Aero S1 at high load full throlle and this for the whole 10 years and 30,000 miles that I owned it. I recall someone telling me it was to do with the cats (maybe the chap that sold it to me) and I never worried about it.

Cheers



Glad to know its not just me, I wonder if it is the cats somehow..
Posted By: James B W

Re: Ammonia smell.. - 07/06/19 04:50 PM

Nick

- just caught up with this thread.

I can confirm that, like Phillipo, I also get the ammonia smell from my Aero under hard load.It doesn't happen all the time so I really can't shed much light on how/why it happens.

I think the major suspect is probably the cat(s) but I'm not sure of the science behind it (and therefore whether I should worry or not!!).

As long as it is not something friable/combustable buried in the engine compartment , I am content to continue in my happy ignorance...... woohoo

James
Posted By: NickCW

Re: Ammonia smell.. - 08/06/19 09:10 AM

Originally Posted By James B W
Nick
I am content to continue in my happy ignorance...... woohoo


You and me both! cheers
Posted By: Peter J

Re: Ammonia smell.. - 08/06/19 03:17 PM

Originally Posted By NickCW
The smell (for now) seems to have gone, no traces of poo or resin bodges so not entirely sure.. perhaps the cat wee'd on the exhaust?

Either way maybe it is an excuse to get some sports cats.. innocent


Have you change fuel supplier? A combination of a tired catalytic converter and supermarket fuel can cause this effect, according to some web reports on other car forums.
Posted By: NickCW

Re: Ammonia smell.. - 09/06/19 04:00 PM

Originally Posted By Peter J
Originally Posted By NickCW
The smell (for now) seems to have gone, no traces of poo or resin bodges so not entirely sure.. perhaps the cat wee'd on the exhaust?

Either way maybe it is an excuse to get some sports cats.. innocent


Have you change fuel supplier? A combination of a tired catalytic converter and supermarket fuel can cause this effect, according to some web reports on other car forums.


I usually use Shell V-Power (think its actually 100ron now) and in Malvern there are a lot less Shell stations and an abundance of BP, so I was using BP Ultimate 97.. could well be this, would love to know the science behind it though.
Posted By: howard

Re: Ammonia smell.. - 10/06/19 09:56 AM

After reading this thread I did notice an ammonia smell from the tailipie of my Merc diesel. Sure it wont be the same chemistry but the relevance to the OP is the possibility of the smell being from the exhaust which in turn would suggest some sort of exhaust leak since the smell is coming from under the bonnet.

The smell having gone away doesnt mean any leak, if any, will also have gone
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