Brake smell on first startup

[Rhubarb13]

Hi all,
I am getting a brake smell on the first startup of the day, but only sometimes and only after it was driven the day before.
Discovery 4 2013, 3.0l SDV6 HSE.

Can be smelt inside and outside the car.

Thoughts.

[libertyts]

I don't have any immediate ideas on what it could be. However, to clarify, do you mean it smells like hot brakes as if you'd ridden the brakes down a super steep hill or like brake fluid burning?

One of the uber experts will have some thoughts after first coffee I'm sure! Haha

Good luck bud.

[Rhubarb13]

I don't have any immediate ideas on what it could be. However, to clarify, do you mean it smells like hot brakes as if you'd ridden the brakes down a super steep hill or like brake fluid burning?

One of the uber experts will have some thoughts after first coffee I'm sure! Haha

Good luck bud.

Hot brakes, not fluid, seems to come from front of car

[Rhubarb13]

No DPF.

[libertyts]

Fair enough. I don't have any immediate ideas unfortunately. There are few things in modern cars that have a pretty similar smell.

Any squeaking, squealing or rumbling at those times that might indicate something rubbing?

Does the smell appear immediately on startup or does it take a little bit of time? Any ideas if it starts at the front or the back? I know ours 2.7L smells a little on first start in the morning from the exhaust, is gone pretty quick and I wouldn't describe it as hot brakes though.

Fingers crossed one of the brighter sparks pops in soon!

[Rhubarb13]

Fair enough. I don't have any immediate ideas unfortunately. There are few things in modern cars that have a pretty similar smell.

Any squeaking, squealing or rumbling at those times that might indicate something rubbing?

Does the smell appear immediately on startup or does it take a little bit of time? Any ideas if it starts at the front or the back? I know ours 2.7L smells a little on first start in the morning from the exhaust, is gone pretty quick and I wouldn't describe it as hot brakes though.

Fingers crossed one of the brighter sparks pops in soon!

Nothing.
Starts immediately.
Except this morning [emoji849], no smell.

[libertyts]

Bugger, I've run out of ideas and silly questions. One of the other fellas will see this soon and will likely know it immediately. Smart arses.... [emoji14]

[DieselLSE]

Well, I've pondered this over my morning espresso but I'm bereft of a possible cause. It may be some fluid on the exhaust. So the first thing I'd do is remove the engine cover and the other two covers and have a good look around with a bright torch. It all should be dry under there, so any fluids should be quite noticeable.

[Rhubarb13]

Well, I've pondered this over my morning espresso but I'm bereft of a possible cause. It may be some fluid on the exhaust. So the first thing I'd do is remove the engine cover and the other two covers and have a good look around with a bright torch. It all should be dry under there, so any fluids should be quite noticeable.

Will do

[Eric SDV6SE]

I'm willing to bet it smells like a mixture between hot brakes and that characteristic acrid diesel exhaust smell you get when first starting up, and stronger around the front of the car...

I believe it would be the EGR valves leaking where the alu pipes flange off the valve and head up towards the manifold. EGRs located down the side of the engine. Both sides. Check with a torch for soot build up on top of the EGR.


Reason for no smell would be that valves were closed fully on last startup.

Mine did the same, could smell exhaust/hot brakes after coming home. Relatively easy to fix, unbolt the EGR pipes from the manifold and retaining clips, then from the EGR valve itself, clean up the flange faces and apply some high temp gasket maker and refit. Need small hands and a 10mm socket with a long extension, and don't drop the flange bolt in between the valve and engine, don't want to go there (again)....

Whilst there, you can actuate the egr rod with your finger, the rod is a black plastic one connected to a dash pot thats connected to a vac line. It should move freely. If not, when the return pipe is off you can get a hooked scraper in there and scrape away the carbon build up. I also spray some throttle body cleaner in there.

[Rhubarb13]

I'm willing to bet it smells like a mixture between hot brakes and that characteristic acrid diesel exhaust smell you get when first starting up, and stronger around the front of the car...

I believe it would be the EGR valves leaking where the alu pipes flange off the valve and head up towards the manifold. EGRs located down the side of the engine. Both sides. Check with a torch for soot build up on top of the EGR.


Reason for no smell would be that valves were closed fully on last startup.

Mine did the same, could smell exhaust/hot brakes after coming home. Relatively easy to fix, unbolt the ear pipes from the manifold and retaining clips, then from the EGR valve itself, clean up the flange faces and apply some high temp gasket maker and refit. Need small hands and a 10mm socket with a long extension, and don't drop the flange bolt in between the valve and engine, don't want to go there (again)....

Whilst there, you can actuate the egr rod with your finger, the rod is a black plastic one connected to a dash pot thats connected to a vac line. It should move freely. If not, when the return pipe is off you can get a hooked scraper in there and scrape away the carbon build up. I also spray some throttle body cleaner in there.

Sounds plausible, will look on Thursday. Tomorrow is supposed to be cold and wet. [emoji849]

[Rhubarb13]

Thanks Eric.

[Graeme]

Check the coolant level in case the smell is from burnt coolant that has leaked from the coolant outlet housing that splits before bursting open and the coolant has leaked onto the exhaust cross-over pipe.

[INter674]

Check the coolant level in case the smell is from burnt coolant that has leaked from the coolant outlet housing that splits before bursting open and the coolant has leaked onto the exhaust cross-over pipe.

Good point..our SC had a burnt smell due to red coolant leaking out the water pump onto the v and then being heated. It was v noticeable first thing in the morning.

[Phideaux]

Good point..our SC had a burnt smell due to red coolant leaking out the water pump onto the v and then being heated. It was v noticeable first thing in the morning.

Apart from 'cooked' I'm not sure I'd know a 'brake smell' but (not a Landie) my 2004 Holden Astra was of a species notorious for weak water pumps. My nose was vital - I'd have killed the motor if I'd not noticed; it was replaced under warranty twice, the second time with a 'suitable for Australian summers' upgrade, and it ran perfectly after that. (A properly maintained, 1.8L manual Astra was a damn good car, actually, while a poorly maintained 1.6L auto was a dog.)

Even if the initial post is an "I was right, it is the brakes!" - I still use my nose whenever I lift the bonnet on any car, usually for nothing more than windscreen washer. And I'd recommend taking 'a good nose' along for any second-hand purchase of any car whatsoever.

One more trick: after a medium drive (40 k or so) park the car over some (weighted down) butcher's paper and 12-24 hours later, check the drips.

[Graeme]

The reason why I suggested coolant is because the 2.7 & 3.0 water outlet housing is renowned for splitting at its seams, leaking a small amount of coolant for some time before suddenly splitting apart often with catastrophic results for the engine, unlike a water pump seal which can leak quite badly but usually getting worse incrementally rather than suddenly.

[Rhubarb13]

The reason why I suggested coolant is because the 2.7 & 3.0 water outlet housing is renowned for splitting at its seams, leaking a small amount of coolant for some time before suddenly splitting apart often with catastrophic results for the engine, unlike a water pump seal which can leak quite badly but usually getting worse incrementally rather than suddenly.

I had the housing changed for an Aluminium one in December.

[Graeme]

An expensive item but you know that you're not risking an engine.

[Rhubarb13]

Checked under the engine cover today and noticed oil under the air inlet to the throttle. Also noticed that the air inlet box was misaligned to the throttle body. This seemed to be the source of the oil and possibly the smell (the fan probably blows accumulated oil smell back through the ventilation) Took inlet off and re-aligned. Noted that the rubber seal is very loose, so not sure if this will fix the problem.

[DiscoJeffster]

Checked under the engine cover today and noticed oil under the air inlet to the throttle. Also noticed that the air inlet box was misaligned to the throttle body. This seemed to be the source of the oil and possibly the smell (the fan probably blows accumulated oil smell back through the ventilation) Took inlet off and re-aligned. Noted that the rubber seal is very loose, so not sure if this will fix the problem.

If yours is like mine and others you’ll need a new seal and inlet section as they fail and leak.

[Eric SDV6SE]

Checked under the engine cover today and noticed oil under the air inlet to the throttle. Also noticed that the air inlet box was misaligned to the throttle body. This seemed to be the source of the oil and possibly the smell (the fan probably blows accumulated oil smell back through the ventilation) Took inlet off and re-aligned. Noted that the rubber seal is very loose, so not sure if this will fix the problem.

Yep, new inlet elbow, o ring and also y piece o rings should sort you out. Around 120 aud delivered from the uk. Easy to fit.

[Rhubarb13]

If yours is like mine and others you’ll need a new seal and inlet section as they fail and leak.

Yep

[DiscoJeffster]

LR014212 - Intake duct

LR008353 - Throttle body seal (large o-ring)

[Rhubarb13]

Yep, new inlet elbow, o ring and also y piece o rings should sort you out. Around 120 aud delivered from the uk. Easy to fit.
Ta.

[Rhubarb13]

LR014212 - Intake duct

LR008353 - Throttle body seal (large o-ring)

Replaced seal - will see what happens

[DiscoJeffster]

Replaced seal - will see what happens

Won’t help. I’ve done that three times. Once you replace the elbow it will fix it. There is wear on that part plus generally small fractures in the plastic where the retaining clip is held in place. It’ll keep skewing and leaking as the mating point for the o-ring is barely past the chamfer.

[Rhubarb13]

Won’t help. I’ve done that three times. Once you replace the elbow it will fix it. There is wear on that part plus generally small fractures in the plastic where the retaining clip is held in place. It’ll keep skewing and leaking as the mating point for the o-ring is barely past the chamfer.

So far so good. Driven from Canberra to Adelaide, with some 150km on dirt (to miss Victoria).