Alfa Romeo Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
459 Posts
Discussion Starter #1
Hello everyone,

Yesterday morning I was driving out of my neighborhood and caught a nasty cloud of smoke in the face. I pulled over, killed the engine, and opened the hood, a steady stream of smoke was coming from near the exhaust manifold. Being 10 minutes late as it was I very carefully took her home and took my other car.

Lately things have been a little strange, the car will start and then die if the gas is not pressed to keep her alive. After the engine is warm this stops and the car functions normally. Also the brakes have been a little strange. I can hear a hissing noise when I press the pedal but no fluid is lost and I still have a solid pedal. It also seems that when I press the brakes and the car is not warm it will help the engine to die faster.

I know I need to do more regular maintenance, but life has been a little crazy for a while. Does this sound like the brake booster? Is that what helps the engine to die when I press the brakes? The smoke smelled like burning rubber. It looked like it could have been the exhaust manifold gasket. What is a safe way to find out? I really don't want to burn down my car/garage.

Thanks,
Andy
 

·
1966-2013
Joined
·
13,741 Posts
Yesterday morning I was driving out of my neighborhood and caught a nasty cloud of smoke in the face. I pulled over, killed the engine, and opened the hood, a steady stream of smoke was coming from near the exhaust manifold. Being 10 minutes late as it was I very carefully took her home and took my other car.
Hard-n-fast guess would be oil spillage onto the manifold from the cam cover or hydraulics.

Check very carefully as while an engine oil leak might be annoying, the hydraulic stuff is flammable.

Lately things have been a little strange, the car will start and then die if the gas is not pressed to keep her alive. After the engine is warm this stops and the car functions normally. Also the brakes have been a little strange. I can hear a hissing noise when I press the pedal but no fluid is lost and I still have a solid pedal. It also seems that when I press the brakes and the car is not warm it will help the engine to die faster.
I'd hazard you've got a leak in either the booster diaphram, the hose from diaphram to intake, or the check valve at the intake is screwed up. (more likely the diaphram as by your description it only acts up when you press the brake, and likely you wouldn't hear a hiss from the hose while in the drivers seat, but as the diaphram is literally right there under your foot.....)

Quick-n-dirty way to check it to run the engine for a while, then shut it down and uncouple the hose from the diaphram. It should give a resounding 'pop' when you pull it off and all the vacuum is released.

If it doesn't, then start checking the above.

You can also do the 'pump test' where you pump up the brakes with the engine off, hold the pedal down with light pressure and start (or in your case crank) the engine to see what the pedal does.

It shouldn't pulse or rise, but should lower a bit.
 

·
Registered
Joined
·
459 Posts
Discussion Starter #3
Thanks Tifosi!

I will try the mentioned. She still runs and even starts without pressing the gas, she just dies about 30 seconds after starting. The sound does seem like it is coming from right under my foot. I will try what you mentioned this afternoon and post the results.

Andy
 

·
Registered
Joined
·
459 Posts
Discussion Starter #6
Took a look today... Ran her for about 2 minutes, no smoke. I did hear what sounded a little like an air leak though. Looking in the manual it appears that a hose running from the brake booster back behind the master cylinder may be leaking. My guess is that it is leaking, dripping down onto the exhaust, and then burning. But what could the noise be? The pedal did drop down when I tried starting it with the pedal down.

Thanks,
Andy
 

·
Registered
Joined
·
3,585 Posts
Just some guesses, but to add to Tifosi's diagnosis, sounds like a mixture of two or more related problems, the noise under the feet and the running problems are the brake booster diaphram leaking air, normally there is no brake fluid in this part of the system but if the brake m/c has leaked in the past or is currently leaking brake fluid may have been gotten into the the booster and possibly on the exhaust manifold in some manner. Now if the hose from the intake manifold to the booster is leaking, that hose being a vacum (air hose) brake fluid that is in the booster from a current or previous leak may have also escaped to get on the manifold causing smoke as you suggest. So do you here the "air" noise when you pump the brakes with the engine off? that is the booster leaking. Start by replacing the booster hose if it is leaking. Also what did the smoke smell like. Oil, coolant, brake fluid all have different identifiable smells when they burn. The smoke also could be some sort of coolant leak, Have you checked the radiator level? What about the overflow bottle and hose, I know on earlier spiders it is on the exhaust side of the engine compartment, not sure where it is located on the later spider. Eliminate known/visable problems to find the hidden problems. A drop of brake fluid on a hot manifold will make quite a bit of smoke. A leak does not have to be large to be a problem.
 

·
Registered
Joined
·
459 Posts
Discussion Starter #8
Thank you so much. I will check the coolant level. Reservoir is located on non-exhaust side of car, but always worth a check. I have smelled lots of burning brake fluid, lots and lots of burning oil, but oddly it didn't smell like either. Smelled like burning rubber, almost like when you throw something rubber or styrofoam on a camp fire (don't ask how I know). I will investigate further tonight or tomorrow. Thank you everyone for your help.

Andy
 

·
Registered
Joined
·
3,585 Posts
Also to answer your question, if the booster is leaking, when you press on the brakes it would cause a cold engine to sputter or die. Think of is this way, when the engine is cold is not operating at it's optimum efficency, now if there is a leak in the booster diaphram, it will enlarge when pressing on the brakes as the diaphram is stretched/moved, now the booster is connected to the intake manifold, so the small leak allows air to be sucked into the intake manifold changing the fuel/air mixture, hence the engine stumbles. I think you need a booster. In the long run, if drive the car with the leaky booster, eventually the air leak into the intake manifold might cause internal engine damage. One more thing about the smoke, maybe unrelated, check your fan belt for glazing/wear/shredding.
 
1 - 9 of 9 Posts
Top