Opinion on engine smoke sought

neilberry · 10-31-02, 08:02 PM

This is an engine question. Though this engine is not likely to appear in a GT40.

I have an all aluminum 4.6l V-8 engine that is rated at 320 hp. When I got it it started smoking on start up. I was able to repeat the smoke only if the car sat for more than 8 hours. It lasted only for a second, but the billow of white smoke could be seen wafting downwind. The manufacturer has made the following claims.
1). Wow, we are sorry. A car should never smoke.
2). Sounds like a problem. Let me get you an tech person.
3). (tech person) Smoking is normal. All cars smoke when they sit for any length of time.
4). Your car only has 1000 miles, come back whem it has 5000 miles.
5). (after 5000 miles) We ruled out oil trouble and fuel injector leak down. Your car shoots fuel for 1/4 second, then the computer levels it out. Main Tech says that your car has a "green engine" program that will stop this behavior around 15000-18000 miles.
6. (after 19000 miles) This behavior is normal for this engine. Though Main Tech might address the concern at a later time.

Additional comment: I watched "Legends of Motorsports" on SpeedVision, and every classic race Ferrari smoked on startup during the show.

Is this NORMAL for an aluminum high power engine? I might try to sell this car some day, and wonder if startup smoking might scare away buyers.

Ron Earp · 10-31-02, 08:46 PM

That car should not smoke. I assume you are speaking of a 4.6L Ford DOHC motor in a Cobra or replica (and I think there is one in a GT40 replica and a few in Panteras even though they are too damn big). If you've got white smoke on start up it sounds like you've got some coolant getting into your combustion chambers, if indeed it is an abnormal amount of smoke. Yes, it would scare me away.

Ron

[ October 31, 2002: Message edited by: Ron Earp ]

John Lind · 10-31-02, 10:29 PM

I would scare me too. As Ron has already said it could be water in which case a compression test might identify which cylinder head or gasket is leaking coolant into the cylinder.

It may also be oil. In the case where you get a puff of smoke at startup that often means it is getting in by running down a valve guide while the engine is stopped. Sometimes engines with this problem produce a puff of smoke when you rev it after they have been idling for a while as well. This problem is usually not serious unless it gets bad. But you don't really expect a new motor to do this.

The it will be OK after 5000 comment usually applies to oil getting past the piston rings which can happen with new motors but I think you are past that stage now. Again a compression test may identify or rule out ring problems.

I would regard any of the Green program???(what ever they said) statements with suspicion.

Certainly, some motors have a reputation for doing this sort of thing (but not many these days). Some other people on the forum with more experience with these motors than I might be able to comment.

Good Luck

John

Mark Worthington · 10-31-02, 10:40 PM

The Ford 4.6 DOHC is notorious for oil consumption problems, including this particular variety, which is due to the poor quality OEM valve guides and seals that Ford uses. i've owned two Cobras and they both did this to some extent.

Ron Earp · 10-31-02, 11:04 PM

White smoke = coolant

Blue smoke = oil

Black smoke = rich

What you have? White? Then I'd say water.

R

neilberry · 10-31-02, 11:44 PM

The engine was tested thoroughly. It has been tracked down to excess fuel in the first moments of running.

The smoke seems to be white by the time I see it.

gweitzel · 11-01-02, 05:59 AM

If it was water, the engine would also blow back into the cooling system and this could be easily identified by testing for hydrocarbons in the cooling water.

11-01-02, 10:33 AM

Neil,

The first time I started my 5.0L it would run a couple of minutes and then quit because of a wiring mixup that was my fault (it wasn't dropping the 12V signal to the computer after cranking.) The point is that during those few minutes it ran, it absolutely poured water and steam out of the exhaust. So, much so that I was convinced that I had screwed up the intake gasket and water was going into the cylinders. What further confused me was that somewhere along the line, I had gotten some water in the dipstick tube which made it look like there was water in the oil. I should have questioned why the oil didn't turn completely milky but only had streaks of milky look on the dipstick.

I changed the oil,pulled the intake and put new gaskets making sure all the block/head junctions were sealed. Started the car and it still poured water out the exhaust. I ignored the problem for the moment and tracked down the wiring problem. Once that was fixed, the car would crank, spit out a few drops of water with white smoke (steam) for about 10 sec. and then ran fine, no problems at all. With the wiring problem, the computer was obviously taking the engine full rich (limp home mode).

ChrisL · 11-01-02, 11:02 AM

While we are on the topic of smoke color, I'd like to get other people's views on my opinion (though its a bit off the subject). [img]images/icons/grin.gif[/img]

The description of a smoke by color has, for a long time, been a point of contention with me. What color is blue for example? For someone who has not closely scrutinized a thousand smoky cars, it could quite easily seem white. And for that matter, a white smoke is not truly white anyway. It has a greyish tinge in bad light, which could bring it into the "rich fuel" range, which is also grey in bright light but described as black.

After many years as an amateur observer of smoke, I can now confidently say that I've finally seen enough smoky cars to be able to tell the difference... but the amount of times that I get a blank face when I now ask others the question of smoke color... The bottom line is that I don't assume any more that the answer isn't just a best effort guess.

Just my 2 cents worth [img]images/icons/grin.gif[/img] [img]images/icons/smile.gif[/img] [img]images/icons/grin.gif[/img]

Gordon Levy · 11-01-02, 11:10 AM

The 4.6 does smoke a little on start up. the 4 valve engines are worse than the 2 valve. The white smoke you see coming out is probably condensation in the exhaust system. With todays fuels it is not uncommon to have water in the exhaust or even pouring out of the tail pipe until the car warms up.

**jimbo** · 11-01-02, 10:04 PM

If it is condensation, why don't you try this: shut the engine off, leave it overnight, with a couple of drop lights under the oil pan to make sure it stays warm in the engine compartment. Then start it up; if the engine hasn't gotten cold enough to have water vapor condense, it may not smoke, if the smoke is due to condensate in the combustion pathway.
I'll put in a plug here; I use Wolverine oil pan heaters on my marine engines, which are diesels. They use about 250 watts each, they keep the engines nice and warm they don't smoke at startup and the oil stays warm enough to get up into the motor right away. The heaters are durable enough to be used outdoors on cattle water troughs out West. I don't think GT40s need these (they probably don't get driven much when it's that cold) but all of us have multiple vehicles and for your daily driver an engine heater is very convenient.

mkast · 11-02-02, 01:37 AM

Hows about dis
Warm the engine up to operational temp.
Do a cylinder leak down test.
Record
Pressurize the cooling system.
Look for leakage.
Act according.