Tell me, exactly what elements in the “normal cold start exhaust” would the operator be smelling in a modern engine?
On what basis do you suggest that the OP must be wrong in what he/she is smelling rather than accepting that he/she can recognize the smell of gasoline?
I wouldn’t. I’d proceed to try to diagnose the source of the gasoline smell.
Exactly how many days would YOU keep it? A week? A month? Would you then start to try to diagnose it? Keeping it is, after all, your idea, not mine.
It’s a 2000 Dodge Caravan.
What year do you think catalytic converters were mandated?
(hint, hint, does the year 1975 mean anything to you??)
Converters WERE mandated. They were eventually moved to the manifold location to heat the platinum-palladium up more quickly, but your implication that a 2000 is not a modern engine (EFI and catalytic converters) is… well, I’d be embarrassed if I wrote that statement. Or perhaps you can explain to me what exactly makes a 2000 engine?
Do you know the difference between a manifold-located cat converter and one attached to the header pipe? Never mind, I guess I gave you the answer already.
Great work. I look forward to seeing the pictures.
The four plugs removed so far being “well worn”, there’s a more than fair chance you’ve already solved the problem. Cold fuel needs a strong, hot spark to get it fully burned. As plugs wear, the strength of their spark declines.
The spark plug’s function is solely to add heat energy to the combustion equation. Heat is a measurement of molecular/atomic activity, and the spark plug has to provide enough energy to the oxygen-surrounded hydrocarbon molecules to cause the hydrogen and the carbon to break free of one another and bond with the oxygen atoms (combustion). A hotter spark from a fresher plug has a far better chance of beginning the process of combustion strong enough to totally burn all the fuel. Lack of one can leave unburned hydrocarbon molecules (gasoline) beyond what the cat converter can clean up, leaving a whiff of gas smell on cold starts.
You have my empathy on the challenge of replacing those rear-bank plugs. That’s the weakness of many V-style engines when transversely mounted… the rear bank’s plugs can cause you to create new words… ones you wouldn’t want your kids using!
Rant unnecessary, I didn’t state that the vehicle was without a catalytic converter, just that it lacked modern type placement of dual converters.
Vehicle emission standards have changed many times since this van was built. You may have forgotten how the old 3.0 liter engine smells during start up but I haven’t. Also they typically produce a rancid odor with old age due to worn valve guide seals.
Until we can stick our noses through the internet we don’t know for sure what the OP smells.
I’ve had in-person experience with drivers and non drivers saying they “smell gas” and the source is really exhaust fumes.
Often while riding in a car, following a pre-cat “classic” car, etc.
A car show is another place to get a whiff of the past.
Not what I expected. Put the new Iridium plugs in, put on the new serpentine belt, reassembled everything needed to run… and… it not only smells rich but it seems to run rougher than before.
Is it possible that timing was adjusted to compensate for worn plugs?
And here are the old plugs - with way more than .044 gap on each one.
Those plugs look relatively okay. Might you have accidentally bent one of the new plugs, changing its gap, during installation?
Personally, I don’t think you had a problem to start with, but you do now if its running rough. My suggestion is to take your car to a mechanic who can analyze your exhaust gasses to see if there really is unburned fuel coming out of your exhaust.
I know that trick and did just that. I swapped each plug one at a time. Same with the distributor cap, one wire at a time and matched the numbers on the new cap to the old one.
The wires on the plugs were difficult to pull out. That’s why my thought is to replace them - one or two might have been damaged removing them.
Maybe be sure you reconnected everything and didn’t knock anything loose. I once had a MAF sensor that was accidentally knocked loose – took a while to track it down.
@bardiferous I like to fix things myself but I do know there are times when I need to have a professional solve the problem. You may have reached the point of wheel spinning and not making progress. You may spend more than you would like but maybe a good shop can fix this thing so you can have years of service.
Having had two Chrysler minivans (1999 and now a 2007), as I recall they recommend changing the plug wires every 100,000 miles, along with the plugs, on their 3.3 and 3.8 L engines. I have done that, using OEM wires from the dealer and the exact plugs used by Chrysler and have had no rough running or MPG issues.
I agree with matching the original plugs in these vans because I did the same (I used new Denso wires though).
And partly because I don’t know what plugs were original for the 3.0 engine, I didn’t want to chime in with suggesting iridium plugs might be adding a question mark into this mix.
The removed plugs looked like Champion RN11YC4, which were listed for the 3.0 on RockAuto.
Quickly ran the new wires, one at a time, of course. Made all the difference, the Caravan is running better than ever.
Watch this space; I will report back the next two fill ups and the mileage.
Plugs are Autolite; I didn’t have the patience to order any brand that the local stores didn’t carry in Iridium. Wanted to put in something that would last longer than 30K because swapping them out is a MAJOR PITA.
