[Genken]

Hey guys, hoping I can get some help here.

a 2000 SE Sedan, with 89,000 on it, bought a couple of months ago.

I have replaced the spark plugs and wires, and had a mechanic change timing belt and water pump last week.


Here's the problem.. When I first bought the car, it had this exhaust smell. It also had 2 error codes when I purchased the vehicle: P1406, and P0420. 1406 I fixed when I found out the DPFE sensor or whatever had one hose tab broken off, so I replaced that, and the error code went away.

The P0420 error is still there. I changed plugs and wires hoping that may have been the problem, but it doesn't look like it.. the old plugs in the car were in fantastic shape, looked like they didn't even need replacing.

So.. the exhaust/gas smell.. it occurs when driving the car with the vents on, and I come to a stop. The smell will leak through the vents into the cabin, and it is really obnoxious. The only way to make the smell go away is to put the air on recirculated, but in January that means my car fogs up to shit in about 5 minutes..

I would really like to be able to get fresh air into my cabin, without it smelling like exhaust any time I come to a stop.

I mentioned the error code in case it might be relevant.

PLEASE advise.

Thanks!

 

[devil_dog_switch]

check your egr tube at the header end.. 10 bux says it's cracked. my 2002 se does the same thing.. and that's the culprit it's leaking exhaust and when you turn on your vents it sucks that air in. you can get it from tosley ford for 45 bux plus shipping new.. most places are more expensive

 

[Genken]

Is the EGR Tube the thing that connects to the DPFE sensor? I traced the hoses off the DPFE sensor to some metal tubes a little bit underneath, and they look to be fine, still connected, and do not look cracked.

Is there a picture of what you are referring to?

 

[devil_dog_switch]

damn it's too dark for my camera. look at your header and on the right side of it a metal tube comes out and works it's way towards the back of the motor, most likely it'll be covered by a treaded blackened canvas looking material. it connects to the header just under the heat shield so you'll need to look a little close. once you identify it it's easy to find. i'll search my pics and see if i have a good motor shot for you

 

[devil_dog_switch]

ok see my tranny dipstick. if you look to the left of it you'll see part of the egr tube.. sorry it's the best pic i got

 

[Genken]

I checked that pipe, and as far as I can visibly see, there is no crack, I also cannot detect any strong exhaust smell coming from that area.

Gah, this sucks.

 

[Genken]

This is really odd, I am at such a loss here as to find out how this is happening.

But it really is obnoxious to have the car do this.. the vents make it uncomfortable to breathe in the car, but without vents it fogs up to shit, and on recirculated it fogs to shit too....

When I peek under the hood I can't find an obvious source of the smell. It just sort of smells like an engine running, nothing near like what comes through the vents in the cabin. The engine also runs pretty smooth and quiet.

Are there any other areas I should try to troubleshoot other than that EGR tube?

 

[Genken]

bump... the smell is worse now, I feel like it is a little "sharper" of smell, if that makes any sense? I tried smelling around the engine, and it kind of had some wafts of the smell come from over in between the Fuse Box under the hood and what I imagine is the air box.

This sucks, the engine runs ok, but this smell is driving me crazy, and I'm freaking out about how bad of a problem is.

 

[MikeInMaine]

Genken, did you ever find the source of the smell? I have the same EXACT problem in a 2000 wagon

 

[niggly51]

The smell is most likely to be antifreeze. Your heater rad has sprung a leak and is leaking coolant into the heater housing. the smell is worse when the heater is on and on recirculate the inside of the car will mist up.

 

[whynotthinkwhynot]

The smell is most likely to be antifreeze. Your heater rad has sprung a leak and is leaking coolant into the heater housing. the smell is worse when the heater is on and on recirculate the inside of the car will mist up.

The most common problem for Zetec engines is the cracking thermostat housing. I'd investigate for leaks there first. Look for white residue around the thermostat housing, and coolant of course. Due to the age of your vehicle, I'd also investigate the overflow cap's sealing ring to be sure it's still intact and serving it's function. Hoses should be checked at about 10 years of age for any signs of damage. If you find any damage to hoses, then the best thing to do- considering the age of the vehicle- is replace all the coolant hoses including the heater hoses. I'm not super familiar with Zetecs, so I'm not sure if there are any more hoses other than the 2 for the heater, and the 2 for the radiator. While the coolant is drained from the vehicle, replace the thermostat ($3), and any gasket. Repair any damage to the plastic thermostat housing with epoxy, or replace the part. Use a hose to flush the radiator and engine forwards and backwards. Just run water through it both ways until nothing comes out in the water. Expect the water to be rusty for a while. I'd also disconnect the heater hoses from the engine, stretch the hoses out, and put the water hose on one of those to flush the heater core, then put the hoses back on the engine, disconnect from the heater core, and flush the what you can through those passages to the rest of the cooling system then flush it out using a radiator hose connection. That should get just about everything built up in there out.

Now if you're really concerned with crud in your cooling system, you can pull an old trick of draining the system, filling it back up with water and using a quart of mineral spirits in there. Then run it around for a little while keeping an eye on the temp- idling in the driveway is good, but revving to 3k or so every once in a while will help. Drain, flush, put on new hoses, fill with coolant mix. The mineral spirits will help break up some of the rust, but really it's not that big of a deal IMO- hose water flushing should do just as good.

Oh, for the gas smell from the exhaust- if I understand correctly, you had broken the vacuum line off your DPFE. That would cause the engine to run lean- vacuum leak- and the PCM would adjust the fuel mix accordingly. Now that you've repaired the problem, the PCM just hasn't reset itself from what was going on. If you have lifetime warranty plug wires, replace those, disconnect the neg battery terminal, and pull the spark plugs, check gap, CLEAN the arcing points with a small wire brush (brass or copper are best). Re-install, reconnect the battery, and start it. Allow the engine to idle for exactly 5 minutes after the idle drops down from startup idle. The PCM times this, and it's how it resets the A/F ratio. When it finishes, you might notice a slight drop in rpm if you have a tach, or a slight difference in exhaust tone if you have an aftermarket exhaust.

Try that first before assuming something else is wrong.

 

[niggly51]

Some good advice, whynotthinkwhynot, but you did not ask the OP to check for leaks from the heater matrix, and I forget to ask whether he had been losing coolant! If the coolant level has been going down and there are no obvious leaks from the thermostat housing or any other hoses- then it is almost certain to be the heater matrix from the symptoms he described.

 

[MikeInMaine]

more info - smell from vents

I have some more info about the smell from the air vents in my ford focus 2000 wagon (SOHC).

1. Smell is only present when engine is warmed up
2. Smell is only present if FRESH AIR is on. Turning on recirculate gets rid of the smell.
3. Temporarily blocked off the EGR tube with a gasket-shaped plate at the exhaust manifold. This had no effect on the smell, hence I don't think its an EGR leak.
4. Extensively checked the exhaust system for leaks. None found.
5. The smell is not present above the fresh air intake in front of the windshield on the driver's side, hence I don't think its getting sucked in from there.
6. Smell is not present when driving faster than 30 mph, even if engine is warm.
7. The smell started after I changed the water pump and timing Belt. I changed the coolant when doing the water pump so I am assuming what I am smelling is coolant and I probably had the leak into the air system before I did the water pump, but just never smelled it because the old coolant had a much milder smell.
8. The smell seems to diminish when I put the temp knob to hot.

So.. at this point I'd like to conclude that I have a leaking heater core, but if so, why does the smell go away when I put it on recirculate and why would it diminish when blowing hot air? Shouldn't that make it worse?

Oh also, I put a CO detector in the car with the windows closed up and let the engine run for 30 minutes with the air blowing (and the smell coming out) and the CO detector never budged from 0 (zero). So I really don't think its exhaust.

Very strange...

 

[MikeInMaine]

Can I bypass the heater core to see if that stops the smell? I assume I can just detach the inlet and outlet hoses in the engine compartment and join them with a fitting..

 

[whynotthinkwhynot]

Yes you can. I've done that before, and at least it will eliminate that possibility.

 

[niggly51]

In my experience leaks from heater matrix tend to be very small or very large. If it is a small leak- usually from the o-rings sealing the plastic end caps to the metal core- then it leaks when the car is standing and collects in the bottom of the heater housing. When you start the blowers you can usually smell the standing liquid. When the heater is on the core dries. I have had great success in sealing my Citroen leak with a US product called K-Seal. It has totally eliminated my leak and the only smell I get now is from my aircon, when an antibacterial product usually clears that. Might be worth trying K-Seal and an anti bac.

 

[MikeInMaine]

More and betterer data on my problem.

1. smell comes from air vents only with FRESH AIR on. Recirculate stops the smell. Therefore, smell is coming from outside the cabin and can't be heater core.
2. smell is worse after coming to a stop after driving or when taking off from a stop (after the engine is warmed up only)
3. heater hoses are disconnected from core and connected to each other, also rules out heater core.
4. I put a blower on the tailpipe and checked for exhaust system leaks. Found a big crack in the exhaust manifold. Replaced the manifold and NO EFFECT WHATSOEVER on the problem.. sigh..
5. Car now overheating (according to the gauge) on hot days (> 80, I live in Maine) with the a/c on.
6. Here's a good one.. the coolant tank smells like EXHAUST!
7. When the engine is warmed up it looks like the coolant tank is bubbling, (this with the temp gauge in the normal range or high)
8. The coolant tank caps seems to seal just fine, that is, opening it when the engine is hot causes the coolant to foam and boil and a big cloud of steam/pressure is released. But on a hot day, when the temp gauge reports overheating, I have witnessed SOME steam escaping from the cap.

So here's my latest theory.

The Head is cracked allowing exhaust into the coolant. This is overheating the coolant (exhaust is hot) as well as making it stink like exhaust. The bubbling I'm seeing in the coolant tank when the engine is in the normal temp range is exhaust, not the coolant boiling. There's probably some of it escaping all the time when the engine is warmed up, which is then escaping from the coolant tank as steam and that's what I'm smelling getting sucked into the cabin vent system. Whats weird is that by the time I can stop and get the hood open, I have never been able to smell the smell in the engine compartment.. even if i manually rev the engine.

Any ideas?

Thanks!

 

[niggly51]

The bubbling of the coolant is normal. The system works a bit like a pressure cooker, in that the coolants' boiling point is raised when at a pressure higher than atmospheric. Releasing the pressure reverts the coolant to atmospheric pressure and the already near 100 degree coolant boils. And yes, hot coolant does smell a bit like exhaust.
Have you considered the possiblity of the 'smell' being electrical. Failing motor windings can give off an acrid smell- heater motor? Is there a motorised flap in the heater box for climate control? Dead animal in the aircon evaporator? Or..........

 

[critter414]

Help

Sorry for bringing up an old thread but I'm currently having a bad gas/exhaust smell in my 2001 LX and I'm getting pathetic gas mileage, around 14-16mpg. I'm leaning towards either the egr valve or sensor. Would that be causing all that? I've replaced so many things on this car and I'm so sick of it. About to drive it across scales. Please help.

 

[Bills86e]

My thought is a bad fuel pressure regulator.

Bills86e



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