Emissions
1984 Mazda 626 Backfiring PDF Print E-mail

Dear Barbara,

I recently changed my car oil etc (I have a 1984 Mazda 626), but it wasn't until I changed the spark plugs that I started getting a backfiring problem. I also replaced the plug wires immediately in order to not mix them up, but I am still getting a problem. I need a couple hints on a solution.

Thanks,

Sharon


Dear Sharon,

A few possibilities here. Your car backfiring problem could be caused by an exhaust leak. If you have cold air getting into your exhaust, this can defiantly be causing a backfire.

If you are experiencing a “miss”, I would recommend that you have a compression test performed on your car to see if you have a bad cylinder. Also, have you double and triple checked that you have all of the plug wires on snug and totally tight?

Thanks for writing in,
BT

 
Smoke Emission from Ford E-150 Club Wagon PDF Print E-mail

Dear Barbara,

I read your reply to the owner of the 2002 Toyota Camry LE emitting white smoke from the exhaust when starting up in the morning.

I have seen a car with a blown head gasket that blows steam as you described. But this owner describes a condition when the car is first started up. I have a Ford E-150 Club Wagon with a 4.6L V8 and it also blows smoke when I start it in the morning. However, the smoke is short-lived, just a big puff when it starts. A friend of mine (not a mechanic) suggested that the cause was a leaking valve guide that allowed oil to leak into one of the cylinders when the engine cools off during the night. When the engine is started in the morning… poof a big puff of smoke.

At first I thought it was condensation, but it has persisted and worsened over time and the puff is looking more blue than white.

Any ideas?

Thanks,

John


Dear John,

Alrighty then, we are obviously not dealing with a major issue like a cracked head gasket; what we are dealing with are leaky valve seals around your valves.

What you are actually seeing is a light blue smoke that may actually look like it is white in color that carries a very pungent fragrance if your nose happened to be by the tailpipe when first starting up your engine in the morning. Your oil is leaking past the valve stem seal and down along the valve guides back down into the cylinders. When you start your car up in the morning or after it has set idle a while, the oil that has leaked down into the cylinders is burning off and that is why after you have driven your car a short distance, it clears up and stops smoking.

The repair should cost you anywhere from $200.00 to $700.00 to get this particular problem fixed, depending on who you use to do the repair. I would recommend getting it fixed before it gets worse, which it will in time and then end up costing you a lot more. Another note: the leaky valve seals are more than likely causing you to burn about a ¼ to a ½ quart of oil between oil changes if you haven’t already noticed or been told that by the person that performs your oil changes.

Thanks for writing in,
BT

 
Diesel Pollution PDF Print E-mail

Dear Barbara,

 

Diesels do not use any fuel to ‘shut down’ or ‘start up’ (assuming a warm or normal operating temperature condition).  You may be thinking of older gas engines with a carburetor that typically boil out their fuel when shutdown.  But diesel engines and modern gas engines are all fuel injected and none use carburetors and haven’t in 20+ years.  A major hybrid vehicle fuel saving strategy is to shut the engine off while idling or at a low power level, haven’t you ever driven a Prius?

I agree with you that the drivers are running the engines to allow the auxiliaries to function. Which is a poor practice and should to be stopped.  Most likely the auxiliaries do not need to be operated and the drivers just want to be comfortable while waiting for the passengers to re-board.  NASA should ban this practice and only allow engine startup say 15 minutes prior to boarding.  The pollution and extremely poor efficiency are wasteful.  It makes little sense to operate a heavy duty 300+ HP engine to run roughly 10 HP of axillaries.  Auxiliary generators or shore power connections are the answer if power needs to be continued. This is a very significant problem at truck stops when drivers take their mandatory layovers when that location has an air quality problem.  Imagine the pollution from 200 big rig engines idling over night during an inversion in say Denver at one of the giant truck stops. 

I disagree that a big diesel engine is efficient at idle.  By definition; efficiency is the total fuel supplied divided by the work produced.  If no work is produced (not including the parasitic auxiliaries) then the efficiency is so poor it is non-existent regardless of the quantity of fuel burned.  FYI recommendations to improve fuel economy for big engines by the manufactures is to shut down when possible and not idle.  Regardless of what operators might say idling of diesel engines is not good for the engine, these engines are designed to be operated loaded and when idled poor piston ring sealing often occurs resulting in lube oil dilution and a host of other problems. 

Joe Schneider

 

Dear Joe,

Is this an argument or a statement? Or you a friend or foe?

A 300hp diesel engine is more efficient at idle than your typical Chevrolet Tahoe, and YES it does take fuel to start up, how else would it start, duh huh.

Yes, I drove a Prius once and once was probably enough for me.

 

Thanks for writing in,

BT

 
Clean Diesel Bus Pollution PDF Print E-mail

Dear Barbara,

 

Your discussion of the fuel cost by idling diesel engines was appreciated as I too have been concerned about county owned buses idling about the Astrodome, various restaurants, or wherever the local politicians want us to pay for their buses to take their voters; especially the county commissioners.

 

Although the buses may use little gas during a ball game, I have wondered about the amount those dozens of buses are adding to Houston's polluted skies.  I realize they probably use modern ”clean" diesel fuel but over several hours, they must add something to the carbon footprint.  I recall in 2000 riding a bus to the Rome Airport and while waiting in traffic at the airport the driver shut the diesel engine off.  Being summertime, I asked our tour guide why the engines were not left running to keep the AC going.  I was told that their was a law against that in order to reduce air pollution!

 

Thanks,

Cornell

 

Dear Cornell,

 

The amount of pollution while idling is as little as it is as when it starts back up.  It takes as much fuel on start-up as it does to sit and idle for hours. 

So it just depends on which politician pushes the air pollution laws as most of them do not take all of the facts into consideration and play a simple game of “follow the leader”.

 

Thanks for writing in,

BT

 
Jeep Cherokee PCV system PDF Print E-mail
Dear Barbara,
I am having a problem with my '95 Jeep Cherokee 2WD 4.0 in-line 6 cyl. In cold weather I get condensation in the dipstick tube.
There is no water in the oil and this only appears in the winter.
Please help.
 
Dear Jeep owner,
 
I would check your PCV system as the valve or the hoses connecting this system could be old, damaged or simply worn out. I think addressing this could help resolve your issue.
 
Thanks for writing in,
BT