Hi all, looking for some help diagnosing a problem with the 2005 ranger I just purchased a couple weeks ago. It has 106k miles on it.

I am NOT mechanically inclined OR knowledgeable about cars so I will do my best to provide information. The symptoms: it lets out a large puff of white smoke at start up most times, but not every time. It also releases a puff occasionally while excellerating after sitting at a stop light. The smoke looks white (I'm having a hard time discerning any blue tint, but it's possible). The smoke doesn't have any particularly noticeable smell...just smells like what I would expect exhaust to smell like. Checked the oil and it was low so we added 2 quarts...a few days later the oil was only a half inch up the dipstick.

There are no leaks or puddles under truck or anywhere immediately visible under the good and it only
Let's out singular, 6-10 second puffs of smoke usually just at start up so I have absolutely no clue where all that oil could be going! The coolant level
Seems fine and does not seem to be changing...no oil in coolant, no coolant in oil, oil color looks fine. It does sometimes spit out a little black liquid out of the exhaust when I start it, but I figure that's just dirty condensation from the dirty tailpipe.

Other than this the car runs perfectly fine. Sounds fine, rides smooth, no overheating, loss of power etc etc.

I'm lost. I will be taking it into a mechanic tomorrow but, as a girl who is clueless about cars aka ripe for being taken advantage of, I wanted to get some input elsewhere as a cross reference. What I've read has led me to lean towards bad valve seals...if ya'll agree, what do you think I can expect to pay for that fix? Pissed I bought a lemon :(


Thanks so much for your help.

 

I should say the truck was only drive maybe 100 miles in those few days that it lost nearly 2 quarts of oil.

 

2 quarts is alot of oil without an obvious leak.

I would check that the dipstick is going in all the way each time you check it.

As for the smoke, start up cold smoke is common on all vehicles depending on weather conditions, you mentioning it would mean you don't see other vehicles doing this in your area at this time of year.

No loss of coolant and no over heating is a good sign the head gaskets are OK.

Valve guide seals are a good bet from your description of when the smoke occurs, these can be changed without pulling the heads.
Vacuum in the intake is highest at idle or when coasting and shifting gears, the high vacuum pulls oil vapor from the valve cover area via worn valve stem/guide seals, so a puff of smoke after idling or coasting usually means intake valve guide seals are worn.

I would first remove the PCV valve and it's hose and make sure both are clean.
Also the Vent hose, usually runs from Oil Fill tube to Air tube, make sure it is clean.

PCV(positive crankcase ventilation) valve is there to create a slight negative pressure in the valve covers and crank case, this can reduce the amount of oil vapor entering the worn valve guide seals.

What should be done first is a dry then wet compression test, this will tell you if the rings are too worn.
Worn rings burn oil as well, and no use changing only the valve seals if rings are bad.

If dry/wet test comes back OK then procedure for valve seal replacement is:
Remove spark plugs
remove valve covers
remove rockers/assembly

Rope method
Feed small rope into a cylinder's spark plug hole so it coils up, piston should be about 1/2 way down
rotate crank manually until rope press's against valves in that cylinder, this prevents valves from falling into cylinder when spring is removed.

Air method
Rotate crank until piston is at TDC(top dead center, as high as it will go) in the cylinder
screw air compressor hose into spark plug hole on that cylinder
turn on air pressure to hold valves in place


Use valve spring compressor to compress spring and release "keepers"
(for DIYers, place a towel across the bottom section of the head, those keepers love to fall down the oil drain holes, lol)
remove spring
replace valve guide seal
replace spring and keepers
repeat for second valve

Repeat for each cylinder

re-install rocker/assemblies
re-install valve covers
re-install spark plugs

Not all mechanics will do this, there are two reasons for this, they are young and have never done it before, or they would rather pull the heads because it's the 'right way to do it', which will cost you alot more.

Once the heads are off they should be cleaned and machined, and that adds alot to the price.

The 'right way to do it', I do have a problem with that statement in general.
Once you start down that road it is in fact a slippery slope, although most don't see that.
Procedures for "the right way" don't take into account the cost, which is fine if that is what "they" want to do, but if cost is not a factor then why fix anything????
Just buy a new truck, if it breaks buy another new truck, cost is not a factor, and there is the slippery slope
Dirty ashtray..........buy a new truck, lol, yes that is the extreme end but still the same "the right way" procedure.

Sorry for the rant

 

Great post, and yeah, most younger tech's will opt for the "right" way 'cause thats what school told them to do. I was lucky and was trained by a bunch of old farts in school and know about the rope method too, but i like the air method better. The rope can leave behind debris and fining the right fitting for the air method can be tough sometimes, its a narrow gap to fit in.

 

wow, thank you RonD. Such good instructions we're tempted to try it ourselves! not really...but I appreciate your post.

The mechanic this morning looked at it for about 15 minutes and said he agreed it was probably the valve guide seals but the only way to be sure was to start taking it apart. I was kind of disappointed he didn't do more testing as I would like to be CERTAIN this is the problem before we spend all that money to have him take the head off....

I think we'll have second mechanic look at it...and if he agrees it's the valve stem seals maybe I will call around and see if I can find someone who will do it without removing the head.

I've done a bit of research on replacing the stem seals with the head on and have come across a couple posts of people saying it's next to impossible to do this on trucks with A/C because the AC box is in the way. Do you have any insight if this applies to my truck/situation?

Also, I will have a look at the PCV valve first off. Do you think a clogged PCV valve could potentially cause this much oil waste or are the seals almost certainly shot?

Again...thanks for the thorough response.

 

Thanks

My mistake, I see now you have the 4.0l SOHC which adds a layer of difficulty, only reason A/C would get in the way would be with valve spring compressor or removing Cam, but I can't say since I haven't pulled one apart...........yet.

What I would suggest for now is to add some Lucas Oil Treatment, this product softens and swells the "rubber" valve seals and main seals, this will reduce oil getting in to intake valves.


Yes, PCV valve creates negative pressure in valve covers, so less oil would be pulled into intake from valve seals.

The issue is pressure, the intake manifold has high negative pressure(vacuum) at idle, the intake valve stems are in this negative pressure, the valve stem seals are in the valve covers and covered with liquid oil, as they wear out(get hard) that liquid oil can get past the seals and is sucked into the intake from the negative pressure and into that cylinder to be burned.
Negative pressure in the intake is highest at idle, this is why you get the puff of smoke after idling, or after coasting, if throttle plate is closed and engine is running vacuum builds up, so more oil is sucked in during that time.

PCV valve use that same negative pressure to pull air out of the valve covers and crankcase, so if PCV valve is dirty then there is less negative pressure in the valve covers so even more oil will be sucked in the valve seals.

On the 4.0l SOHC there were problem with the PCV hoses, the elbows would wear out and crack, so check those very carefully.

 

Well we pulled the PVC valve and both valve and hose look fine. Valve rattled and looked clean. We were really hoping that would be the fix.

So...I guess it's the valve seals and we've been told it will likely cost nearly 2k to take care of. What a bummer....I'm not even sure it's worth paying for on this truck.

 

I would certainly check on it further.
106k miles is low miles for an '05 so truck could have been sitting for long periods which allows seals to dry out and crack.
Low milers are great for interiors and exteriors, but can be hard on engine and drive train parts if they sat for long periods.


I would do a vacuum test, you could do this one yourself, vacuum gauges are $25 and very easy to use.
Read here: http://www.gregsengine.com/using-a-vacuum-gauge.html
And here: Tips on Reading Gauges: Vacuum Gauges

I would expect a drifting needle on the gauge if valve seals are worn, as not all seals will be leaking exactly the same.
Also pull off the PCV valve hose and cover intake hole with your hand to block vacuum leak, or plug it with something.
See what needle does.

I would pay for a compression test, dry and wet.


$2,000 would be pulling the top end out, and if valve guide seals are the issue then there will be other problems that should be addressed, so I would pass on that option.

To remove and reinstall the whole engine you should be looking at $750-$1,000, 10 hours at $75/hr-$100/hr
4 hours to remove and 6 hours to reinstall

New 4.0l SOHC engine is $2,500
low mile used $1,000-$1,500

I would call a few Machine shops and ask the price to rebuild your 4.0l SOHC, prices very so call a few.
Let them know the current miles on the engine, I doubt they would replace pistons and rods but let them know.

Once you have all the options on paper it will be easier to decide the best course of action.

Selling the truck "as is" is also an option, that is how you bought it, but if you plan on keeping it for a few years then spending even $4,000 on a new engine comes out to $65/month over 5 years.
Which is less than buying a new truck, which is almost what you would have if engine is new.
IMO rebuild is the best option if you decide not to sell it "as is"

 

well, the saga continues.

After confirming with two mechanics that the problem was likely worn valve guides, I called the dealer whom after some coercion agreed to pay half of the cost of the repair if we bring it to their mechanic who will do the job for $700.

A few days after bringing it to their mechanic, he pulls the engine and says it's not the guides, its the rings. The estimate for the repair increases to $1500. The dealer says it would be a better idea to just replace the whole engine with a used, low mileage engine. He estimated this to cost $1500...or says find an engine and add $300 for labor.

Does this seem right? Only $300 for labor costs? Isn't this at least a 10 hour job?

This whole thing has turned into an absolute nightmare. The stress, time, running around, not to mention rental car fees we are racking up is just wearing me down. I cannot believe a dealership sold us a truck that needs a new engine. damn.

 

by the way, I had it wrong to begin with....it is a 3.0L engine not 4.0

 

that sounds ok, i have seen a few people get low mileage engines installed in the 2,500$ to 3,500$ area. the 300$ may just be the difference from the original job. and a skilled tech can swap a motor in 4 to 5 hours but they will still charge the full labor cost.

 

Anyone know of a good place to find a used engine? The engine they proposed putting in actually has more miles than the original one...

 

well i dont know about your area but in Phoenix there were like 7 or 8 reputable shops that sold and installed them. just had to look in the yellow pages.

also remember that miles are not as big of a deal as they used to be, with 232,000 miles on my 2.3l and its probably less than halfway through its life.

also that $2,500 to $3,500 was a price from them that included a new engine, and they kept your old one as a core.

 

I'm new to the forum, but have a 2000 Mazda B2300 with a 2.5l I was given due to the oil smoke and very high oil consumption (2 qt/hr @ highway speed). I'll perform a compression test over the weekend, and post the results. Fearing worn rings which ain't worth dealing with on this truck.....