If you chase the money you will find that most of the "lube shops"
(Jiffy Lube, etc) are owned by the oil companies.
Pretty sure Shell owns Jiffy Lube.
These days, the last thing an oil company needs is bad press,
especially for a $5 item.
If that is true, why do they get so much bad press? I've read enough
about their shady tactics that I'd never go to one. Mind you, most is
probably the local owner/manager and not corporate policy, but I don't
trust any of the quick change chains. I have a local shop and I can
stand right next tot he car as it is serviced.
I will agree with you thought's on the oil change places. Typically the
turn over rate is high so they certainly not investing much technical
training. So for the most part you have a guy that flipped burgers 6
months ago and the next time you go in he will be long gone.
Having been in the automotive field most of my pro life I always did the
repairs to our vehicles. Then I cut half my thumb off and during the
healing period I took my wife's Acura to the local oil change place. I
recall the guy yelling something about the drain plug being tight. I
also noticed that the oil had already been drained. The next time I
changed the oil the drain plug was indeed tight, and stripped. This guy
cross threaded the plug and continued to tighten it until the crush
washer flattened out. I had to rethread the pan and replace the plug.
Another trip I witnessed a sales guy come walking in quickly with the
air filter to a lady's vehicle. He told her that the filter was dirty
and needed to be replaced. She looked at and said that it did not look
dirty to her. He pointed at the single dirty spot on the filter that
was directly in line with the snorkel of the air cleaner. This was the
old style round air filter. I was almost embarrassed for every one that
worked there that they used those tactics to sell things that were not
needed. The lady probably knew squat about cars but had more knowledge
about what was dirty than the guy working there.
That is the term for engines that are designed without clearance to avoid
the pistons from smashing into the valves if the valve train skips time or
stops while the crankshaft still keeps going for a short time.
This pistons come up and smash into the valves, usually breaking or bending
valves, and/or smashing holes in pistons and other knarly stuff like that.
You want to make sure you change the timing belt early on those engines,
because if you wait til they break, you have an expensive, heavy
Actually the term is interference engines. The heads do not necessarily
have any thing to do with valve to piston clearance unless the heads are
milled beyond factory specs to increase compression. It is the lift of
the cam that causes the piston to hit the valve should the timing
belt/chain break or the timing gears strip, and the valve is in or near
it's fully open position. Non interference engines do not have enough
cam lift to push the valves far enough open to interfere with the piston
as it approaches TDC whether the valve should be open or closed.
And FWIW before the days of RPM limiters it was not unusual during
excessive RPMS for the valves to float, meaning the valve springs were
not strong enough to push the valve shut fast enough after the cam lobe
relieved pressure on the valve train. In these cases, and even with the
timing belt/chain, and gears in proper order the pistons could come in
contact with the pistons. In those cases it was more desirable that a
push rod got bent vs a valve being bent. With OHC engines you don't
have as many moving parts and valve/piston damage is more likely.
Since we were talking about the ease of removing oil filters, spark
plugs, external parts, etc, I was a bit puzzled why an interference
engine would present a problem with being able to replace anything on an
I'm pretty sure there might have been some confusion as to what
interference an interference engine actually presented to some one
working on it. For the most part there is no difference in the engines
as far as convenience to the person servicing or replacing parts inside
Now having said all of that, I retired from the automotive field some 20
years ago at 40. Up until then I never ever heard the term interference
heads. That may have changed in the last 20 years.
I at one time was the service sales manager for an Oldsmobile dealer.
We had to be careful with terminology when taking with the factory reps.
Ironically if you talked about the repair of paint on a vehicle with a
factory rep the repair description never included the word paint. The
repair involved color coating the affected panel. ;~)
Many people have no idea that their car becomes a time bomb at about
65,000 miles. Mostly is is the smaller 4 cylinder models, but you can
check yours on the Gates Belt web site.
If you buy a used car with more than 65k and an interference engine you
may not know if the belt was changed or not. I've heard $300 to $500
for parts and labor to do a belt change and you may as well get the
water pump done on some and save labor later.
If you want to keep them from being pulled out but still removeable, extend
a portion of the back upwards so it will hit the horizontal stop in the
frame when the drawer is all the way forward, then round over the bottom
edge of the back, including the sides where they meet the back. Remove the
drawer by lifting the front up until the extended back clears the stop.
I don't like them but they used to make - probably still do - little plastic
rollers for drawers like this. A pair of rollers was attached to the frame
at the front so the drawer sides rolled on them, another pair on the drawer
at the top back corners so that as the drawer was extended and tipped, those
rollers contacted the "kick" and rolled on it.
Same concept, but even simpler, quicker and easier way to insure a
drawer pulls out only as far as you want it to:
To pull the drawer all the way out, simply reach in and turn the drawer
stop a quarter turn.
Either folks or I or both have had one or more Buicks since '64 and nary
a one has ever been a bad 'un...only bad experience I've ever had w/ GM
was an '88 88 w/ a newly-introduced overdrive tranny design that went
south early. Counting all the farm trucks and pickups going back to
'28, I'd expect it would push 100 vehicles between personal and work
use. I'm confirmed GM guy, meself from our experience. There's still a
'58 C60 in use on the farm; I've been using it again today that's only
had brakes and some body work (ensilage is _very_ corrosive and it had
many, many years of use on feed-patrol)...current list includes '10
Enclave, '11 Lucerne, '98 and '99 PUs in the car, small truck varieties
plus a half-dozen assorted single- and tandem-axle medium-duty trucks
from '80s up.
In case you hadn't considered the possibility, the CEO of Shell Oil
doesn't personally change your filter. The droid on the line doesn't
One of these places didn't bother to check my antifreeze one Winter (I
had just bought the car, which had previously been registered in TX).
I specifically told them to make sure they checked it, even though it
was on their list of "service points". Of course it froze the next
night (its freezing point was +10F).
I have a Sonata Limited with the 2.0 liter turbo. I've noticed that a
few other brands have a 2.0 liter turbo. I have to wonder if they are
all out of the same engine plant.
Audi, Cadillac, Ford, Honda, Nissan all have a 2.0. Coincidence?
My last Sonata had a V-6. It did me well and I read it was developed
with Chrysler and another car maker, maybe Mitsubishi.
There will be no similarities in these different brands of engines other
than their size and number of cylinders. Just like in the 60,s Buick,
Chevrolet, Pontiac, and Oldsmobile all had 350ci V8's they were all
built with the same displacement but were all very unique.
Now in some instances these days the engines are the same. Audi being
owned by VW, shares engines with the VW. You will actually find Audi
branded parts under the hood of a VW.
Back in the 80's Chevrolet Isuzu and Honda had similar models. Isuzu
built the LUV pick-up for Chevrolet but later Chevrolet built the Isuzu
Rodeo for Isuzu. Strangely enough Isuzu had built for Honda, by
Chevrolet. a Honda version of the Rodeo, I forget what Honda called it.
Toyota used to build the Nova for Chevrolet in the 80's.
Let's see, today's plugs are about $15-$20 each.
Wires are also in the $15-$20 range.
IOW, a plug and a wire costs from $30-$40 per cyl.
Using an average, a plug/wire set costs about $35/cyl
or $140 for a 4 cyl engine.
If the labor charge is only $10/ cyl or $40 for a 4 cyl.
Now we are up to $180 and nothing has been included
for overhead and profit.
What about the electronics to test the newly installed
Where does the DIY'r gain access to this test equipment?
I have been very fortunate finding good mechanics since
coming to California.
Mechanics that will bring me back home while they work
on the truck, then come back and pick me up when they
My present mechanic has a base business of working on
hot rods and treats me like his long lost wayward step
His choice if he does the repair as long as he uses Toyota
Sheet metal OTOH, is strictly a dealer item.
Like anything else, you pays your money and you takes
I use dealers as a source for renewal parts, body work
and little else.
Today's use of onboard vehicle computers and high
powered computerized test equipment, have made back
yard car maintenance a thing of the past IMHO.
4-5 years ago, the local NBC-TV investigative reporter
did a piece one of the oil change quickies and uncovered
a real mess.
Got a mea culpa from the chain.
Followed up with another investigation about 2 years ago
and guess what, back to the same old tricks.
Don't know what the outcome of this investigation was.
This was a chain that was attempting to increase their
revenue stream by offering added services above and beyond
the basic oil change.
Glad to see you found a local shop that works for you.
I have found a chain location that works for me.
As far as my comment about "bad press" is concerned,
the oil companies have enough "bad press" problems
with their base business' to have a headache with quick
change operations which are in business to maintain a
path to the retail market for their oil products.
What the quick change lube shops have done is establish
a price level for their service.
A price level that has basically put the DIY'r out of
I missed the small difference in the post calling it interference heads.
Still, I knew what the point was that was being made...
Interesting to note that many engines are interference engines, if the
pistons were totally flat on the crown. Many pistons have two or more
semi=circular depressions cast into their tops, so if a valve is open when
the piston comes up, it does not smack the piston, because of the depression
in the piston.
I believe you understood the terminology however I was not at all
certain that the original poster mentioning it, did. Kinda reminds me
of the TV shows where a guy is doing something under the hood and
telling some one that he was putting water in a completely sealed
battery. Or pouring coolant in the master cylinder. ;~) The term
really did not fit the way the conversations was headed. I could have
totally missed on that but that is the way I took it.
Correct, but it is not really a question of if the valve is open when
the piston comes up, every other revolution of the crank shaft the valve
is open when the piston comes up. And I know you probably know that but
you might be surprised how very close the valve and piston come to each
other. Some times you need a feeler gauge to measure the clearance on
higher performance engines.
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