The "Ask a Mechanic" Thread

[Kosher Ham]

15 minutes ago, Elessar78 said:

Is it acceptable for drivers of Asian descent to a) drive a car without a spoiler and b. drift? Asking for a friend.

 

Absolutely. 99% of them don't. 

Same as 99% of blacks don't have spinners as rims. 

[twa]

47 minutes ago, Elessar78 said:

Is it acceptable for drivers of Asian descent to a) drive a car without a spoiler and b. drift? Asking for a friend.

 

 Only if it makes that buzzing sound.

[Springfield]

El, you’re too old for that stuff man.

[Malapropismic Depository]

This might seem like a dumb question, but the following situation has me confused.

I have an extra compartment for my coolant, that one might naturally assume is simply an overflow reservoir.

But I'm not so sure.

In addition to the standard radiator cap, there's another cap to add coolant. However, unlike typical "overflows",

this container has a dipstick with measurement levels. So of course, that would lead me to believe it's an indicator

of the actual level of coolant.

However, on the other hand, I question that possibility because of this : when the dipstick on this "extra" compartment

shows extremely low on coolant, and just about empty - if I then go to the radiator cap, the coolant is visibly still filled to

the top.

Attached below is - of course, the standard radiator cap - followed by the cap to the 2nd compartment, followed by the dipstick to the 2nd one.

So, what's the difference between the 2 "openings" ? And how do I know the true level, if they seem to contradict ?

 

 

 

 

[twa]

the dipstick is simply there because you cannot see the level, and it allows both intake to the radiator if radiator is low and overflow if pressure is excessive(they do not vent unless well overheated)

[Springfield]

Yes.  Fill them both to the correct level.  Naturally, the coolant level

in the radiator is more important.  Never check the radiator when the engine is hot (unless you know what you’re doing).

[twa]

Just now, Springfield said:

 Never check the radiator when the engine is hot (unless you know what you’re doing).

 

I though I knew what I was doing, the skin washing off my chest and arms  argued differently.

99 out of a hundred seemed good odds

[Malapropismic Depository]

Thanks, so I guess the main purpose of the 2nd one is so you can get a general idea of the level, when the radiator is too hot to open.

[Malapropismic Depository]

Hello gentlemen, may I ask a question twice in one week ?

 

Basically, within the first 10 minutes of driving, my engine will stutter, sputter, and hesitate a few times - so only when it's cold.

Before now, it's always runned very smooth. This never happened before, but just started happening a couple weeks ago.

So after a couple weeks of this happening, all of a sudden my Check Engine Light goes on. But again, only when it's cold -

so again after about 10 minutes of running, the light goes off. So clearly, the 2 things are related.

 

I researched, and found that this could be due to multiple causes. I just figured you all would be able to help me prioritize,

with which ones to have checked first, as the most likely causes, or the easiest cheapest parts to check/replace.

[Kosher Ham]

What are the things that you have read that it might be??? 

[Malapropismic Depository]

1 hour ago, Kosher Ham said:

What are the things that you have read that it might be??? 

 

I found the below troubleshooter, but several things on it are beyond my low level of expertise.

Among the things that are within my abilities :

 

I changed the spark plugs and plug wires about 2 years ago. And I changed the distributor rotor about a year ago.

I changed the O2 sensor approximately 3 years ago. I suppose it might be time to change any of these again.

But then there's the other things, such as DME control unit, Air Flow Electrical Box, Idle Stabilizer Valve, that are above my mechanical limits. Although one of the guys here may be able to simplify it, so I realize it's not as difficult as it appears.

 

This is the troubleshooter that I referenced above, that seemed like a decent source.

Note, I do not have trouble starting it, just the symptom of rough running when cold, and when I accelerate. I hoped that whatever the issue, I could nip it at the bud, before, and if, the problem worsens.

 

http://www.clarks-garage.com/shop-manual/eng-15.htm

 

Quote

Running Problems

Rough Idle

a. If the car starts when cold but, idles rough or does not want to stay running, this can indicate a problem with the engine temperature sensor. When the engine is started cold, the engine temperature sensor sends a signal to the DME control unit to provide a richer mixture. As the engine temperature sensor starts to fail, it sends a higher than actual temperature signal to the DME control unit. The DME control unit leans the fuel mixture thinking the engine is at normal operating temperature. This causes the engine to run rough. As the engine warms, it not longer needs the richer cold idle mixture and the engine runs smoother.

b. If the car idles rough this can also be indicative of bad plug wires, distributor, or rotor. One way to check for bad plug wires is to inspect the plug wire runs with the car running in a very dark area. If the plug wires are bad you should see some arching to the cylinder head or fuel rail.

c. If the car idles rough or cuts off at low RPM or idle, the cause could be a failing O2 sensor. The O2 sensor is out of the loop at full throttle and will not affect the way the car runs.

d. A rough idle can also be caused by a problem with the air flow box. The damper for the air flow box can fail mechanically or the contacts inside the box can get dirty and send a errant signal to the DME control unit. This can sometimes be corrected by cleaning the electrical contacts inside the air box. This requires removing the cover on the air box which is held in place by caulk. You will need to cut through the caulk and gently pry the cover off. Once the cover is removed, clean the circuit board inside with a good contact cleaner. When you have finished cleaning the circuit board, reattach the cover using a non-corrosive caulk.

e. If the car experiences a rough idle or idle fluctuates several hundred RPM, this can indicate a sticking idle stabilizer valve. Many people have removed and cleaned them but, this is normally a temporary fix and the valve should be replaced. A faulty O2 sensor can also cause RPM to fluctuate at idle. Unplug the O2 sensor and see if the idle still fluctuates.

 

 

 

Edited December 15, 2017 by Malapropismic Depository

[twa]

4 hours ago, Malapropismic Depository said:

Hello gentlemen, may I ask a question twice in one week ?

 

Basically, within the first 10 minutes of driving, my engine will stutter, sputter, and hesitate a few times - so only when it's cold.

Before now, it's always runned very smooth. This never happened before, but just started happening a couple weeks ago.

So after a couple weeks of this happening, all of a sudden my Check Engine Light goes on. But again, only when it's cold -

so again after about 10 minutes of running, the light goes off. So clearly, the 2 things are related.

 

I researched, and found that this could be due to multiple causes. I just figured you all would be able to help me prioritize,

with which ones to have checked first, as the most likely causes, or the easiest cheapest parts to check/replace.

 

Have you had it scanned for codes?....light coming on should throw codes

 

Ya can get a spray bottle of water and spray the wires and cap and see if it runs rough or arcs(which is my guess)

[Malapropismic Depository]

8 minutes ago, twa said:

 

Have you had it scanned for codes?....light coming on should throw codes

 

Ya can get a spray bottle of water and spray the wires and cap and see if it runs rough or arcs(which is my guess)

 

I assume you mean the ones from the auto parts store ? I have found those to be either unreliable or limited in potential from experience. But it's certainly worth a try, since they do it for free.

And am I right to assume that extreme caution should be taken when spraying water around the wires and cap, since water and electricity

can be a dangerous combination ?

[twa]

Just now, Malapropismic Depository said:

 

I assume you mean the ones from the auto parts store ? I have found those to be either unreliable or limited in potential from experience. But it's certainly worth a try, since they do it for free.

And am I right to assume that extreme caution should be taken when spraying water around the wires and cap, since water and electricity

can be a dangerous combination ?

 

they are the cheapest option if you don't have a scanner(you can buy a cheap bluetooth one for a smartphone cheap)

 

not very hazardous(just don't grab the wires ), just spray each wire individually and then the cap, ya can also pull the cap and check the contacts....sounds like a cracked/bad fitting cap to me

[Malapropismic Depository]

1 hour ago, twa said:

 

not very hazardous(just don't grab the wires ),

 

This thread sometimes sorta reminds of that TV show "1000 Ways to Die"

I bet a good percentage of those are covered in this thread.

[twa]

Just now, Malapropismic Depository said:

 

This thread sometimes sorta reminds of that TV show "1000 Ways to Die"

I bet a good percentage of those are covered in this thread.

 

that won't kill ya. it will perk ya up a bit.

not like it is 220v and make ya sound like Mel Tillis

 

[Springfield]

What year, make and model?

 

Step one is scanning for codes.  There are dozens of possibilities for what can cause rough running when cold.  It would be very helpful to know what code(s) is set.

[TheGreatBuzz]

I got a question for any diesel folks in here.  I got my first diesel and am wondering about how to prepare it for when I go to sea.  With a gas vehicle, I would just unplug the battery and put in fuel stabilizer.  Do I need to do anything different?  It's a 2016 F-350 King Ranch.  I'll be gone about 7 months.

Edited December 16, 2017 by TheGreatBuzz

[Springfield]

4 hours ago, TheGreatBuzz said:

I got a question for any diesel folks in here.  I got my first diesel and am wondering about how to prepare it for when I go to see.  With a gas vehicle, I would just unplug the battery and put in fuel stabilizer.  Do I need to do anything different?  It's a 2016 F-350 King Ranch.  I'll be gone about 7 months.

 

I’m not a diesel guy but I’d imagine you do the same.  Maybe run the tank down to low so when you refuel it will be mostly new stuff.

Edited December 16, 2017 by Springfield

[twa]

leaving the tank full is better w a additive, mostly empty diesel tanks tend to get a bacteria growth and diesel alone is good for yrs

some folk fill the engine completely with oil, but I think that overkill for 7 months

ya might try to critter proof it

[Kosher Ham]

Both of these guys are dead wrong. 

Send it my way. Hell, I'll come pick it up for you. 

I'll drive it at least once a week and you should be fine. 

I won't wreck it and I won't charge you any storage fees. 

 

 

[Elessar78]

Tech noted that brakes are at "4"

Dies that mean replace soon?

[twa]

1 hour ago, Elessar78 said:

Tech noted that brakes are at "4"

Dies that mean replace soon?

 

Ask him is he using a 1-10 scale and which is new,whatever happened to %?

[Springfield]

25 minutes ago, twa said:

 

Ask him is he using a 1-10 scale and which is new,whatever happened to %?

 

A common method now is to use millimeters, so I’d assume it’s 4 mm which is getting close but not worn out yet.  I’d have them replaced around 2 mm or below.

 

We used to use brake percentages when I first got into the business but we found that using percentage can lead to a lot of subjective readings (ie: one person’s 50% is another person’s 30%).  For the sake of consistency, it’s easier to use a standard measuremen, whether it be in 32nds of an inch or millimeters.

Edited December 22, 2017 by Springfield

[twa]

new pad is about 10mm isn't lt?

or just over 3/8' for us dinosaurs.