Ask a mechanic. - Non-Ski Gabber - Forums

Quoting SkiThe603 from Jan 24 2011 10:23:03:
My car randomly shuts off, it will turn on, then just shuts off. I can turn it right back on, but i feel as if this is still a problem.

Quoting charmander from Jan 24 2011 9:59:31:
sooo if i put a 4/9 cam in my ls1 how much horsepower would i have?
what about open headers, better than full exhaust?

also what kind of cfm should i be looking for in a carb?

keep in mind this is strictly for rock crawling.

Quoting ~~~~~~~~$ from Jan 24 2011 10:17:11:
my dad says it sounds like my valves are sticking, should I be concerned?

The referenced post has been removed.

Quoting Funkadelic$ from Jan 24 2011 10:20:00:
This morning when I turned on my car it made a really weird revving sound for about 5 minutes and it took the stereo about 5 minutes to start playing because it was so cold.  Oh, and the steering wheel was kind of stuck for a little while too.  Should I be concerned?

Quoting SkiThe603 from Jan 24 2011 10:23:03:
My car randomly shuts off, it will turn on, then just shuts off. I can turn it right back on, but i feel as if this is still a problem.

Quoting californiagrown from Jan 24 2011 10:23:50:
so running my car at 25mph puts it almost exactly between 2nd and 3rd gear. There is no RPM dial so i just have to change based on sound. Is it better to run the car at a higher rpm and lower gear, or lower rpm and higher gear?

Quoting .jersey from Jan 24 2011 10:59:34:
a 2001 jeep cherokee sport with 68K miles on it for 8 grand. good deal and how will it handle the snow?

Quoting Bi-ShredinalGuy from Jan 24 2011 11:00:09:
not really a mechanic type question but how bad does a couple pair of skiis on top of my car bite into my gas milage?

Quoting Tasche from Jan 24 2011 11:21:59:
I have a 2002 Subaru 2.5 RS and most times when starting in first gear the car surges, almost like it is stalling. It also does this in other gears always below 2,000 RPM or so. For example driving in traffic and starting at a lower speed in second the car shudders and surges when you push on the gas, sometimes pretty violently. Recently I have been hearing some noise, can't be sure if it is a backfire or something else knocking around.

I have been driving a stick for 10 years, it is not typical low RPM engine stalling. It is something different and something mechanically wrong. The engine seems to be running strong when not in gear and even when it is surging I can't be sure that its the engine.

My dad is an airline mechanic and does a lot of car work on his off time. I took it over there and of course it wasn't doing it, possibly because there was snow on the ground.

As a kicker the check engine light is on, I couldn't find the codes from when I got the computer downloaded but one was the knock sensor, one was the cat, and one was something to do with igntion efficiency. I put a tube of fuel injector cleaner in and the light will go off for like 10 mins then come back on. It has been on for a long time.

Anyway, I have been asking around and got everything from the cat being clogged to some bearing in the drive shaft being fucked up. We did the clutch about a year or so ago and it was running great after we replaced that and the throw out bearing.

I am pretty close to taking it to a mechanic because it is getting worse and I cant figure out what is going on.

Thanks for any help you can offer.

Quoting Tasche from Jan 24 2011 11:21:59:
I have a 2002 Subaru 2.5 RS and most times when starting in first gear the car surges, almost like it is stalling. It also does this in other gears always below 2,000 RPM or so. For example driving in traffic and starting at a lower speed in second the car shudders and surges when you push on the gas, sometimes pretty violently. Recently I have been hearing some noise, can't be sure if it is a backfire or something else knocking around.

I have been driving a stick for 10 years, it is not typical low RPM engine stalling. It is something different and something mechanically wrong. The engine seems to be running strong when not in gear and even when it is surging I can't be sure that its the engine.

My dad is an airline mechanic and does a lot of car work on his off time. I took it over there and of course it wasn't doing it, possibly because there was snow on the ground.

As a kicker the check engine light is on, I couldn't find the codes from when I got the computer downloaded but one was the knock sensor, one was the cat, and one was something to do with igntion efficiency. I put a tube of fuel injector cleaner in and the light will go off for like 10 mins then come back on. It has been on for a long time.

Anyway, I have been asking around and got everything from the cat being clogged to some bearing in the drive shaft being fucked up. We did the clutch about a year or so ago and it was running great after we replaced that and the throw out bearing.

I am pretty close to taking it to a mechanic because it is getting worse and I cant figure out what is going on.

Thanks for any help you can offer.

Quoting No_Dub from Jan 24 2011 10:16:35:
how many horsepower does each vtec sticker add?

Quoting tronned from Jan 25 2011 12:00:51:
That sounds like a pretty tough one to diag without looking at the car but I can certainly help you eliminate stuff with some easy checks.

First of all, if you feel like your dad or yourself are mechanically inclined I have a few checks you can do to start eliminating things to help to start to narrow down issues.

If there is a noise you have to figure out if its engine noise or drivetrain noise. That can be really tough for an untrained ear but sometimes engine issues can cause drivetrain noise so the stuff im going to tell you to do will be good for your car no matter what. Its pretty much a process for a "true" tune up that will make very big leaps in driveability of car.

First, the codes you mention all go hand in hand. Knock sensors are small crystals that produce AC voltage when they are vibrated, which means your crankshaft of your car vibrated enough from most likely a ignition issue called detenation ( the spark plug fired before top dead center of the pistons compression stroke causing the crankshaft to shake violently sending an AC signal to the ECU which will automatically set off a CEL). This is a very big issue can destroy an engine in a hurry, but modern electric fuel injection systems will lean out the fuel mixture of a car till the knock sensor starts to vibrate and sends a signal to the ecu to stop advancing the engine timing. The reason the engine wants to run so lean all the time is to get emissions as clean as possible. Most knock sensor related DTC's are from ignition issues or unmetered air getting into the cylinders ( faulty spark plug, coil packs, intake leaks after the throttle plates ). I would first of all, suggest checking your spark plugs and their gaps. Spark plugs from factory will have incorrect gap 80 percent of the time from shipping and being thrown into giant piles after production, so pull your plugs and check gap. If your car is a coilpack ignition system, its a little tough to check coilpack function unless you know exactly which cylinder is acting up and you can swap the coilpacks around and see if the problem follows the coil pack from cylinder to cylinder. If you have a waste spark/distributor system, you can check resistence of your spark plug wires with a multimeter, the specs can vary car to car but a standard spec to follow with high tension spark plug wires is 7 thousand ohms per foot of cable with a total maximum of 30 thousand ohms allowed total per wire. Very easy to check the wire if your car uses wires, just unhook take your meter and put one lead on each end of the disconnected wire and switch meter to ohms. Repeat that for each wire. You can also check availible voltage to the spark plugs with a spark tester, but im not sure if you are familiar with that tool.

Another possible issue is with air supply. Find out if your car uses a MAP or MAF sensor to meter air going into the engine. Some cars will use both sensors for a air measure system called speed density. If your car has a MAF it is very common for a dirty MAF sensor to cause exactly the problem you are describing. Remove the MAF housing and look into the backside and you should see a tiny wire strung across the housing in the center. Use pure alcohol and a q tip and be VERY careful ( im talking insanely careful, its super easy to break that wire) to LIGHTLY dab the wire and resistor with that alcohol soaked q tip. After you clean the maf, let it sit out in the air for a couple hours to completely dry out and reinstall. Even if this wasnt the issue, it will make your car run like new when the other issue is resolved, people often over look the cleaning of the MAF and can never get a car to run like new again. After cleaning of the MAF sensor, Inspect your throttle body and see if there is any carbon build up blocking the sweeping path of the plates. If there is some crud in there, clean with alcohol in the same fashion. DO NOT get alcohol into the intake of your engine without removing the throttle body , it can blow up your motor if youre not careful.

The cat fault from your ECU goes hand in hand with the knock sensor. The second there is any misfire on a car, the cat code will automatically come aswell. If you feel your cat is clogged, you can physically hear it when you rev your engine under load ( foot on brake and gas with park brake engaged all the same time ). The sound will be an odd sound from your intake system and smell from the intake.

There is no way you can check your o2 sensor without a proper scan tool. I would try all this other junk before you randomly go buy an o2 sensor, not to mention there is 2 o2 sensors on most cars. One before the cat, and one after. Their primary job is to monitor cat performance. There is no way to check an o2 without a lab scope.


This is atleast a start, if you have any questions, let me know dude.

Quoting tronned from Jan 25 2011 12:38:52:
Thanks for the +k guys. I am just really happy to help people through car issues, I know it can be really expensive to fix them and if you arent exactly sure about what is happening with your car it can be a bit scary to the normal person.


I forgot to give you some advice in regards to fuel issues. I know subaru has had some issues with fuel injectors. My cousin just had 3 injectors replaced on his STi. It will be very difficult for you to get specs for your fuel system but I can tell you a quick and easy way to test your fuel pump function just incase it maybe a fuel related issue. The easiest way to test a fuel pump is to get a fuel pressure master kit from a local parts store or something of the likes, they are fairly cheap and have all the tools for most servicing issues with fuel supply and injector testing. To test flow of the fuel pump what you need to do is tap into the fuel system prior to the injectors from a quick disconnect port or removeable line, after you get a line free find a measuring cup that can show you 500ml of fluid. Get your friend or dad to sit in the drivers seat and crank the engine over for you till either you get 500ml of gas into your measuring cup or 30 seconds of cranking... which ever comes first. Its pretty much a universal spec that your car must pump ATLEAST 500ml of fluid in less than 30 seconds. That is the quick and easy way to check a fuel pump, but remember the longer you stay cranking on your starter without releasing the higher risk you have of melting the windings inside of the starter so only do this 2 or so times without a long cooldown for your starter, and also make sure your battery has a full charge of atleast 12.4volts prior to the test because lower battery voltage can slow the cranking speed and fuel pump operation of a car. As for the injector testing, if your dad by some miracle has a injector drop testing kit, you can test all your injectors fairly easy. A injector drop test kit is a same electric transistor that pulses (on /off ) at insane speeds. In order to use this test you need that transistor box, and a fuel pressure master set like previously mentioned. Hookup the fuel pressure gauge inline prior to the injectors and keep the ignition in the on position but the motor is not running ( KOEO - key on engine off). You disconnect the electric connector to the back of your fuel injector and hook up your FI drop kit on to the injector while its still installed on the car, after that is done you hit the activate button and it will pulse the injector at a set speed. Prior to hitting the button, note the static fuel pressure via your master gauge that you have hooked inline and make not of the initial reading (KPA), after the button is pressed recheck the gauge and record the number after the button is hit once... after that is done turn the key off in the ignition. Repeat this step for all 4 injectors and record all the numbers. After you have finished all 4 injectors you must compare the injector with the least pressure dropped in KPA to the injector with the most pressure dropped, if the difference is greater than 10KPA, you have a faulty injector. Congrats on reading how to do a injector drop test, I hope this has made sense. I maybe going out on a limb her explaining these things to you, but I thought maybe if you are even curious on how everything is tested you might find this info useful.

Good luck dude, after you do all these things once, it will just be a breeze the 2nd time around and it all must sound like alot of work but just take your time and be extremely careful. If you follow these tests you should be able to confidently say your engine is working properly and the issue may lie in drivetrain.

Quoting tronned from Jan 24 2011 11:15:13:
car pricing varies city to city so i would just compare it with other decent shape jeeps in the area. I would just make sure they have a service history to show you prior to purchase and get it inspected before buying it. The best way to get an inspection done is for you to figure out where you would like it inspected ( I would say a jeep dealership because they will know all the common issues and problems ) and tell the owner of the jeep to drop it off there one day for an inspection and once that inspection is done, you show up to pay for the bill and pick up ONLY the sheet of paper with the inspection results. Most dealerships have a inspection package that is set out for used cars that has 3 copies (one for you, dealership for their files, and the owner of the jeep). If the results are good, and you feel good about the price buy the beast. The most common mistake people make with used cars is not getting them inspected before purchase and if the owner refuses or puts up a fight about an inspection that is a major red flag and just walk away. At my dealership we do quite a few of the inspections I just described to you and on atleast 60-70 percent of the cars that get inspected, they need quite a bit of work sometimes up into the 2k-3k range. If the car has some problems you can also use the inspection to low ball him on the asking price, its a win win situation. As for winter driving in a jeep GC, I have 3 friends with them and all swear by them and we currently have about 3 feet of snow on the ground, so im assuming they have no issues. Just check the tire depths because SUV/truck tires are quite a bit a costly than passenger car tires.

Quoting Evilchris from Jan 25 2011 10:56:10:
this question is a little diffrent than the others. After you subtract the costs of replacement parts, how much does your shop typically charge per hour of labour,

Quoting .AR6rider.$ from Jan 25 2011 12:16:35:
Ffffuuuu that was my question!

Quoting Triceraclops from Jan 25 2011 6:36:29:
ok, so i have a manual transmission 2010 impreza 2.5i. No mods. Its got about 10,000 miles on it and im having an issue. Im fairly knowledgeable about cars but im not too sure about this. When i go to drive my car, even after warming her up for 10 or so minutes it will shut off when coming to a stop in the cold. (say anywhere below 35 degrees Fahrenheit)
It does not have a lurching stall feeling, it simply shuts off quietly and i wont know until i go to press the gas again which is obviously dangerous because i lose power steering and such. As i come to a stop sign or light or even sometimes when i go to take a slow turn, the revs drop below 500 or so and this happens. It will do this about 2 or 3 times a morning and then just snaps out of it. It seems quite odd for such a new car but is it simply the cold?
The only temporary solution i have is to clutch or throw it in neutral as i stop and give it a little gas. Maybe its just the cold but it doesnt happen to my step dads 2010 wrx. Thank you for the help.

Quoting Triceraclops from Jan 25 2011 6:36:29:
ok, so i have a manual transmission 2010 impreza 2.5i. No mods. Its got about 10,000 miles on it and im having an issue. Im fairly knowledgeable about cars but im not too sure about this. When i go to drive my car, even after warming her up for 10 or so minutes it will shut off when coming to a stop in the cold. (say anywhere below 35 degrees Fahrenheit)
It does not have a lurching stall feeling, it simply shuts off quietly and i wont know until i go to press the gas again which is obviously dangerous because i lose power steering and such. As i come to a stop sign or light or even sometimes when i go to take a slow turn, the revs drop below 500 or so and this happens. It will do this about 2 or 3 times a morning and then just snaps out of it. It seems quite odd for such a new car but is it simply the cold?
The only temporary solution i have is to clutch or throw it in neutral as i stop and give it a little gas. Maybe its just the cold but it doesnt happen to my step dads 2010 wrx. Thank you for the help.

Quoting shr@gler from Jan 25 2011 8:51:10:
Hi tronned,
 Im having a shitty problem with my power steering. Basically it seemed fine when i bought the car 2 months ago, since then the power steering started moaning and then crapped out. basically it started bubbling and turned brown!!!! in previous vehicles i have checked the level and it has usually solved this problem. However I have just payed  a mechanic to replace the PS pump and it seems that the exact same problem is happening!!!!!
He now thinks that there is a leak at the rack. I am sort of confused by this as i continue to check the level and it seems to not be losing fluid! so could it be a clog? do you have any ideas on how to determine the actuall problem or fix it?? I have spent way too much money already and im fuckin pissed and not sure if this mechanic is just fuckin with me to cash himself up!
Any insight will be met with much +K and will happily reward with schwag!
So do i pay for more work? is there anything i can do to stop the noise? why is is screaming at me?should i get mad at mechanic? what the fuck is the bubbling? will an additive maybe help? do I really need to spend another 500 on this shit bucket of hate??
Thank you

Quoting aquinn from Jan 25 2011 9:58:58:
I'M A BOAT MECHANIC! Drop dem questions too

Quoting rich53 from Jan 24 2011 10:15:04:
which color of flames add the most horsepower?If i put spinners hub caps on my neon will i get more ladies?

Quoting tronned from Jan 25 2011 9:41:04:
what brand of car is it? If its a ford, they are known for shotty power steering pumps, so hopefully its not a ford. My advice to you is to take it back to that mechanic and demand some sort of warranty or compensation for a faulty diagnosis if the problem has continued after his "repairs". If he wont budge on that, you might be up shit creek. If the fluid is its normal color, that automatically means you need to swap the fluid because it has lost its viscosity and may mess your pump. The easiest way that i drain a power steering system is to pull a line off the pump and just let it drip out into a catch can. Reinstall line with new gaskets and hardware and fill up the power steering system again. After you have filled the system with new fluid, keep the cap off and get a buddy to sit in the drivers seat with the engine running and keep turning the wheel stop to stop slowly and watch the fluid reservoir and watch till all the bubbles in the system have worked out, this process is basically getting all the air out of the lines and rack, then top off the system after this is done. The easiest way to check to see if your rack is leaking fluid is just look under your car and spot the inner tie rods for your car, they are covered with plastic accordian looking things called bellows with some pinch clamps holding them on.... If your rack is leaking, it will leak out the bellows and be all scummy and oily which is fairly easy to spot. You can tell when a PS pump has shit the bed when there is no longer power assist on the steering AND there is metal flakes/ metallic color in the fluid. Hopefully the mechanic just used some shitty powersteering fluid or was a complete dumbass and used automatic transmission fluid instead of power steering fluid because back in the day that was acceptable but now a days it destroys seals for fluid inside the steering rack. I hope this is some info you have been looking for, if not let me know and ill try my best to help you through further.

Quoting BROSEIDON$ from Jan 25 2011 10:38:41:
2000 vw passat v6 5spd, "emissions workshop" the engine has a skip and i recently replaced the spark plugs and the ignition coil. help