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theabortionator
April, 2025

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Ask a mechanic.

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tronned
Posts: 1098 - Karma: 790
It seems every so often there is a "car help" related question posted on NS and I thought I could maybe help out people who dont want to make a thread but want to ask a quick question about an issue they are having with their car. I am a mechanic at a higher end german car company so I thought i could maybe give my 2 cents or point you in the right direction to resolving your issue on your own or give you an idea what to tell your mechanic the issue is.

No question is stupid and I will try to help out.
14 years ago
23 3
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tronned
Posts: 1098 - Karma: 790
jibbinc.Truck is giving me tranny problems

runs ok when its cold. once its warm, starts to shift rough. and if i turn it on and off, O/D light flashes and tranny goes into limp mode. ( shifts 1st 2nd neutral, stuck at 50km/h)

its a 97 ford f 250 7.3l diesel

Got it scanned

p0236 Turbo Boost Sensor A Circut Performance
p0708 Transmission Range Sensor Circut High
p0713 Transmission Fluid Temperature Sensor Circut High

My truck has always had a voltage fluctuation. goes from 11.5 - 14v constantly. Unless above 1300rpm.
The lights dim and get brighter the battery gauge goes up and down, the idle moves SLIGHTLY. barley noticeable.


From my reading it could be something with the PCM wiring harness. Doesn't seem like the sensors are blown, they are just getting incorrect voltage. Which i think is linked to my fluctuation problem.

I dont want to start getting random shit fixed. Would rather get 4 birds stoned at once.


It is hard to say, but a turbo fault is most likely not related to transmission faults. It could be but I am not too sure of how the limp mode in a ford diesel works but there are completely different control units. Turbo circuit faults could be a million different things from a boost leak, over boost, no boost, vac leaks, faulty turbine in turbo, wastegate issues... etc etc so its really hard to guess on what your turbo related fault is.

The first thing i would do is pop the transmission harness connector off the transmission if possible and look for corrosion on the terminal pins of the connector. Also, check to see if gear oil has soaked the terminal pins, I have seen some kooky shitty from gear oil soaked wiring harness connectors due to the capillary effect... the seal of the harness inside of the transmission could be leaking and allowing gear oil onto the terminals... when electricity is applied it actually draws the oil out of the gear box on the wires... I have seen it come all the way to the TCM/ECM.

that is a good starting ground.

Typically transmission fault codes are not cureable with basic parts, most of the time it is either a valve body or gearbox failure if you can confirm the electric control circuit is ok. If your voltage is jumping, that sounds like a bad ground or corrosion in the wiring somewhere, it could be very tricky to track down.
11 years ago
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Bodhisattva_
Posts: 5749 - Karma: 2,009
Should I have any specific questions to ask the dealer about a 99 Forester w/ the 2.5l engine 4spd automatic? It has 151k miles and I was just curious if there are any specific problems/parts etc I should ask about?
11 years ago
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SkierPT
Posts: 2209 - Karma: 4,910
When looking at used cars, how can I tell how much rust on the frame is too much? And rust on the body. I live in buffalo so cars rust a lot
11 years ago
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tronned
Posts: 1098 - Karma: 790
nick21861When looking at used cars, how can I tell how much rust on the frame is too much? And rust on the body. I live in buffalo so cars rust a lot


sorry, didnt realize this thread got bumped.

Any rust on the frame is terrible unless repaired properly at a frame shop. IMO, none is acceptable.
11 years ago
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tronned
Posts: 1098 - Karma: 790
Thizzle.Should I have any specific questions to ask the dealer about a 99 Forester w/ the 2.5l engine 4spd automatic? It has 151k miles and I was just curious if there are any specific problems/parts etc I should ask about?


find out if there is a service schd for the transmission and if it was performed. If there is a hitch installed on the car, walk away as well.
11 years ago
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speedin
Posts: 731 - Karma: 131
2009 Honda CRV
72K miles

I recently moved to the mountains. (elevation 6000 ft)
It has been really cold here lately. -7f or more the past few nights.

The past few mornings I have been having a hard time getting my car to start in the mornings. The battery is brand new, has plenty of juice to turn the starter over. It just doesn't want to start. Took me probably 30+ seconds to get it to start this morning. Once the motor gets warmed up, it runs fine and will start right back up no problem.
When its cold and sits out over night, I get problems.
This is not a battery issue.
10 years ago
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Bar_Down
Posts: 5896 - Karma: 395
speedin2009 Honda CRV
72K miles

I recently moved to the mountains. (elevation 6000 ft)
It has been really cold here lately. -7f or more the past few nights.

The past few mornings I have been having a hard time getting my car to start in the mornings. The battery is brand new, has plenty of juice to turn the starter over. It just doesn't want to start. Took me probably 30+ seconds to get it to start this morning. Once the motor gets warmed up, it runs fine and will start right back up no problem.
When its cold and sits out over night, I get problems.
This is not a battery issue.


Sounds like you need a block heater
10 years ago
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speedin
Posts: 731 - Karma: 131
Bar_DownSounds like you need a block heater


Never heard of anyone needing a block heater on a gasoline engine at these temps. Maybe up in Alaska where its -40 for days on end...but a low of -7 for less then 12 hours should not give my car this much trouble.
Anyone else?
10 years ago
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Caucasian_Asian
Posts: 2447 - Karma: 1,665
Bar_DownSounds like you need a block heater


This or change to a lighter weight oil. Or both.

My truck will start at -20C, but it's not super happy about it. And it warms up faster.
10 years ago
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speedin
Posts: 731 - Karma: 131
Caucasian_AsianThis or change to a lighter weight oil. Or both.

My truck will start at -20C, but it's not super happy about it. And it warms up faster.


using 5w20 right now. It has never done this before in the past. Last year we had the coldest winter ever, and it did not do this. Why now a block heater, and or changing types of oil?
10 years ago
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000000000000
Posts: 843 - Karma: 1,552
How long was you're apprenticeship to be a mechanic?
10 years ago
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tronned
Posts: 1098 - Karma: 790
speedin2009 Honda CRV
72K miles

I recently moved to the mountains. (elevation 6000 ft)
It has been really cold here lately. -7f or more the past few nights.

The past few mornings I have been having a hard time getting my car to start in the mornings. The battery is brand new, has plenty of juice to turn the starter over. It just doesn't want to start. Took me probably 30+ seconds to get it to start this morning. Once the motor gets warmed up, it runs fine and will start right back up no problem.
When its cold and sits out over night, I get problems.
This is not a battery issue.


sounds like your fuel pump. if you let it sit, the check valve in the fuel line/ pump be leaking down over time, hence the long crank to start again to build the fuel pressure again.

The first thing i would do is verify fuel is getting to the engine after you let it sit overnight. On the weekend, take off the fuel supply line to the fuel rail and rest it in a clear plastic water bottle that has been emptied and crank that puppy for 5 seconds and see how much fuel is getting to the fuel rail. I am willing to bet that is your issue.
10 years ago
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tronned
Posts: 1098 - Karma: 790
CheeFHow long was you're apprenticeship to be a mechanic?


ive been working cars professionally about 8 years now.
10 years ago
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tronned
Posts: 1098 - Karma: 790
on a side note, here is a photo from a few weeks back. Pretty slick ride.
10 years ago
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Titus69
Posts: 9332 - Karma: 17,963
2001 crv

when at speeds around 40mph is sounds like somethings going on around my transmission, like a rattle.

A few others that occur every few days that Ill listen for this week.
10 years ago
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000000000000
Posts: 843 - Karma: 1,552
tronnedive been working cars professionally about 8 years now.


That's awesome, cars would be fun. I am going to be working on heavy equipment and diesel engines.
10 years ago
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speedin
Posts: 731 - Karma: 131
tronnedsounds like your fuel pump. if you let it sit, the check valve in the fuel line/ pump be leaking down over time, hence the long crank to start again to build the fuel pressure again.

The first thing i would do is verify fuel is getting to the engine after you let it sit overnight. On the weekend, take off the fuel supply line to the fuel rail and rest it in a clear plastic water bottle that has been emptied and crank that puppy for 5 seconds and see how much fuel is getting to the fuel rail. I am willing to bet that is your issue.


Ok I will try that. Are you sure the check valve isn't located in the fuel pressure regulator?
Also this only happening when the temps get to single digits or below.
If it was a fuel pump/ regulator issue then why would it start up no problem when it is warmer out?
Thanks
10 years ago
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KravtZ
Posts: 6637 - Karma: 2,629
Purchased an after market CAT to pass an inspection (non California resident). The new CAT took my engine light off but still fails on the emissions. Any way around it? I heard its a hit/miss on these after market cats so maybe I try again with a better one. New OEM factory is like 1400 bucks for my car plus labor. Car is only worth around 2000-2500 bucks so id be better off buying a new car at that point
10 years ago
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timmi
Posts: 12874 - Karma: 3,460
2014 focus or 2015 golf?
Focus is cheaper and IMO a better looking car.
10 years ago
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JGWI
Posts: 2842 - Karma: 7,812
Had some problems last year with my 540 BBC in terms of coolant not staying where it was suppose to. Found out 6 of the 8 exhaust guides were leaking so in response to this we got new aluminum heads (much better than the old iron ones we had on there). Obviously in the process we replaced the head gaskets and drain all the water. Ever since we refilled it, it has been an SOB to keep it at a reasonable level. As is true with most rail cars, the cooling system is rather ineffective and about one run down the track will have the water well over 190F on a hot day which results in the over flow tank getting filled and hot water spitting out of the cap like a fire breathing dragon.

So, does anyone have any ideas on how to keep a reasonable level of water in the system to keep it cool but yet not so much that I get 3rd degree burns?
10 years ago
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stickerman
Posts: 2043 - Karma: 147
How do you tell if your struts are shot/leaking. Was in for an oil change at the dealer and advised new struts, strut seats, bearings and mounts. I put my winters on the other day and there was no physical sign of leaking oil anywhere. Car has 150,xxx km 2009 Volvo xc90 original struts.

What's your insight?

Luke
10 years ago
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CheddarJack
Posts: 5203 - Karma: 7,380
Around Thanksgiving, my windshield wiper motor shit the bed. It slowly became more unreliable, as it would get stuck in some position and wouldn't move unless you physically pushed it hard enough (What I liked to call manual assist. Reaching out the window and yanking on my wipers going 50 mph was fun) or sometimes just waited 5 or 10 seconds. Sometimes it just wouldn't work at all.

Last week, I got the motor replaced. Seemed like it fixed it but the new one shit out the second day while driving back at night from skiing on the highway while it was snowing. I had to leave my car overnight at a park n ride. When I popped the hood it started working again for a minute, but I couldn't get it to go after that. The shop put a second new one in free of charge. They said that both motors would work only when you tapped on them. They claimed that the first replacement was just a faulty motor. What I'm wondering is if it could be an electrical issue and that the motors are possibly shorting out. Does that seem likely? Are there any easy ways to check?
10 years ago
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KravtZ
Posts: 6637 - Karma: 2,629
The other night my window in my 2003 VW Jetta came off the track and fell into the door. Is this an easy DIY fix for someone not to experienced with cars or should I just take it to the mechanic. Apparently its a common problem on jetta's around this time period.
10 years ago
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TheStamos
Posts: 9311 - Karma: 910
Just.Go.With.ItHad some problems last year with my 540 BBC in terms of coolant not staying where it was suppose to. Found out 6 of the 8 exhaust guides were leaking so in response to this we got new aluminum heads (much better than the old iron ones we had on there). Obviously in the process we replaced the head gaskets and drain all the water. Ever since we refilled it, it has been an SOB to keep it at a reasonable level. As is true with most rail cars, the cooling system is rather ineffective and about one run down the track will have the water well over 190F on a hot day which results in the over flow tank getting filled and hot water spitting out of the cap like a fire breathing dragon.

So, does anyone have any ideas on how to keep a reasonable level of water in the system to keep it cool but yet not so much that I get 3rd degree burns?


By water do you really mean water? or coolant?
10 years ago
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DrZoidberg
Posts: 5676 - Karma: 4,299
Bump...

My 04 forester brake system light goes on and off while driving. I looked into the causes. It could just be worn pads and whatever. These have at least 30k on them, maybe more. I bought the car at 80k and haven't done anything to them since. Not sure how old these pads are. Stopping performance seems the same.

But before I go doing that, I'm wondering if it's a fluid issue? The light stayed off last time I drove the car far away. It goes on and off if I drive around the block, and doesn't seem to relate to how I drive. I've also noticed no change in braking performance. The fluid level is about halfway between min and max. Can I just add new fluid of the appropriate type without flushing? I have no equipment to bleed or anything. I just want to top it off to see if that's the issue. Or maybe the moisture content of my fluid is too high? It's as old as the brake pads are, I believe.

Or I could just need new pads and they've finally passed the threshold for a warning light, but the decrease in performance was minimal and gradual so I wouldn't notice. They do squeak sometimes. I'd rather try the fluid before I take it somewhere for brakes, since I have no jacks or tools to do that.
10 years ago
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crotchvent
Posts: 1527 - Karma: 2,185
DrZoidbergBump...

My 04 forester brake system light goes on and off while driving. I looked into the causes. It could just be worn pads and whatever. These have at least 30k on them, maybe more. I bought the car at 80k and haven't done anything to them since. Not sure how old these pads are. Stopping performance seems the same.

But before I go doing that, I'm wondering if it's a fluid issue? The light stayed off last time I drove the car far away. It goes on and off if I drive around the block, and doesn't seem to relate to how I drive. I've also noticed no change in braking performance. The fluid level is about halfway between min and max. Can I just add new fluid of the appropriate type without flushing? I have no equipment to bleed or anything. I just want to top it off to see if that's the issue. Or maybe the moisture content of my fluid is too high? It's as old as the brake pads are, I believe.

Or I could just need new pads and they've finally passed the threshold for a warning light, but the decrease in performance was minimal and gradual so I wouldn't notice. They do squeak sometimes. I'd rather try the fluid before I take it somewhere for brakes, since I have no jacks or tools to do that.


Like the same light that same light that comes on when you put the handbrake on? If so my 02 forester does the same exact thing. took it to mechanic and he said it was just a short somewhere and to not worry about it.
10 years ago
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DrZoidberg
Posts: 5676 - Karma: 4,299
Yeah, that light. It's just BRAKE in red.

I'd prefer to make it go away, or confirm a short with hard evidence, to avoid loss of braking force or something
10 years ago
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JGWI
Posts: 2842 - Karma: 7,812
TheStamosBy water do you really mean water? or coolant?


Wow I missed that one. Sorry for not responding.

I mean water. NHRA does not allow coolant to be ran in any sportsman classes faster than 8.90.
10 years ago
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Shredsterr
Posts: 2090 - Karma: 6,930
2012 Lamborghini Gallardo Balboni special edition. Every time I drive around town in it, I just feel too damn cool, and can't stop thinking about how much better I am than everyone else around me. Is this a transmission issue, should I consider getting the gearbox looked at? I've heard of other Gallardo owners experiencing similar issues.
10 years ago
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