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44 votes

Spark plug broke off in engine - can I drive the car?

That sounds very risky to me. The portions of the plugs that reside in the combustion chamber are designed to tolerate the heat and pressure there. I don't think they will melt. So what will happen ...
  • 14.3k
33 votes

Spark plug broke off in engine - can I drive the car?

Do NOT drive a car with a piece of sparkplug inside the engine. It can (and likely will) lead to serious damage (up to a catastrophic engine failure). Get your car towed to a service and have the ...
  • 581
24 votes

Spark plug broke off in engine - can I drive the car?

That's a nice car - don't be a consumer and break it because you're too lazy to fix it properly. Sadly the "proper" fix is to tow it to your mechanic, who will take the head off and fish out the ...
  • 2,633
20 votes

Can a vehicle be harmed with bad inputs via an OBD-2 port?

It is highly probable that the reason your car was reluctant to start was that the time you were running diagnostics had sapped some of the charge from the battery. The battery on the car will not ...
18 votes

Spark plug broke off in engine - can I drive the car?

If this happened during a plug change If you have roadside assistance/towing, I would highly recommend getting it towed home, then purchase a cheap USB inspection camera or a inspection unit like this ...
  • 291
14 votes
Accepted

Volvo engine parts

What you have circled are the connectors for the fuel injectors (and obviously the fuel injectors are underneath of them). They have seals which protect from moisture, dirt, and debris, so in most ...
10 votes
Accepted

Bump on the floor in the back of sedans

The hump provides longitudinal rigidity in the unibody. The fact that it also provides a place to route the exhaust is a bonus. Notice that modern CAD-designed vehicles have much less of an obvious ...
  • 1,723
10 votes
Accepted

Hood Unlatches but Won't Pop Up

I would guess that there is an issue with the spring on your latch. Most hood latches follow the same basic design. As you push the hood closed, a bar on the hood pushes into a hook in the latch, and ...
  • 3,002
9 votes

Can a vehicle be harmed with bad inputs via an OBD-2 port?

To my knowledge there is no way a scanner can cause issues with your computer electronics. This device is a read only device. It doesn't change anything in your computer. It does, however, communicate ...
9 votes

Spark plug broke off in engine - can I drive the car?

No question - running the engine will break it. If you're "unlucky", there's enough clearance between the piston and the valves to fit the spark plug. In that case you'll have the spark plug ...
  • 1,509
8 votes

Bump on the floor in the back of sedans

Anyone can feel free to disagree with me since I'm not 100% on this, but I believe those bumps are placed into the design in order to give the exhaust system a little more breathing room. Note the ...
  • 1,948
8 votes

Bump on the floor in the back of sedans

I don't think the hump is there just for the exhaust, although as was pointed out in the comment it adds ground clearance which is a nice thing. The "transmission hump" (in honor of rear wheel drive ...
  • 14.3k
7 votes

How are fuel injectors controlled?

The injector has a plunger/pintle which is controlled by an electromagnet. The humming you heard is from that. The plunger/pintle has a spring which pushes back against the electromagnet so when the ...
7 votes
Accepted

Will never charging the batteries of a hybrid electric plug-in vehicle damage it?

No, it won't get damaged. But you also shouldn't let the battery totally empty for long periods. Li-ion batteries are best stored with some charge (normally about 40% is recommended charge level for ...
6 votes

Can a vehicle be harmed with bad inputs via an OBD-2 port?

No. The tool in and of itself cannot do any "harm" to the vehicle. If you were testing apps with the engine off, it is quite possible that the battery may have drained to the extent that it gave ...
  • 39k
6 votes
Accepted

What steps can I take to keep my car (V70, driven primarily for short commuting) in good condition?

Regular service and fixing what's broken will keep just about any car running for a long time. The main difference with driving short distances, is that your engine spends more time at less than ...
  • 8,413
6 votes

Will never charging the batteries of a hybrid electric plug-in vehicle damage it?

The car will charge its battery while driving, e.g. when you brake. This allows the electric motor to augment the diesel engine, reducing overall fuel usage. The result is that the charge state of the ...
  • 4,412
6 votes

How to release fuel injectors from Volvo T5 engine?

The trick is not to pull on the spring clip but rather to depress it by pushing it into the fuel injector in order to clear the locking tabs which then permit the fuel injector to be pulled out of the ...
  • 1,694
6 votes
Accepted

Where is the XC90 V8 2007 battery terminal?

The battery in this vehicle is hidden and is not located under the hood. It is under a deck cover inside the rear of the vehicle. https://www.youtube.com/watch?v=pTjenuS3l-w The above YouTube video ...
  • 3,737
5 votes

Low beam headlights failing every 3-4 weeks

The most common reason for this is getting skin oil onto the bulb during changing of the bulb. This will kill most every bulb on the market today. This creates hot spots on the bulb which will cause ...
5 votes

Can a vehicle be harmed with bad inputs via an OBD-2 port?

Just this morning I connected an ELM327 to a '05 Volvo XC90. After only 1km, the message was displayed for "Anti-skid service required", and then "Anti-skid temporarily unavailable". I removed the ELM,...
  • 51
5 votes

Anyone have experience with a faulty fuel press? Regulator?

Nice engine you got there! While your issues do sound like a MAF problem (check the MAF readings via OBD!), some turbocharged Volvos are notorious for fuel pressure regulator issues. Basically the ...
5 votes
Accepted

Volvo V60 key needs new battery, will it 'forget' the car?

In most cars it's not the key remembering the car, but the car remembering the key. Your Volvo should be no different. Reading through your owners manual, it gives no warnings about taking this to the ...
5 votes

Driving without oxygen sensor

Which sensor was removed? Pre- or post-cat? If pre-cat, it could be causing the engine to run differently. If post-cat, it's just noise and your engine shouldn't be running any differently ... it just ...
5 votes
Accepted

Volvo XC90 8V AWD car speed to piston revolution speed ratio changed after repair

Yes, I'd take it back to the shop to see if there is something they missed. While 300 rpm at 60mph is not a huge difference, to me this is about the difference of when a lock up torque converter isn't ...
5 votes

Aftermarket Exhaust

There is another possibility : in the UK there are companies that will make you a stainless exhaust from scratch - don't have a name to hand, but a friend had his subaru done and it is much better. ...
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5 votes
Accepted

Brake pedal goes to floor "sometimes" only

It's not a stupid question at all! You are right to be concerned, brakes are critical for safety and you need to deal with this before you get in an accident. The ABS light turning on while it was on ...
  • 15.1k
5 votes
Accepted

How to do an amateur repair of a tiny ding on my almost new car?

What is the mistake a rank amateur at this is most likely to make? Honestly.. it's attempting to do it themselves. You mention: I am an OCD type I can pretty much guarantee that the result of ...
  • 9,787
4 votes
Accepted

Can I disable my 2009 Volvo S40's remote key fob panic button?

I think the easiest way to disable it would be to take the fob apart and put a very small piece of tape on the contacts for the button. This would make it so you could reverse this without too much ...
4 votes

Car feels like it's filling up with fumes

Exhausts inside the car is not healthy at all. As someone said, perhaps another mechanic should be considered. As to the problem, it sounds like the exhaust pipe is leaking before the catalytic ...
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