01 v70 xc problems

[rrob311]

my 01 pings bad under acceleration. it occasionally throws a p0420 code. It also throws a camshaft reset valve code sometimes. Right now the ce light is not on but it pings very bad. This thing hasn't had good power since ive owned it. It has 138k on it. I am thinking the converter may be clogged. SHould I run premium in this? What causes these to ping?

[Astro14]

Let's see if I've got this right: it throws codes for multiple problems.

You want to try premium gas to fix it?

Not actually discover the problem?

Here's what I think happened: the previous owner got the timing belt changed. It was done wrong and the cam timing is off. He knew it ran badly, the shop wanted more money to fix it, even though it was their screw up, but he didn't want to put more money into a 15 year old car.

He dumped it on you.

Check the timing marks on the belt first. I've got $20 that says your timing belt is on wrong and your cams are misaligned. That's why it doesn't have any power, that's why it pings, that's why you get codes.

Once you get the belt on correctly, it will run like a whole different car. Then, you should try better gas. It runs better on higher octane but until you get the cams phased correctly, it will run like crap no matter what you put in the tank.

[hoonk]

my 01 pings bad under acceleration. throws a p0420 code. throws a camshaft reset valve code
I am thinking the converter may be clogged.
Should I run premium in this?
What causes these to ping?

These engines have knock sensors on the side of the block to retard the timing to hopefully prevent pre ignition. So noises from "spark knock" or pinging are rare. If an engine does ping the timing will retard (on individual cylinders as needed and usually before you can hear it) and cause a reduction in power.

420 is a cat efficiency code - can be caused by a damaged, or partially clogged converter, or bad sensors. If cat was damaged what was the cause? (lean or rich mixture for years caused by lack of maintenance or bad sensors?) Cam shaft code could be incorrect installation or bad valve/lack of oil flow/bad gear.

I believe Volvo recommends 91 octane but there are many opinions on what octane to use - http://www.volvoxc.com/forums/showthread.php?6342-which-fuel-grade-93-or-89-or-87

[rrob311]

Let's see if I've got this right: it throws codes for multiple problems.

You want to try premium gas to fix it?

Not actually discover the problem?

Here's what I think happened: the previous owner got the timing belt changed. It was done wrong and the cam timing is off. He knew it ran badly, the shop wanted more money to fix it, even though it was their screw up, but he didn't want to put more money into a 15 year old car.

He dumped it on you.

Check the timing marks on the belt first. I've got $20 that says your timing belt is on wrong and your cams are misaligned. That's why it doesn't have any power, that's why it pings, that's why you get codes.

Once you get the belt on correctly, it will run like a whole different car. Then, you should try better gas. It runs better on higher octane but until you get the cams phased correctly, it will run like crap no matter what you put in the tank.

What I was asking was if these cars required premium as I have been running 87.

[vtl]

What I was asking was if these cars required premium as I have been running 87.
Difference between premium and regular is about 10%, about $3-4 per tank. Half of a six-pack (not the best one).

It will run on a 87, but MPG will be a bit worse and the power will be slightly retarded.

[JRL]

89 is fine, 87 is a waste for the above reasons

[Astro14]

What I was asking was if these cars required premium as I have been running 87.

What your car requires is mechanical repair.

The car doesn't require premium, but it does run better on higher octane gas. Knock sensors protect the engine from low octane gasoline by allowing the ECU to retard the timing.

[rrob311]

Great, so I checked the valve timing today and the front 3 marks line up. I also checked the data on the scanner and the camshaft values are close to 0%. 644a is the code.