00 VR: shuddering, sputtering when hot at idle

[MoVolvos]

the ETM fix was done by the PO so I'll assume (for the moment) that that is not the problem. Again, it is OK when cold. Rock solid. Needle doesn't move. Accelerates nicely. This only happens when hot, after a period of driving, sometimes 10 or more miles but the only reliable factor is that the car is hot when it occurs.

You might try this as it is fairly straight forward and there is a Post on MVS with Pic's on here some place and I recall seeing it not too long ago.

http://volvoforums.com/forum/volvo-s70- ... -up-39706/

Blessings,
BKM
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[MoVolvos]

the ETM fix was done by the PO so I'll assume (for the moment) that that is not the problem. Again, it is OK when cold. Rock solid. Needle doesn't move. Accelerates nicely. This only happens when hot, after a period of driving, sometimes 10 or more miles but the only reliable factor is that the car is hot when it occurs.

You might try this as it is fairly straight forward and there is a Post on MVS with Pic's on here some place and I recall seeing it not too long ago.

http://volvoforums.com/forum/volvo-s70- ... -up-39706/

Blessings,
BKM
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The MVS Post I mentioned was on cleaning and it seemed to solve the problem as the Volvo Forum members replaced it.

Blessings,
BKM
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[sanfelice]

<returned from vacation>

update: checked plugs that I installed about 60 miles ago and they are SOOTED. They're still good once I wiped then down and the car will start and drive fine after a while sitting, but there is some amount of fuel that is not getting burned (confirmed by the bad smells emanating from the cat after this happens). To reiterate, it only happens once the engine is hot, I'm guessing at that point the plugs become so fouled it is misfiring.

I'm wondering what is causing the sooted plugs. Any ideas?

[sanfelice]

Also, could this be a symptom of the fuel pump going bad? (hard starting does occur when warm, as noted)

Would the check valve fix be appropriate here?

[jblackburn]

<returned from vacation>

update: checked plugs that I installed about 60 miles ago and they are SOOTED. They're still good once I wiped then down and the car will start and drive fine after a while sitting, but there is some amount of fuel that is not getting burned (confirmed by the bad smells emanating from the cat after this happens). To reiterate, it only happens once the engine is hot, I'm guessing at that point the plugs become so fouled it is misfiring.

I'm wondering what is causing the sooted plugs. Any ideas?

Test the resistance on your coolant temperature sensor, which may be flooding the engine with fuel when warmed up [because it still thinks the engine is cold]. On a warmed up engine, after 10-15 minutes of running, you should see resistance values at the plug of under 300 ohms.

A mass airflow sensor or bad O2 sensor may also be to blame. I also had a bad fuel pressure regulator, but your car would run like crap ALL of the time, not just when warm.

[jblackburn]

Do you notice the temperature needle doing anything funny?

[sanfelice]

I don't notice the temp needle bouncing around, but I'll have to look when the sputtering happens.

Where is the coolant temp sensor on these cars (fairly new to the AWD world). Thanks.

[jblackburn]

Follow the upper radiator hose to the thermostat housing. The coolant temp sensor is the brass plug there.

[sanfelice]

Today it happened again and I noticed the speedo sort of shut down, although it started working again. Could this be an indication of something to do with a sensor?

I cleaned the MAF to no avail. The smoke coming from the pipe is black, so I have a really rich condition.

[MoVolvos]

Today it happened again and I noticed the speedo sort of shut down, although it started working again. Could this be an indication of something to do with a sensor?

I cleaned the MAF to no avail. The smoke coming from the pipe is black, so I have a really rich condition.

See if there is anything here that can be of help

http://www.2carpros.com/articles/engine-black-smoke

Blessings,
BKM
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