2006 S60 2.5T stuttering mystery Topic is solved

[RSAmbassador]

No Dice on Volvo offering a replacement sensor, my model wasn't under a recall for the FPS. Does anyone has suggestions on what brand of sensor I should look into purchasing that wont break the bank or is it worth it replacing with an OEM Bosch?

[chrism]

If you opt to replace it you want Bosch. About $57 right now at FCP Euro. I don't think I've ever seen them that cheap before.

I don't know how Volvo picks what VINs get a free one when they're all the same for several years - Well, turbo and NA take different ones but they ALL fail.

When my wife's failed. it "Wasn't included in the recall".

When mine failed, the "Previous owner had already gotten the one free one."

The story of my life....

[abscate]

If you opt to replace it you want Bosch. About $57 right now at FCP Euro. I don't think I've ever seen them that cheap before.

I don't know how Volvo picks what VINs get a free one when they're all the same for several years - Well, turbo and NA take different ones but they ALL fail.

When my wife's failed. it "Wasn't included in the recall".

When mine failed, the "Previous owner had already gotten the one free one."

The story of my life....

This is about car parts , right?

[chrism]

[/quote]

This is about car parts , right?


[/quote]

You know, when I go back re-read what I wrote, it sometimes takes on a WHOLE NEW meaning....... (But the story still kinda fits)

[RSAmbassador]

I've ordered a new sensor from FCP (thanks chrism). Hopefully should be in the next few days. I'll update as soon as I get it in.

[RSAmbassador]

This thread should be renamed the curious case of my Volvo named Bette. So FPS didn't resolve the problem. Still stuttered. But today a new symptom appeared. The heat gauge has stopped working, the fan kicks on and the stutter has mysteriously subsided for the moment. I'm beyond confused.

[mrbrian200]

The heat gauge has stopped working, the fan kicks on and the stutter has mysteriously subsided for the moment. I'm beyond confused.

That actually makes sense to me. Out of range coolant temp sensor or failing thermostat got worse. The ecu finally decided something is broken at which point it disregards the sensor reading and uses assumption/fail safe data for fuel enrichment/timing (stutter disappeared), and alters gauge behavior so it indicates low temp.

A word on how OEs have evolved how this gauge works: many years ago this gauge indicated the literal engine temperature. The gauge would bump up and down a little as the thermostat opened and closed, and would tick up before the radiator fan kicked on, then back down. Many people don't understand temperature fluctuations are normal and complain something was broke. So they 'fixed' it. Sometime in the 90's OEs began controlling this gauge with software so that once the engine warmed up to normal operating temperature the gauge will hold at a certain position unless the ecu decides something might be wrong. At such time the hold is released and the gauge position correlates more directly to changing/actual engine temperature. Its more useful than an light in the sense that we can tell when the engine is up to temp (safe to drive hard), and when there is a problem we can glance at it to determine whether continued driving presents risk of damage. I've only seen mine budge once - a 108 degree day at a stoplight after exiting the interstate. It released the hold to indicate (not quite) to the next higher mark above halfway to let me know if the radiator fan didn't manage to bring it down there might be trouble (fan did it's thing/volvo was fine).

[RSAmbassador]

So, it finally threw a check engine light. Not even related to what I think or anything. Buying a coil today and just gonna do trial and error. But the code was P0459. Something about the evap system. Can someone chime in on what exactly is wrong

[mrbrian200]

Temp sender issue and purge solenoid circuit open or short: These could be related. Volvos electrical diagrams aren't laid out in such a way make it easy to spot shared electrical/ground connections between separate systems. It's in there but gets a little confusing by the time you reference information on 2 or 3 different diagrams while flipping back to the list of components repeatedly to determine what's what in the diagrams.

Check the 'main engine system relay' in the engine compartment fuse/relay box. Position MA3. You can switch it with the starter relay, Position MA1, they are the same PN. See if there's a change in behavior. If the starter doesn't crank after switching these you'll know right away. The three square relays on the bottom row are a different part# and not interchangeable with the others. If no change you'll probably want to verify main battery cables/power/ground connections before resigning to dig deeper into the engine management system/electricals. Which isn't for the faint of heart.

[RSAmbassador]

Is it possible to run the car without the temp sender connected for an experiment