Reduced Power - No CEL or Messages

LittleRedRidingHood · Jan 12, 2017

LizardOfBodom said:
Maybe its not it then What about your bearings and springs&shocks? All in good condition?

I think the wheel bearings are OK. The front passenger side shock was diagnosed as weak by Volvo, but not so much so that it needs replacing right away. It's not leaking or anything. Could this be an issue even when accelerating on very smooth pavement?

JN2k108 · Jan 12, 2017

Since you've resettled the ecu multiple times, it will take the car a couple cycles until it will throw codes

Sent from my iPhone using Tapatalk

LizardOfBodom · Jan 12, 2017

LittleRedRidingHood said:
I think the wheel bearings are OK. The front passenger side shock was diagnosed as weak by Volvo, but not so much so that it needs replacing right away. It's not leaking or anything. Could this be an issue even when accelerating on very smooth pavement?

In my case it was - what was happening, car was detecting "something is wrong" (i.e. one tyre was rotating in different speed vs the other due to reduced circumference) and was throwing out code "vehicle speed sensor - wrong signal" and switching itself to this weird reduced performance mode permanently, regardless of surface etc. After few startups it did come back to normal, same after clearing the code manually.
I dont know if suspension can cause this aswell (f.e. broken spring) or if in my case the electronic was too sensitive or is that normal, but I can tell you 1 thing for sure - there was ALWAYS a fault code present when that was happening. So not sure why you have none.... maybe it is time to look into TCV as that would be my second guess.

LittleRedRidingHood · Jan 12, 2017

Updated symptoms:

The car will hold what feels like full boost for about a second or two from anywhere in the rev range, especially when applying throttle quickly from foot off the accelerator. It will then suddenly dump all boost out the wastegate (seems like it's going out the wastegate anyways..), and not seal back up until foot comes off the accelerator again. It is possible to do this repeatedly.

Does that sound like it could be a failing TCV?

Taniil · Jan 13, 2017

Hi

Currently getting the exact same symptoms on my C70 T5 2007 . Hooked it up to VIDA last week and got the code ECM-603C Turbo control - Pressure too high . Otherwise no CEL. So I think a new TCV is the way to go.

Will give an update on my original thread when I get the new part in http://forums.swedespeed.com/showthread.php?404425-wavy-power-under-hard-acceleration .

LizardOfBodom · Jan 13, 2017

In both cases looks like overboosting, doesnt it?
My TCV was behaving a bit differently (not keeping the pressure) as it was physically cracked, so didnt have this dump-valve symptom, but for both of you replacing TCV is probably safest and cheapest first option. I didnt bother with pricy aftermarket ones as lots of people here discouraged me from that - replaced with OEM Pierburg brand but bought online for 23eur rather than from Volvo with their markup. Had it fitted in local shop as its a bit hassle, but it fixed all issues.

LittleRedRidingHood · Jan 16, 2017

Took the car into the dealership for diagnostics today. It was diagnosed as a turbo pressure sensor (which I think is synonymous for the MAP sensor). I may replace the TCV while I'm at it just for the peace of mind - thoughts on that? Should I leave well enough alone if the new MAP does the trick?

tmtalpey · Jan 16, 2017

That sensor is often a problem, I had to replace mine a few years back. It's a combined IAT/MAP - Intake Air Temperature / Manifold Absolute Pressure. It's relatively easy to replace.

I would not replace the TCV. For one thing its a totally different job and therefore doesn't offer any financial advantage to do together. For another, it won't tell you if there was an issue. If the car still has trouble, *then* take it in and have them re-diagnose.

LittleRedRidingHood · Jan 16, 2017

tmtalpey said:
That sensor is often a problem, I had to replace mine a few years back. It's a combined IAT/MAP - Intake Air Temperature / Manifold Absolute Pressure. It's relatively easy to replace.

I would not replace the TCV. For one thing its a totally different job and therefore doesn't offer any financial advantage to do together. For another, it won't tell you if there was an issue. If the car still has trouble, *then* take it in and have them re-diagnose.

Thanks, I will hold off on the TCV until it seems necessary. When I spoke to someone at the dealership in person, they said they replace far more IAT/MAP's (and that they often go bad around this mileage - 72,000 miles on mine) than TCV's and that the TCV isn't in fact commonly an issue. He said that he suspects the TCV may have been designed by someone who had worked the truck division because they are so robust. I had gotten the impression from browsing the forum that it is a very common problem and is destined for failure at one point or another.

LizardOfBodom · Jan 17, 2017

LittleRedRidingHood said:
He said that he suspects the TCV may have been designed by someone who had worked the truck division because they are so robust.....

I have something to contradict that statement :/

Of course its up to you and nothing stops you from doing it later if necessary but keep in mind it IS a awkwardly accessible part and if you ever do something with turbo or in the area of firewall, for the sake of 25-30dollars you may think of replacing it as a preventitive measure. They actually do go bad pretty often as I researched it before replacing mine and its worth to have on "todo" list when for example doing Bypass Compressor Valve or something.
just saying :}

LittleRedRidingHood · Jan 17, 2017

LizardOfBodom said:
I have something to contradict that statement :/

Of course its up to you and nothing stops you from doing it later if necessary but keep in mind it IS a awkwardly accessible part and if you ever do something with turbo or in the area of firewall, for the sake of 25-30dollars you may think of replacing it as a preventitive measure. They actually do go bad pretty often as I researched it before replacing mine and its worth to have on "todo" list when for example doing Bypass Compressor Valve or something.
just saying :}

Maybe I'll add that to my 75,000 mile service list this Spring. I'm going to be doing the timing & serpentine belts as well, so it might make the TCV seem like a smaller PITA than it is.

LittleRedRidingHood · Jan 17, 2017

I think the person I spoke to at the dealer must have misspoken, or used different nomenclature. It seems to me that it was in fact the TCV, also known as the Boost Pressure Valve, part number 30670449.

https://www.fcpeuro.com/products/volvo-boost-pressure-valve-genuine-volvo-30670449oe

TG · Jan 19, 2017

LittleRedRidingHood said:
Thanks, I will hold off on the TCV until it seems necessary. When I spoke to someone at the dealership in person, they said they replace far more IAT/MAP's (and that they often go bad around this mileage - 72,000 miles on mine) than TCV's and that the TCV isn't in fact commonly an issue. He said that he suspects the TCV may have been designed by someone who had worked the truck division because they are so robust. I had gotten the impression from browsing the forum that it is a very common problem and is destined for failure at one point or another.

LittleRedRidingHood said:
I think the person I spoke to at the dealer must have misspoken, or used different nomenclature. It seems to me that it was in fact the TCV, also known as the Boost Pressure Valve, part number 30670449.

https://www.fcpeuro.com/products/volvo-boost-pressure-valve-genuine-volvo-30670449oe

TCV is not necessarily a common problem. A lot of people talk about the TCV because it's an easy thing to upgrade. Why do we upgrade? Because we're silly when it comes to upgrades ...

, and we think black plastic is not as durable as shiny aluminum. Hey I'm right there. Few years after I had the car, the IPD TCV was mounted. Did I ever had an issue with the OE one. Hmmm nope. Aftermarket shops loves us.

If you look closely on the forum you will notice that there are far more people who talk about the TCV, than there are actual people who had to change it due to failure...

However, when the problem is a turbo boost issue, than it is often among the culprits.

LittleRedRidingHood · Jan 19, 2017

TG said:
TCV is not necessarily a common problem. A lot of people talk about the TCV because it's an easy thing to upgrade. Why do we upgrade? Because we're silly when it comes to upgrades ... , and we think black plastic is not as durable as shiny aluminum. Hey I'm right there. Few years after I had the car, the IPD TCV was mounted. Did I ever had an issue with the OE one. Hmmm nope. Aftermarket shops loves us.

If you look closely on the forum you will notice that there are far more people who talk about the TCV, than there are actual people who had to change it due to failure...

However, when the problem is a turbo boost issue, than it is often among the culprits.

Thanks for the insight. I have only had the car for a couple of months now and already know what you mean about the upgrade fever. If the dealer was clear about what they were replacing I could have gone for the IPD TCV. I'm sure the OEM replacement will last long enough that I won't have any regrets, even after some basic performance mods and tuning.

I am happy regardless, as if my memory and butt dyno serve me well, my car has picked up some top-end power over when I purchased it and thought the engine was near its peak factory performance. If only I had saved the labour charges... oh well, I don't have an indoor space to work on my car and it's cold enough in Ontario that I don't want to be doing anything too involving.

tmtalpey · Jan 19, 2017

LittleRedRidingHood said:
if my memory and butt dyno serve me well, my car has picked up some top-end power over when I purchased it and thought the engine was near its peak factory performance. If only I had saved the labour charges... oh well, I don't have an indoor space to work on my car and it's cold enough in Ontario ...

Ontario. Cold. Say, did you ever read this thread? http://forums.swedespeed.com/showthread.php?151776-T5-Boost-Level-vs-Temperature

LizardOfBodom · Jan 19, 2017

LittleRedRidingHood said:
....If the dealer was clear about what they were replacing I could have gone for the IPD TCV. I'm sure the OEM replacement will last long enough that I won't have any regrets, even after some basic performance mods and tuning.....

Dont worry too much about it. I did extensive research before replacing mine and advantages/disadvantages of aftermarket TCVs. At the end I decided to go the reliable and cheap route (over 100e for aftermarket one vs 25e for OEM!!) and I cant say I regret at all. (btw - 75dollars for TCV? wow, some prices you have there... :/) plus - some upgrades like Hilton tune, if I remember correctly, actually require you to have OEM TCV anyway, so no need to regret going stock, I think :]

TG · Jan 19, 2017

tmtalpey said:
Ontario. Cold. Say, did you ever read this thread? http://forums.swedespeed.com/showthread.php?151776-T5-Boost-Level-vs-Temperature

Missed this thread... interesting read for sure...

LittleRedRidingHood · Jan 19, 2017

tmtalpey said:
Ontario. Cold. Say, did you ever read this thread? http://forums.swedespeed.com/showthread.php?151776-T5-Boost-Level-vs-Temperature

I like the look of that. Why else would I live here if not to get the coldest, most dense air into my engine possible?

mmustangsrus · Jan 21, 2017

......

Sent from my iPhone using Tapatalk

Reduced Power - No CEL or Messages

LittleRedRidingHood

JN2k108

LizardOfBodom

LittleRedRidingHood

Taniil

LizardOfBodom

LittleRedRidingHood

tmtalpey

LittleRedRidingHood

LizardOfBodom

LittleRedRidingHood

LittleRedRidingHood

TG

LittleRedRidingHood

tmtalpey

LizardOfBodom

TG

LittleRedRidingHood

mmustangsrus

Top Contributors this Month

Recommended Communities