Hi and thank you in advance for your replies.

I have a 2004 XC90 T6. Lately, it has been surging at idle when coming to a stop. Often it will drop RPM's and stall. It does start up again. Note...it only does this when the gas pedal is released. Otherwise drives fine. I also notice the engine surges/hunts when the cruise control is used. Also and perhaps critical to the diagnosis is that when I open the gas cap and fill the tank, the stalling becomes more frequent. This is not my imagination as it does this consistently when the tank is filled. I will also make mention that for the past year the engine has to crank for longer than usual to start (like a bad check valve or something).

Here's what I have done: Cleaned ETM...no change, replaced ETM with used unit....no change, Replaced MAF sensor with new Bosch unit. Taken apart everything to check for vacuum leaks. Taken apart APP sensor (Gas pedal) and cleaned it. Checked fuel pressure=58 PSI at the rail. I did notice that if left for a few hours the fuel pressure drops to 0.

Question: After changing the MAF and ETM/APP, does the car need to be hooked up to VADIS to be recalibrated? I had just done a battery disconnect.

Please advise as I am at my wits end. I cannot let my wife and kids use this car as it is not safe to drive.

Thank-you.
RSD911

 

Same 2004 XC90 T6, same problem, the dealer replaced spark plugs, replaced ignition coils, replace all turbo tubing, now stalling stopped, but very hard to start when warm.

 

i am not familiar with that particular model
but am wondering if it has an idle air control valve ( IAC )

 

No, these cars don't have idle valves. If they had mechanical throttles and idle valves they wouldn't break down. There is no need for all these electronics...just more stuff to break down

 

try checking the rubber turbo tubing on the top of the radiator that goes from the engine to the intercooler, when I removed it it was half melted.

 

I have a 2004 T6 with the EXACT same problem. Not only will mine stall when coming to a stop sometimes, but I notice it seems to happen frequently on twisty canyon roads. It won't do it if driving in a straight line. I notice it is also harder to start after filling up. Someone please help.

 

Hello,
In searching for a solution with my 09 xc90's front end issues, I recall reading about your problem on a few forums.
IIRC, it's an electronic problem with one or more control modules that need replacement.
Good luck.

 

Dr. Entech-

I appreciate your trying to help, but that post is almost pointless. Like if you were in high school and your buddy told you he found out a really hot girl said some very flattering things about you. But he couldn't remember who the girl was or what exactly she said.

 

Then go search every forum, visit every local repair shop and go **** off!

 

RSD hey, how many miles you got on that thing?

 

Hi,
I have 50k miles. I am now suspecting the MAP sensor. After much research it seams that this particular model has the IAT sensor built into the MAP sensor. Usually the IAT is part of the MAF unit (which I already replaced). Anyhow, after cleaning the MAP/IAT the car is running better. I will change it out and report back. I am getting tired of changing out $200 parts, but there cannot but much left to replace as far as sensors go. I figure its still cheaper than going to the stealership who I have already left the car with once with no success.

Thanks all for your advise.
RSD911

 

U get a MAF fault if u have a crankcase blockage.

 

possibly, not always

 

check to see if u have blockage from ur crankcase system also check fuel pressure. There is a recall for a faulty pump .

 

I have an 04 xc90 t6 that had similar issue. Took a long time to figure out but it turned out to be a crack (quater size hole) in the turbo air handler (big plastic thing that sits on top of the motor). I think the guy who replaced my timing belt must have dropped it and or cracked it somehow.

 

Just had my first stall experience tonight. Power went off, steering locked, and car went off road. No damage. Gas tank filled two days ago. Stall occurred just after a stop and beginning a turn.

 

thanks jgardella, that was exactly what was causing similar issues with my 04' T6. Top air hose, side chamber had a large hole knocked out of it. Upon looking further to what could have caused it, I found the top engine mount connected to the strut bar had the mount broken on the inside. The vibration of the broken motor mount seemed to have been the culprit.

So got the top motor mount replaced, duct tape the air hose chamber (for now, will order part when more funds are available) and cleaned the MAF sensor with electrical cleaner. Runs like a Volvo should again and no raping by the local stealership. Yeah for me!

 

05 xc90 having surging problems just started its the 5cyl turbo

 

for the past year i've had similar intermitent issues with my 04 xc90 (166k miles) and tried many of the above fixes without success. I recently had the RPM sensor replaced along with plugs and it seems to have done the trick. No stalls or difficult starts in the past 3 weeks.....fingers still crossed for now

 

I have a 2004 Volvo XC90 T6 with about 157k miles on it. I replaced what I believe were the original spark plugs (maintenance documentation from previous owner had no indication of spark plug replacement). My first choice was the NGK Iridium IX spark plugs. After replacing, I noticed erratic cold start idling, and the car would stall at deceleration after warmed up.

I replaced the MAF sensor, and noticed when comparing the new to the old that the old one was missing the filament and electrode on the sensor itself. After replacing the engine ran much better for about a day, then the low idle and stall came back.

I had read on another post, and learned from my mechanic, that while the NGK Iridiums are good plugs, the copper plugs seem to be the way to go. So yesterday I pulled the Iridiums and installed NGK V-power copper plugs. So far, the car is running much better.