A couple weeks ago my XC90 started idling rough and surging up and down with no fault lights. I took it in for repair and it had a (120D) "air mass meter too low" fault and they did a smoke test for vacuum leaks. They found the charge air hose leaking and replaced it. It seemed fine when I left and the mechanic said to keep and eye out for any fault lights and in the notes on the receipt it says the "MAF may still need to be replaced." The next day it started doing the same thing again. I called the mechanic back and he said to bring it back in and they would re-smoke it to be sure and then replace the MAF. I pulled the MAF out and cleaned it with air flow sensor cleaner and it made no difference.

They want $375 to replace it at the shop but I can buy one on Amazon for $90 and do it myself. Any ideas of anything else to try before replacing the sensor? Thank you.

My 06 XC90 was surging, searched the net trying to find solutions with no luck. My friend bought an 06 XC90 from Clayton's in Knoxville and it started surging right after he purchased it. Neither would throw a code. He took back to dealer and they fixed it for him at no charge (Way to go Claytons, good customer service). I asked him to find out what they did to it. He shot me a copy of the receipt and it listed some of the PVC system hoses being replaced and cleaning the throttle body.

Since I had just cleaned and sealed my pvc hoses and no improvement I figured to try the throttle body. Took it out. Pretty easy from the bottom with a couple of 1/4 inch drive extensions and a deep well socket.

It only had a little carbon build up on one side and I thought this was a waste. Took my time and cleaned ALL the carbon out. Carb cleaner and maybe 15 minutes. Looked good as new when I put it back in. Started it and purred like a kitten!!!! I could not believe that little amount of build up was causing it to surge like that.

Have a 2001 V70 T5 that was also surging. Dropped and cleaned the throttle body. This time total job only took about an hour. Little carbon. Clean and now purrs like a kitten! If you haven't already, clean the throttle body. Two for two for me.

good luck.

Keith
1996 855 345K sold. 1999 S70 T5 Sold (this car would fly) 2003 S60 2.4T sold, 2001 V70 T5 170K, 2006 XC90 170K.

Tasca has a MAF for $165:

http://www.tascaparts.com/parts/2005/VOLVO/XC90/T6/?siteid=213668&vehicleid=1434037&diagram=9730275

#7

Because your engine idled normally without the MAF, that is probably the problem. Cleaning doesn't always help. If you order, I suggest using the phone and have your part number written down. The one I selected was for a T6.

You do need to check the hoses for leaks...
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My name is Klaus and I am a V♂lv♂holic

After the new MAF didn't fix the issue, I took my car over to a friend's place to look for more vacuum leaks etc. We ended up removing some of the intake ducting and taking a look inside. We found oil downstream from the turbo and figured that wasn't good. However, I spoke to another buddy who is a Volvo guy and he said that is relatively normal if it is not excessive and that the intercooler even has an oil drain plug.

A couple weeks ago, I saw a video on YouTube of a guy who had idling issues with his S80 and cleaning electronic throttle module was the answer. Here is the link if this can help anyone... http://www.youtube.com/watch?v=8Zaxtm-hdyo

Anyway, we figured why not? We pulled the ETM hoses off and looked inside from underneath with a mirror. The butterfly valve looked pretty gunked up. We decided that actually taking it out might not be a good idea because we might damage the gasket and not be able to get it back together. We went and bought a can of Berrymans B12 cleaner and found a hose that fed into the main hose to the ETM. We sprayed it in a few times, ran the engine, it sputtered and choked out a bit but at the end, we re-connected the hoses and it idled smoothly and has been running fine since Saturday.

I'm looking into how serious the oil from the turbo is and I am considering either buying a used or rebuilt one to put in. Any advice or suggestions about turbos would be appreciated! Thanks John

The faulty MAF check:

Turn car off. Unplug MAF. Turn engine on, just idle. If the idle is fine, the MAF is bad. Turn engine off, plug MAF back in.

With the MAF disconnected, the engine computer runs at default mode rather than what it is told to do my the air flow past the MAF.

You could have another air leak? Check the work that was done and make sure the hose is on snug. Look around for other air leaks.
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My name is Klaus and I am a V♂lv♂holic

Klaus

Thank for the quick response! I tried unplugging the MAF today and let it idle and it seemed to idle pretty steady without any surges. I plugged it back in and idled kind of wacky again, steady at times and surging at times. I think the MAF is flaky at best and the computer is probably a little confused from the unplugging and plugging.


I'm thinking to go ahead and replace the MAF just to eliminate it as a possible cause and go from there. Regarding MAFs, some research says only replace it with the Bosch MAF like one one that is installed and other places I have seen the remanufactured ones from Napa or whatever will work fine as well. Any suggestions?

Thanks,
John

When it comes to critical parts, I only use OEM. A remaned MAF??? I wouldn't go there. As far as knock offs go, why bother. If it fails, you got a problem.

The MAF is specific to your model/year.

Tasca web site is closed on weekends, but the best place to buy OEM.
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My name is Klaus and I am a V♂lv♂holic

I bought a new MAF and replaced the old one. I disconnected the battery for the process as to hopefully reset the computer. When I connected everything back up with the new MAF it was still the same. Luckily, I was able to return it. I also checked the MAF fuse under the hood just to see if it was blown, it was good. Back to the drawing board...