I have an issue with my Volvo listed above where the car surges under normal driving conditions, meaning it accelerates and then slows down approximately every 2 seconds. I have had the throttle body and PCV systems cleaned and the car receives periodic Sea Foam treatments and the MAF sensor has been replaced. Also, a new fuel pump and filter have been installed. The car has 220K miles, uses no oil and has been well maintained by myself and the original, previous owner. The car is in almost pristine condition otherwise. Can any one suggest what might be wrong? I should add that no dash lights are on and no codes are stored.

Also, when any car door is opened, what sounds like a small fan noise is coming from the lower dash. It eventually stops, until the next time a door is opened, and is frustratingly difficult to locate. I appreciate any help my fellow Volvo enthusiasts can provide. Thank you!

 

When was your known to fail often Magnetti Marelli (sp) throttle housing replaced? And save your sea foam money for something the car really needs.

 

I don't know. This is the first time I've ever heard of it. You've been amazingly helpful.

 

I think that was the first part that xemodex was rebuilding - they (and others) have re-engineered the potentiometers (sp) in them to be a non contact type - The module is coded to the VIN number of the car. A new one requires a software download to make it work. Xemodex preprograms theirs if you wish or others have been able to get used ones to work if from the right year, correct sticker on it, moon is in the right phase and you clasp your hands just right when you try to restart the car. Don't choke on the price - those modules were used from 99-02, and before xemodex came along the only option was at least $1300 for a new one with programming. Replaced at least 20 of those that way, using new parts until reman was a choice.

 

There is a small fan that pulls air across the temp sensor for the interior of the car. It's located behind the little slots above the passenger temperature setting **** on the CCM. I'm certain by now that is full of dust - don't try to remove the dust bunny by mechanical force - you will damage the temp sensor and that destroys the CCM. You can't purchase a sensor by itself . A vacuum or gentle blast of air might remove the bunny. Removing and cleaning the fan/motor might be needed if it's your noise - take the CCM out to get to it. It's #5 in the diagram.

 

Hoonk,

You are awesome! You've given me more information than I had hoped for from this forum!

So, you believe that a new electronic throttle body unit will solve my problem? I sure appreciate you including the source and price information. A bit salty for me right now, so I'll just sell it and adjust the price for the repair. Really is a nice car otherwise.

You are a valued reason for having this forum. Thanks again for your help.

 

No - I believe a reasonable diagnostic path might lead you/your service provider to a solution for your complaint/s.

 

Appreciate your advice.