2004 XC70 Engine Surging and Dying at Idle No Error Codes

[Build]

Hi everyone!

My 2004 XC70 has 139K and has always had regular maintenance. It recently started strong surging at idle, and dies occasionally. If the engine is revved above idle, it runs smoothly with normal power. There are no error codes.

When first started it idles normally for 10-15 seconds, then almost dies, then rpms rev to 1000-1500, then almost dies again. This repeats 3-5 times, then it runs ok.

At any time during the surging/dying, I can rev the rpm and everything is ok until it returns to idle.

Anytime the car is idling, the surging/dying can return randomly. The only time it consistently surges is when the car is started, and those 3-5 times happen.

It had a new Volvo fuel pump, all filters, timing belt, tensioners, belts, oil, trans flush, etc in the last 10k miles. I've checked for vacuum leaks and all good with strong vacuum. All electrical connections are good.

Does anyone have any ideas?

Thanks much!

[Vovo_merz]

if you haven't solved this I would try MAF sensor, it tends to do weird things with out a check engine light or codes, used are fairly cheap on ebay

[abscate]

A leak in the induction path will give lousy idle and ok running above 2000 rpm.

To test for vacuum leaks, you have to remove every hose, inspect, test by blocking and blowing, and usually you replace them since you already have the 15 year old ones off. Otherwise, you can throw parts for weeks at a 50 cent hose problem. It isnt pretty work, but there are not workarounds.

[shiloh51933]

Hi everyone!

My 2004 XC70 has 139K and has always had regular maintenance. It recently started strong surging at idle, and dies occasionally. If the engine is revved above idle, it runs smoothly with normal power. There are no error codes.

When first started it idles normally for 10-15 seconds, then almost dies, then rpms rev to 1000-1500, then almost dies again. This repeats 3-5 times, then it runs ok.

At any time during the surging/dying, I can rev the rpm and everything is ok until it returns to idle.

Anytime the car is idling, the surging/dying can return randomly. The only time it consistently surges is when the car is started, and those 3-5 times happen.

It had a new Volvo fuel pump, all filters, timing belt, tensioners, belts, oil, trans flush, etc in the last 10k miles. I've checked for vacuum leaks and all good with strong vacuum. All electrical connections are good.

Does anyone have any ideas?

Thanks much!

I'd check the air charge tubing for the Turbo System due to fact that you don't have a "CEL" on dash cluster. Make sure all the clamps are properly installed, look at the rubber air charge tubing very closely for splits. The aluminum air charge tubing obviously won't rip or split but all the rubber air charge tubing will eventually fail. I'd take all of the air charge tubing off for proper inspection. Sometimes vacuum hoses collapse but only when vacuum is being pulled through the hose, so you won't notice this while car is off and it will only happen when vacuum is present, very hard to find but dry rot is a good sign for possible collapse.