1999 V70 T5 Incident Report MAF Turbo (FIx: Induction Leak) Topic is solved

Post by **abscate** » 30 Jun 2016, 12:33

Rolling between NYC and BOS, felt a distinct kick followed by cruise control INOP.

I also noticed the no-MAF driving behavior - car was lumpy, especially on float condition (engine just matched to rolling load)

While still driving to meet appointment, I read P1238 and P1711 pending. NO CEL light,

Probable MAF failure. I then heard a distinctly louder turbo whistle when loaded, though. Maybe a turbo hose is loose?

Made appt, cleared codes. Horrible mistake. Car now badly hunts between 500-1200 rpm , ETS light on, CEL light on. Now Im 200 miles from home and can't drive. Well done there, Rookie.'

It worsens - tool kit is in the P2 back home.

Use AC thermometer to pry loose MAF electrical and disconnect. Car settles to nice hum. Back on the Mass Pike, 70 mph, 26 mpg indicated. Turbo whistle still present. NO CEL on ???? Codes pending to come.

On way home, stopped for lunch, ordered new MAF on sale at FCP - thanks FCP!

Post by **abscate** » 30 Jun 2016, 15:32

Update

Made it home ok, 27 mpg.

Cleared DTC , which cleared CEL and ETS light. Car still lumpy.

I'm wondering if I've popped the BOV and am hearing boost leak whistle

Second breakdown on this car this past year, but has gotten me home both times on schedule.

Post by **scot850** » 30 Jun 2016, 16:02

Ouch! Sorry to hear of the troubles in Volvo world. If your turbo is whistling and wasn't before, you need to follow your own great advice and give all the intercooler, turbo pipes a good looking at, and check if any have come loose or split.

BOV try a vacuum pull down on it and see if it hold vacuum.

Neil.

Post by **abscate** » 30 Jun 2016, 18:52

They look great, except where I can't see them. Does that mean they are ok? Do I need to reprogram my ECU?

Post by **scot850** » 30 Jun 2016, 20:00

If you are getting a turbo whistle you were not before 'the incident' something has changed. Time to get out the mirror on a stick and crawl around the car with a flash-light! Why would you need to re-program the ECU?

Neil.

Post by **abscate** » 30 Jun 2016, 20:07

Sarcasm. It's not sexy checking hoses but you are exactly right , that's what needs to be done

Post by **scot850** » 30 Jun 2016, 23:03

I thought it might be, you are just procrastinating!!!

Neil.

Post by **MadeInJapan** » 01 Jul 2016, 09:29

I hope you figure out the turbo whistle. I have had MAF issues on the road too. This can happen most unexpectedly and abruptly with no warning. Besides a general "tool kit" and jumper cables, I have learned to carry a couple of things in the spare tire well- this includes the radiator over-flow cap (our old 850 would crack one of these at least once a year) and a known good MAF sensor. If you keep your eyes peeled, there's always someone selling one for cheap if you can't source one from a junk yard.

For those not-in-the-know, for one from a junk yard, you want to test before you reserve as a spare part. Just take your current one off and install the junk yard MAF- drive for awhile to make sure it works and sets no trouble codes. If all is well, put your original one back on and tuck the junk yard MAF into your spare wheel well. Having a spare MAF especially on a long trip has saved us at least once, but as I said earlier, MAF failures are often abrupt and can happen when you least expect them!

On a separate but related note, the intercooler short hose that fits at the bottom on the driver's side has a tendency to get oil soaked and can slip off during hard boosting. This has happened to me a couple of times (and will cause whistling) as well as a MAF malfunction reading. I once thought to replace a bad MAF so when I did with one of my spares, I still had the code and the whistle. It wasn't until I actually got up under the car to check (taking the air guide loose) did I find the culprit. Some cleaning and really syncing down the clamp for that particular hose was the solution!

Post by **abscate** » 09 Jul 2016, 12:57

Been out of town all week but I'm expecting to find induction failure as root cause here. The sudden jerk nature of it doesn't jive with a component failure and the running is almost identical to the original poor running that had be find MVS just 3 years ago!

Post by **abscate** » 09 Jul 2016, 17:41

Well - using the new turbo whistle as a guide to check the induction, before replacing the MAF led me to..

: Induction intercooler connection T5 1999

Reusing original clamp >> Rust through >> induction hose popped off >> MAF no longer reports accurate air inflow >> horrible running and CEL.

Disconnecting MAF hooks up ECU to rpm mapped fuel flow which works well.

Fix was 30 minutes labor and 5 bucks of SS hose clamps nice and tight.