Rough idle 1999 V70 T5 FWD RESOLVED, loose hose Topic is solved

Post by **abscate** » 19 Feb 2013, 07:38

Im splitting my post from the other rough idle thread to document my diagnosis..

Im having trouble with the same symptom on my 1999 V70T5 after I had the air system open (radiator R/R)

I got two codes P0327 (knock sensor) which has been occasionally showing on this car for two years

P1238 "trouble code definition not found"

Cold running is undriveable, but it settles down once hot. It ran great for one day after the radiator job. Water in fuel or gunk in MAF ?

The car drove great for one day after the radiator replacement, where a lot of hoses got knocked around - I suspect something might be loose or a hose cracked during the repair

Post by **abscate** » 19 Feb 2013, 07:41

Update this morning

Cold start, 15F - car stalls several times, very rough idle. Can keep engine running with pedal at about 1500 rpm

After 1 minute car will run, but fluctuates between very low (<500 rpm) and 1200 rpm at 2 times per second intervals.

After about 3 minutes, I hear a solenoid click and it smooths out, then the solenoid clicks again adn the roughness returns. This cycles in and out for next few minutes, then car settles down. Performance above 2000 rpm fine.

The P1238 code reported above comes up on ALLDATA DIY as a Turbocharger Pressure Too High fault.

Im suspecting a loose hose or purge valve, or perhaps bad plug or coil

Post by **jblackburn** » 19 Feb 2013, 09:10

Double-check your turbo control valve hoses.

Red to the compressor side of the turbo. Yellow to the wastegate. Blue to the LOWER port of the fresh air intake hose.

Post by **abscate** » 19 Feb 2013, 12:08

Thanks, will do. Might be I broke a turbo control hose during the radiator job.

Post by **abscate** » 19 Feb 2013, 13:25

Update - the temperature was 11F this morning. Horrible starting. Would not stay running unless I held throttle at 2000 rpm or more. Inspected hoses, listened and looked for vacuum leaks - no help

6 hours later, outside temp is 40F. Still bad hunting at idle on starting, after 3 minutes settled down to hum. Filled tank (from 1/2 empty, added DryGas). Horrible running for about one minute,undriveable. Then suddenly settled down to steady idle and 28 mpg at 45 mph. Drove around for 30 minutes with no change.

Sounds like I have/had a slug of water in fuel to me??

Post by **jblackburn** » 19 Feb 2013, 13:38

Interesting. Wait and see what happens when it's at a cold start again, I suppose...

Post by **abscate** » 19 Feb 2013, 13:44

Exactly. Good thing is I have the perfect weather for testing....

Selling this car this summer would be very, very bad karma....

Post by **abscate** » 20 Feb 2013, 06:04

This morning update. Ambient temperature 27F

Starts and hunted at idle for about 5 seconds, then settled purring at 1000 rpm.
After three minutes, I test drove around the block, and it had the stumbling issue of yesterday for about 10 seconds, which then cleared. It then drove around suburbia fine for 15 minutes.

More and more, Im thinking a case of bad water contamination in fuel - icing in freezing temps. Im guessing above 32F this will all go away. Ill keep feeding it dry gas on fillups. I have a 5 hour car trip this weekend, and am debating tempting the car gods and taking the V70 on the trip. I sure like that seat on long trips.

Post by **Pauloil** » 20 Feb 2013, 20:41

how would water get in the fuel while working on the radiator. you did not disconnect fuel lines at that time. if your maf coincidentally went bad, try unplugging it. look at the big intercooler hoses near where you were working. did you knock a vacuum line off?

Post by **abscate** » 21 Feb 2013, 04:54

I think getting a tank of gas with some water was coincidental with the radiator job. My wife's car stumbled about two weeks ago on startup, my T5 had been filled from the same station at a similar time but then had sat for two weeks.

The fact that I had a perfect day of running right after the job (warm day) is guiding me away from a loose hose diagnosis.